1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  *  NSA Security-Enhanced Linux (SELinux) security module
4  *
5  *  This file contains the SELinux hook function implementations.
6  *
7  *  Authors:  Stephen Smalley, <sds@tycho.nsa.gov>
8  *	      Chris Vance, <cvance@nai.com>
9  *	      Wayne Salamon, <wsalamon@nai.com>
10  *	      James Morris <jmorris@redhat.com>
11  *
12  *  Copyright (C) 2001,2002 Networks Associates Technology, Inc.
13  *  Copyright (C) 2003-2008 Red Hat, Inc., James Morris <jmorris@redhat.com>
14  *					   Eric Paris <eparis@redhat.com>
15  *  Copyright (C) 2004-2005 Trusted Computer Solutions, Inc.
16  *			    <dgoeddel@trustedcs.com>
17  *  Copyright (C) 2006, 2007, 2009 Hewlett-Packard Development Company, L.P.
18  *	Paul Moore <paul@paul-moore.com>
19  *  Copyright (C) 2007 Hitachi Software Engineering Co., Ltd.
20  *		       Yuichi Nakamura <ynakam@hitachisoft.jp>
21  *  Copyright (C) 2016 Mellanox Technologies
22  */
23 
24 #include <linux/init.h>
25 #include <linux/kd.h>
26 #include <linux/kernel.h>
27 #include <linux/kernel_read_file.h>
28 #include <linux/errno.h>
29 #include <linux/sched/signal.h>
30 #include <linux/sched/task.h>
31 #include <linux/lsm_hooks.h>
32 #include <linux/xattr.h>
33 #include <linux/capability.h>
34 #include <linux/unistd.h>
35 #include <linux/mm.h>
36 #include <linux/mman.h>
37 #include <linux/slab.h>
38 #include <linux/pagemap.h>
39 #include <linux/proc_fs.h>
40 #include <linux/swap.h>
41 #include <linux/spinlock.h>
42 #include <linux/syscalls.h>
43 #include <linux/dcache.h>
44 #include <linux/file.h>
45 #include <linux/fdtable.h>
46 #include <linux/namei.h>
47 #include <linux/mount.h>
48 #include <linux/fs_context.h>
49 #include <linux/fs_parser.h>
50 #include <linux/netfilter_ipv4.h>
51 #include <linux/netfilter_ipv6.h>
52 #include <linux/tty.h>
53 #include <net/icmp.h>
54 #include <net/ip.h>		/* for local_port_range[] */
55 #include <net/tcp.h>		/* struct or_callable used in sock_rcv_skb */
56 #include <net/inet_connection_sock.h>
57 #include <net/net_namespace.h>
58 #include <net/netlabel.h>
59 #include <linux/uaccess.h>
60 #include <asm/ioctls.h>
61 #include <linux/atomic.h>
62 #include <linux/bitops.h>
63 #include <linux/interrupt.h>
64 #include <linux/netdevice.h>	/* for network interface checks */
65 #include <net/netlink.h>
66 #include <linux/tcp.h>
67 #include <linux/udp.h>
68 #include <linux/dccp.h>
69 #include <linux/sctp.h>
70 #include <net/sctp/structs.h>
71 #include <linux/quota.h>
72 #include <linux/un.h>		/* for Unix socket types */
73 #include <net/af_unix.h>	/* for Unix socket types */
74 #include <linux/parser.h>
75 #include <linux/nfs_mount.h>
76 #include <net/ipv6.h>
77 #include <linux/hugetlb.h>
78 #include <linux/personality.h>
79 #include <linux/audit.h>
80 #include <linux/string.h>
81 #include <linux/mutex.h>
82 #include <linux/posix-timers.h>
83 #include <linux/syslog.h>
84 #include <linux/user_namespace.h>
85 #include <linux/export.h>
86 #include <linux/msg.h>
87 #include <linux/shm.h>
88 #include <linux/bpf.h>
89 #include <linux/kernfs.h>
90 #include <linux/stringhash.h>	/* for hashlen_string() */
91 #include <uapi/linux/mount.h>
92 #include <linux/fsnotify.h>
93 #include <linux/fanotify.h>
94 #include <linux/io_uring.h>
95 
96 #include "avc.h"
97 #include "objsec.h"
98 #include "netif.h"
99 #include "netnode.h"
100 #include "netport.h"
101 #include "ibpkey.h"
102 #include "xfrm.h"
103 #include "netlabel.h"
104 #include "audit.h"
105 #include "avc_ss.h"
106 
107 struct selinux_state selinux_state;
108 
109 /* SECMARK reference count */
110 static atomic_t selinux_secmark_refcount = ATOMIC_INIT(0);
111 
112 #ifdef CONFIG_SECURITY_SELINUX_DEVELOP
113 static int selinux_enforcing_boot __initdata;
114 
enforcing_setup(char * str)115 static int __init enforcing_setup(char *str)
116 {
117 	unsigned long enforcing;
118 	if (!kstrtoul(str, 0, &enforcing))
119 		selinux_enforcing_boot = enforcing ? 1 : 0;
120 	return 1;
121 }
122 __setup("enforcing=", enforcing_setup);
123 #else
124 #define selinux_enforcing_boot 1
125 #endif
126 
127 int selinux_enabled_boot __initdata = 1;
128 #ifdef CONFIG_SECURITY_SELINUX_BOOTPARAM
selinux_enabled_setup(char * str)129 static int __init selinux_enabled_setup(char *str)
130 {
131 	unsigned long enabled;
132 	if (!kstrtoul(str, 0, &enabled))
133 		selinux_enabled_boot = enabled ? 1 : 0;
134 	return 1;
135 }
136 __setup("selinux=", selinux_enabled_setup);
137 #endif
138 
139 static unsigned int selinux_checkreqprot_boot =
140 	CONFIG_SECURITY_SELINUX_CHECKREQPROT_VALUE;
141 
checkreqprot_setup(char * str)142 static int __init checkreqprot_setup(char *str)
143 {
144 	unsigned long checkreqprot;
145 
146 	if (!kstrtoul(str, 0, &checkreqprot)) {
147 		selinux_checkreqprot_boot = checkreqprot ? 1 : 0;
148 		if (checkreqprot)
149 			pr_err("SELinux: checkreqprot set to 1 via kernel parameter.  This is deprecated and will be rejected in a future kernel release.\n");
150 	}
151 	return 1;
152 }
153 __setup("checkreqprot=", checkreqprot_setup);
154 
155 /**
156  * selinux_secmark_enabled - Check to see if SECMARK is currently enabled
157  *
158  * Description:
159  * This function checks the SECMARK reference counter to see if any SECMARK
160  * targets are currently configured, if the reference counter is greater than
161  * zero SECMARK is considered to be enabled.  Returns true (1) if SECMARK is
162  * enabled, false (0) if SECMARK is disabled.  If the always_check_network
163  * policy capability is enabled, SECMARK is always considered enabled.
164  *
165  */
selinux_secmark_enabled(void)166 static int selinux_secmark_enabled(void)
167 {
168 	return (selinux_policycap_alwaysnetwork() ||
169 		atomic_read(&selinux_secmark_refcount));
170 }
171 
172 /**
173  * selinux_peerlbl_enabled - Check to see if peer labeling is currently enabled
174  *
175  * Description:
176  * This function checks if NetLabel or labeled IPSEC is enabled.  Returns true
177  * (1) if any are enabled or false (0) if neither are enabled.  If the
178  * always_check_network policy capability is enabled, peer labeling
179  * is always considered enabled.
180  *
181  */
selinux_peerlbl_enabled(void)182 static int selinux_peerlbl_enabled(void)
183 {
184 	return (selinux_policycap_alwaysnetwork() ||
185 		netlbl_enabled() || selinux_xfrm_enabled());
186 }
187 
selinux_netcache_avc_callback(u32 event)188 static int selinux_netcache_avc_callback(u32 event)
189 {
190 	if (event == AVC_CALLBACK_RESET) {
191 		sel_netif_flush();
192 		sel_netnode_flush();
193 		sel_netport_flush();
194 		synchronize_net();
195 	}
196 	return 0;
197 }
198 
selinux_lsm_notifier_avc_callback(u32 event)199 static int selinux_lsm_notifier_avc_callback(u32 event)
200 {
201 	if (event == AVC_CALLBACK_RESET) {
202 		sel_ib_pkey_flush();
203 		call_blocking_lsm_notifier(LSM_POLICY_CHANGE, NULL);
204 	}
205 
206 	return 0;
207 }
208 
209 /*
210  * initialise the security for the init task
211  */
cred_init_security(void)212 static void cred_init_security(void)
213 {
214 	struct task_security_struct *tsec;
215 
216 	tsec = selinux_cred(unrcu_pointer(current->real_cred));
217 	tsec->osid = tsec->sid = SECINITSID_KERNEL;
218 }
219 
220 /*
221  * get the security ID of a set of credentials
222  */
cred_sid(const struct cred * cred)223 static inline u32 cred_sid(const struct cred *cred)
224 {
225 	const struct task_security_struct *tsec;
226 
227 	tsec = selinux_cred(cred);
228 	return tsec->sid;
229 }
230 
231 /*
232  * get the objective security ID of a task
233  */
task_sid_obj(const struct task_struct * task)234 static inline u32 task_sid_obj(const struct task_struct *task)
235 {
236 	u32 sid;
237 
238 	rcu_read_lock();
239 	sid = cred_sid(__task_cred(task));
240 	rcu_read_unlock();
241 	return sid;
242 }
243 
244 static int inode_doinit_with_dentry(struct inode *inode, struct dentry *opt_dentry);
245 
246 /*
247  * Try reloading inode security labels that have been marked as invalid.  The
248  * @may_sleep parameter indicates when sleeping and thus reloading labels is
249  * allowed; when set to false, returns -ECHILD when the label is
250  * invalid.  The @dentry parameter should be set to a dentry of the inode.
251  */
__inode_security_revalidate(struct inode * inode,struct dentry * dentry,bool may_sleep)252 static int __inode_security_revalidate(struct inode *inode,
253 				       struct dentry *dentry,
254 				       bool may_sleep)
255 {
256 	struct inode_security_struct *isec = selinux_inode(inode);
257 
258 	might_sleep_if(may_sleep);
259 
260 	if (selinux_initialized(&selinux_state) &&
261 	    isec->initialized != LABEL_INITIALIZED) {
262 		if (!may_sleep)
263 			return -ECHILD;
264 
265 		/*
266 		 * Try reloading the inode security label.  This will fail if
267 		 * @opt_dentry is NULL and no dentry for this inode can be
268 		 * found; in that case, continue using the old label.
269 		 */
270 		inode_doinit_with_dentry(inode, dentry);
271 	}
272 	return 0;
273 }
274 
inode_security_novalidate(struct inode * inode)275 static struct inode_security_struct *inode_security_novalidate(struct inode *inode)
276 {
277 	return selinux_inode(inode);
278 }
279 
inode_security_rcu(struct inode * inode,bool rcu)280 static struct inode_security_struct *inode_security_rcu(struct inode *inode, bool rcu)
281 {
282 	int error;
283 
284 	error = __inode_security_revalidate(inode, NULL, !rcu);
285 	if (error)
286 		return ERR_PTR(error);
287 	return selinux_inode(inode);
288 }
289 
290 /*
291  * Get the security label of an inode.
292  */
inode_security(struct inode * inode)293 static struct inode_security_struct *inode_security(struct inode *inode)
294 {
295 	__inode_security_revalidate(inode, NULL, true);
296 	return selinux_inode(inode);
297 }
298 
backing_inode_security_novalidate(struct dentry * dentry)299 static struct inode_security_struct *backing_inode_security_novalidate(struct dentry *dentry)
300 {
301 	struct inode *inode = d_backing_inode(dentry);
302 
303 	return selinux_inode(inode);
304 }
305 
306 /*
307  * Get the security label of a dentry's backing inode.
308  */
backing_inode_security(struct dentry * dentry)309 static struct inode_security_struct *backing_inode_security(struct dentry *dentry)
310 {
311 	struct inode *inode = d_backing_inode(dentry);
312 
313 	__inode_security_revalidate(inode, dentry, true);
314 	return selinux_inode(inode);
315 }
316 
inode_free_security(struct inode * inode)317 static void inode_free_security(struct inode *inode)
318 {
319 	struct inode_security_struct *isec = selinux_inode(inode);
320 	struct superblock_security_struct *sbsec;
321 
322 	if (!isec)
323 		return;
324 	sbsec = selinux_superblock(inode->i_sb);
325 	/*
326 	 * As not all inode security structures are in a list, we check for
327 	 * empty list outside of the lock to make sure that we won't waste
328 	 * time taking a lock doing nothing.
329 	 *
330 	 * The list_del_init() function can be safely called more than once.
331 	 * It should not be possible for this function to be called with
332 	 * concurrent list_add(), but for better safety against future changes
333 	 * in the code, we use list_empty_careful() here.
334 	 */
335 	if (!list_empty_careful(&isec->list)) {
336 		spin_lock(&sbsec->isec_lock);
337 		list_del_init(&isec->list);
338 		spin_unlock(&sbsec->isec_lock);
339 	}
340 }
341 
342 struct selinux_mnt_opts {
343 	u32 fscontext_sid;
344 	u32 context_sid;
345 	u32 rootcontext_sid;
346 	u32 defcontext_sid;
347 };
348 
selinux_free_mnt_opts(void * mnt_opts)349 static void selinux_free_mnt_opts(void *mnt_opts)
350 {
351 	kfree(mnt_opts);
352 }
353 
354 enum {
355 	Opt_error = -1,
356 	Opt_context = 0,
357 	Opt_defcontext = 1,
358 	Opt_fscontext = 2,
359 	Opt_rootcontext = 3,
360 	Opt_seclabel = 4,
361 };
362 
363 #define A(s, has_arg) {#s, sizeof(#s) - 1, Opt_##s, has_arg}
364 static struct {
365 	const char *name;
366 	int len;
367 	int opt;
368 	bool has_arg;
369 } tokens[] = {
370 	A(context, true),
371 	A(fscontext, true),
372 	A(defcontext, true),
373 	A(rootcontext, true),
374 	A(seclabel, false),
375 };
376 #undef A
377 
match_opt_prefix(char * s,int l,char ** arg)378 static int match_opt_prefix(char *s, int l, char **arg)
379 {
380 	int i;
381 
382 	for (i = 0; i < ARRAY_SIZE(tokens); i++) {
383 		size_t len = tokens[i].len;
384 		if (len > l || memcmp(s, tokens[i].name, len))
385 			continue;
386 		if (tokens[i].has_arg) {
387 			if (len == l || s[len] != '=')
388 				continue;
389 			*arg = s + len + 1;
390 		} else if (len != l)
391 			continue;
392 		return tokens[i].opt;
393 	}
394 	return Opt_error;
395 }
396 
397 #define SEL_MOUNT_FAIL_MSG "SELinux:  duplicate or incompatible mount options\n"
398 
may_context_mount_sb_relabel(u32 sid,struct superblock_security_struct * sbsec,const struct cred * cred)399 static int may_context_mount_sb_relabel(u32 sid,
400 			struct superblock_security_struct *sbsec,
401 			const struct cred *cred)
402 {
403 	const struct task_security_struct *tsec = selinux_cred(cred);
404 	int rc;
405 
406 	rc = avc_has_perm(&selinux_state,
407 			  tsec->sid, sbsec->sid, SECCLASS_FILESYSTEM,
408 			  FILESYSTEM__RELABELFROM, NULL);
409 	if (rc)
410 		return rc;
411 
412 	rc = avc_has_perm(&selinux_state,
413 			  tsec->sid, sid, SECCLASS_FILESYSTEM,
414 			  FILESYSTEM__RELABELTO, NULL);
415 	return rc;
416 }
417 
may_context_mount_inode_relabel(u32 sid,struct superblock_security_struct * sbsec,const struct cred * cred)418 static int may_context_mount_inode_relabel(u32 sid,
419 			struct superblock_security_struct *sbsec,
420 			const struct cred *cred)
421 {
422 	const struct task_security_struct *tsec = selinux_cred(cred);
423 	int rc;
424 	rc = avc_has_perm(&selinux_state,
425 			  tsec->sid, sbsec->sid, SECCLASS_FILESYSTEM,
426 			  FILESYSTEM__RELABELFROM, NULL);
427 	if (rc)
428 		return rc;
429 
430 	rc = avc_has_perm(&selinux_state,
431 			  sid, sbsec->sid, SECCLASS_FILESYSTEM,
432 			  FILESYSTEM__ASSOCIATE, NULL);
433 	return rc;
434 }
435 
selinux_is_genfs_special_handling(struct super_block * sb)436 static int selinux_is_genfs_special_handling(struct super_block *sb)
437 {
438 	/* Special handling. Genfs but also in-core setxattr handler */
439 	return	!strcmp(sb->s_type->name, "sysfs") ||
440 		!strcmp(sb->s_type->name, "pstore") ||
441 		!strcmp(sb->s_type->name, "debugfs") ||
442 		!strcmp(sb->s_type->name, "tracefs") ||
443 		!strcmp(sb->s_type->name, "rootfs") ||
444 		(selinux_policycap_cgroupseclabel() &&
445 		 (!strcmp(sb->s_type->name, "cgroup") ||
446 		  !strcmp(sb->s_type->name, "cgroup2")));
447 }
448 
selinux_is_sblabel_mnt(struct super_block * sb)449 static int selinux_is_sblabel_mnt(struct super_block *sb)
450 {
451 	struct superblock_security_struct *sbsec = selinux_superblock(sb);
452 
453 	/*
454 	 * IMPORTANT: Double-check logic in this function when adding a new
455 	 * SECURITY_FS_USE_* definition!
456 	 */
457 	BUILD_BUG_ON(SECURITY_FS_USE_MAX != 7);
458 
459 	switch (sbsec->behavior) {
460 	case SECURITY_FS_USE_XATTR:
461 	case SECURITY_FS_USE_TRANS:
462 	case SECURITY_FS_USE_TASK:
463 	case SECURITY_FS_USE_NATIVE:
464 		return 1;
465 
466 	case SECURITY_FS_USE_GENFS:
467 		return selinux_is_genfs_special_handling(sb);
468 
469 	/* Never allow relabeling on context mounts */
470 	case SECURITY_FS_USE_MNTPOINT:
471 	case SECURITY_FS_USE_NONE:
472 	default:
473 		return 0;
474 	}
475 }
476 
sb_check_xattr_support(struct super_block * sb)477 static int sb_check_xattr_support(struct super_block *sb)
478 {
479 	struct superblock_security_struct *sbsec = selinux_superblock(sb);
480 	struct dentry *root = sb->s_root;
481 	struct inode *root_inode = d_backing_inode(root);
482 	u32 sid;
483 	int rc;
484 
485 	/*
486 	 * Make sure that the xattr handler exists and that no
487 	 * error other than -ENODATA is returned by getxattr on
488 	 * the root directory.  -ENODATA is ok, as this may be
489 	 * the first boot of the SELinux kernel before we have
490 	 * assigned xattr values to the filesystem.
491 	 */
492 	if (!(root_inode->i_opflags & IOP_XATTR)) {
493 		pr_warn("SELinux: (dev %s, type %s) has no xattr support\n",
494 			sb->s_id, sb->s_type->name);
495 		goto fallback;
496 	}
497 
498 	rc = __vfs_getxattr(root, root_inode, XATTR_NAME_SELINUX, NULL, 0);
499 	if (rc < 0 && rc != -ENODATA) {
500 		if (rc == -EOPNOTSUPP) {
501 			pr_warn("SELinux: (dev %s, type %s) has no security xattr handler\n",
502 				sb->s_id, sb->s_type->name);
503 			goto fallback;
504 		} else {
505 			pr_warn("SELinux: (dev %s, type %s) getxattr errno %d\n",
506 				sb->s_id, sb->s_type->name, -rc);
507 			return rc;
508 		}
509 	}
510 	return 0;
511 
512 fallback:
513 	/* No xattr support - try to fallback to genfs if possible. */
514 	rc = security_genfs_sid(&selinux_state, sb->s_type->name, "/",
515 				SECCLASS_DIR, &sid);
516 	if (rc)
517 		return -EOPNOTSUPP;
518 
519 	pr_warn("SELinux: (dev %s, type %s) falling back to genfs\n",
520 		sb->s_id, sb->s_type->name);
521 	sbsec->behavior = SECURITY_FS_USE_GENFS;
522 	sbsec->sid = sid;
523 	return 0;
524 }
525 
sb_finish_set_opts(struct super_block * sb)526 static int sb_finish_set_opts(struct super_block *sb)
527 {
528 	struct superblock_security_struct *sbsec = selinux_superblock(sb);
529 	struct dentry *root = sb->s_root;
530 	struct inode *root_inode = d_backing_inode(root);
531 	int rc = 0;
532 
533 	if (sbsec->behavior == SECURITY_FS_USE_XATTR) {
534 		rc = sb_check_xattr_support(sb);
535 		if (rc)
536 			return rc;
537 	}
538 
539 	sbsec->flags |= SE_SBINITIALIZED;
540 
541 	/*
542 	 * Explicitly set or clear SBLABEL_MNT.  It's not sufficient to simply
543 	 * leave the flag untouched because sb_clone_mnt_opts might be handing
544 	 * us a superblock that needs the flag to be cleared.
545 	 */
546 	if (selinux_is_sblabel_mnt(sb))
547 		sbsec->flags |= SBLABEL_MNT;
548 	else
549 		sbsec->flags &= ~SBLABEL_MNT;
550 
551 	/* Initialize the root inode. */
552 	rc = inode_doinit_with_dentry(root_inode, root);
553 
554 	/* Initialize any other inodes associated with the superblock, e.g.
555 	   inodes created prior to initial policy load or inodes created
556 	   during get_sb by a pseudo filesystem that directly
557 	   populates itself. */
558 	spin_lock(&sbsec->isec_lock);
559 	while (!list_empty(&sbsec->isec_head)) {
560 		struct inode_security_struct *isec =
561 				list_first_entry(&sbsec->isec_head,
562 					   struct inode_security_struct, list);
563 		struct inode *inode = isec->inode;
564 		list_del_init(&isec->list);
565 		spin_unlock(&sbsec->isec_lock);
566 		inode = igrab(inode);
567 		if (inode) {
568 			if (!IS_PRIVATE(inode))
569 				inode_doinit_with_dentry(inode, NULL);
570 			iput(inode);
571 		}
572 		spin_lock(&sbsec->isec_lock);
573 	}
574 	spin_unlock(&sbsec->isec_lock);
575 	return rc;
576 }
577 
bad_option(struct superblock_security_struct * sbsec,char flag,u32 old_sid,u32 new_sid)578 static int bad_option(struct superblock_security_struct *sbsec, char flag,
579 		      u32 old_sid, u32 new_sid)
580 {
581 	char mnt_flags = sbsec->flags & SE_MNTMASK;
582 
583 	/* check if the old mount command had the same options */
584 	if (sbsec->flags & SE_SBINITIALIZED)
585 		if (!(sbsec->flags & flag) ||
586 		    (old_sid != new_sid))
587 			return 1;
588 
589 	/* check if we were passed the same options twice,
590 	 * aka someone passed context=a,context=b
591 	 */
592 	if (!(sbsec->flags & SE_SBINITIALIZED))
593 		if (mnt_flags & flag)
594 			return 1;
595 	return 0;
596 }
597 
598 /*
599  * Allow filesystems with binary mount data to explicitly set mount point
600  * labeling information.
601  */
selinux_set_mnt_opts(struct super_block * sb,void * mnt_opts,unsigned long kern_flags,unsigned long * set_kern_flags)602 static int selinux_set_mnt_opts(struct super_block *sb,
603 				void *mnt_opts,
604 				unsigned long kern_flags,
605 				unsigned long *set_kern_flags)
606 {
607 	const struct cred *cred = current_cred();
608 	struct superblock_security_struct *sbsec = selinux_superblock(sb);
609 	struct dentry *root = sb->s_root;
610 	struct selinux_mnt_opts *opts = mnt_opts;
611 	struct inode_security_struct *root_isec;
612 	u32 fscontext_sid = 0, context_sid = 0, rootcontext_sid = 0;
613 	u32 defcontext_sid = 0;
614 	int rc = 0;
615 
616 	mutex_lock(&sbsec->lock);
617 
618 	if (!selinux_initialized(&selinux_state)) {
619 		if (!opts) {
620 			/* Defer initialization until selinux_complete_init,
621 			   after the initial policy is loaded and the security
622 			   server is ready to handle calls. */
623 			goto out;
624 		}
625 		rc = -EINVAL;
626 		pr_warn("SELinux: Unable to set superblock options "
627 			"before the security server is initialized\n");
628 		goto out;
629 	}
630 	if (kern_flags && !set_kern_flags) {
631 		/* Specifying internal flags without providing a place to
632 		 * place the results is not allowed */
633 		rc = -EINVAL;
634 		goto out;
635 	}
636 
637 	/*
638 	 * Binary mount data FS will come through this function twice.  Once
639 	 * from an explicit call and once from the generic calls from the vfs.
640 	 * Since the generic VFS calls will not contain any security mount data
641 	 * we need to skip the double mount verification.
642 	 *
643 	 * This does open a hole in which we will not notice if the first
644 	 * mount using this sb set explict options and a second mount using
645 	 * this sb does not set any security options.  (The first options
646 	 * will be used for both mounts)
647 	 */
648 	if ((sbsec->flags & SE_SBINITIALIZED) && (sb->s_type->fs_flags & FS_BINARY_MOUNTDATA)
649 	    && !opts)
650 		goto out;
651 
652 	root_isec = backing_inode_security_novalidate(root);
653 
654 	/*
655 	 * parse the mount options, check if they are valid sids.
656 	 * also check if someone is trying to mount the same sb more
657 	 * than once with different security options.
658 	 */
659 	if (opts) {
660 		if (opts->fscontext_sid) {
661 			fscontext_sid = opts->fscontext_sid;
662 			if (bad_option(sbsec, FSCONTEXT_MNT, sbsec->sid,
663 					fscontext_sid))
664 				goto out_double_mount;
665 			sbsec->flags |= FSCONTEXT_MNT;
666 		}
667 		if (opts->context_sid) {
668 			context_sid = opts->context_sid;
669 			if (bad_option(sbsec, CONTEXT_MNT, sbsec->mntpoint_sid,
670 					context_sid))
671 				goto out_double_mount;
672 			sbsec->flags |= CONTEXT_MNT;
673 		}
674 		if (opts->rootcontext_sid) {
675 			rootcontext_sid = opts->rootcontext_sid;
676 			if (bad_option(sbsec, ROOTCONTEXT_MNT, root_isec->sid,
677 					rootcontext_sid))
678 				goto out_double_mount;
679 			sbsec->flags |= ROOTCONTEXT_MNT;
680 		}
681 		if (opts->defcontext_sid) {
682 			defcontext_sid = opts->defcontext_sid;
683 			if (bad_option(sbsec, DEFCONTEXT_MNT, sbsec->def_sid,
684 					defcontext_sid))
685 				goto out_double_mount;
686 			sbsec->flags |= DEFCONTEXT_MNT;
687 		}
688 	}
689 
690 	if (sbsec->flags & SE_SBINITIALIZED) {
691 		/* previously mounted with options, but not on this attempt? */
692 		if ((sbsec->flags & SE_MNTMASK) && !opts)
693 			goto out_double_mount;
694 		rc = 0;
695 		goto out;
696 	}
697 
698 	if (strcmp(sb->s_type->name, "proc") == 0)
699 		sbsec->flags |= SE_SBPROC | SE_SBGENFS;
700 
701 	if (!strcmp(sb->s_type->name, "debugfs") ||
702 	    !strcmp(sb->s_type->name, "tracefs") ||
703 	    !strcmp(sb->s_type->name, "binder") ||
704 	    !strcmp(sb->s_type->name, "bpf") ||
705 	    !strcmp(sb->s_type->name, "pstore") ||
706 	    !strcmp(sb->s_type->name, "securityfs"))
707 		sbsec->flags |= SE_SBGENFS;
708 
709 	if (!strcmp(sb->s_type->name, "sysfs") ||
710 	    !strcmp(sb->s_type->name, "cgroup") ||
711 	    !strcmp(sb->s_type->name, "cgroup2"))
712 		sbsec->flags |= SE_SBGENFS | SE_SBGENFS_XATTR;
713 
714 	if (!sbsec->behavior) {
715 		/*
716 		 * Determine the labeling behavior to use for this
717 		 * filesystem type.
718 		 */
719 		rc = security_fs_use(&selinux_state, sb);
720 		if (rc) {
721 			pr_warn("%s: security_fs_use(%s) returned %d\n",
722 					__func__, sb->s_type->name, rc);
723 			goto out;
724 		}
725 	}
726 
727 	/*
728 	 * If this is a user namespace mount and the filesystem type is not
729 	 * explicitly whitelisted, then no contexts are allowed on the command
730 	 * line and security labels must be ignored.
731 	 */
732 	if (sb->s_user_ns != &init_user_ns &&
733 	    strcmp(sb->s_type->name, "tmpfs") &&
734 	    strcmp(sb->s_type->name, "ramfs") &&
735 	    strcmp(sb->s_type->name, "devpts") &&
736 	    strcmp(sb->s_type->name, "overlay")) {
737 		if (context_sid || fscontext_sid || rootcontext_sid ||
738 		    defcontext_sid) {
739 			rc = -EACCES;
740 			goto out;
741 		}
742 		if (sbsec->behavior == SECURITY_FS_USE_XATTR) {
743 			sbsec->behavior = SECURITY_FS_USE_MNTPOINT;
744 			rc = security_transition_sid(&selinux_state,
745 						     current_sid(),
746 						     current_sid(),
747 						     SECCLASS_FILE, NULL,
748 						     &sbsec->mntpoint_sid);
749 			if (rc)
750 				goto out;
751 		}
752 		goto out_set_opts;
753 	}
754 
755 	/* sets the context of the superblock for the fs being mounted. */
756 	if (fscontext_sid) {
757 		rc = may_context_mount_sb_relabel(fscontext_sid, sbsec, cred);
758 		if (rc)
759 			goto out;
760 
761 		sbsec->sid = fscontext_sid;
762 	}
763 
764 	/*
765 	 * Switch to using mount point labeling behavior.
766 	 * sets the label used on all file below the mountpoint, and will set
767 	 * the superblock context if not already set.
768 	 */
769 	if (kern_flags & SECURITY_LSM_NATIVE_LABELS && !context_sid) {
770 		sbsec->behavior = SECURITY_FS_USE_NATIVE;
771 		*set_kern_flags |= SECURITY_LSM_NATIVE_LABELS;
772 	}
773 
774 	if (context_sid) {
775 		if (!fscontext_sid) {
776 			rc = may_context_mount_sb_relabel(context_sid, sbsec,
777 							  cred);
778 			if (rc)
779 				goto out;
780 			sbsec->sid = context_sid;
781 		} else {
782 			rc = may_context_mount_inode_relabel(context_sid, sbsec,
783 							     cred);
784 			if (rc)
785 				goto out;
786 		}
787 		if (!rootcontext_sid)
788 			rootcontext_sid = context_sid;
789 
790 		sbsec->mntpoint_sid = context_sid;
791 		sbsec->behavior = SECURITY_FS_USE_MNTPOINT;
792 	}
793 
794 	if (rootcontext_sid) {
795 		rc = may_context_mount_inode_relabel(rootcontext_sid, sbsec,
796 						     cred);
797 		if (rc)
798 			goto out;
799 
800 		root_isec->sid = rootcontext_sid;
801 		root_isec->initialized = LABEL_INITIALIZED;
802 	}
803 
804 	if (defcontext_sid) {
805 		if (sbsec->behavior != SECURITY_FS_USE_XATTR &&
806 			sbsec->behavior != SECURITY_FS_USE_NATIVE) {
807 			rc = -EINVAL;
808 			pr_warn("SELinux: defcontext option is "
809 			       "invalid for this filesystem type\n");
810 			goto out;
811 		}
812 
813 		if (defcontext_sid != sbsec->def_sid) {
814 			rc = may_context_mount_inode_relabel(defcontext_sid,
815 							     sbsec, cred);
816 			if (rc)
817 				goto out;
818 		}
819 
820 		sbsec->def_sid = defcontext_sid;
821 	}
822 
823 out_set_opts:
824 	rc = sb_finish_set_opts(sb);
825 out:
826 	mutex_unlock(&sbsec->lock);
827 	return rc;
828 out_double_mount:
829 	rc = -EINVAL;
830 	pr_warn("SELinux: mount invalid.  Same superblock, different "
831 	       "security settings for (dev %s, type %s)\n", sb->s_id,
832 	       sb->s_type->name);
833 	goto out;
834 }
835 
selinux_cmp_sb_context(const struct super_block * oldsb,const struct super_block * newsb)836 static int selinux_cmp_sb_context(const struct super_block *oldsb,
837 				    const struct super_block *newsb)
838 {
839 	struct superblock_security_struct *old = selinux_superblock(oldsb);
840 	struct superblock_security_struct *new = selinux_superblock(newsb);
841 	char oldflags = old->flags & SE_MNTMASK;
842 	char newflags = new->flags & SE_MNTMASK;
843 
844 	if (oldflags != newflags)
845 		goto mismatch;
846 	if ((oldflags & FSCONTEXT_MNT) && old->sid != new->sid)
847 		goto mismatch;
848 	if ((oldflags & CONTEXT_MNT) && old->mntpoint_sid != new->mntpoint_sid)
849 		goto mismatch;
850 	if ((oldflags & DEFCONTEXT_MNT) && old->def_sid != new->def_sid)
851 		goto mismatch;
852 	if (oldflags & ROOTCONTEXT_MNT) {
853 		struct inode_security_struct *oldroot = backing_inode_security(oldsb->s_root);
854 		struct inode_security_struct *newroot = backing_inode_security(newsb->s_root);
855 		if (oldroot->sid != newroot->sid)
856 			goto mismatch;
857 	}
858 	return 0;
859 mismatch:
860 	pr_warn("SELinux: mount invalid.  Same superblock, "
861 			    "different security settings for (dev %s, "
862 			    "type %s)\n", newsb->s_id, newsb->s_type->name);
863 	return -EBUSY;
864 }
865 
selinux_sb_clone_mnt_opts(const struct super_block * oldsb,struct super_block * newsb,unsigned long kern_flags,unsigned long * set_kern_flags)866 static int selinux_sb_clone_mnt_opts(const struct super_block *oldsb,
867 					struct super_block *newsb,
868 					unsigned long kern_flags,
869 					unsigned long *set_kern_flags)
870 {
871 	int rc = 0;
872 	const struct superblock_security_struct *oldsbsec =
873 						selinux_superblock(oldsb);
874 	struct superblock_security_struct *newsbsec = selinux_superblock(newsb);
875 
876 	int set_fscontext =	(oldsbsec->flags & FSCONTEXT_MNT);
877 	int set_context =	(oldsbsec->flags & CONTEXT_MNT);
878 	int set_rootcontext =	(oldsbsec->flags & ROOTCONTEXT_MNT);
879 
880 	/*
881 	 * if the parent was able to be mounted it clearly had no special lsm
882 	 * mount options.  thus we can safely deal with this superblock later
883 	 */
884 	if (!selinux_initialized(&selinux_state))
885 		return 0;
886 
887 	/*
888 	 * Specifying internal flags without providing a place to
889 	 * place the results is not allowed.
890 	 */
891 	if (kern_flags && !set_kern_flags)
892 		return -EINVAL;
893 
894 	/* how can we clone if the old one wasn't set up?? */
895 	BUG_ON(!(oldsbsec->flags & SE_SBINITIALIZED));
896 
897 	/* if fs is reusing a sb, make sure that the contexts match */
898 	if (newsbsec->flags & SE_SBINITIALIZED) {
899 		if ((kern_flags & SECURITY_LSM_NATIVE_LABELS) && !set_context)
900 			*set_kern_flags |= SECURITY_LSM_NATIVE_LABELS;
901 		return selinux_cmp_sb_context(oldsb, newsb);
902 	}
903 
904 	mutex_lock(&newsbsec->lock);
905 
906 	newsbsec->flags = oldsbsec->flags;
907 
908 	newsbsec->sid = oldsbsec->sid;
909 	newsbsec->def_sid = oldsbsec->def_sid;
910 	newsbsec->behavior = oldsbsec->behavior;
911 
912 	if (newsbsec->behavior == SECURITY_FS_USE_NATIVE &&
913 		!(kern_flags & SECURITY_LSM_NATIVE_LABELS) && !set_context) {
914 		rc = security_fs_use(&selinux_state, newsb);
915 		if (rc)
916 			goto out;
917 	}
918 
919 	if (kern_flags & SECURITY_LSM_NATIVE_LABELS && !set_context) {
920 		newsbsec->behavior = SECURITY_FS_USE_NATIVE;
921 		*set_kern_flags |= SECURITY_LSM_NATIVE_LABELS;
922 	}
923 
924 	if (set_context) {
925 		u32 sid = oldsbsec->mntpoint_sid;
926 
927 		if (!set_fscontext)
928 			newsbsec->sid = sid;
929 		if (!set_rootcontext) {
930 			struct inode_security_struct *newisec = backing_inode_security(newsb->s_root);
931 			newisec->sid = sid;
932 		}
933 		newsbsec->mntpoint_sid = sid;
934 	}
935 	if (set_rootcontext) {
936 		const struct inode_security_struct *oldisec = backing_inode_security(oldsb->s_root);
937 		struct inode_security_struct *newisec = backing_inode_security(newsb->s_root);
938 
939 		newisec->sid = oldisec->sid;
940 	}
941 
942 	sb_finish_set_opts(newsb);
943 out:
944 	mutex_unlock(&newsbsec->lock);
945 	return rc;
946 }
947 
selinux_add_opt(int token,const char * s,void ** mnt_opts)948 static int selinux_add_opt(int token, const char *s, void **mnt_opts)
949 {
950 	struct selinux_mnt_opts *opts = *mnt_opts;
951 	bool is_alloc_opts = false;
952 	u32 *dst_sid;
953 	int rc;
954 
955 	if (token == Opt_seclabel)
956 		/* eaten and completely ignored */
957 		return 0;
958 	if (!s)
959 		return -ENOMEM;
960 
961 	if (!selinux_initialized(&selinux_state)) {
962 		pr_warn("SELinux: Unable to set superblock options before the security server is initialized\n");
963 		return -EINVAL;
964 	}
965 
966 	if (!opts) {
967 		opts = kzalloc(sizeof(*opts), GFP_KERNEL);
968 		if (!opts)
969 			return -ENOMEM;
970 		*mnt_opts = opts;
971 		is_alloc_opts = true;
972 	}
973 
974 	switch (token) {
975 	case Opt_context:
976 		if (opts->context_sid || opts->defcontext_sid)
977 			goto err;
978 		dst_sid = &opts->context_sid;
979 		break;
980 	case Opt_fscontext:
981 		if (opts->fscontext_sid)
982 			goto err;
983 		dst_sid = &opts->fscontext_sid;
984 		break;
985 	case Opt_rootcontext:
986 		if (opts->rootcontext_sid)
987 			goto err;
988 		dst_sid = &opts->rootcontext_sid;
989 		break;
990 	case Opt_defcontext:
991 		if (opts->context_sid || opts->defcontext_sid)
992 			goto err;
993 		dst_sid = &opts->defcontext_sid;
994 		break;
995 	default:
996 		WARN_ON(1);
997 		return -EINVAL;
998 	}
999 	rc = security_context_str_to_sid(&selinux_state, s, dst_sid, GFP_KERNEL);
1000 	if (rc)
1001 		pr_warn("SELinux: security_context_str_to_sid (%s) failed with errno=%d\n",
1002 			s, rc);
1003 	return rc;
1004 
1005 err:
1006 	if (is_alloc_opts) {
1007 		kfree(opts);
1008 		*mnt_opts = NULL;
1009 	}
1010 	pr_warn(SEL_MOUNT_FAIL_MSG);
1011 	return -EINVAL;
1012 }
1013 
show_sid(struct seq_file * m,u32 sid)1014 static int show_sid(struct seq_file *m, u32 sid)
1015 {
1016 	char *context = NULL;
1017 	u32 len;
1018 	int rc;
1019 
1020 	rc = security_sid_to_context(&selinux_state, sid,
1021 					     &context, &len);
1022 	if (!rc) {
1023 		bool has_comma = context && strchr(context, ',');
1024 
1025 		seq_putc(m, '=');
1026 		if (has_comma)
1027 			seq_putc(m, '\"');
1028 		seq_escape(m, context, "\"\n\\");
1029 		if (has_comma)
1030 			seq_putc(m, '\"');
1031 	}
1032 	kfree(context);
1033 	return rc;
1034 }
1035 
selinux_sb_show_options(struct seq_file * m,struct super_block * sb)1036 static int selinux_sb_show_options(struct seq_file *m, struct super_block *sb)
1037 {
1038 	struct superblock_security_struct *sbsec = selinux_superblock(sb);
1039 	int rc;
1040 
1041 	if (!(sbsec->flags & SE_SBINITIALIZED))
1042 		return 0;
1043 
1044 	if (!selinux_initialized(&selinux_state))
1045 		return 0;
1046 
1047 	if (sbsec->flags & FSCONTEXT_MNT) {
1048 		seq_putc(m, ',');
1049 		seq_puts(m, FSCONTEXT_STR);
1050 		rc = show_sid(m, sbsec->sid);
1051 		if (rc)
1052 			return rc;
1053 	}
1054 	if (sbsec->flags & CONTEXT_MNT) {
1055 		seq_putc(m, ',');
1056 		seq_puts(m, CONTEXT_STR);
1057 		rc = show_sid(m, sbsec->mntpoint_sid);
1058 		if (rc)
1059 			return rc;
1060 	}
1061 	if (sbsec->flags & DEFCONTEXT_MNT) {
1062 		seq_putc(m, ',');
1063 		seq_puts(m, DEFCONTEXT_STR);
1064 		rc = show_sid(m, sbsec->def_sid);
1065 		if (rc)
1066 			return rc;
1067 	}
1068 	if (sbsec->flags & ROOTCONTEXT_MNT) {
1069 		struct dentry *root = sb->s_root;
1070 		struct inode_security_struct *isec = backing_inode_security(root);
1071 		seq_putc(m, ',');
1072 		seq_puts(m, ROOTCONTEXT_STR);
1073 		rc = show_sid(m, isec->sid);
1074 		if (rc)
1075 			return rc;
1076 	}
1077 	if (sbsec->flags & SBLABEL_MNT) {
1078 		seq_putc(m, ',');
1079 		seq_puts(m, SECLABEL_STR);
1080 	}
1081 	return 0;
1082 }
1083 
inode_mode_to_security_class(umode_t mode)1084 static inline u16 inode_mode_to_security_class(umode_t mode)
1085 {
1086 	switch (mode & S_IFMT) {
1087 	case S_IFSOCK:
1088 		return SECCLASS_SOCK_FILE;
1089 	case S_IFLNK:
1090 		return SECCLASS_LNK_FILE;
1091 	case S_IFREG:
1092 		return SECCLASS_FILE;
1093 	case S_IFBLK:
1094 		return SECCLASS_BLK_FILE;
1095 	case S_IFDIR:
1096 		return SECCLASS_DIR;
1097 	case S_IFCHR:
1098 		return SECCLASS_CHR_FILE;
1099 	case S_IFIFO:
1100 		return SECCLASS_FIFO_FILE;
1101 
1102 	}
1103 
1104 	return SECCLASS_FILE;
1105 }
1106 
default_protocol_stream(int protocol)1107 static inline int default_protocol_stream(int protocol)
1108 {
1109 	return (protocol == IPPROTO_IP || protocol == IPPROTO_TCP ||
1110 		protocol == IPPROTO_MPTCP);
1111 }
1112 
default_protocol_dgram(int protocol)1113 static inline int default_protocol_dgram(int protocol)
1114 {
1115 	return (protocol == IPPROTO_IP || protocol == IPPROTO_UDP);
1116 }
1117 
socket_type_to_security_class(int family,int type,int protocol)1118 static inline u16 socket_type_to_security_class(int family, int type, int protocol)
1119 {
1120 	int extsockclass = selinux_policycap_extsockclass();
1121 
1122 	switch (family) {
1123 	case PF_UNIX:
1124 		switch (type) {
1125 		case SOCK_STREAM:
1126 		case SOCK_SEQPACKET:
1127 			return SECCLASS_UNIX_STREAM_SOCKET;
1128 		case SOCK_DGRAM:
1129 		case SOCK_RAW:
1130 			return SECCLASS_UNIX_DGRAM_SOCKET;
1131 		}
1132 		break;
1133 	case PF_INET:
1134 	case PF_INET6:
1135 		switch (type) {
1136 		case SOCK_STREAM:
1137 		case SOCK_SEQPACKET:
1138 			if (default_protocol_stream(protocol))
1139 				return SECCLASS_TCP_SOCKET;
1140 			else if (extsockclass && protocol == IPPROTO_SCTP)
1141 				return SECCLASS_SCTP_SOCKET;
1142 			else
1143 				return SECCLASS_RAWIP_SOCKET;
1144 		case SOCK_DGRAM:
1145 			if (default_protocol_dgram(protocol))
1146 				return SECCLASS_UDP_SOCKET;
1147 			else if (extsockclass && (protocol == IPPROTO_ICMP ||
1148 						  protocol == IPPROTO_ICMPV6))
1149 				return SECCLASS_ICMP_SOCKET;
1150 			else
1151 				return SECCLASS_RAWIP_SOCKET;
1152 		case SOCK_DCCP:
1153 			return SECCLASS_DCCP_SOCKET;
1154 		default:
1155 			return SECCLASS_RAWIP_SOCKET;
1156 		}
1157 		break;
1158 	case PF_NETLINK:
1159 		switch (protocol) {
1160 		case NETLINK_ROUTE:
1161 			return SECCLASS_NETLINK_ROUTE_SOCKET;
1162 		case NETLINK_SOCK_DIAG:
1163 			return SECCLASS_NETLINK_TCPDIAG_SOCKET;
1164 		case NETLINK_NFLOG:
1165 			return SECCLASS_NETLINK_NFLOG_SOCKET;
1166 		case NETLINK_XFRM:
1167 			return SECCLASS_NETLINK_XFRM_SOCKET;
1168 		case NETLINK_SELINUX:
1169 			return SECCLASS_NETLINK_SELINUX_SOCKET;
1170 		case NETLINK_ISCSI:
1171 			return SECCLASS_NETLINK_ISCSI_SOCKET;
1172 		case NETLINK_AUDIT:
1173 			return SECCLASS_NETLINK_AUDIT_SOCKET;
1174 		case NETLINK_FIB_LOOKUP:
1175 			return SECCLASS_NETLINK_FIB_LOOKUP_SOCKET;
1176 		case NETLINK_CONNECTOR:
1177 			return SECCLASS_NETLINK_CONNECTOR_SOCKET;
1178 		case NETLINK_NETFILTER:
1179 			return SECCLASS_NETLINK_NETFILTER_SOCKET;
1180 		case NETLINK_DNRTMSG:
1181 			return SECCLASS_NETLINK_DNRT_SOCKET;
1182 		case NETLINK_KOBJECT_UEVENT:
1183 			return SECCLASS_NETLINK_KOBJECT_UEVENT_SOCKET;
1184 		case NETLINK_GENERIC:
1185 			return SECCLASS_NETLINK_GENERIC_SOCKET;
1186 		case NETLINK_SCSITRANSPORT:
1187 			return SECCLASS_NETLINK_SCSITRANSPORT_SOCKET;
1188 		case NETLINK_RDMA:
1189 			return SECCLASS_NETLINK_RDMA_SOCKET;
1190 		case NETLINK_CRYPTO:
1191 			return SECCLASS_NETLINK_CRYPTO_SOCKET;
1192 		default:
1193 			return SECCLASS_NETLINK_SOCKET;
1194 		}
1195 	case PF_PACKET:
1196 		return SECCLASS_PACKET_SOCKET;
1197 	case PF_KEY:
1198 		return SECCLASS_KEY_SOCKET;
1199 	case PF_APPLETALK:
1200 		return SECCLASS_APPLETALK_SOCKET;
1201 	}
1202 
1203 	if (extsockclass) {
1204 		switch (family) {
1205 		case PF_AX25:
1206 			return SECCLASS_AX25_SOCKET;
1207 		case PF_IPX:
1208 			return SECCLASS_IPX_SOCKET;
1209 		case PF_NETROM:
1210 			return SECCLASS_NETROM_SOCKET;
1211 		case PF_ATMPVC:
1212 			return SECCLASS_ATMPVC_SOCKET;
1213 		case PF_X25:
1214 			return SECCLASS_X25_SOCKET;
1215 		case PF_ROSE:
1216 			return SECCLASS_ROSE_SOCKET;
1217 		case PF_DECnet:
1218 			return SECCLASS_DECNET_SOCKET;
1219 		case PF_ATMSVC:
1220 			return SECCLASS_ATMSVC_SOCKET;
1221 		case PF_RDS:
1222 			return SECCLASS_RDS_SOCKET;
1223 		case PF_IRDA:
1224 			return SECCLASS_IRDA_SOCKET;
1225 		case PF_PPPOX:
1226 			return SECCLASS_PPPOX_SOCKET;
1227 		case PF_LLC:
1228 			return SECCLASS_LLC_SOCKET;
1229 		case PF_CAN:
1230 			return SECCLASS_CAN_SOCKET;
1231 		case PF_TIPC:
1232 			return SECCLASS_TIPC_SOCKET;
1233 		case PF_BLUETOOTH:
1234 			return SECCLASS_BLUETOOTH_SOCKET;
1235 		case PF_IUCV:
1236 			return SECCLASS_IUCV_SOCKET;
1237 		case PF_RXRPC:
1238 			return SECCLASS_RXRPC_SOCKET;
1239 		case PF_ISDN:
1240 			return SECCLASS_ISDN_SOCKET;
1241 		case PF_PHONET:
1242 			return SECCLASS_PHONET_SOCKET;
1243 		case PF_IEEE802154:
1244 			return SECCLASS_IEEE802154_SOCKET;
1245 		case PF_CAIF:
1246 			return SECCLASS_CAIF_SOCKET;
1247 		case PF_ALG:
1248 			return SECCLASS_ALG_SOCKET;
1249 		case PF_NFC:
1250 			return SECCLASS_NFC_SOCKET;
1251 		case PF_VSOCK:
1252 			return SECCLASS_VSOCK_SOCKET;
1253 		case PF_KCM:
1254 			return SECCLASS_KCM_SOCKET;
1255 		case PF_QIPCRTR:
1256 			return SECCLASS_QIPCRTR_SOCKET;
1257 		case PF_SMC:
1258 			return SECCLASS_SMC_SOCKET;
1259 		case PF_XDP:
1260 			return SECCLASS_XDP_SOCKET;
1261 		case PF_MCTP:
1262 			return SECCLASS_MCTP_SOCKET;
1263 #if PF_MAX > 46
1264 #error New address family defined, please update this function.
1265 #endif
1266 		}
1267 	}
1268 
1269 	return SECCLASS_SOCKET;
1270 }
1271 
selinux_genfs_get_sid(struct dentry * dentry,u16 tclass,u16 flags,u32 * sid)1272 static int selinux_genfs_get_sid(struct dentry *dentry,
1273 				 u16 tclass,
1274 				 u16 flags,
1275 				 u32 *sid)
1276 {
1277 	int rc;
1278 	struct super_block *sb = dentry->d_sb;
1279 	char *buffer, *path;
1280 
1281 	buffer = (char *)__get_free_page(GFP_KERNEL);
1282 	if (!buffer)
1283 		return -ENOMEM;
1284 
1285 	path = dentry_path_raw(dentry, buffer, PAGE_SIZE);
1286 	if (IS_ERR(path))
1287 		rc = PTR_ERR(path);
1288 	else {
1289 		if (flags & SE_SBPROC) {
1290 			/* each process gets a /proc/PID/ entry. Strip off the
1291 			 * PID part to get a valid selinux labeling.
1292 			 * e.g. /proc/1/net/rpc/nfs -> /net/rpc/nfs */
1293 			while (path[1] >= '0' && path[1] <= '9') {
1294 				path[1] = '/';
1295 				path++;
1296 			}
1297 		}
1298 		rc = security_genfs_sid(&selinux_state, sb->s_type->name,
1299 					path, tclass, sid);
1300 		if (rc == -ENOENT) {
1301 			/* No match in policy, mark as unlabeled. */
1302 			*sid = SECINITSID_UNLABELED;
1303 			rc = 0;
1304 		}
1305 	}
1306 	free_page((unsigned long)buffer);
1307 	return rc;
1308 }
1309 
inode_doinit_use_xattr(struct inode * inode,struct dentry * dentry,u32 def_sid,u32 * sid)1310 static int inode_doinit_use_xattr(struct inode *inode, struct dentry *dentry,
1311 				  u32 def_sid, u32 *sid)
1312 {
1313 #define INITCONTEXTLEN 255
1314 	char *context;
1315 	unsigned int len;
1316 	int rc;
1317 
1318 	len = INITCONTEXTLEN;
1319 	context = kmalloc(len + 1, GFP_NOFS);
1320 	if (!context)
1321 		return -ENOMEM;
1322 
1323 	context[len] = '\0';
1324 	rc = __vfs_getxattr(dentry, inode, XATTR_NAME_SELINUX, context, len);
1325 	if (rc == -ERANGE) {
1326 		kfree(context);
1327 
1328 		/* Need a larger buffer.  Query for the right size. */
1329 		rc = __vfs_getxattr(dentry, inode, XATTR_NAME_SELINUX, NULL, 0);
1330 		if (rc < 0)
1331 			return rc;
1332 
1333 		len = rc;
1334 		context = kmalloc(len + 1, GFP_NOFS);
1335 		if (!context)
1336 			return -ENOMEM;
1337 
1338 		context[len] = '\0';
1339 		rc = __vfs_getxattr(dentry, inode, XATTR_NAME_SELINUX,
1340 				    context, len);
1341 	}
1342 	if (rc < 0) {
1343 		kfree(context);
1344 		if (rc != -ENODATA) {
1345 			pr_warn("SELinux: %s:  getxattr returned %d for dev=%s ino=%ld\n",
1346 				__func__, -rc, inode->i_sb->s_id, inode->i_ino);
1347 			return rc;
1348 		}
1349 		*sid = def_sid;
1350 		return 0;
1351 	}
1352 
1353 	rc = security_context_to_sid_default(&selinux_state, context, rc, sid,
1354 					     def_sid, GFP_NOFS);
1355 	if (rc) {
1356 		char *dev = inode->i_sb->s_id;
1357 		unsigned long ino = inode->i_ino;
1358 
1359 		if (rc == -EINVAL) {
1360 			pr_notice_ratelimited("SELinux: inode=%lu on dev=%s was found to have an invalid context=%s.  This indicates you may need to relabel the inode or the filesystem in question.\n",
1361 					      ino, dev, context);
1362 		} else {
1363 			pr_warn("SELinux: %s:  context_to_sid(%s) returned %d for dev=%s ino=%ld\n",
1364 				__func__, context, -rc, dev, ino);
1365 		}
1366 	}
1367 	kfree(context);
1368 	return 0;
1369 }
1370 
1371 /* The inode's security attributes must be initialized before first use. */
inode_doinit_with_dentry(struct inode * inode,struct dentry * opt_dentry)1372 static int inode_doinit_with_dentry(struct inode *inode, struct dentry *opt_dentry)
1373 {
1374 	struct superblock_security_struct *sbsec = NULL;
1375 	struct inode_security_struct *isec = selinux_inode(inode);
1376 	u32 task_sid, sid = 0;
1377 	u16 sclass;
1378 	struct dentry *dentry;
1379 	int rc = 0;
1380 
1381 	if (isec->initialized == LABEL_INITIALIZED)
1382 		return 0;
1383 
1384 	spin_lock(&isec->lock);
1385 	if (isec->initialized == LABEL_INITIALIZED)
1386 		goto out_unlock;
1387 
1388 	if (isec->sclass == SECCLASS_FILE)
1389 		isec->sclass = inode_mode_to_security_class(inode->i_mode);
1390 
1391 	sbsec = selinux_superblock(inode->i_sb);
1392 	if (!(sbsec->flags & SE_SBINITIALIZED)) {
1393 		/* Defer initialization until selinux_complete_init,
1394 		   after the initial policy is loaded and the security
1395 		   server is ready to handle calls. */
1396 		spin_lock(&sbsec->isec_lock);
1397 		if (list_empty(&isec->list))
1398 			list_add(&isec->list, &sbsec->isec_head);
1399 		spin_unlock(&sbsec->isec_lock);
1400 		goto out_unlock;
1401 	}
1402 
1403 	sclass = isec->sclass;
1404 	task_sid = isec->task_sid;
1405 	sid = isec->sid;
1406 	isec->initialized = LABEL_PENDING;
1407 	spin_unlock(&isec->lock);
1408 
1409 	switch (sbsec->behavior) {
1410 	case SECURITY_FS_USE_NATIVE:
1411 		break;
1412 	case SECURITY_FS_USE_XATTR:
1413 		if (!(inode->i_opflags & IOP_XATTR)) {
1414 			sid = sbsec->def_sid;
1415 			break;
1416 		}
1417 		/* Need a dentry, since the xattr API requires one.
1418 		   Life would be simpler if we could just pass the inode. */
1419 		if (opt_dentry) {
1420 			/* Called from d_instantiate or d_splice_alias. */
1421 			dentry = dget(opt_dentry);
1422 		} else {
1423 			/*
1424 			 * Called from selinux_complete_init, try to find a dentry.
1425 			 * Some filesystems really want a connected one, so try
1426 			 * that first.  We could split SECURITY_FS_USE_XATTR in
1427 			 * two, depending upon that...
1428 			 */
1429 			dentry = d_find_alias(inode);
1430 			if (!dentry)
1431 				dentry = d_find_any_alias(inode);
1432 		}
1433 		if (!dentry) {
1434 			/*
1435 			 * this is can be hit on boot when a file is accessed
1436 			 * before the policy is loaded.  When we load policy we
1437 			 * may find inodes that have no dentry on the
1438 			 * sbsec->isec_head list.  No reason to complain as these
1439 			 * will get fixed up the next time we go through
1440 			 * inode_doinit with a dentry, before these inodes could
1441 			 * be used again by userspace.
1442 			 */
1443 			goto out_invalid;
1444 		}
1445 
1446 		rc = inode_doinit_use_xattr(inode, dentry, sbsec->def_sid,
1447 					    &sid);
1448 		dput(dentry);
1449 		if (rc)
1450 			goto out;
1451 		break;
1452 	case SECURITY_FS_USE_TASK:
1453 		sid = task_sid;
1454 		break;
1455 	case SECURITY_FS_USE_TRANS:
1456 		/* Default to the fs SID. */
1457 		sid = sbsec->sid;
1458 
1459 		/* Try to obtain a transition SID. */
1460 		rc = security_transition_sid(&selinux_state, task_sid, sid,
1461 					     sclass, NULL, &sid);
1462 		if (rc)
1463 			goto out;
1464 		break;
1465 	case SECURITY_FS_USE_MNTPOINT:
1466 		sid = sbsec->mntpoint_sid;
1467 		break;
1468 	default:
1469 		/* Default to the fs superblock SID. */
1470 		sid = sbsec->sid;
1471 
1472 		if ((sbsec->flags & SE_SBGENFS) &&
1473 		     (!S_ISLNK(inode->i_mode) ||
1474 		      selinux_policycap_genfs_seclabel_symlinks())) {
1475 			/* We must have a dentry to determine the label on
1476 			 * procfs inodes */
1477 			if (opt_dentry) {
1478 				/* Called from d_instantiate or
1479 				 * d_splice_alias. */
1480 				dentry = dget(opt_dentry);
1481 			} else {
1482 				/* Called from selinux_complete_init, try to
1483 				 * find a dentry.  Some filesystems really want
1484 				 * a connected one, so try that first.
1485 				 */
1486 				dentry = d_find_alias(inode);
1487 				if (!dentry)
1488 					dentry = d_find_any_alias(inode);
1489 			}
1490 			/*
1491 			 * This can be hit on boot when a file is accessed
1492 			 * before the policy is loaded.  When we load policy we
1493 			 * may find inodes that have no dentry on the
1494 			 * sbsec->isec_head list.  No reason to complain as
1495 			 * these will get fixed up the next time we go through
1496 			 * inode_doinit() with a dentry, before these inodes
1497 			 * could be used again by userspace.
1498 			 */
1499 			if (!dentry)
1500 				goto out_invalid;
1501 			rc = selinux_genfs_get_sid(dentry, sclass,
1502 						   sbsec->flags, &sid);
1503 			if (rc) {
1504 				dput(dentry);
1505 				goto out;
1506 			}
1507 
1508 			if ((sbsec->flags & SE_SBGENFS_XATTR) &&
1509 			    (inode->i_opflags & IOP_XATTR)) {
1510 				rc = inode_doinit_use_xattr(inode, dentry,
1511 							    sid, &sid);
1512 				if (rc) {
1513 					dput(dentry);
1514 					goto out;
1515 				}
1516 			}
1517 			dput(dentry);
1518 		}
1519 		break;
1520 	}
1521 
1522 out:
1523 	spin_lock(&isec->lock);
1524 	if (isec->initialized == LABEL_PENDING) {
1525 		if (rc) {
1526 			isec->initialized = LABEL_INVALID;
1527 			goto out_unlock;
1528 		}
1529 		isec->initialized = LABEL_INITIALIZED;
1530 		isec->sid = sid;
1531 	}
1532 
1533 out_unlock:
1534 	spin_unlock(&isec->lock);
1535 	return rc;
1536 
1537 out_invalid:
1538 	spin_lock(&isec->lock);
1539 	if (isec->initialized == LABEL_PENDING) {
1540 		isec->initialized = LABEL_INVALID;
1541 		isec->sid = sid;
1542 	}
1543 	spin_unlock(&isec->lock);
1544 	return 0;
1545 }
1546 
1547 /* Convert a Linux signal to an access vector. */
signal_to_av(int sig)1548 static inline u32 signal_to_av(int sig)
1549 {
1550 	u32 perm = 0;
1551 
1552 	switch (sig) {
1553 	case SIGCHLD:
1554 		/* Commonly granted from child to parent. */
1555 		perm = PROCESS__SIGCHLD;
1556 		break;
1557 	case SIGKILL:
1558 		/* Cannot be caught or ignored */
1559 		perm = PROCESS__SIGKILL;
1560 		break;
1561 	case SIGSTOP:
1562 		/* Cannot be caught or ignored */
1563 		perm = PROCESS__SIGSTOP;
1564 		break;
1565 	default:
1566 		/* All other signals. */
1567 		perm = PROCESS__SIGNAL;
1568 		break;
1569 	}
1570 
1571 	return perm;
1572 }
1573 
1574 #if CAP_LAST_CAP > 63
1575 #error Fix SELinux to handle capabilities > 63.
1576 #endif
1577 
1578 /* Check whether a task is allowed to use a capability. */
cred_has_capability(const struct cred * cred,int cap,unsigned int opts,bool initns)1579 static int cred_has_capability(const struct cred *cred,
1580 			       int cap, unsigned int opts, bool initns)
1581 {
1582 	struct common_audit_data ad;
1583 	struct av_decision avd;
1584 	u16 sclass;
1585 	u32 sid = cred_sid(cred);
1586 	u32 av = CAP_TO_MASK(cap);
1587 	int rc;
1588 
1589 	ad.type = LSM_AUDIT_DATA_CAP;
1590 	ad.u.cap = cap;
1591 
1592 	switch (CAP_TO_INDEX(cap)) {
1593 	case 0:
1594 		sclass = initns ? SECCLASS_CAPABILITY : SECCLASS_CAP_USERNS;
1595 		break;
1596 	case 1:
1597 		sclass = initns ? SECCLASS_CAPABILITY2 : SECCLASS_CAP2_USERNS;
1598 		break;
1599 	default:
1600 		pr_err("SELinux:  out of range capability %d\n", cap);
1601 		BUG();
1602 		return -EINVAL;
1603 	}
1604 
1605 	rc = avc_has_perm_noaudit(&selinux_state,
1606 				  sid, sid, sclass, av, 0, &avd);
1607 	if (!(opts & CAP_OPT_NOAUDIT)) {
1608 		int rc2 = avc_audit(&selinux_state,
1609 				    sid, sid, sclass, av, &avd, rc, &ad);
1610 		if (rc2)
1611 			return rc2;
1612 	}
1613 	return rc;
1614 }
1615 
1616 /* Check whether a task has a particular permission to an inode.
1617    The 'adp' parameter is optional and allows other audit
1618    data to be passed (e.g. the dentry). */
inode_has_perm(const struct cred * cred,struct inode * inode,u32 perms,struct common_audit_data * adp)1619 static int inode_has_perm(const struct cred *cred,
1620 			  struct inode *inode,
1621 			  u32 perms,
1622 			  struct common_audit_data *adp)
1623 {
1624 	struct inode_security_struct *isec;
1625 	u32 sid;
1626 
1627 	validate_creds(cred);
1628 
1629 	if (unlikely(IS_PRIVATE(inode)))
1630 		return 0;
1631 
1632 	sid = cred_sid(cred);
1633 	isec = selinux_inode(inode);
1634 
1635 	return avc_has_perm(&selinux_state,
1636 			    sid, isec->sid, isec->sclass, perms, adp);
1637 }
1638 
1639 /* Same as inode_has_perm, but pass explicit audit data containing
1640    the dentry to help the auditing code to more easily generate the
1641    pathname if needed. */
dentry_has_perm(const struct cred * cred,struct dentry * dentry,u32 av)1642 static inline int dentry_has_perm(const struct cred *cred,
1643 				  struct dentry *dentry,
1644 				  u32 av)
1645 {
1646 	struct inode *inode = d_backing_inode(dentry);
1647 	struct common_audit_data ad;
1648 
1649 	ad.type = LSM_AUDIT_DATA_DENTRY;
1650 	ad.u.dentry = dentry;
1651 	__inode_security_revalidate(inode, dentry, true);
1652 	return inode_has_perm(cred, inode, av, &ad);
1653 }
1654 
1655 /* Same as inode_has_perm, but pass explicit audit data containing
1656    the path to help the auditing code to more easily generate the
1657    pathname if needed. */
path_has_perm(const struct cred * cred,const struct path * path,u32 av)1658 static inline int path_has_perm(const struct cred *cred,
1659 				const struct path *path,
1660 				u32 av)
1661 {
1662 	struct inode *inode = d_backing_inode(path->dentry);
1663 	struct common_audit_data ad;
1664 
1665 	ad.type = LSM_AUDIT_DATA_PATH;
1666 	ad.u.path = *path;
1667 	__inode_security_revalidate(inode, path->dentry, true);
1668 	return inode_has_perm(cred, inode, av, &ad);
1669 }
1670 
1671 /* Same as path_has_perm, but uses the inode from the file struct. */
file_path_has_perm(const struct cred * cred,struct file * file,u32 av)1672 static inline int file_path_has_perm(const struct cred *cred,
1673 				     struct file *file,
1674 				     u32 av)
1675 {
1676 	struct common_audit_data ad;
1677 
1678 	ad.type = LSM_AUDIT_DATA_FILE;
1679 	ad.u.file = file;
1680 	return inode_has_perm(cred, file_inode(file), av, &ad);
1681 }
1682 
1683 #ifdef CONFIG_BPF_SYSCALL
1684 static int bpf_fd_pass(struct file *file, u32 sid);
1685 #endif
1686 
1687 /* Check whether a task can use an open file descriptor to
1688    access an inode in a given way.  Check access to the
1689    descriptor itself, and then use dentry_has_perm to
1690    check a particular permission to the file.
1691    Access to the descriptor is implicitly granted if it
1692    has the same SID as the process.  If av is zero, then
1693    access to the file is not checked, e.g. for cases
1694    where only the descriptor is affected like seek. */
file_has_perm(const struct cred * cred,struct file * file,u32 av)1695 static int file_has_perm(const struct cred *cred,
1696 			 struct file *file,
1697 			 u32 av)
1698 {
1699 	struct file_security_struct *fsec = selinux_file(file);
1700 	struct inode *inode = file_inode(file);
1701 	struct common_audit_data ad;
1702 	u32 sid = cred_sid(cred);
1703 	int rc;
1704 
1705 	ad.type = LSM_AUDIT_DATA_FILE;
1706 	ad.u.file = file;
1707 
1708 	if (sid != fsec->sid) {
1709 		rc = avc_has_perm(&selinux_state,
1710 				  sid, fsec->sid,
1711 				  SECCLASS_FD,
1712 				  FD__USE,
1713 				  &ad);
1714 		if (rc)
1715 			goto out;
1716 	}
1717 
1718 #ifdef CONFIG_BPF_SYSCALL
1719 	rc = bpf_fd_pass(file, cred_sid(cred));
1720 	if (rc)
1721 		return rc;
1722 #endif
1723 
1724 	/* av is zero if only checking access to the descriptor. */
1725 	rc = 0;
1726 	if (av)
1727 		rc = inode_has_perm(cred, inode, av, &ad);
1728 
1729 out:
1730 	return rc;
1731 }
1732 
1733 /*
1734  * Determine the label for an inode that might be unioned.
1735  */
1736 static int
selinux_determine_inode_label(const struct task_security_struct * tsec,struct inode * dir,const struct qstr * name,u16 tclass,u32 * _new_isid)1737 selinux_determine_inode_label(const struct task_security_struct *tsec,
1738 				 struct inode *dir,
1739 				 const struct qstr *name, u16 tclass,
1740 				 u32 *_new_isid)
1741 {
1742 	const struct superblock_security_struct *sbsec =
1743 						selinux_superblock(dir->i_sb);
1744 
1745 	if ((sbsec->flags & SE_SBINITIALIZED) &&
1746 	    (sbsec->behavior == SECURITY_FS_USE_MNTPOINT)) {
1747 		*_new_isid = sbsec->mntpoint_sid;
1748 	} else if ((sbsec->flags & SBLABEL_MNT) &&
1749 		   tsec->create_sid) {
1750 		*_new_isid = tsec->create_sid;
1751 	} else {
1752 		const struct inode_security_struct *dsec = inode_security(dir);
1753 		return security_transition_sid(&selinux_state, tsec->sid,
1754 					       dsec->sid, tclass,
1755 					       name, _new_isid);
1756 	}
1757 
1758 	return 0;
1759 }
1760 
1761 /* Check whether a task can create a file. */
may_create(struct inode * dir,struct dentry * dentry,u16 tclass)1762 static int may_create(struct inode *dir,
1763 		      struct dentry *dentry,
1764 		      u16 tclass)
1765 {
1766 	const struct task_security_struct *tsec = selinux_cred(current_cred());
1767 	struct inode_security_struct *dsec;
1768 	struct superblock_security_struct *sbsec;
1769 	u32 sid, newsid;
1770 	struct common_audit_data ad;
1771 	int rc;
1772 
1773 	dsec = inode_security(dir);
1774 	sbsec = selinux_superblock(dir->i_sb);
1775 
1776 	sid = tsec->sid;
1777 
1778 	ad.type = LSM_AUDIT_DATA_DENTRY;
1779 	ad.u.dentry = dentry;
1780 
1781 	rc = avc_has_perm(&selinux_state,
1782 			  sid, dsec->sid, SECCLASS_DIR,
1783 			  DIR__ADD_NAME | DIR__SEARCH,
1784 			  &ad);
1785 	if (rc)
1786 		return rc;
1787 
1788 	rc = selinux_determine_inode_label(tsec, dir, &dentry->d_name, tclass,
1789 					   &newsid);
1790 	if (rc)
1791 		return rc;
1792 
1793 	rc = avc_has_perm(&selinux_state,
1794 			  sid, newsid, tclass, FILE__CREATE, &ad);
1795 	if (rc)
1796 		return rc;
1797 
1798 	return avc_has_perm(&selinux_state,
1799 			    newsid, sbsec->sid,
1800 			    SECCLASS_FILESYSTEM,
1801 			    FILESYSTEM__ASSOCIATE, &ad);
1802 }
1803 
1804 #define MAY_LINK	0
1805 #define MAY_UNLINK	1
1806 #define MAY_RMDIR	2
1807 
1808 /* Check whether a task can link, unlink, or rmdir a file/directory. */
may_link(struct inode * dir,struct dentry * dentry,int kind)1809 static int may_link(struct inode *dir,
1810 		    struct dentry *dentry,
1811 		    int kind)
1812 
1813 {
1814 	struct inode_security_struct *dsec, *isec;
1815 	struct common_audit_data ad;
1816 	u32 sid = current_sid();
1817 	u32 av;
1818 	int rc;
1819 
1820 	dsec = inode_security(dir);
1821 	isec = backing_inode_security(dentry);
1822 
1823 	ad.type = LSM_AUDIT_DATA_DENTRY;
1824 	ad.u.dentry = dentry;
1825 
1826 	av = DIR__SEARCH;
1827 	av |= (kind ? DIR__REMOVE_NAME : DIR__ADD_NAME);
1828 	rc = avc_has_perm(&selinux_state,
1829 			  sid, dsec->sid, SECCLASS_DIR, av, &ad);
1830 	if (rc)
1831 		return rc;
1832 
1833 	switch (kind) {
1834 	case MAY_LINK:
1835 		av = FILE__LINK;
1836 		break;
1837 	case MAY_UNLINK:
1838 		av = FILE__UNLINK;
1839 		break;
1840 	case MAY_RMDIR:
1841 		av = DIR__RMDIR;
1842 		break;
1843 	default:
1844 		pr_warn("SELinux: %s:  unrecognized kind %d\n",
1845 			__func__, kind);
1846 		return 0;
1847 	}
1848 
1849 	rc = avc_has_perm(&selinux_state,
1850 			  sid, isec->sid, isec->sclass, av, &ad);
1851 	return rc;
1852 }
1853 
may_rename(struct inode * old_dir,struct dentry * old_dentry,struct inode * new_dir,struct dentry * new_dentry)1854 static inline int may_rename(struct inode *old_dir,
1855 			     struct dentry *old_dentry,
1856 			     struct inode *new_dir,
1857 			     struct dentry *new_dentry)
1858 {
1859 	struct inode_security_struct *old_dsec, *new_dsec, *old_isec, *new_isec;
1860 	struct common_audit_data ad;
1861 	u32 sid = current_sid();
1862 	u32 av;
1863 	int old_is_dir, new_is_dir;
1864 	int rc;
1865 
1866 	old_dsec = inode_security(old_dir);
1867 	old_isec = backing_inode_security(old_dentry);
1868 	old_is_dir = d_is_dir(old_dentry);
1869 	new_dsec = inode_security(new_dir);
1870 
1871 	ad.type = LSM_AUDIT_DATA_DENTRY;
1872 
1873 	ad.u.dentry = old_dentry;
1874 	rc = avc_has_perm(&selinux_state,
1875 			  sid, old_dsec->sid, SECCLASS_DIR,
1876 			  DIR__REMOVE_NAME | DIR__SEARCH, &ad);
1877 	if (rc)
1878 		return rc;
1879 	rc = avc_has_perm(&selinux_state,
1880 			  sid, old_isec->sid,
1881 			  old_isec->sclass, FILE__RENAME, &ad);
1882 	if (rc)
1883 		return rc;
1884 	if (old_is_dir && new_dir != old_dir) {
1885 		rc = avc_has_perm(&selinux_state,
1886 				  sid, old_isec->sid,
1887 				  old_isec->sclass, DIR__REPARENT, &ad);
1888 		if (rc)
1889 			return rc;
1890 	}
1891 
1892 	ad.u.dentry = new_dentry;
1893 	av = DIR__ADD_NAME | DIR__SEARCH;
1894 	if (d_is_positive(new_dentry))
1895 		av |= DIR__REMOVE_NAME;
1896 	rc = avc_has_perm(&selinux_state,
1897 			  sid, new_dsec->sid, SECCLASS_DIR, av, &ad);
1898 	if (rc)
1899 		return rc;
1900 	if (d_is_positive(new_dentry)) {
1901 		new_isec = backing_inode_security(new_dentry);
1902 		new_is_dir = d_is_dir(new_dentry);
1903 		rc = avc_has_perm(&selinux_state,
1904 				  sid, new_isec->sid,
1905 				  new_isec->sclass,
1906 				  (new_is_dir ? DIR__RMDIR : FILE__UNLINK), &ad);
1907 		if (rc)
1908 			return rc;
1909 	}
1910 
1911 	return 0;
1912 }
1913 
1914 /* Check whether a task can perform a filesystem operation. */
superblock_has_perm(const struct cred * cred,struct super_block * sb,u32 perms,struct common_audit_data * ad)1915 static int superblock_has_perm(const struct cred *cred,
1916 			       struct super_block *sb,
1917 			       u32 perms,
1918 			       struct common_audit_data *ad)
1919 {
1920 	struct superblock_security_struct *sbsec;
1921 	u32 sid = cred_sid(cred);
1922 
1923 	sbsec = selinux_superblock(sb);
1924 	return avc_has_perm(&selinux_state,
1925 			    sid, sbsec->sid, SECCLASS_FILESYSTEM, perms, ad);
1926 }
1927 
1928 /* Convert a Linux mode and permission mask to an access vector. */
file_mask_to_av(int mode,int mask)1929 static inline u32 file_mask_to_av(int mode, int mask)
1930 {
1931 	u32 av = 0;
1932 
1933 	if (!S_ISDIR(mode)) {
1934 		if (mask & MAY_EXEC)
1935 			av |= FILE__EXECUTE;
1936 		if (mask & MAY_READ)
1937 			av |= FILE__READ;
1938 
1939 		if (mask & MAY_APPEND)
1940 			av |= FILE__APPEND;
1941 		else if (mask & MAY_WRITE)
1942 			av |= FILE__WRITE;
1943 
1944 	} else {
1945 		if (mask & MAY_EXEC)
1946 			av |= DIR__SEARCH;
1947 		if (mask & MAY_WRITE)
1948 			av |= DIR__WRITE;
1949 		if (mask & MAY_READ)
1950 			av |= DIR__READ;
1951 	}
1952 
1953 	return av;
1954 }
1955 
1956 /* Convert a Linux file to an access vector. */
file_to_av(struct file * file)1957 static inline u32 file_to_av(struct file *file)
1958 {
1959 	u32 av = 0;
1960 
1961 	if (file->f_mode & FMODE_READ)
1962 		av |= FILE__READ;
1963 	if (file->f_mode & FMODE_WRITE) {
1964 		if (file->f_flags & O_APPEND)
1965 			av |= FILE__APPEND;
1966 		else
1967 			av |= FILE__WRITE;
1968 	}
1969 	if (!av) {
1970 		/*
1971 		 * Special file opened with flags 3 for ioctl-only use.
1972 		 */
1973 		av = FILE__IOCTL;
1974 	}
1975 
1976 	return av;
1977 }
1978 
1979 /*
1980  * Convert a file to an access vector and include the correct
1981  * open permission.
1982  */
open_file_to_av(struct file * file)1983 static inline u32 open_file_to_av(struct file *file)
1984 {
1985 	u32 av = file_to_av(file);
1986 	struct inode *inode = file_inode(file);
1987 
1988 	if (selinux_policycap_openperm() &&
1989 	    inode->i_sb->s_magic != SOCKFS_MAGIC)
1990 		av |= FILE__OPEN;
1991 
1992 	return av;
1993 }
1994 
1995 /* Hook functions begin here. */
1996 
selinux_binder_set_context_mgr(const struct cred * mgr)1997 static int selinux_binder_set_context_mgr(const struct cred *mgr)
1998 {
1999 	return avc_has_perm(&selinux_state,
2000 			    current_sid(), cred_sid(mgr), SECCLASS_BINDER,
2001 			    BINDER__SET_CONTEXT_MGR, NULL);
2002 }
2003 
selinux_binder_transaction(const struct cred * from,const struct cred * to)2004 static int selinux_binder_transaction(const struct cred *from,
2005 				      const struct cred *to)
2006 {
2007 	u32 mysid = current_sid();
2008 	u32 fromsid = cred_sid(from);
2009 	u32 tosid = cred_sid(to);
2010 	int rc;
2011 
2012 	if (mysid != fromsid) {
2013 		rc = avc_has_perm(&selinux_state,
2014 				  mysid, fromsid, SECCLASS_BINDER,
2015 				  BINDER__IMPERSONATE, NULL);
2016 		if (rc)
2017 			return rc;
2018 	}
2019 
2020 	return avc_has_perm(&selinux_state, fromsid, tosid,
2021 			    SECCLASS_BINDER, BINDER__CALL, NULL);
2022 }
2023 
selinux_binder_transfer_binder(const struct cred * from,const struct cred * to)2024 static int selinux_binder_transfer_binder(const struct cred *from,
2025 					  const struct cred *to)
2026 {
2027 	return avc_has_perm(&selinux_state,
2028 			    cred_sid(from), cred_sid(to),
2029 			    SECCLASS_BINDER, BINDER__TRANSFER,
2030 			    NULL);
2031 }
2032 
selinux_binder_transfer_file(const struct cred * from,const struct cred * to,struct file * file)2033 static int selinux_binder_transfer_file(const struct cred *from,
2034 					const struct cred *to,
2035 					struct file *file)
2036 {
2037 	u32 sid = cred_sid(to);
2038 	struct file_security_struct *fsec = selinux_file(file);
2039 	struct dentry *dentry = file->f_path.dentry;
2040 	struct inode_security_struct *isec;
2041 	struct common_audit_data ad;
2042 	int rc;
2043 
2044 	ad.type = LSM_AUDIT_DATA_PATH;
2045 	ad.u.path = file->f_path;
2046 
2047 	if (sid != fsec->sid) {
2048 		rc = avc_has_perm(&selinux_state,
2049 				  sid, fsec->sid,
2050 				  SECCLASS_FD,
2051 				  FD__USE,
2052 				  &ad);
2053 		if (rc)
2054 			return rc;
2055 	}
2056 
2057 #ifdef CONFIG_BPF_SYSCALL
2058 	rc = bpf_fd_pass(file, sid);
2059 	if (rc)
2060 		return rc;
2061 #endif
2062 
2063 	if (unlikely(IS_PRIVATE(d_backing_inode(dentry))))
2064 		return 0;
2065 
2066 	isec = backing_inode_security(dentry);
2067 	return avc_has_perm(&selinux_state,
2068 			    sid, isec->sid, isec->sclass, file_to_av(file),
2069 			    &ad);
2070 }
2071 
selinux_ptrace_access_check(struct task_struct * child,unsigned int mode)2072 static int selinux_ptrace_access_check(struct task_struct *child,
2073 				       unsigned int mode)
2074 {
2075 	u32 sid = current_sid();
2076 	u32 csid = task_sid_obj(child);
2077 
2078 	if (mode & PTRACE_MODE_READ)
2079 		return avc_has_perm(&selinux_state,
2080 				    sid, csid, SECCLASS_FILE, FILE__READ, NULL);
2081 
2082 	return avc_has_perm(&selinux_state,
2083 			    sid, csid, SECCLASS_PROCESS, PROCESS__PTRACE, NULL);
2084 }
2085 
selinux_ptrace_traceme(struct task_struct * parent)2086 static int selinux_ptrace_traceme(struct task_struct *parent)
2087 {
2088 	return avc_has_perm(&selinux_state,
2089 			    task_sid_obj(parent), task_sid_obj(current),
2090 			    SECCLASS_PROCESS, PROCESS__PTRACE, NULL);
2091 }
2092 
selinux_capget(struct task_struct * target,kernel_cap_t * effective,kernel_cap_t * inheritable,kernel_cap_t * permitted)2093 static int selinux_capget(struct task_struct *target, kernel_cap_t *effective,
2094 			  kernel_cap_t *inheritable, kernel_cap_t *permitted)
2095 {
2096 	return avc_has_perm(&selinux_state,
2097 			    current_sid(), task_sid_obj(target), SECCLASS_PROCESS,
2098 			    PROCESS__GETCAP, NULL);
2099 }
2100 
selinux_capset(struct cred * new,const struct cred * old,const kernel_cap_t * effective,const kernel_cap_t * inheritable,const kernel_cap_t * permitted)2101 static int selinux_capset(struct cred *new, const struct cred *old,
2102 			  const kernel_cap_t *effective,
2103 			  const kernel_cap_t *inheritable,
2104 			  const kernel_cap_t *permitted)
2105 {
2106 	return avc_has_perm(&selinux_state,
2107 			    cred_sid(old), cred_sid(new), SECCLASS_PROCESS,
2108 			    PROCESS__SETCAP, NULL);
2109 }
2110 
2111 /*
2112  * (This comment used to live with the selinux_task_setuid hook,
2113  * which was removed).
2114  *
2115  * Since setuid only affects the current process, and since the SELinux
2116  * controls are not based on the Linux identity attributes, SELinux does not
2117  * need to control this operation.  However, SELinux does control the use of
2118  * the CAP_SETUID and CAP_SETGID capabilities using the capable hook.
2119  */
2120 
selinux_capable(const struct cred * cred,struct user_namespace * ns,int cap,unsigned int opts)2121 static int selinux_capable(const struct cred *cred, struct user_namespace *ns,
2122 			   int cap, unsigned int opts)
2123 {
2124 	return cred_has_capability(cred, cap, opts, ns == &init_user_ns);
2125 }
2126 
selinux_quotactl(int cmds,int type,int id,struct super_block * sb)2127 static int selinux_quotactl(int cmds, int type, int id, struct super_block *sb)
2128 {
2129 	const struct cred *cred = current_cred();
2130 	int rc = 0;
2131 
2132 	if (!sb)
2133 		return 0;
2134 
2135 	switch (cmds) {
2136 	case Q_SYNC:
2137 	case Q_QUOTAON:
2138 	case Q_QUOTAOFF:
2139 	case Q_SETINFO:
2140 	case Q_SETQUOTA:
2141 	case Q_XQUOTAOFF:
2142 	case Q_XQUOTAON:
2143 	case Q_XSETQLIM:
2144 		rc = superblock_has_perm(cred, sb, FILESYSTEM__QUOTAMOD, NULL);
2145 		break;
2146 	case Q_GETFMT:
2147 	case Q_GETINFO:
2148 	case Q_GETQUOTA:
2149 	case Q_XGETQUOTA:
2150 	case Q_XGETQSTAT:
2151 	case Q_XGETQSTATV:
2152 	case Q_XGETNEXTQUOTA:
2153 		rc = superblock_has_perm(cred, sb, FILESYSTEM__QUOTAGET, NULL);
2154 		break;
2155 	default:
2156 		rc = 0;  /* let the kernel handle invalid cmds */
2157 		break;
2158 	}
2159 	return rc;
2160 }
2161 
selinux_quota_on(struct dentry * dentry)2162 static int selinux_quota_on(struct dentry *dentry)
2163 {
2164 	const struct cred *cred = current_cred();
2165 
2166 	return dentry_has_perm(cred, dentry, FILE__QUOTAON);
2167 }
2168 
selinux_syslog(int type)2169 static int selinux_syslog(int type)
2170 {
2171 	switch (type) {
2172 	case SYSLOG_ACTION_READ_ALL:	/* Read last kernel messages */
2173 	case SYSLOG_ACTION_SIZE_BUFFER:	/* Return size of the log buffer */
2174 		return avc_has_perm(&selinux_state,
2175 				    current_sid(), SECINITSID_KERNEL,
2176 				    SECCLASS_SYSTEM, SYSTEM__SYSLOG_READ, NULL);
2177 	case SYSLOG_ACTION_CONSOLE_OFF:	/* Disable logging to console */
2178 	case SYSLOG_ACTION_CONSOLE_ON:	/* Enable logging to console */
2179 	/* Set level of messages printed to console */
2180 	case SYSLOG_ACTION_CONSOLE_LEVEL:
2181 		return avc_has_perm(&selinux_state,
2182 				    current_sid(), SECINITSID_KERNEL,
2183 				    SECCLASS_SYSTEM, SYSTEM__SYSLOG_CONSOLE,
2184 				    NULL);
2185 	}
2186 	/* All other syslog types */
2187 	return avc_has_perm(&selinux_state,
2188 			    current_sid(), SECINITSID_KERNEL,
2189 			    SECCLASS_SYSTEM, SYSTEM__SYSLOG_MOD, NULL);
2190 }
2191 
2192 /*
2193  * Check that a process has enough memory to allocate a new virtual
2194  * mapping. 0 means there is enough memory for the allocation to
2195  * succeed and -ENOMEM implies there is not.
2196  *
2197  * Do not audit the selinux permission check, as this is applied to all
2198  * processes that allocate mappings.
2199  */
selinux_vm_enough_memory(struct mm_struct * mm,long pages)2200 static int selinux_vm_enough_memory(struct mm_struct *mm, long pages)
2201 {
2202 	int rc, cap_sys_admin = 0;
2203 
2204 	rc = cred_has_capability(current_cred(), CAP_SYS_ADMIN,
2205 				 CAP_OPT_NOAUDIT, true);
2206 	if (rc == 0)
2207 		cap_sys_admin = 1;
2208 
2209 	return cap_sys_admin;
2210 }
2211 
2212 /* binprm security operations */
2213 
ptrace_parent_sid(void)2214 static u32 ptrace_parent_sid(void)
2215 {
2216 	u32 sid = 0;
2217 	struct task_struct *tracer;
2218 
2219 	rcu_read_lock();
2220 	tracer = ptrace_parent(current);
2221 	if (tracer)
2222 		sid = task_sid_obj(tracer);
2223 	rcu_read_unlock();
2224 
2225 	return sid;
2226 }
2227 
check_nnp_nosuid(const struct linux_binprm * bprm,const struct task_security_struct * old_tsec,const struct task_security_struct * new_tsec)2228 static int check_nnp_nosuid(const struct linux_binprm *bprm,
2229 			    const struct task_security_struct *old_tsec,
2230 			    const struct task_security_struct *new_tsec)
2231 {
2232 	int nnp = (bprm->unsafe & LSM_UNSAFE_NO_NEW_PRIVS);
2233 	int nosuid = !mnt_may_suid(bprm->file->f_path.mnt);
2234 	int rc;
2235 	u32 av;
2236 
2237 	if (!nnp && !nosuid)
2238 		return 0; /* neither NNP nor nosuid */
2239 
2240 	if (new_tsec->sid == old_tsec->sid)
2241 		return 0; /* No change in credentials */
2242 
2243 	/*
2244 	 * If the policy enables the nnp_nosuid_transition policy capability,
2245 	 * then we permit transitions under NNP or nosuid if the
2246 	 * policy allows the corresponding permission between
2247 	 * the old and new contexts.
2248 	 */
2249 	if (selinux_policycap_nnp_nosuid_transition()) {
2250 		av = 0;
2251 		if (nnp)
2252 			av |= PROCESS2__NNP_TRANSITION;
2253 		if (nosuid)
2254 			av |= PROCESS2__NOSUID_TRANSITION;
2255 		rc = avc_has_perm(&selinux_state,
2256 				  old_tsec->sid, new_tsec->sid,
2257 				  SECCLASS_PROCESS2, av, NULL);
2258 		if (!rc)
2259 			return 0;
2260 	}
2261 
2262 	/*
2263 	 * We also permit NNP or nosuid transitions to bounded SIDs,
2264 	 * i.e. SIDs that are guaranteed to only be allowed a subset
2265 	 * of the permissions of the current SID.
2266 	 */
2267 	rc = security_bounded_transition(&selinux_state, old_tsec->sid,
2268 					 new_tsec->sid);
2269 	if (!rc)
2270 		return 0;
2271 
2272 	/*
2273 	 * On failure, preserve the errno values for NNP vs nosuid.
2274 	 * NNP:  Operation not permitted for caller.
2275 	 * nosuid:  Permission denied to file.
2276 	 */
2277 	if (nnp)
2278 		return -EPERM;
2279 	return -EACCES;
2280 }
2281 
selinux_bprm_creds_for_exec(struct linux_binprm * bprm)2282 static int selinux_bprm_creds_for_exec(struct linux_binprm *bprm)
2283 {
2284 	const struct task_security_struct *old_tsec;
2285 	struct task_security_struct *new_tsec;
2286 	struct inode_security_struct *isec;
2287 	struct common_audit_data ad;
2288 	struct inode *inode = file_inode(bprm->file);
2289 	int rc;
2290 
2291 	/* SELinux context only depends on initial program or script and not
2292 	 * the script interpreter */
2293 
2294 	old_tsec = selinux_cred(current_cred());
2295 	new_tsec = selinux_cred(bprm->cred);
2296 	isec = inode_security(inode);
2297 
2298 	/* Default to the current task SID. */
2299 	new_tsec->sid = old_tsec->sid;
2300 	new_tsec->osid = old_tsec->sid;
2301 
2302 	/* Reset fs, key, and sock SIDs on execve. */
2303 	new_tsec->create_sid = 0;
2304 	new_tsec->keycreate_sid = 0;
2305 	new_tsec->sockcreate_sid = 0;
2306 
2307 	if (old_tsec->exec_sid) {
2308 		new_tsec->sid = old_tsec->exec_sid;
2309 		/* Reset exec SID on execve. */
2310 		new_tsec->exec_sid = 0;
2311 
2312 		/* Fail on NNP or nosuid if not an allowed transition. */
2313 		rc = check_nnp_nosuid(bprm, old_tsec, new_tsec);
2314 		if (rc)
2315 			return rc;
2316 	} else {
2317 		/* Check for a default transition on this program. */
2318 		rc = security_transition_sid(&selinux_state, old_tsec->sid,
2319 					     isec->sid, SECCLASS_PROCESS, NULL,
2320 					     &new_tsec->sid);
2321 		if (rc)
2322 			return rc;
2323 
2324 		/*
2325 		 * Fallback to old SID on NNP or nosuid if not an allowed
2326 		 * transition.
2327 		 */
2328 		rc = check_nnp_nosuid(bprm, old_tsec, new_tsec);
2329 		if (rc)
2330 			new_tsec->sid = old_tsec->sid;
2331 	}
2332 
2333 	ad.type = LSM_AUDIT_DATA_FILE;
2334 	ad.u.file = bprm->file;
2335 
2336 	if (new_tsec->sid == old_tsec->sid) {
2337 		rc = avc_has_perm(&selinux_state,
2338 				  old_tsec->sid, isec->sid,
2339 				  SECCLASS_FILE, FILE__EXECUTE_NO_TRANS, &ad);
2340 		if (rc)
2341 			return rc;
2342 	} else {
2343 		/* Check permissions for the transition. */
2344 		rc = avc_has_perm(&selinux_state,
2345 				  old_tsec->sid, new_tsec->sid,
2346 				  SECCLASS_PROCESS, PROCESS__TRANSITION, &ad);
2347 		if (rc)
2348 			return rc;
2349 
2350 		rc = avc_has_perm(&selinux_state,
2351 				  new_tsec->sid, isec->sid,
2352 				  SECCLASS_FILE, FILE__ENTRYPOINT, &ad);
2353 		if (rc)
2354 			return rc;
2355 
2356 		/* Check for shared state */
2357 		if (bprm->unsafe & LSM_UNSAFE_SHARE) {
2358 			rc = avc_has_perm(&selinux_state,
2359 					  old_tsec->sid, new_tsec->sid,
2360 					  SECCLASS_PROCESS, PROCESS__SHARE,
2361 					  NULL);
2362 			if (rc)
2363 				return -EPERM;
2364 		}
2365 
2366 		/* Make sure that anyone attempting to ptrace over a task that
2367 		 * changes its SID has the appropriate permit */
2368 		if (bprm->unsafe & LSM_UNSAFE_PTRACE) {
2369 			u32 ptsid = ptrace_parent_sid();
2370 			if (ptsid != 0) {
2371 				rc = avc_has_perm(&selinux_state,
2372 						  ptsid, new_tsec->sid,
2373 						  SECCLASS_PROCESS,
2374 						  PROCESS__PTRACE, NULL);
2375 				if (rc)
2376 					return -EPERM;
2377 			}
2378 		}
2379 
2380 		/* Clear any possibly unsafe personality bits on exec: */
2381 		bprm->per_clear |= PER_CLEAR_ON_SETID;
2382 
2383 		/* Enable secure mode for SIDs transitions unless
2384 		   the noatsecure permission is granted between
2385 		   the two SIDs, i.e. ahp returns 0. */
2386 		rc = avc_has_perm(&selinux_state,
2387 				  old_tsec->sid, new_tsec->sid,
2388 				  SECCLASS_PROCESS, PROCESS__NOATSECURE,
2389 				  NULL);
2390 		bprm->secureexec |= !!rc;
2391 	}
2392 
2393 	return 0;
2394 }
2395 
match_file(const void * p,struct file * file,unsigned fd)2396 static int match_file(const void *p, struct file *file, unsigned fd)
2397 {
2398 	return file_has_perm(p, file, file_to_av(file)) ? fd + 1 : 0;
2399 }
2400 
2401 /* Derived from fs/exec.c:flush_old_files. */
flush_unauthorized_files(const struct cred * cred,struct files_struct * files)2402 static inline void flush_unauthorized_files(const struct cred *cred,
2403 					    struct files_struct *files)
2404 {
2405 	struct file *file, *devnull = NULL;
2406 	struct tty_struct *tty;
2407 	int drop_tty = 0;
2408 	unsigned n;
2409 
2410 	tty = get_current_tty();
2411 	if (tty) {
2412 		spin_lock(&tty->files_lock);
2413 		if (!list_empty(&tty->tty_files)) {
2414 			struct tty_file_private *file_priv;
2415 
2416 			/* Revalidate access to controlling tty.
2417 			   Use file_path_has_perm on the tty path directly
2418 			   rather than using file_has_perm, as this particular
2419 			   open file may belong to another process and we are
2420 			   only interested in the inode-based check here. */
2421 			file_priv = list_first_entry(&tty->tty_files,
2422 						struct tty_file_private, list);
2423 			file = file_priv->file;
2424 			if (file_path_has_perm(cred, file, FILE__READ | FILE__WRITE))
2425 				drop_tty = 1;
2426 		}
2427 		spin_unlock(&tty->files_lock);
2428 		tty_kref_put(tty);
2429 	}
2430 	/* Reset controlling tty. */
2431 	if (drop_tty)
2432 		no_tty();
2433 
2434 	/* Revalidate access to inherited open files. */
2435 	n = iterate_fd(files, 0, match_file, cred);
2436 	if (!n) /* none found? */
2437 		return;
2438 
2439 	devnull = dentry_open(&selinux_null, O_RDWR, cred);
2440 	if (IS_ERR(devnull))
2441 		devnull = NULL;
2442 	/* replace all the matching ones with this */
2443 	do {
2444 		replace_fd(n - 1, devnull, 0);
2445 	} while ((n = iterate_fd(files, n, match_file, cred)) != 0);
2446 	if (devnull)
2447 		fput(devnull);
2448 }
2449 
2450 /*
2451  * Prepare a process for imminent new credential changes due to exec
2452  */
selinux_bprm_committing_creds(struct linux_binprm * bprm)2453 static void selinux_bprm_committing_creds(struct linux_binprm *bprm)
2454 {
2455 	struct task_security_struct *new_tsec;
2456 	struct rlimit *rlim, *initrlim;
2457 	int rc, i;
2458 
2459 	new_tsec = selinux_cred(bprm->cred);
2460 	if (new_tsec->sid == new_tsec->osid)
2461 		return;
2462 
2463 	/* Close files for which the new task SID is not authorized. */
2464 	flush_unauthorized_files(bprm->cred, current->files);
2465 
2466 	/* Always clear parent death signal on SID transitions. */
2467 	current->pdeath_signal = 0;
2468 
2469 	/* Check whether the new SID can inherit resource limits from the old
2470 	 * SID.  If not, reset all soft limits to the lower of the current
2471 	 * task's hard limit and the init task's soft limit.
2472 	 *
2473 	 * Note that the setting of hard limits (even to lower them) can be
2474 	 * controlled by the setrlimit check.  The inclusion of the init task's
2475 	 * soft limit into the computation is to avoid resetting soft limits
2476 	 * higher than the default soft limit for cases where the default is
2477 	 * lower than the hard limit, e.g. RLIMIT_CORE or RLIMIT_STACK.
2478 	 */
2479 	rc = avc_has_perm(&selinux_state,
2480 			  new_tsec->osid, new_tsec->sid, SECCLASS_PROCESS,
2481 			  PROCESS__RLIMITINH, NULL);
2482 	if (rc) {
2483 		/* protect against do_prlimit() */
2484 		task_lock(current);
2485 		for (i = 0; i < RLIM_NLIMITS; i++) {
2486 			rlim = current->signal->rlim + i;
2487 			initrlim = init_task.signal->rlim + i;
2488 			rlim->rlim_cur = min(rlim->rlim_max, initrlim->rlim_cur);
2489 		}
2490 		task_unlock(current);
2491 		if (IS_ENABLED(CONFIG_POSIX_TIMERS))
2492 			update_rlimit_cpu(current, rlimit(RLIMIT_CPU));
2493 	}
2494 }
2495 
2496 /*
2497  * Clean up the process immediately after the installation of new credentials
2498  * due to exec
2499  */
selinux_bprm_committed_creds(struct linux_binprm * bprm)2500 static void selinux_bprm_committed_creds(struct linux_binprm *bprm)
2501 {
2502 	const struct task_security_struct *tsec = selinux_cred(current_cred());
2503 	u32 osid, sid;
2504 	int rc;
2505 
2506 	osid = tsec->osid;
2507 	sid = tsec->sid;
2508 
2509 	if (sid == osid)
2510 		return;
2511 
2512 	/* Check whether the new SID can inherit signal state from the old SID.
2513 	 * If not, clear itimers to avoid subsequent signal generation and
2514 	 * flush and unblock signals.
2515 	 *
2516 	 * This must occur _after_ the task SID has been updated so that any
2517 	 * kill done after the flush will be checked against the new SID.
2518 	 */
2519 	rc = avc_has_perm(&selinux_state,
2520 			  osid, sid, SECCLASS_PROCESS, PROCESS__SIGINH, NULL);
2521 	if (rc) {
2522 		clear_itimer();
2523 
2524 		spin_lock_irq(&unrcu_pointer(current->sighand)->siglock);
2525 		if (!fatal_signal_pending(current)) {
2526 			flush_sigqueue(&current->pending);
2527 			flush_sigqueue(&current->signal->shared_pending);
2528 			flush_signal_handlers(current, 1);
2529 			sigemptyset(&current->blocked);
2530 			recalc_sigpending();
2531 		}
2532 		spin_unlock_irq(&unrcu_pointer(current->sighand)->siglock);
2533 	}
2534 
2535 	/* Wake up the parent if it is waiting so that it can recheck
2536 	 * wait permission to the new task SID. */
2537 	read_lock(&tasklist_lock);
2538 	__wake_up_parent(current, unrcu_pointer(current->real_parent));
2539 	read_unlock(&tasklist_lock);
2540 }
2541 
2542 /* superblock security operations */
2543 
selinux_sb_alloc_security(struct super_block * sb)2544 static int selinux_sb_alloc_security(struct super_block *sb)
2545 {
2546 	struct superblock_security_struct *sbsec = selinux_superblock(sb);
2547 
2548 	mutex_init(&sbsec->lock);
2549 	INIT_LIST_HEAD(&sbsec->isec_head);
2550 	spin_lock_init(&sbsec->isec_lock);
2551 	sbsec->sid = SECINITSID_UNLABELED;
2552 	sbsec->def_sid = SECINITSID_FILE;
2553 	sbsec->mntpoint_sid = SECINITSID_UNLABELED;
2554 
2555 	return 0;
2556 }
2557 
opt_len(const char * s)2558 static inline int opt_len(const char *s)
2559 {
2560 	bool open_quote = false;
2561 	int len;
2562 	char c;
2563 
2564 	for (len = 0; (c = s[len]) != '\0'; len++) {
2565 		if (c == '"')
2566 			open_quote = !open_quote;
2567 		if (c == ',' && !open_quote)
2568 			break;
2569 	}
2570 	return len;
2571 }
2572 
selinux_sb_eat_lsm_opts(char * options,void ** mnt_opts)2573 static int selinux_sb_eat_lsm_opts(char *options, void **mnt_opts)
2574 {
2575 	char *from = options;
2576 	char *to = options;
2577 	bool first = true;
2578 	int rc;
2579 
2580 	while (1) {
2581 		int len = opt_len(from);
2582 		int token;
2583 		char *arg = NULL;
2584 
2585 		token = match_opt_prefix(from, len, &arg);
2586 
2587 		if (token != Opt_error) {
2588 			char *p, *q;
2589 
2590 			/* strip quotes */
2591 			if (arg) {
2592 				for (p = q = arg; p < from + len; p++) {
2593 					char c = *p;
2594 					if (c != '"')
2595 						*q++ = c;
2596 				}
2597 				arg = kmemdup_nul(arg, q - arg, GFP_KERNEL);
2598 				if (!arg) {
2599 					rc = -ENOMEM;
2600 					goto free_opt;
2601 				}
2602 			}
2603 			rc = selinux_add_opt(token, arg, mnt_opts);
2604 			kfree(arg);
2605 			arg = NULL;
2606 			if (unlikely(rc)) {
2607 				goto free_opt;
2608 			}
2609 		} else {
2610 			if (!first) {	// copy with preceding comma
2611 				from--;
2612 				len++;
2613 			}
2614 			if (to != from)
2615 				memmove(to, from, len);
2616 			to += len;
2617 			first = false;
2618 		}
2619 		if (!from[len])
2620 			break;
2621 		from += len + 1;
2622 	}
2623 	*to = '\0';
2624 	return 0;
2625 
2626 free_opt:
2627 	if (*mnt_opts) {
2628 		selinux_free_mnt_opts(*mnt_opts);
2629 		*mnt_opts = NULL;
2630 	}
2631 	return rc;
2632 }
2633 
selinux_sb_mnt_opts_compat(struct super_block * sb,void * mnt_opts)2634 static int selinux_sb_mnt_opts_compat(struct super_block *sb, void *mnt_opts)
2635 {
2636 	struct selinux_mnt_opts *opts = mnt_opts;
2637 	struct superblock_security_struct *sbsec = selinux_superblock(sb);
2638 
2639 	/*
2640 	 * Superblock not initialized (i.e. no options) - reject if any
2641 	 * options specified, otherwise accept.
2642 	 */
2643 	if (!(sbsec->flags & SE_SBINITIALIZED))
2644 		return opts ? 1 : 0;
2645 
2646 	/*
2647 	 * Superblock initialized and no options specified - reject if
2648 	 * superblock has any options set, otherwise accept.
2649 	 */
2650 	if (!opts)
2651 		return (sbsec->flags & SE_MNTMASK) ? 1 : 0;
2652 
2653 	if (opts->fscontext_sid) {
2654 		if (bad_option(sbsec, FSCONTEXT_MNT, sbsec->sid,
2655 			       opts->fscontext_sid))
2656 			return 1;
2657 	}
2658 	if (opts->context_sid) {
2659 		if (bad_option(sbsec, CONTEXT_MNT, sbsec->mntpoint_sid,
2660 			       opts->context_sid))
2661 			return 1;
2662 	}
2663 	if (opts->rootcontext_sid) {
2664 		struct inode_security_struct *root_isec;
2665 
2666 		root_isec = backing_inode_security(sb->s_root);
2667 		if (bad_option(sbsec, ROOTCONTEXT_MNT, root_isec->sid,
2668 			       opts->rootcontext_sid))
2669 			return 1;
2670 	}
2671 	if (opts->defcontext_sid) {
2672 		if (bad_option(sbsec, DEFCONTEXT_MNT, sbsec->def_sid,
2673 			       opts->defcontext_sid))
2674 			return 1;
2675 	}
2676 	return 0;
2677 }
2678 
selinux_sb_remount(struct super_block * sb,void * mnt_opts)2679 static int selinux_sb_remount(struct super_block *sb, void *mnt_opts)
2680 {
2681 	struct selinux_mnt_opts *opts = mnt_opts;
2682 	struct superblock_security_struct *sbsec = selinux_superblock(sb);
2683 
2684 	if (!(sbsec->flags & SE_SBINITIALIZED))
2685 		return 0;
2686 
2687 	if (!opts)
2688 		return 0;
2689 
2690 	if (opts->fscontext_sid) {
2691 		if (bad_option(sbsec, FSCONTEXT_MNT, sbsec->sid,
2692 			       opts->fscontext_sid))
2693 			goto out_bad_option;
2694 	}
2695 	if (opts->context_sid) {
2696 		if (bad_option(sbsec, CONTEXT_MNT, sbsec->mntpoint_sid,
2697 			       opts->context_sid))
2698 			goto out_bad_option;
2699 	}
2700 	if (opts->rootcontext_sid) {
2701 		struct inode_security_struct *root_isec;
2702 		root_isec = backing_inode_security(sb->s_root);
2703 		if (bad_option(sbsec, ROOTCONTEXT_MNT, root_isec->sid,
2704 			       opts->rootcontext_sid))
2705 			goto out_bad_option;
2706 	}
2707 	if (opts->defcontext_sid) {
2708 		if (bad_option(sbsec, DEFCONTEXT_MNT, sbsec->def_sid,
2709 			       opts->defcontext_sid))
2710 			goto out_bad_option;
2711 	}
2712 	return 0;
2713 
2714 out_bad_option:
2715 	pr_warn("SELinux: unable to change security options "
2716 	       "during remount (dev %s, type=%s)\n", sb->s_id,
2717 	       sb->s_type->name);
2718 	return -EINVAL;
2719 }
2720 
selinux_sb_kern_mount(struct super_block * sb)2721 static int selinux_sb_kern_mount(struct super_block *sb)
2722 {
2723 	const struct cred *cred = current_cred();
2724 	struct common_audit_data ad;
2725 
2726 	ad.type = LSM_AUDIT_DATA_DENTRY;
2727 	ad.u.dentry = sb->s_root;
2728 	return superblock_has_perm(cred, sb, FILESYSTEM__MOUNT, &ad);
2729 }
2730 
selinux_sb_statfs(struct dentry * dentry)2731 static int selinux_sb_statfs(struct dentry *dentry)
2732 {
2733 	const struct cred *cred = current_cred();
2734 	struct common_audit_data ad;
2735 
2736 	ad.type = LSM_AUDIT_DATA_DENTRY;
2737 	ad.u.dentry = dentry->d_sb->s_root;
2738 	return superblock_has_perm(cred, dentry->d_sb, FILESYSTEM__GETATTR, &ad);
2739 }
2740 
selinux_mount(const char * dev_name,const struct path * path,const char * type,unsigned long flags,void * data)2741 static int selinux_mount(const char *dev_name,
2742 			 const struct path *path,
2743 			 const char *type,
2744 			 unsigned long flags,
2745 			 void *data)
2746 {
2747 	const struct cred *cred = current_cred();
2748 
2749 	if (flags & MS_REMOUNT)
2750 		return superblock_has_perm(cred, path->dentry->d_sb,
2751 					   FILESYSTEM__REMOUNT, NULL);
2752 	else
2753 		return path_has_perm(cred, path, FILE__MOUNTON);
2754 }
2755 
selinux_move_mount(const struct path * from_path,const struct path * to_path)2756 static int selinux_move_mount(const struct path *from_path,
2757 			      const struct path *to_path)
2758 {
2759 	const struct cred *cred = current_cred();
2760 
2761 	return path_has_perm(cred, to_path, FILE__MOUNTON);
2762 }
2763 
selinux_umount(struct vfsmount * mnt,int flags)2764 static int selinux_umount(struct vfsmount *mnt, int flags)
2765 {
2766 	const struct cred *cred = current_cred();
2767 
2768 	return superblock_has_perm(cred, mnt->mnt_sb,
2769 				   FILESYSTEM__UNMOUNT, NULL);
2770 }
2771 
selinux_fs_context_dup(struct fs_context * fc,struct fs_context * src_fc)2772 static int selinux_fs_context_dup(struct fs_context *fc,
2773 				  struct fs_context *src_fc)
2774 {
2775 	const struct selinux_mnt_opts *src = src_fc->security;
2776 
2777 	if (!src)
2778 		return 0;
2779 
2780 	fc->security = kmemdup(src, sizeof(*src), GFP_KERNEL);
2781 	return fc->security ? 0 : -ENOMEM;
2782 }
2783 
2784 static const struct fs_parameter_spec selinux_fs_parameters[] = {
2785 	fsparam_string(CONTEXT_STR,	Opt_context),
2786 	fsparam_string(DEFCONTEXT_STR,	Opt_defcontext),
2787 	fsparam_string(FSCONTEXT_STR,	Opt_fscontext),
2788 	fsparam_string(ROOTCONTEXT_STR,	Opt_rootcontext),
2789 	fsparam_flag  (SECLABEL_STR,	Opt_seclabel),
2790 	{}
2791 };
2792 
selinux_fs_context_parse_param(struct fs_context * fc,struct fs_parameter * param)2793 static int selinux_fs_context_parse_param(struct fs_context *fc,
2794 					  struct fs_parameter *param)
2795 {
2796 	struct fs_parse_result result;
2797 	int opt;
2798 
2799 	opt = fs_parse(fc, selinux_fs_parameters, param, &result);
2800 	if (opt < 0)
2801 		return opt;
2802 
2803 	return selinux_add_opt(opt, param->string, &fc->security);
2804 }
2805 
2806 /* inode security operations */
2807 
selinux_inode_alloc_security(struct inode * inode)2808 static int selinux_inode_alloc_security(struct inode *inode)
2809 {
2810 	struct inode_security_struct *isec = selinux_inode(inode);
2811 	u32 sid = current_sid();
2812 
2813 	spin_lock_init(&isec->lock);
2814 	INIT_LIST_HEAD(&isec->list);
2815 	isec->inode = inode;
2816 	isec->sid = SECINITSID_UNLABELED;
2817 	isec->sclass = SECCLASS_FILE;
2818 	isec->task_sid = sid;
2819 	isec->initialized = LABEL_INVALID;
2820 
2821 	return 0;
2822 }
2823 
selinux_inode_free_security(struct inode * inode)2824 static void selinux_inode_free_security(struct inode *inode)
2825 {
2826 	inode_free_security(inode);
2827 }
2828 
selinux_dentry_init_security(struct dentry * dentry,int mode,const struct qstr * name,const char ** xattr_name,void ** ctx,u32 * ctxlen)2829 static int selinux_dentry_init_security(struct dentry *dentry, int mode,
2830 					const struct qstr *name,
2831 					const char **xattr_name, void **ctx,
2832 					u32 *ctxlen)
2833 {
2834 	u32 newsid;
2835 	int rc;
2836 
2837 	rc = selinux_determine_inode_label(selinux_cred(current_cred()),
2838 					   d_inode(dentry->d_parent), name,
2839 					   inode_mode_to_security_class(mode),
2840 					   &newsid);
2841 	if (rc)
2842 		return rc;
2843 
2844 	if (xattr_name)
2845 		*xattr_name = XATTR_NAME_SELINUX;
2846 
2847 	return security_sid_to_context(&selinux_state, newsid, (char **)ctx,
2848 				       ctxlen);
2849 }
2850 
selinux_dentry_create_files_as(struct dentry * dentry,int mode,struct qstr * name,const struct cred * old,struct cred * new)2851 static int selinux_dentry_create_files_as(struct dentry *dentry, int mode,
2852 					  struct qstr *name,
2853 					  const struct cred *old,
2854 					  struct cred *new)
2855 {
2856 	u32 newsid;
2857 	int rc;
2858 	struct task_security_struct *tsec;
2859 
2860 	rc = selinux_determine_inode_label(selinux_cred(old),
2861 					   d_inode(dentry->d_parent), name,
2862 					   inode_mode_to_security_class(mode),
2863 					   &newsid);
2864 	if (rc)
2865 		return rc;
2866 
2867 	tsec = selinux_cred(new);
2868 	tsec->create_sid = newsid;
2869 	return 0;
2870 }
2871 
selinux_inode_init_security(struct inode * inode,struct inode * dir,const struct qstr * qstr,const char ** name,void ** value,size_t * len)2872 static int selinux_inode_init_security(struct inode *inode, struct inode *dir,
2873 				       const struct qstr *qstr,
2874 				       const char **name,
2875 				       void **value, size_t *len)
2876 {
2877 	const struct task_security_struct *tsec = selinux_cred(current_cred());
2878 	struct superblock_security_struct *sbsec;
2879 	u32 newsid, clen;
2880 	int rc;
2881 	char *context;
2882 
2883 	sbsec = selinux_superblock(dir->i_sb);
2884 
2885 	newsid = tsec->create_sid;
2886 
2887 	rc = selinux_determine_inode_label(tsec, dir, qstr,
2888 		inode_mode_to_security_class(inode->i_mode),
2889 		&newsid);
2890 	if (rc)
2891 		return rc;
2892 
2893 	/* Possibly defer initialization to selinux_complete_init. */
2894 	if (sbsec->flags & SE_SBINITIALIZED) {
2895 		struct inode_security_struct *isec = selinux_inode(inode);
2896 		isec->sclass = inode_mode_to_security_class(inode->i_mode);
2897 		isec->sid = newsid;
2898 		isec->initialized = LABEL_INITIALIZED;
2899 	}
2900 
2901 	if (!selinux_initialized(&selinux_state) ||
2902 	    !(sbsec->flags & SBLABEL_MNT))
2903 		return -EOPNOTSUPP;
2904 
2905 	if (name)
2906 		*name = XATTR_SELINUX_SUFFIX;
2907 
2908 	if (value && len) {
2909 		rc = security_sid_to_context_force(&selinux_state, newsid,
2910 						   &context, &clen);
2911 		if (rc)
2912 			return rc;
2913 		*value = context;
2914 		*len = clen;
2915 	}
2916 
2917 	return 0;
2918 }
2919 
selinux_inode_init_security_anon(struct inode * inode,const struct qstr * name,const struct inode * context_inode)2920 static int selinux_inode_init_security_anon(struct inode *inode,
2921 					    const struct qstr *name,
2922 					    const struct inode *context_inode)
2923 {
2924 	const struct task_security_struct *tsec = selinux_cred(current_cred());
2925 	struct common_audit_data ad;
2926 	struct inode_security_struct *isec;
2927 	int rc;
2928 
2929 	if (unlikely(!selinux_initialized(&selinux_state)))
2930 		return 0;
2931 
2932 	isec = selinux_inode(inode);
2933 
2934 	/*
2935 	 * We only get here once per ephemeral inode.  The inode has
2936 	 * been initialized via inode_alloc_security but is otherwise
2937 	 * untouched.
2938 	 */
2939 
2940 	if (context_inode) {
2941 		struct inode_security_struct *context_isec =
2942 			selinux_inode(context_inode);
2943 		if (context_isec->initialized != LABEL_INITIALIZED) {
2944 			pr_err("SELinux:  context_inode is not initialized");
2945 			return -EACCES;
2946 		}
2947 
2948 		isec->sclass = context_isec->sclass;
2949 		isec->sid = context_isec->sid;
2950 	} else {
2951 		isec->sclass = SECCLASS_ANON_INODE;
2952 		rc = security_transition_sid(
2953 			&selinux_state, tsec->sid, tsec->sid,
2954 			isec->sclass, name, &isec->sid);
2955 		if (rc)
2956 			return rc;
2957 	}
2958 
2959 	isec->initialized = LABEL_INITIALIZED;
2960 	/*
2961 	 * Now that we've initialized security, check whether we're
2962 	 * allowed to actually create this type of anonymous inode.
2963 	 */
2964 
2965 	ad.type = LSM_AUDIT_DATA_ANONINODE;
2966 	ad.u.anonclass = name ? (const char *)name->name : "?";
2967 
2968 	return avc_has_perm(&selinux_state,
2969 			    tsec->sid,
2970 			    isec->sid,
2971 			    isec->sclass,
2972 			    FILE__CREATE,
2973 			    &ad);
2974 }
2975 
selinux_inode_create(struct inode * dir,struct dentry * dentry,umode_t mode)2976 static int selinux_inode_create(struct inode *dir, struct dentry *dentry, umode_t mode)
2977 {
2978 	return may_create(dir, dentry, SECCLASS_FILE);
2979 }
2980 
selinux_inode_link(struct dentry * old_dentry,struct inode * dir,struct dentry * new_dentry)2981 static int selinux_inode_link(struct dentry *old_dentry, struct inode *dir, struct dentry *new_dentry)
2982 {
2983 	return may_link(dir, old_dentry, MAY_LINK);
2984 }
2985 
selinux_inode_unlink(struct inode * dir,struct dentry * dentry)2986 static int selinux_inode_unlink(struct inode *dir, struct dentry *dentry)
2987 {
2988 	return may_link(dir, dentry, MAY_UNLINK);
2989 }
2990 
selinux_inode_symlink(struct inode * dir,struct dentry * dentry,const char * name)2991 static int selinux_inode_symlink(struct inode *dir, struct dentry *dentry, const char *name)
2992 {
2993 	return may_create(dir, dentry, SECCLASS_LNK_FILE);
2994 }
2995 
selinux_inode_mkdir(struct inode * dir,struct dentry * dentry,umode_t mask)2996 static int selinux_inode_mkdir(struct inode *dir, struct dentry *dentry, umode_t mask)
2997 {
2998 	return may_create(dir, dentry, SECCLASS_DIR);
2999 }
3000 
selinux_inode_rmdir(struct inode * dir,struct dentry * dentry)3001 static int selinux_inode_rmdir(struct inode *dir, struct dentry *dentry)
3002 {
3003 	return may_link(dir, dentry, MAY_RMDIR);
3004 }
3005 
selinux_inode_mknod(struct inode * dir,struct dentry * dentry,umode_t mode,dev_t dev)3006 static int selinux_inode_mknod(struct inode *dir, struct dentry *dentry, umode_t mode, dev_t dev)
3007 {
3008 	return may_create(dir, dentry, inode_mode_to_security_class(mode));
3009 }
3010 
selinux_inode_rename(struct inode * old_inode,struct dentry * old_dentry,struct inode * new_inode,struct dentry * new_dentry)3011 static int selinux_inode_rename(struct inode *old_inode, struct dentry *old_dentry,
3012 				struct inode *new_inode, struct dentry *new_dentry)
3013 {
3014 	return may_rename(old_inode, old_dentry, new_inode, new_dentry);
3015 }
3016 
selinux_inode_readlink(struct dentry * dentry)3017 static int selinux_inode_readlink(struct dentry *dentry)
3018 {
3019 	const struct cred *cred = current_cred();
3020 
3021 	return dentry_has_perm(cred, dentry, FILE__READ);
3022 }
3023 
selinux_inode_follow_link(struct dentry * dentry,struct inode * inode,bool rcu)3024 static int selinux_inode_follow_link(struct dentry *dentry, struct inode *inode,
3025 				     bool rcu)
3026 {
3027 	const struct cred *cred = current_cred();
3028 	struct common_audit_data ad;
3029 	struct inode_security_struct *isec;
3030 	u32 sid;
3031 
3032 	validate_creds(cred);
3033 
3034 	ad.type = LSM_AUDIT_DATA_DENTRY;
3035 	ad.u.dentry = dentry;
3036 	sid = cred_sid(cred);
3037 	isec = inode_security_rcu(inode, rcu);
3038 	if (IS_ERR(isec))
3039 		return PTR_ERR(isec);
3040 
3041 	return avc_has_perm(&selinux_state,
3042 				  sid, isec->sid, isec->sclass, FILE__READ, &ad);
3043 }
3044 
audit_inode_permission(struct inode * inode,u32 perms,u32 audited,u32 denied,int result)3045 static noinline int audit_inode_permission(struct inode *inode,
3046 					   u32 perms, u32 audited, u32 denied,
3047 					   int result)
3048 {
3049 	struct common_audit_data ad;
3050 	struct inode_security_struct *isec = selinux_inode(inode);
3051 
3052 	ad.type = LSM_AUDIT_DATA_INODE;
3053 	ad.u.inode = inode;
3054 
3055 	return slow_avc_audit(&selinux_state,
3056 			    current_sid(), isec->sid, isec->sclass, perms,
3057 			    audited, denied, result, &ad);
3058 }
3059 
selinux_inode_permission(struct inode * inode,int mask)3060 static int selinux_inode_permission(struct inode *inode, int mask)
3061 {
3062 	const struct cred *cred = current_cred();
3063 	u32 perms;
3064 	bool from_access;
3065 	bool no_block = mask & MAY_NOT_BLOCK;
3066 	struct inode_security_struct *isec;
3067 	u32 sid;
3068 	struct av_decision avd;
3069 	int rc, rc2;
3070 	u32 audited, denied;
3071 
3072 	from_access = mask & MAY_ACCESS;
3073 	mask &= (MAY_READ|MAY_WRITE|MAY_EXEC|MAY_APPEND);
3074 
3075 	/* No permission to check.  Existence test. */
3076 	if (!mask)
3077 		return 0;
3078 
3079 	validate_creds(cred);
3080 
3081 	if (unlikely(IS_PRIVATE(inode)))
3082 		return 0;
3083 
3084 	perms = file_mask_to_av(inode->i_mode, mask);
3085 
3086 	sid = cred_sid(cred);
3087 	isec = inode_security_rcu(inode, no_block);
3088 	if (IS_ERR(isec))
3089 		return PTR_ERR(isec);
3090 
3091 	rc = avc_has_perm_noaudit(&selinux_state,
3092 				  sid, isec->sid, isec->sclass, perms, 0,
3093 				  &avd);
3094 	audited = avc_audit_required(perms, &avd, rc,
3095 				     from_access ? FILE__AUDIT_ACCESS : 0,
3096 				     &denied);
3097 	if (likely(!audited))
3098 		return rc;
3099 
3100 	rc2 = audit_inode_permission(inode, perms, audited, denied, rc);
3101 	if (rc2)
3102 		return rc2;
3103 	return rc;
3104 }
3105 
selinux_inode_setattr(struct dentry * dentry,struct iattr * iattr)3106 static int selinux_inode_setattr(struct dentry *dentry, struct iattr *iattr)
3107 {
3108 	const struct cred *cred = current_cred();
3109 	struct inode *inode = d_backing_inode(dentry);
3110 	unsigned int ia_valid = iattr->ia_valid;
3111 	__u32 av = FILE__WRITE;
3112 
3113 	/* ATTR_FORCE is just used for ATTR_KILL_S[UG]ID. */
3114 	if (ia_valid & ATTR_FORCE) {
3115 		ia_valid &= ~(ATTR_KILL_SUID | ATTR_KILL_SGID | ATTR_MODE |
3116 			      ATTR_FORCE);
3117 		if (!ia_valid)
3118 			return 0;
3119 	}
3120 
3121 	if (ia_valid & (ATTR_MODE | ATTR_UID | ATTR_GID |
3122 			ATTR_ATIME_SET | ATTR_MTIME_SET | ATTR_TIMES_SET))
3123 		return dentry_has_perm(cred, dentry, FILE__SETATTR);
3124 
3125 	if (selinux_policycap_openperm() &&
3126 	    inode->i_sb->s_magic != SOCKFS_MAGIC &&
3127 	    (ia_valid & ATTR_SIZE) &&
3128 	    !(ia_valid & ATTR_FILE))
3129 		av |= FILE__OPEN;
3130 
3131 	return dentry_has_perm(cred, dentry, av);
3132 }
3133 
selinux_inode_getattr(const struct path * path)3134 static int selinux_inode_getattr(const struct path *path)
3135 {
3136 	return path_has_perm(current_cred(), path, FILE__GETATTR);
3137 }
3138 
has_cap_mac_admin(bool audit)3139 static bool has_cap_mac_admin(bool audit)
3140 {
3141 	const struct cred *cred = current_cred();
3142 	unsigned int opts = audit ? CAP_OPT_NONE : CAP_OPT_NOAUDIT;
3143 
3144 	if (cap_capable(cred, &init_user_ns, CAP_MAC_ADMIN, opts))
3145 		return false;
3146 	if (cred_has_capability(cred, CAP_MAC_ADMIN, opts, true))
3147 		return false;
3148 	return true;
3149 }
3150 
selinux_inode_setxattr(struct user_namespace * mnt_userns,struct dentry * dentry,const char * name,const void * value,size_t size,int flags)3151 static int selinux_inode_setxattr(struct user_namespace *mnt_userns,
3152 				  struct dentry *dentry, const char *name,
3153 				  const void *value, size_t size, int flags)
3154 {
3155 	struct inode *inode = d_backing_inode(dentry);
3156 	struct inode_security_struct *isec;
3157 	struct superblock_security_struct *sbsec;
3158 	struct common_audit_data ad;
3159 	u32 newsid, sid = current_sid();
3160 	int rc = 0;
3161 
3162 	if (strcmp(name, XATTR_NAME_SELINUX)) {
3163 		rc = cap_inode_setxattr(dentry, name, value, size, flags);
3164 		if (rc)
3165 			return rc;
3166 
3167 		/* Not an attribute we recognize, so just check the
3168 		   ordinary setattr permission. */
3169 		return dentry_has_perm(current_cred(), dentry, FILE__SETATTR);
3170 	}
3171 
3172 	if (!selinux_initialized(&selinux_state))
3173 		return (inode_owner_or_capable(mnt_userns, inode) ? 0 : -EPERM);
3174 
3175 	sbsec = selinux_superblock(inode->i_sb);
3176 	if (!(sbsec->flags & SBLABEL_MNT))
3177 		return -EOPNOTSUPP;
3178 
3179 	if (!inode_owner_or_capable(mnt_userns, inode))
3180 		return -EPERM;
3181 
3182 	ad.type = LSM_AUDIT_DATA_DENTRY;
3183 	ad.u.dentry = dentry;
3184 
3185 	isec = backing_inode_security(dentry);
3186 	rc = avc_has_perm(&selinux_state,
3187 			  sid, isec->sid, isec->sclass,
3188 			  FILE__RELABELFROM, &ad);
3189 	if (rc)
3190 		return rc;
3191 
3192 	rc = security_context_to_sid(&selinux_state, value, size, &newsid,
3193 				     GFP_KERNEL);
3194 	if (rc == -EINVAL) {
3195 		if (!has_cap_mac_admin(true)) {
3196 			struct audit_buffer *ab;
3197 			size_t audit_size;
3198 
3199 			/* We strip a nul only if it is at the end, otherwise the
3200 			 * context contains a nul and we should audit that */
3201 			if (value) {
3202 				const char *str = value;
3203 
3204 				if (str[size - 1] == '\0')
3205 					audit_size = size - 1;
3206 				else
3207 					audit_size = size;
3208 			} else {
3209 				audit_size = 0;
3210 			}
3211 			ab = audit_log_start(audit_context(),
3212 					     GFP_ATOMIC, AUDIT_SELINUX_ERR);
3213 			if (!ab)
3214 				return rc;
3215 			audit_log_format(ab, "op=setxattr invalid_context=");
3216 			audit_log_n_untrustedstring(ab, value, audit_size);
3217 			audit_log_end(ab);
3218 
3219 			return rc;
3220 		}
3221 		rc = security_context_to_sid_force(&selinux_state, value,
3222 						   size, &newsid);
3223 	}
3224 	if (rc)
3225 		return rc;
3226 
3227 	rc = avc_has_perm(&selinux_state,
3228 			  sid, newsid, isec->sclass,
3229 			  FILE__RELABELTO, &ad);
3230 	if (rc)
3231 		return rc;
3232 
3233 	rc = security_validate_transition(&selinux_state, isec->sid, newsid,
3234 					  sid, isec->sclass);
3235 	if (rc)
3236 		return rc;
3237 
3238 	return avc_has_perm(&selinux_state,
3239 			    newsid,
3240 			    sbsec->sid,
3241 			    SECCLASS_FILESYSTEM,
3242 			    FILESYSTEM__ASSOCIATE,
3243 			    &ad);
3244 }
3245 
selinux_inode_post_setxattr(struct dentry * dentry,const char * name,const void * value,size_t size,int flags)3246 static void selinux_inode_post_setxattr(struct dentry *dentry, const char *name,
3247 					const void *value, size_t size,
3248 					int flags)
3249 {
3250 	struct inode *inode = d_backing_inode(dentry);
3251 	struct inode_security_struct *isec;
3252 	u32 newsid;
3253 	int rc;
3254 
3255 	if (strcmp(name, XATTR_NAME_SELINUX)) {
3256 		/* Not an attribute we recognize, so nothing to do. */
3257 		return;
3258 	}
3259 
3260 	if (!selinux_initialized(&selinux_state)) {
3261 		/* If we haven't even been initialized, then we can't validate
3262 		 * against a policy, so leave the label as invalid. It may
3263 		 * resolve to a valid label on the next revalidation try if
3264 		 * we've since initialized.
3265 		 */
3266 		return;
3267 	}
3268 
3269 	rc = security_context_to_sid_force(&selinux_state, value, size,
3270 					   &newsid);
3271 	if (rc) {
3272 		pr_err("SELinux:  unable to map context to SID"
3273 		       "for (%s, %lu), rc=%d\n",
3274 		       inode->i_sb->s_id, inode->i_ino, -rc);
3275 		return;
3276 	}
3277 
3278 	isec = backing_inode_security(dentry);
3279 	spin_lock(&isec->lock);
3280 	isec->sclass = inode_mode_to_security_class(inode->i_mode);
3281 	isec->sid = newsid;
3282 	isec->initialized = LABEL_INITIALIZED;
3283 	spin_unlock(&isec->lock);
3284 }
3285 
selinux_inode_getxattr(struct dentry * dentry,const char * name)3286 static int selinux_inode_getxattr(struct dentry *dentry, const char *name)
3287 {
3288 	const struct cred *cred = current_cred();
3289 
3290 	return dentry_has_perm(cred, dentry, FILE__GETATTR);
3291 }
3292 
selinux_inode_listxattr(struct dentry * dentry)3293 static int selinux_inode_listxattr(struct dentry *dentry)
3294 {
3295 	const struct cred *cred = current_cred();
3296 
3297 	return dentry_has_perm(cred, dentry, FILE__GETATTR);
3298 }
3299 
selinux_inode_removexattr(struct user_namespace * mnt_userns,struct dentry * dentry,const char * name)3300 static int selinux_inode_removexattr(struct user_namespace *mnt_userns,
3301 				     struct dentry *dentry, const char *name)
3302 {
3303 	if (strcmp(name, XATTR_NAME_SELINUX)) {
3304 		int rc = cap_inode_removexattr(mnt_userns, dentry, name);
3305 		if (rc)
3306 			return rc;
3307 
3308 		/* Not an attribute we recognize, so just check the
3309 		   ordinary setattr permission. */
3310 		return dentry_has_perm(current_cred(), dentry, FILE__SETATTR);
3311 	}
3312 
3313 	if (!selinux_initialized(&selinux_state))
3314 		return 0;
3315 
3316 	/* No one is allowed to remove a SELinux security label.
3317 	   You can change the label, but all data must be labeled. */
3318 	return -EACCES;
3319 }
3320 
selinux_path_notify(const struct path * path,u64 mask,unsigned int obj_type)3321 static int selinux_path_notify(const struct path *path, u64 mask,
3322 						unsigned int obj_type)
3323 {
3324 	int ret;
3325 	u32 perm;
3326 
3327 	struct common_audit_data ad;
3328 
3329 	ad.type = LSM_AUDIT_DATA_PATH;
3330 	ad.u.path = *path;
3331 
3332 	/*
3333 	 * Set permission needed based on the type of mark being set.
3334 	 * Performs an additional check for sb watches.
3335 	 */
3336 	switch (obj_type) {
3337 	case FSNOTIFY_OBJ_TYPE_VFSMOUNT:
3338 		perm = FILE__WATCH_MOUNT;
3339 		break;
3340 	case FSNOTIFY_OBJ_TYPE_SB:
3341 		perm = FILE__WATCH_SB;
3342 		ret = superblock_has_perm(current_cred(), path->dentry->d_sb,
3343 						FILESYSTEM__WATCH, &ad);
3344 		if (ret)
3345 			return ret;
3346 		break;
3347 	case FSNOTIFY_OBJ_TYPE_INODE:
3348 		perm = FILE__WATCH;
3349 		break;
3350 	default:
3351 		return -EINVAL;
3352 	}
3353 
3354 	/* blocking watches require the file:watch_with_perm permission */
3355 	if (mask & (ALL_FSNOTIFY_PERM_EVENTS))
3356 		perm |= FILE__WATCH_WITH_PERM;
3357 
3358 	/* watches on read-like events need the file:watch_reads permission */
3359 	if (mask & (FS_ACCESS | FS_ACCESS_PERM | FS_CLOSE_NOWRITE))
3360 		perm |= FILE__WATCH_READS;
3361 
3362 	return path_has_perm(current_cred(), path, perm);
3363 }
3364 
3365 /*
3366  * Copy the inode security context value to the user.
3367  *
3368  * Permission check is handled by selinux_inode_getxattr hook.
3369  */
selinux_inode_getsecurity(struct user_namespace * mnt_userns,struct inode * inode,const char * name,void ** buffer,bool alloc)3370 static int selinux_inode_getsecurity(struct user_namespace *mnt_userns,
3371 				     struct inode *inode, const char *name,
3372 				     void **buffer, bool alloc)
3373 {
3374 	u32 size;
3375 	int error;
3376 	char *context = NULL;
3377 	struct inode_security_struct *isec;
3378 
3379 	/*
3380 	 * If we're not initialized yet, then we can't validate contexts, so
3381 	 * just let vfs_getxattr fall back to using the on-disk xattr.
3382 	 */
3383 	if (!selinux_initialized(&selinux_state) ||
3384 	    strcmp(name, XATTR_SELINUX_SUFFIX))
3385 		return -EOPNOTSUPP;
3386 
3387 	/*
3388 	 * If the caller has CAP_MAC_ADMIN, then get the raw context
3389 	 * value even if it is not defined by current policy; otherwise,
3390 	 * use the in-core value under current policy.
3391 	 * Use the non-auditing forms of the permission checks since
3392 	 * getxattr may be called by unprivileged processes commonly
3393 	 * and lack of permission just means that we fall back to the
3394 	 * in-core context value, not a denial.
3395 	 */
3396 	isec = inode_security(inode);
3397 	if (has_cap_mac_admin(false))
3398 		error = security_sid_to_context_force(&selinux_state,
3399 						      isec->sid, &context,
3400 						      &size);
3401 	else
3402 		error = security_sid_to_context(&selinux_state, isec->sid,
3403 						&context, &size);
3404 	if (error)
3405 		return error;
3406 	error = size;
3407 	if (alloc) {
3408 		*buffer = context;
3409 		goto out_nofree;
3410 	}
3411 	kfree(context);
3412 out_nofree:
3413 	return error;
3414 }
3415 
selinux_inode_setsecurity(struct inode * inode,const char * name,const void * value,size_t size,int flags)3416 static int selinux_inode_setsecurity(struct inode *inode, const char *name,
3417 				     const void *value, size_t size, int flags)
3418 {
3419 	struct inode_security_struct *isec = inode_security_novalidate(inode);
3420 	struct superblock_security_struct *sbsec;
3421 	u32 newsid;
3422 	int rc;
3423 
3424 	if (strcmp(name, XATTR_SELINUX_SUFFIX))
3425 		return -EOPNOTSUPP;
3426 
3427 	sbsec = selinux_superblock(inode->i_sb);
3428 	if (!(sbsec->flags & SBLABEL_MNT))
3429 		return -EOPNOTSUPP;
3430 
3431 	if (!value || !size)
3432 		return -EACCES;
3433 
3434 	rc = security_context_to_sid(&selinux_state, value, size, &newsid,
3435 				     GFP_KERNEL);
3436 	if (rc)
3437 		return rc;
3438 
3439 	spin_lock(&isec->lock);
3440 	isec->sclass = inode_mode_to_security_class(inode->i_mode);
3441 	isec->sid = newsid;
3442 	isec->initialized = LABEL_INITIALIZED;
3443 	spin_unlock(&isec->lock);
3444 	return 0;
3445 }
3446 
selinux_inode_listsecurity(struct inode * inode,char * buffer,size_t buffer_size)3447 static int selinux_inode_listsecurity(struct inode *inode, char *buffer, size_t buffer_size)
3448 {
3449 	const int len = sizeof(XATTR_NAME_SELINUX);
3450 
3451 	if (!selinux_initialized(&selinux_state))
3452 		return 0;
3453 
3454 	if (buffer && len <= buffer_size)
3455 		memcpy(buffer, XATTR_NAME_SELINUX, len);
3456 	return len;
3457 }
3458 
selinux_inode_getsecid(struct inode * inode,u32 * secid)3459 static void selinux_inode_getsecid(struct inode *inode, u32 *secid)
3460 {
3461 	struct inode_security_struct *isec = inode_security_novalidate(inode);
3462 	*secid = isec->sid;
3463 }
3464 
selinux_inode_copy_up(struct dentry * src,struct cred ** new)3465 static int selinux_inode_copy_up(struct dentry *src, struct cred **new)
3466 {
3467 	u32 sid;
3468 	struct task_security_struct *tsec;
3469 	struct cred *new_creds = *new;
3470 
3471 	if (new_creds == NULL) {
3472 		new_creds = prepare_creds();
3473 		if (!new_creds)
3474 			return -ENOMEM;
3475 	}
3476 
3477 	tsec = selinux_cred(new_creds);
3478 	/* Get label from overlay inode and set it in create_sid */
3479 	selinux_inode_getsecid(d_inode(src), &sid);
3480 	tsec->create_sid = sid;
3481 	*new = new_creds;
3482 	return 0;
3483 }
3484 
selinux_inode_copy_up_xattr(const char * name)3485 static int selinux_inode_copy_up_xattr(const char *name)
3486 {
3487 	/* The copy_up hook above sets the initial context on an inode, but we
3488 	 * don't then want to overwrite it by blindly copying all the lower
3489 	 * xattrs up.  Instead, we have to filter out SELinux-related xattrs.
3490 	 */
3491 	if (strcmp(name, XATTR_NAME_SELINUX) == 0)
3492 		return 1; /* Discard */
3493 	/*
3494 	 * Any other attribute apart from SELINUX is not claimed, supported
3495 	 * by selinux.
3496 	 */
3497 	return -EOPNOTSUPP;
3498 }
3499 
3500 /* kernfs node operations */
3501 
selinux_kernfs_init_security(struct kernfs_node * kn_dir,struct kernfs_node * kn)3502 static int selinux_kernfs_init_security(struct kernfs_node *kn_dir,
3503 					struct kernfs_node *kn)
3504 {
3505 	const struct task_security_struct *tsec = selinux_cred(current_cred());
3506 	u32 parent_sid, newsid, clen;
3507 	int rc;
3508 	char *context;
3509 
3510 	rc = kernfs_xattr_get(kn_dir, XATTR_NAME_SELINUX, NULL, 0);
3511 	if (rc == -ENODATA)
3512 		return 0;
3513 	else if (rc < 0)
3514 		return rc;
3515 
3516 	clen = (u32)rc;
3517 	context = kmalloc(clen, GFP_KERNEL);
3518 	if (!context)
3519 		return -ENOMEM;
3520 
3521 	rc = kernfs_xattr_get(kn_dir, XATTR_NAME_SELINUX, context, clen);
3522 	if (rc < 0) {
3523 		kfree(context);
3524 		return rc;
3525 	}
3526 
3527 	rc = security_context_to_sid(&selinux_state, context, clen, &parent_sid,
3528 				     GFP_KERNEL);
3529 	kfree(context);
3530 	if (rc)
3531 		return rc;
3532 
3533 	if (tsec->create_sid) {
3534 		newsid = tsec->create_sid;
3535 	} else {
3536 		u16 secclass = inode_mode_to_security_class(kn->mode);
3537 		struct qstr q;
3538 
3539 		q.name = kn->name;
3540 		q.hash_len = hashlen_string(kn_dir, kn->name);
3541 
3542 		rc = security_transition_sid(&selinux_state, tsec->sid,
3543 					     parent_sid, secclass, &q,
3544 					     &newsid);
3545 		if (rc)
3546 			return rc;
3547 	}
3548 
3549 	rc = security_sid_to_context_force(&selinux_state, newsid,
3550 					   &context, &clen);
3551 	if (rc)
3552 		return rc;
3553 
3554 	rc = kernfs_xattr_set(kn, XATTR_NAME_SELINUX, context, clen,
3555 			      XATTR_CREATE);
3556 	kfree(context);
3557 	return rc;
3558 }
3559 
3560 
3561 /* file security operations */
3562 
selinux_revalidate_file_permission(struct file * file,int mask)3563 static int selinux_revalidate_file_permission(struct file *file, int mask)
3564 {
3565 	const struct cred *cred = current_cred();
3566 	struct inode *inode = file_inode(file);
3567 
3568 	/* file_mask_to_av won't add FILE__WRITE if MAY_APPEND is set */
3569 	if ((file->f_flags & O_APPEND) && (mask & MAY_WRITE))
3570 		mask |= MAY_APPEND;
3571 
3572 	return file_has_perm(cred, file,
3573 			     file_mask_to_av(inode->i_mode, mask));
3574 }
3575 
selinux_file_permission(struct file * file,int mask)3576 static int selinux_file_permission(struct file *file, int mask)
3577 {
3578 	struct inode *inode = file_inode(file);
3579 	struct file_security_struct *fsec = selinux_file(file);
3580 	struct inode_security_struct *isec;
3581 	u32 sid = current_sid();
3582 
3583 	if (!mask)
3584 		/* No permission to check.  Existence test. */
3585 		return 0;
3586 
3587 	isec = inode_security(inode);
3588 	if (sid == fsec->sid && fsec->isid == isec->sid &&
3589 	    fsec->pseqno == avc_policy_seqno(&selinux_state))
3590 		/* No change since file_open check. */
3591 		return 0;
3592 
3593 	return selinux_revalidate_file_permission(file, mask);
3594 }
3595 
selinux_file_alloc_security(struct file * file)3596 static int selinux_file_alloc_security(struct file *file)
3597 {
3598 	struct file_security_struct *fsec = selinux_file(file);
3599 	u32 sid = current_sid();
3600 
3601 	fsec->sid = sid;
3602 	fsec->fown_sid = sid;
3603 
3604 	return 0;
3605 }
3606 
3607 /*
3608  * Check whether a task has the ioctl permission and cmd
3609  * operation to an inode.
3610  */
ioctl_has_perm(const struct cred * cred,struct file * file,u32 requested,u16 cmd)3611 static int ioctl_has_perm(const struct cred *cred, struct file *file,
3612 		u32 requested, u16 cmd)
3613 {
3614 	struct common_audit_data ad;
3615 	struct file_security_struct *fsec = selinux_file(file);
3616 	struct inode *inode = file_inode(file);
3617 	struct inode_security_struct *isec;
3618 	struct lsm_ioctlop_audit ioctl;
3619 	u32 ssid = cred_sid(cred);
3620 	int rc;
3621 	u8 driver = cmd >> 8;
3622 	u8 xperm = cmd & 0xff;
3623 
3624 	ad.type = LSM_AUDIT_DATA_IOCTL_OP;
3625 	ad.u.op = &ioctl;
3626 	ad.u.op->cmd = cmd;
3627 	ad.u.op->path = file->f_path;
3628 
3629 	if (ssid != fsec->sid) {
3630 		rc = avc_has_perm(&selinux_state,
3631 				  ssid, fsec->sid,
3632 				SECCLASS_FD,
3633 				FD__USE,
3634 				&ad);
3635 		if (rc)
3636 			goto out;
3637 	}
3638 
3639 	if (unlikely(IS_PRIVATE(inode)))
3640 		return 0;
3641 
3642 	isec = inode_security(inode);
3643 	rc = avc_has_extended_perms(&selinux_state,
3644 				    ssid, isec->sid, isec->sclass,
3645 				    requested, driver, xperm, &ad);
3646 out:
3647 	return rc;
3648 }
3649 
selinux_file_ioctl(struct file * file,unsigned int cmd,unsigned long arg)3650 static int selinux_file_ioctl(struct file *file, unsigned int cmd,
3651 			      unsigned long arg)
3652 {
3653 	const struct cred *cred = current_cred();
3654 	int error = 0;
3655 
3656 	switch (cmd) {
3657 	case FIONREAD:
3658 	case FIBMAP:
3659 	case FIGETBSZ:
3660 	case FS_IOC_GETFLAGS:
3661 	case FS_IOC_GETVERSION:
3662 		error = file_has_perm(cred, file, FILE__GETATTR);
3663 		break;
3664 
3665 	case FS_IOC_SETFLAGS:
3666 	case FS_IOC_SETVERSION:
3667 		error = file_has_perm(cred, file, FILE__SETATTR);
3668 		break;
3669 
3670 	/* sys_ioctl() checks */
3671 	case FIONBIO:
3672 	case FIOASYNC:
3673 		error = file_has_perm(cred, file, 0);
3674 		break;
3675 
3676 	case KDSKBENT:
3677 	case KDSKBSENT:
3678 		error = cred_has_capability(cred, CAP_SYS_TTY_CONFIG,
3679 					    CAP_OPT_NONE, true);
3680 		break;
3681 
3682 	case FIOCLEX:
3683 	case FIONCLEX:
3684 		if (!selinux_policycap_ioctl_skip_cloexec())
3685 			error = ioctl_has_perm(cred, file, FILE__IOCTL, (u16) cmd);
3686 		break;
3687 
3688 	/* default case assumes that the command will go
3689 	 * to the file's ioctl() function.
3690 	 */
3691 	default:
3692 		error = ioctl_has_perm(cred, file, FILE__IOCTL, (u16) cmd);
3693 	}
3694 	return error;
3695 }
3696 
3697 static int default_noexec __ro_after_init;
3698 
file_map_prot_check(struct file * file,unsigned long prot,int shared)3699 static int file_map_prot_check(struct file *file, unsigned long prot, int shared)
3700 {
3701 	const struct cred *cred = current_cred();
3702 	u32 sid = cred_sid(cred);
3703 	int rc = 0;
3704 
3705 	if (default_noexec &&
3706 	    (prot & PROT_EXEC) && (!file || IS_PRIVATE(file_inode(file)) ||
3707 				   (!shared && (prot & PROT_WRITE)))) {
3708 		/*
3709 		 * We are making executable an anonymous mapping or a
3710 		 * private file mapping that will also be writable.
3711 		 * This has an additional check.
3712 		 */
3713 		rc = avc_has_perm(&selinux_state,
3714 				  sid, sid, SECCLASS_PROCESS,
3715 				  PROCESS__EXECMEM, NULL);
3716 		if (rc)
3717 			goto error;
3718 	}
3719 
3720 	if (file) {
3721 		/* read access is always possible with a mapping */
3722 		u32 av = FILE__READ;
3723 
3724 		/* write access only matters if the mapping is shared */
3725 		if (shared && (prot & PROT_WRITE))
3726 			av |= FILE__WRITE;
3727 
3728 		if (prot & PROT_EXEC)
3729 			av |= FILE__EXECUTE;
3730 
3731 		return file_has_perm(cred, file, av);
3732 	}
3733 
3734 error:
3735 	return rc;
3736 }
3737 
selinux_mmap_addr(unsigned long addr)3738 static int selinux_mmap_addr(unsigned long addr)
3739 {
3740 	int rc = 0;
3741 
3742 	if (addr < CONFIG_LSM_MMAP_MIN_ADDR) {
3743 		u32 sid = current_sid();
3744 		rc = avc_has_perm(&selinux_state,
3745 				  sid, sid, SECCLASS_MEMPROTECT,
3746 				  MEMPROTECT__MMAP_ZERO, NULL);
3747 	}
3748 
3749 	return rc;
3750 }
3751 
selinux_mmap_file(struct file * file,unsigned long reqprot,unsigned long prot,unsigned long flags)3752 static int selinux_mmap_file(struct file *file, unsigned long reqprot,
3753 			     unsigned long prot, unsigned long flags)
3754 {
3755 	struct common_audit_data ad;
3756 	int rc;
3757 
3758 	if (file) {
3759 		ad.type = LSM_AUDIT_DATA_FILE;
3760 		ad.u.file = file;
3761 		rc = inode_has_perm(current_cred(), file_inode(file),
3762 				    FILE__MAP, &ad);
3763 		if (rc)
3764 			return rc;
3765 	}
3766 
3767 	if (checkreqprot_get(&selinux_state))
3768 		prot = reqprot;
3769 
3770 	return file_map_prot_check(file, prot,
3771 				   (flags & MAP_TYPE) == MAP_SHARED);
3772 }
3773 
selinux_file_mprotect(struct vm_area_struct * vma,unsigned long reqprot,unsigned long prot)3774 static int selinux_file_mprotect(struct vm_area_struct *vma,
3775 				 unsigned long reqprot,
3776 				 unsigned long prot)
3777 {
3778 	const struct cred *cred = current_cred();
3779 	u32 sid = cred_sid(cred);
3780 
3781 	if (checkreqprot_get(&selinux_state))
3782 		prot = reqprot;
3783 
3784 	if (default_noexec &&
3785 	    (prot & PROT_EXEC) && !(vma->vm_flags & VM_EXEC)) {
3786 		int rc = 0;
3787 		if (vma->vm_start >= vma->vm_mm->start_brk &&
3788 		    vma->vm_end <= vma->vm_mm->brk) {
3789 			rc = avc_has_perm(&selinux_state,
3790 					  sid, sid, SECCLASS_PROCESS,
3791 					  PROCESS__EXECHEAP, NULL);
3792 		} else if (!vma->vm_file &&
3793 			   ((vma->vm_start <= vma->vm_mm->start_stack &&
3794 			     vma->vm_end >= vma->vm_mm->start_stack) ||
3795 			    vma_is_stack_for_current(vma))) {
3796 			rc = avc_has_perm(&selinux_state,
3797 					  sid, sid, SECCLASS_PROCESS,
3798 					  PROCESS__EXECSTACK, NULL);
3799 		} else if (vma->vm_file && vma->anon_vma) {
3800 			/*
3801 			 * We are making executable a file mapping that has
3802 			 * had some COW done. Since pages might have been
3803 			 * written, check ability to execute the possibly
3804 			 * modified content.  This typically should only
3805 			 * occur for text relocations.
3806 			 */
3807 			rc = file_has_perm(cred, vma->vm_file, FILE__EXECMOD);
3808 		}
3809 		if (rc)
3810 			return rc;
3811 	}
3812 
3813 	return file_map_prot_check(vma->vm_file, prot, vma->vm_flags&VM_SHARED);
3814 }
3815 
selinux_file_lock(struct file * file,unsigned int cmd)3816 static int selinux_file_lock(struct file *file, unsigned int cmd)
3817 {
3818 	const struct cred *cred = current_cred();
3819 
3820 	return file_has_perm(cred, file, FILE__LOCK);
3821 }
3822 
selinux_file_fcntl(struct file * file,unsigned int cmd,unsigned long arg)3823 static int selinux_file_fcntl(struct file *file, unsigned int cmd,
3824 			      unsigned long arg)
3825 {
3826 	const struct cred *cred = current_cred();
3827 	int err = 0;
3828 
3829 	switch (cmd) {
3830 	case F_SETFL:
3831 		if ((file->f_flags & O_APPEND) && !(arg & O_APPEND)) {
3832 			err = file_has_perm(cred, file, FILE__WRITE);
3833 			break;
3834 		}
3835 		fallthrough;
3836 	case F_SETOWN:
3837 	case F_SETSIG:
3838 	case F_GETFL:
3839 	case F_GETOWN:
3840 	case F_GETSIG:
3841 	case F_GETOWNER_UIDS:
3842 		/* Just check FD__USE permission */
3843 		err = file_has_perm(cred, file, 0);
3844 		break;
3845 	case F_GETLK:
3846 	case F_SETLK:
3847 	case F_SETLKW:
3848 	case F_OFD_GETLK:
3849 	case F_OFD_SETLK:
3850 	case F_OFD_SETLKW:
3851 #if BITS_PER_LONG == 32
3852 	case F_GETLK64:
3853 	case F_SETLK64:
3854 	case F_SETLKW64:
3855 #endif
3856 		err = file_has_perm(cred, file, FILE__LOCK);
3857 		break;
3858 	}
3859 
3860 	return err;
3861 }
3862 
selinux_file_set_fowner(struct file * file)3863 static void selinux_file_set_fowner(struct file *file)
3864 {
3865 	struct file_security_struct *fsec;
3866 
3867 	fsec = selinux_file(file);
3868 	fsec->fown_sid = current_sid();
3869 }
3870 
selinux_file_send_sigiotask(struct task_struct * tsk,struct fown_struct * fown,int signum)3871 static int selinux_file_send_sigiotask(struct task_struct *tsk,
3872 				       struct fown_struct *fown, int signum)
3873 {
3874 	struct file *file;
3875 	u32 sid = task_sid_obj(tsk);
3876 	u32 perm;
3877 	struct file_security_struct *fsec;
3878 
3879 	/* struct fown_struct is never outside the context of a struct file */
3880 	file = container_of(fown, struct file, f_owner);
3881 
3882 	fsec = selinux_file(file);
3883 
3884 	if (!signum)
3885 		perm = signal_to_av(SIGIO); /* as per send_sigio_to_task */
3886 	else
3887 		perm = signal_to_av(signum);
3888 
3889 	return avc_has_perm(&selinux_state,
3890 			    fsec->fown_sid, sid,
3891 			    SECCLASS_PROCESS, perm, NULL);
3892 }
3893 
selinux_file_receive(struct file * file)3894 static int selinux_file_receive(struct file *file)
3895 {
3896 	const struct cred *cred = current_cred();
3897 
3898 	return file_has_perm(cred, file, file_to_av(file));
3899 }
3900 
selinux_file_open(struct file * file)3901 static int selinux_file_open(struct file *file)
3902 {
3903 	struct file_security_struct *fsec;
3904 	struct inode_security_struct *isec;
3905 
3906 	fsec = selinux_file(file);
3907 	isec = inode_security(file_inode(file));
3908 	/*
3909 	 * Save inode label and policy sequence number
3910 	 * at open-time so that selinux_file_permission
3911 	 * can determine whether revalidation is necessary.
3912 	 * Task label is already saved in the file security
3913 	 * struct as its SID.
3914 	 */
3915 	fsec->isid = isec->sid;
3916 	fsec->pseqno = avc_policy_seqno(&selinux_state);
3917 	/*
3918 	 * Since the inode label or policy seqno may have changed
3919 	 * between the selinux_inode_permission check and the saving
3920 	 * of state above, recheck that access is still permitted.
3921 	 * Otherwise, access might never be revalidated against the
3922 	 * new inode label or new policy.
3923 	 * This check is not redundant - do not remove.
3924 	 */
3925 	return file_path_has_perm(file->f_cred, file, open_file_to_av(file));
3926 }
3927 
3928 /* task security operations */
3929 
selinux_task_alloc(struct task_struct * task,unsigned long clone_flags)3930 static int selinux_task_alloc(struct task_struct *task,
3931 			      unsigned long clone_flags)
3932 {
3933 	u32 sid = current_sid();
3934 
3935 	return avc_has_perm(&selinux_state,
3936 			    sid, sid, SECCLASS_PROCESS, PROCESS__FORK, NULL);
3937 }
3938 
3939 /*
3940  * prepare a new set of credentials for modification
3941  */
selinux_cred_prepare(struct cred * new,const struct cred * old,gfp_t gfp)3942 static int selinux_cred_prepare(struct cred *new, const struct cred *old,
3943 				gfp_t gfp)
3944 {
3945 	const struct task_security_struct *old_tsec = selinux_cred(old);
3946 	struct task_security_struct *tsec = selinux_cred(new);
3947 
3948 	*tsec = *old_tsec;
3949 	return 0;
3950 }
3951 
3952 /*
3953  * transfer the SELinux data to a blank set of creds
3954  */
selinux_cred_transfer(struct cred * new,const struct cred * old)3955 static void selinux_cred_transfer(struct cred *new, const struct cred *old)
3956 {
3957 	const struct task_security_struct *old_tsec = selinux_cred(old);
3958 	struct task_security_struct *tsec = selinux_cred(new);
3959 
3960 	*tsec = *old_tsec;
3961 }
3962 
selinux_cred_getsecid(const struct cred * c,u32 * secid)3963 static void selinux_cred_getsecid(const struct cred *c, u32 *secid)
3964 {
3965 	*secid = cred_sid(c);
3966 }
3967 
3968 /*
3969  * set the security data for a kernel service
3970  * - all the creation contexts are set to unlabelled
3971  */
selinux_kernel_act_as(struct cred * new,u32 secid)3972 static int selinux_kernel_act_as(struct cred *new, u32 secid)
3973 {
3974 	struct task_security_struct *tsec = selinux_cred(new);
3975 	u32 sid = current_sid();
3976 	int ret;
3977 
3978 	ret = avc_has_perm(&selinux_state,
3979 			   sid, secid,
3980 			   SECCLASS_KERNEL_SERVICE,
3981 			   KERNEL_SERVICE__USE_AS_OVERRIDE,
3982 			   NULL);
3983 	if (ret == 0) {
3984 		tsec->sid = secid;
3985 		tsec->create_sid = 0;
3986 		tsec->keycreate_sid = 0;
3987 		tsec->sockcreate_sid = 0;
3988 	}
3989 	return ret;
3990 }
3991 
3992 /*
3993  * set the file creation context in a security record to the same as the
3994  * objective context of the specified inode
3995  */
selinux_kernel_create_files_as(struct cred * new,struct inode * inode)3996 static int selinux_kernel_create_files_as(struct cred *new, struct inode *inode)
3997 {
3998 	struct inode_security_struct *isec = inode_security(inode);
3999 	struct task_security_struct *tsec = selinux_cred(new);
4000 	u32 sid = current_sid();
4001 	int ret;
4002 
4003 	ret = avc_has_perm(&selinux_state,
4004 			   sid, isec->sid,
4005 			   SECCLASS_KERNEL_SERVICE,
4006 			   KERNEL_SERVICE__CREATE_FILES_AS,
4007 			   NULL);
4008 
4009 	if (ret == 0)
4010 		tsec->create_sid = isec->sid;
4011 	return ret;
4012 }
4013 
selinux_kernel_module_request(char * kmod_name)4014 static int selinux_kernel_module_request(char *kmod_name)
4015 {
4016 	struct common_audit_data ad;
4017 
4018 	ad.type = LSM_AUDIT_DATA_KMOD;
4019 	ad.u.kmod_name = kmod_name;
4020 
4021 	return avc_has_perm(&selinux_state,
4022 			    current_sid(), SECINITSID_KERNEL, SECCLASS_SYSTEM,
4023 			    SYSTEM__MODULE_REQUEST, &ad);
4024 }
4025 
selinux_kernel_module_from_file(struct file * file)4026 static int selinux_kernel_module_from_file(struct file *file)
4027 {
4028 	struct common_audit_data ad;
4029 	struct inode_security_struct *isec;
4030 	struct file_security_struct *fsec;
4031 	u32 sid = current_sid();
4032 	int rc;
4033 
4034 	/* init_module */
4035 	if (file == NULL)
4036 		return avc_has_perm(&selinux_state,
4037 				    sid, sid, SECCLASS_SYSTEM,
4038 					SYSTEM__MODULE_LOAD, NULL);
4039 
4040 	/* finit_module */
4041 
4042 	ad.type = LSM_AUDIT_DATA_FILE;
4043 	ad.u.file = file;
4044 
4045 	fsec = selinux_file(file);
4046 	if (sid != fsec->sid) {
4047 		rc = avc_has_perm(&selinux_state,
4048 				  sid, fsec->sid, SECCLASS_FD, FD__USE, &ad);
4049 		if (rc)
4050 			return rc;
4051 	}
4052 
4053 	isec = inode_security(file_inode(file));
4054 	return avc_has_perm(&selinux_state,
4055 			    sid, isec->sid, SECCLASS_SYSTEM,
4056 				SYSTEM__MODULE_LOAD, &ad);
4057 }
4058 
selinux_kernel_read_file(struct file * file,enum kernel_read_file_id id,bool contents)4059 static int selinux_kernel_read_file(struct file *file,
4060 				    enum kernel_read_file_id id,
4061 				    bool contents)
4062 {
4063 	int rc = 0;
4064 
4065 	switch (id) {
4066 	case READING_MODULE:
4067 		rc = selinux_kernel_module_from_file(contents ? file : NULL);
4068 		break;
4069 	default:
4070 		break;
4071 	}
4072 
4073 	return rc;
4074 }
4075 
selinux_kernel_load_data(enum kernel_load_data_id id,bool contents)4076 static int selinux_kernel_load_data(enum kernel_load_data_id id, bool contents)
4077 {
4078 	int rc = 0;
4079 
4080 	switch (id) {
4081 	case LOADING_MODULE:
4082 		rc = selinux_kernel_module_from_file(NULL);
4083 		break;
4084 	default:
4085 		break;
4086 	}
4087 
4088 	return rc;
4089 }
4090 
selinux_task_setpgid(struct task_struct * p,pid_t pgid)4091 static int selinux_task_setpgid(struct task_struct *p, pid_t pgid)
4092 {
4093 	return avc_has_perm(&selinux_state,
4094 			    current_sid(), task_sid_obj(p), SECCLASS_PROCESS,
4095 			    PROCESS__SETPGID, NULL);
4096 }
4097 
selinux_task_getpgid(struct task_struct * p)4098 static int selinux_task_getpgid(struct task_struct *p)
4099 {
4100 	return avc_has_perm(&selinux_state,
4101 			    current_sid(), task_sid_obj(p), SECCLASS_PROCESS,
4102 			    PROCESS__GETPGID, NULL);
4103 }
4104 
selinux_task_getsid(struct task_struct * p)4105 static int selinux_task_getsid(struct task_struct *p)
4106 {
4107 	return avc_has_perm(&selinux_state,
4108 			    current_sid(), task_sid_obj(p), SECCLASS_PROCESS,
4109 			    PROCESS__GETSESSION, NULL);
4110 }
4111 
selinux_current_getsecid_subj(u32 * secid)4112 static void selinux_current_getsecid_subj(u32 *secid)
4113 {
4114 	*secid = current_sid();
4115 }
4116 
selinux_task_getsecid_obj(struct task_struct * p,u32 * secid)4117 static void selinux_task_getsecid_obj(struct task_struct *p, u32 *secid)
4118 {
4119 	*secid = task_sid_obj(p);
4120 }
4121 
selinux_task_setnice(struct task_struct * p,int nice)4122 static int selinux_task_setnice(struct task_struct *p, int nice)
4123 {
4124 	return avc_has_perm(&selinux_state,
4125 			    current_sid(), task_sid_obj(p), SECCLASS_PROCESS,
4126 			    PROCESS__SETSCHED, NULL);
4127 }
4128 
selinux_task_setioprio(struct task_struct * p,int ioprio)4129 static int selinux_task_setioprio(struct task_struct *p, int ioprio)
4130 {
4131 	return avc_has_perm(&selinux_state,
4132 			    current_sid(), task_sid_obj(p), SECCLASS_PROCESS,
4133 			    PROCESS__SETSCHED, NULL);
4134 }
4135 
selinux_task_getioprio(struct task_struct * p)4136 static int selinux_task_getioprio(struct task_struct *p)
4137 {
4138 	return avc_has_perm(&selinux_state,
4139 			    current_sid(), task_sid_obj(p), SECCLASS_PROCESS,
4140 			    PROCESS__GETSCHED, NULL);
4141 }
4142 
selinux_task_prlimit(const struct cred * cred,const struct cred * tcred,unsigned int flags)4143 static int selinux_task_prlimit(const struct cred *cred, const struct cred *tcred,
4144 				unsigned int flags)
4145 {
4146 	u32 av = 0;
4147 
4148 	if (!flags)
4149 		return 0;
4150 	if (flags & LSM_PRLIMIT_WRITE)
4151 		av |= PROCESS__SETRLIMIT;
4152 	if (flags & LSM_PRLIMIT_READ)
4153 		av |= PROCESS__GETRLIMIT;
4154 	return avc_has_perm(&selinux_state,
4155 			    cred_sid(cred), cred_sid(tcred),
4156 			    SECCLASS_PROCESS, av, NULL);
4157 }
4158 
selinux_task_setrlimit(struct task_struct * p,unsigned int resource,struct rlimit * new_rlim)4159 static int selinux_task_setrlimit(struct task_struct *p, unsigned int resource,
4160 		struct rlimit *new_rlim)
4161 {
4162 	struct rlimit *old_rlim = p->signal->rlim + resource;
4163 
4164 	/* Control the ability to change the hard limit (whether
4165 	   lowering or raising it), so that the hard limit can
4166 	   later be used as a safe reset point for the soft limit
4167 	   upon context transitions.  See selinux_bprm_committing_creds. */
4168 	if (old_rlim->rlim_max != new_rlim->rlim_max)
4169 		return avc_has_perm(&selinux_state,
4170 				    current_sid(), task_sid_obj(p),
4171 				    SECCLASS_PROCESS, PROCESS__SETRLIMIT, NULL);
4172 
4173 	return 0;
4174 }
4175 
selinux_task_setscheduler(struct task_struct * p)4176 static int selinux_task_setscheduler(struct task_struct *p)
4177 {
4178 	return avc_has_perm(&selinux_state,
4179 			    current_sid(), task_sid_obj(p), SECCLASS_PROCESS,
4180 			    PROCESS__SETSCHED, NULL);
4181 }
4182 
selinux_task_getscheduler(struct task_struct * p)4183 static int selinux_task_getscheduler(struct task_struct *p)
4184 {
4185 	return avc_has_perm(&selinux_state,
4186 			    current_sid(), task_sid_obj(p), SECCLASS_PROCESS,
4187 			    PROCESS__GETSCHED, NULL);
4188 }
4189 
selinux_task_movememory(struct task_struct * p)4190 static int selinux_task_movememory(struct task_struct *p)
4191 {
4192 	return avc_has_perm(&selinux_state,
4193 			    current_sid(), task_sid_obj(p), SECCLASS_PROCESS,
4194 			    PROCESS__SETSCHED, NULL);
4195 }
4196 
selinux_task_kill(struct task_struct * p,struct kernel_siginfo * info,int sig,const struct cred * cred)4197 static int selinux_task_kill(struct task_struct *p, struct kernel_siginfo *info,
4198 				int sig, const struct cred *cred)
4199 {
4200 	u32 secid;
4201 	u32 perm;
4202 
4203 	if (!sig)
4204 		perm = PROCESS__SIGNULL; /* null signal; existence test */
4205 	else
4206 		perm = signal_to_av(sig);
4207 	if (!cred)
4208 		secid = current_sid();
4209 	else
4210 		secid = cred_sid(cred);
4211 	return avc_has_perm(&selinux_state,
4212 			    secid, task_sid_obj(p), SECCLASS_PROCESS, perm, NULL);
4213 }
4214 
selinux_task_to_inode(struct task_struct * p,struct inode * inode)4215 static void selinux_task_to_inode(struct task_struct *p,
4216 				  struct inode *inode)
4217 {
4218 	struct inode_security_struct *isec = selinux_inode(inode);
4219 	u32 sid = task_sid_obj(p);
4220 
4221 	spin_lock(&isec->lock);
4222 	isec->sclass = inode_mode_to_security_class(inode->i_mode);
4223 	isec->sid = sid;
4224 	isec->initialized = LABEL_INITIALIZED;
4225 	spin_unlock(&isec->lock);
4226 }
4227 
4228 /* Returns error only if unable to parse addresses */
selinux_parse_skb_ipv4(struct sk_buff * skb,struct common_audit_data * ad,u8 * proto)4229 static int selinux_parse_skb_ipv4(struct sk_buff *skb,
4230 			struct common_audit_data *ad, u8 *proto)
4231 {
4232 	int offset, ihlen, ret = -EINVAL;
4233 	struct iphdr _iph, *ih;
4234 
4235 	offset = skb_network_offset(skb);
4236 	ih = skb_header_pointer(skb, offset, sizeof(_iph), &_iph);
4237 	if (ih == NULL)
4238 		goto out;
4239 
4240 	ihlen = ih->ihl * 4;
4241 	if (ihlen < sizeof(_iph))
4242 		goto out;
4243 
4244 	ad->u.net->v4info.saddr = ih->saddr;
4245 	ad->u.net->v4info.daddr = ih->daddr;
4246 	ret = 0;
4247 
4248 	if (proto)
4249 		*proto = ih->protocol;
4250 
4251 	switch (ih->protocol) {
4252 	case IPPROTO_TCP: {
4253 		struct tcphdr _tcph, *th;
4254 
4255 		if (ntohs(ih->frag_off) & IP_OFFSET)
4256 			break;
4257 
4258 		offset += ihlen;
4259 		th = skb_header_pointer(skb, offset, sizeof(_tcph), &_tcph);
4260 		if (th == NULL)
4261 			break;
4262 
4263 		ad->u.net->sport = th->source;
4264 		ad->u.net->dport = th->dest;
4265 		break;
4266 	}
4267 
4268 	case IPPROTO_UDP: {
4269 		struct udphdr _udph, *uh;
4270 
4271 		if (ntohs(ih->frag_off) & IP_OFFSET)
4272 			break;
4273 
4274 		offset += ihlen;
4275 		uh = skb_header_pointer(skb, offset, sizeof(_udph), &_udph);
4276 		if (uh == NULL)
4277 			break;
4278 
4279 		ad->u.net->sport = uh->source;
4280 		ad->u.net->dport = uh->dest;
4281 		break;
4282 	}
4283 
4284 	case IPPROTO_DCCP: {
4285 		struct dccp_hdr _dccph, *dh;
4286 
4287 		if (ntohs(ih->frag_off) & IP_OFFSET)
4288 			break;
4289 
4290 		offset += ihlen;
4291 		dh = skb_header_pointer(skb, offset, sizeof(_dccph), &_dccph);
4292 		if (dh == NULL)
4293 			break;
4294 
4295 		ad->u.net->sport = dh->dccph_sport;
4296 		ad->u.net->dport = dh->dccph_dport;
4297 		break;
4298 	}
4299 
4300 #if IS_ENABLED(CONFIG_IP_SCTP)
4301 	case IPPROTO_SCTP: {
4302 		struct sctphdr _sctph, *sh;
4303 
4304 		if (ntohs(ih->frag_off) & IP_OFFSET)
4305 			break;
4306 
4307 		offset += ihlen;
4308 		sh = skb_header_pointer(skb, offset, sizeof(_sctph), &_sctph);
4309 		if (sh == NULL)
4310 			break;
4311 
4312 		ad->u.net->sport = sh->source;
4313 		ad->u.net->dport = sh->dest;
4314 		break;
4315 	}
4316 #endif
4317 	default:
4318 		break;
4319 	}
4320 out:
4321 	return ret;
4322 }
4323 
4324 #if IS_ENABLED(CONFIG_IPV6)
4325 
4326 /* Returns error only if unable to parse addresses */
selinux_parse_skb_ipv6(struct sk_buff * skb,struct common_audit_data * ad,u8 * proto)4327 static int selinux_parse_skb_ipv6(struct sk_buff *skb,
4328 			struct common_audit_data *ad, u8 *proto)
4329 {
4330 	u8 nexthdr;
4331 	int ret = -EINVAL, offset;
4332 	struct ipv6hdr _ipv6h, *ip6;
4333 	__be16 frag_off;
4334 
4335 	offset = skb_network_offset(skb);
4336 	ip6 = skb_header_pointer(skb, offset, sizeof(_ipv6h), &_ipv6h);
4337 	if (ip6 == NULL)
4338 		goto out;
4339 
4340 	ad->u.net->v6info.saddr = ip6->saddr;
4341 	ad->u.net->v6info.daddr = ip6->daddr;
4342 	ret = 0;
4343 
4344 	nexthdr = ip6->nexthdr;
4345 	offset += sizeof(_ipv6h);
4346 	offset = ipv6_skip_exthdr(skb, offset, &nexthdr, &frag_off);
4347 	if (offset < 0)
4348 		goto out;
4349 
4350 	if (proto)
4351 		*proto = nexthdr;
4352 
4353 	switch (nexthdr) {
4354 	case IPPROTO_TCP: {
4355 		struct tcphdr _tcph, *th;
4356 
4357 		th = skb_header_pointer(skb, offset, sizeof(_tcph), &_tcph);
4358 		if (th == NULL)
4359 			break;
4360 
4361 		ad->u.net->sport = th->source;
4362 		ad->u.net->dport = th->dest;
4363 		break;
4364 	}
4365 
4366 	case IPPROTO_UDP: {
4367 		struct udphdr _udph, *uh;
4368 
4369 		uh = skb_header_pointer(skb, offset, sizeof(_udph), &_udph);
4370 		if (uh == NULL)
4371 			break;
4372 
4373 		ad->u.net->sport = uh->source;
4374 		ad->u.net->dport = uh->dest;
4375 		break;
4376 	}
4377 
4378 	case IPPROTO_DCCP: {
4379 		struct dccp_hdr _dccph, *dh;
4380 
4381 		dh = skb_header_pointer(skb, offset, sizeof(_dccph), &_dccph);
4382 		if (dh == NULL)
4383 			break;
4384 
4385 		ad->u.net->sport = dh->dccph_sport;
4386 		ad->u.net->dport = dh->dccph_dport;
4387 		break;
4388 	}
4389 
4390 #if IS_ENABLED(CONFIG_IP_SCTP)
4391 	case IPPROTO_SCTP: {
4392 		struct sctphdr _sctph, *sh;
4393 
4394 		sh = skb_header_pointer(skb, offset, sizeof(_sctph), &_sctph);
4395 		if (sh == NULL)
4396 			break;
4397 
4398 		ad->u.net->sport = sh->source;
4399 		ad->u.net->dport = sh->dest;
4400 		break;
4401 	}
4402 #endif
4403 	/* includes fragments */
4404 	default:
4405 		break;
4406 	}
4407 out:
4408 	return ret;
4409 }
4410 
4411 #endif /* IPV6 */
4412 
selinux_parse_skb(struct sk_buff * skb,struct common_audit_data * ad,char ** _addrp,int src,u8 * proto)4413 static int selinux_parse_skb(struct sk_buff *skb, struct common_audit_data *ad,
4414 			     char **_addrp, int src, u8 *proto)
4415 {
4416 	char *addrp;
4417 	int ret;
4418 
4419 	switch (ad->u.net->family) {
4420 	case PF_INET:
4421 		ret = selinux_parse_skb_ipv4(skb, ad, proto);
4422 		if (ret)
4423 			goto parse_error;
4424 		addrp = (char *)(src ? &ad->u.net->v4info.saddr :
4425 				       &ad->u.net->v4info.daddr);
4426 		goto okay;
4427 
4428 #if IS_ENABLED(CONFIG_IPV6)
4429 	case PF_INET6:
4430 		ret = selinux_parse_skb_ipv6(skb, ad, proto);
4431 		if (ret)
4432 			goto parse_error;
4433 		addrp = (char *)(src ? &ad->u.net->v6info.saddr :
4434 				       &ad->u.net->v6info.daddr);
4435 		goto okay;
4436 #endif	/* IPV6 */
4437 	default:
4438 		addrp = NULL;
4439 		goto okay;
4440 	}
4441 
4442 parse_error:
4443 	pr_warn(
4444 	       "SELinux: failure in selinux_parse_skb(),"
4445 	       " unable to parse packet\n");
4446 	return ret;
4447 
4448 okay:
4449 	if (_addrp)
4450 		*_addrp = addrp;
4451 	return 0;
4452 }
4453 
4454 /**
4455  * selinux_skb_peerlbl_sid - Determine the peer label of a packet
4456  * @skb: the packet
4457  * @family: protocol family
4458  * @sid: the packet's peer label SID
4459  *
4460  * Description:
4461  * Check the various different forms of network peer labeling and determine
4462  * the peer label/SID for the packet; most of the magic actually occurs in
4463  * the security server function security_net_peersid_cmp().  The function
4464  * returns zero if the value in @sid is valid (although it may be SECSID_NULL)
4465  * or -EACCES if @sid is invalid due to inconsistencies with the different
4466  * peer labels.
4467  *
4468  */
selinux_skb_peerlbl_sid(struct sk_buff * skb,u16 family,u32 * sid)4469 static int selinux_skb_peerlbl_sid(struct sk_buff *skb, u16 family, u32 *sid)
4470 {
4471 	int err;
4472 	u32 xfrm_sid;
4473 	u32 nlbl_sid;
4474 	u32 nlbl_type;
4475 
4476 	err = selinux_xfrm_skb_sid(skb, &xfrm_sid);
4477 	if (unlikely(err))
4478 		return -EACCES;
4479 	err = selinux_netlbl_skbuff_getsid(skb, family, &nlbl_type, &nlbl_sid);
4480 	if (unlikely(err))
4481 		return -EACCES;
4482 
4483 	err = security_net_peersid_resolve(&selinux_state, nlbl_sid,
4484 					   nlbl_type, xfrm_sid, sid);
4485 	if (unlikely(err)) {
4486 		pr_warn(
4487 		       "SELinux: failure in selinux_skb_peerlbl_sid(),"
4488 		       " unable to determine packet's peer label\n");
4489 		return -EACCES;
4490 	}
4491 
4492 	return 0;
4493 }
4494 
4495 /**
4496  * selinux_conn_sid - Determine the child socket label for a connection
4497  * @sk_sid: the parent socket's SID
4498  * @skb_sid: the packet's SID
4499  * @conn_sid: the resulting connection SID
4500  *
4501  * If @skb_sid is valid then the user:role:type information from @sk_sid is
4502  * combined with the MLS information from @skb_sid in order to create
4503  * @conn_sid.  If @skb_sid is not valid then @conn_sid is simply a copy
4504  * of @sk_sid.  Returns zero on success, negative values on failure.
4505  *
4506  */
selinux_conn_sid(u32 sk_sid,u32 skb_sid,u32 * conn_sid)4507 static int selinux_conn_sid(u32 sk_sid, u32 skb_sid, u32 *conn_sid)
4508 {
4509 	int err = 0;
4510 
4511 	if (skb_sid != SECSID_NULL)
4512 		err = security_sid_mls_copy(&selinux_state, sk_sid, skb_sid,
4513 					    conn_sid);
4514 	else
4515 		*conn_sid = sk_sid;
4516 
4517 	return err;
4518 }
4519 
4520 /* socket security operations */
4521 
socket_sockcreate_sid(const struct task_security_struct * tsec,u16 secclass,u32 * socksid)4522 static int socket_sockcreate_sid(const struct task_security_struct *tsec,
4523 				 u16 secclass, u32 *socksid)
4524 {
4525 	if (tsec->sockcreate_sid > SECSID_NULL) {
4526 		*socksid = tsec->sockcreate_sid;
4527 		return 0;
4528 	}
4529 
4530 	return security_transition_sid(&selinux_state, tsec->sid, tsec->sid,
4531 				       secclass, NULL, socksid);
4532 }
4533 
sock_has_perm(struct sock * sk,u32 perms)4534 static int sock_has_perm(struct sock *sk, u32 perms)
4535 {
4536 	struct sk_security_struct *sksec = sk->sk_security;
4537 	struct common_audit_data ad;
4538 	struct lsm_network_audit net = {0,};
4539 
4540 	if (sksec->sid == SECINITSID_KERNEL)
4541 		return 0;
4542 
4543 	ad.type = LSM_AUDIT_DATA_NET;
4544 	ad.u.net = &net;
4545 	ad.u.net->sk = sk;
4546 
4547 	return avc_has_perm(&selinux_state,
4548 			    current_sid(), sksec->sid, sksec->sclass, perms,
4549 			    &ad);
4550 }
4551 
selinux_socket_create(int family,int type,int protocol,int kern)4552 static int selinux_socket_create(int family, int type,
4553 				 int protocol, int kern)
4554 {
4555 	const struct task_security_struct *tsec = selinux_cred(current_cred());
4556 	u32 newsid;
4557 	u16 secclass;
4558 	int rc;
4559 
4560 	if (kern)
4561 		return 0;
4562 
4563 	secclass = socket_type_to_security_class(family, type, protocol);
4564 	rc = socket_sockcreate_sid(tsec, secclass, &newsid);
4565 	if (rc)
4566 		return rc;
4567 
4568 	return avc_has_perm(&selinux_state,
4569 			    tsec->sid, newsid, secclass, SOCKET__CREATE, NULL);
4570 }
4571 
selinux_socket_post_create(struct socket * sock,int family,int type,int protocol,int kern)4572 static int selinux_socket_post_create(struct socket *sock, int family,
4573 				      int type, int protocol, int kern)
4574 {
4575 	const struct task_security_struct *tsec = selinux_cred(current_cred());
4576 	struct inode_security_struct *isec = inode_security_novalidate(SOCK_INODE(sock));
4577 	struct sk_security_struct *sksec;
4578 	u16 sclass = socket_type_to_security_class(family, type, protocol);
4579 	u32 sid = SECINITSID_KERNEL;
4580 	int err = 0;
4581 
4582 	if (!kern) {
4583 		err = socket_sockcreate_sid(tsec, sclass, &sid);
4584 		if (err)
4585 			return err;
4586 	}
4587 
4588 	isec->sclass = sclass;
4589 	isec->sid = sid;
4590 	isec->initialized = LABEL_INITIALIZED;
4591 
4592 	if (sock->sk) {
4593 		sksec = sock->sk->sk_security;
4594 		sksec->sclass = sclass;
4595 		sksec->sid = sid;
4596 		/* Allows detection of the first association on this socket */
4597 		if (sksec->sclass == SECCLASS_SCTP_SOCKET)
4598 			sksec->sctp_assoc_state = SCTP_ASSOC_UNSET;
4599 
4600 		err = selinux_netlbl_socket_post_create(sock->sk, family);
4601 	}
4602 
4603 	return err;
4604 }
4605 
selinux_socket_socketpair(struct socket * socka,struct socket * sockb)4606 static int selinux_socket_socketpair(struct socket *socka,
4607 				     struct socket *sockb)
4608 {
4609 	struct sk_security_struct *sksec_a = socka->sk->sk_security;
4610 	struct sk_security_struct *sksec_b = sockb->sk->sk_security;
4611 
4612 	sksec_a->peer_sid = sksec_b->sid;
4613 	sksec_b->peer_sid = sksec_a->sid;
4614 
4615 	return 0;
4616 }
4617 
4618 /* Range of port numbers used to automatically bind.
4619    Need to determine whether we should perform a name_bind
4620    permission check between the socket and the port number. */
4621 
selinux_socket_bind(struct socket * sock,struct sockaddr * address,int addrlen)4622 static int selinux_socket_bind(struct socket *sock, struct sockaddr *address, int addrlen)
4623 {
4624 	struct sock *sk = sock->sk;
4625 	struct sk_security_struct *sksec = sk->sk_security;
4626 	u16 family;
4627 	int err;
4628 
4629 	err = sock_has_perm(sk, SOCKET__BIND);
4630 	if (err)
4631 		goto out;
4632 
4633 	/* If PF_INET or PF_INET6, check name_bind permission for the port. */
4634 	family = sk->sk_family;
4635 	if (family == PF_INET || family == PF_INET6) {
4636 		char *addrp;
4637 		struct common_audit_data ad;
4638 		struct lsm_network_audit net = {0,};
4639 		struct sockaddr_in *addr4 = NULL;
4640 		struct sockaddr_in6 *addr6 = NULL;
4641 		u16 family_sa;
4642 		unsigned short snum;
4643 		u32 sid, node_perm;
4644 
4645 		/*
4646 		 * sctp_bindx(3) calls via selinux_sctp_bind_connect()
4647 		 * that validates multiple binding addresses. Because of this
4648 		 * need to check address->sa_family as it is possible to have
4649 		 * sk->sk_family = PF_INET6 with addr->sa_family = AF_INET.
4650 		 */
4651 		if (addrlen < offsetofend(struct sockaddr, sa_family))
4652 			return -EINVAL;
4653 		family_sa = address->sa_family;
4654 		switch (family_sa) {
4655 		case AF_UNSPEC:
4656 		case AF_INET:
4657 			if (addrlen < sizeof(struct sockaddr_in))
4658 				return -EINVAL;
4659 			addr4 = (struct sockaddr_in *)address;
4660 			if (family_sa == AF_UNSPEC) {
4661 				/* see __inet_bind(), we only want to allow
4662 				 * AF_UNSPEC if the address is INADDR_ANY
4663 				 */
4664 				if (addr4->sin_addr.s_addr != htonl(INADDR_ANY))
4665 					goto err_af;
4666 				family_sa = AF_INET;
4667 			}
4668 			snum = ntohs(addr4->sin_port);
4669 			addrp = (char *)&addr4->sin_addr.s_addr;
4670 			break;
4671 		case AF_INET6:
4672 			if (addrlen < SIN6_LEN_RFC2133)
4673 				return -EINVAL;
4674 			addr6 = (struct sockaddr_in6 *)address;
4675 			snum = ntohs(addr6->sin6_port);
4676 			addrp = (char *)&addr6->sin6_addr.s6_addr;
4677 			break;
4678 		default:
4679 			goto err_af;
4680 		}
4681 
4682 		ad.type = LSM_AUDIT_DATA_NET;
4683 		ad.u.net = &net;
4684 		ad.u.net->sport = htons(snum);
4685 		ad.u.net->family = family_sa;
4686 
4687 		if (snum) {
4688 			int low, high;
4689 
4690 			inet_get_local_port_range(sock_net(sk), &low, &high);
4691 
4692 			if (inet_port_requires_bind_service(sock_net(sk), snum) ||
4693 			    snum < low || snum > high) {
4694 				err = sel_netport_sid(sk->sk_protocol,
4695 						      snum, &sid);
4696 				if (err)
4697 					goto out;
4698 				err = avc_has_perm(&selinux_state,
4699 						   sksec->sid, sid,
4700 						   sksec->sclass,
4701 						   SOCKET__NAME_BIND, &ad);
4702 				if (err)
4703 					goto out;
4704 			}
4705 		}
4706 
4707 		switch (sksec->sclass) {
4708 		case SECCLASS_TCP_SOCKET:
4709 			node_perm = TCP_SOCKET__NODE_BIND;
4710 			break;
4711 
4712 		case SECCLASS_UDP_SOCKET:
4713 			node_perm = UDP_SOCKET__NODE_BIND;
4714 			break;
4715 
4716 		case SECCLASS_DCCP_SOCKET:
4717 			node_perm = DCCP_SOCKET__NODE_BIND;
4718 			break;
4719 
4720 		case SECCLASS_SCTP_SOCKET:
4721 			node_perm = SCTP_SOCKET__NODE_BIND;
4722 			break;
4723 
4724 		default:
4725 			node_perm = RAWIP_SOCKET__NODE_BIND;
4726 			break;
4727 		}
4728 
4729 		err = sel_netnode_sid(addrp, family_sa, &sid);
4730 		if (err)
4731 			goto out;
4732 
4733 		if (family_sa == AF_INET)
4734 			ad.u.net->v4info.saddr = addr4->sin_addr.s_addr;
4735 		else
4736 			ad.u.net->v6info.saddr = addr6->sin6_addr;
4737 
4738 		err = avc_has_perm(&selinux_state,
4739 				   sksec->sid, sid,
4740 				   sksec->sclass, node_perm, &ad);
4741 		if (err)
4742 			goto out;
4743 	}
4744 out:
4745 	return err;
4746 err_af:
4747 	/* Note that SCTP services expect -EINVAL, others -EAFNOSUPPORT. */
4748 	if (sksec->sclass == SECCLASS_SCTP_SOCKET)
4749 		return -EINVAL;
4750 	return -EAFNOSUPPORT;
4751 }
4752 
4753 /* This supports connect(2) and SCTP connect services such as sctp_connectx(3)
4754  * and sctp_sendmsg(3) as described in Documentation/security/SCTP.rst
4755  */
selinux_socket_connect_helper(struct socket * sock,struct sockaddr * address,int addrlen)4756 static int selinux_socket_connect_helper(struct socket *sock,
4757 					 struct sockaddr *address, int addrlen)
4758 {
4759 	struct sock *sk = sock->sk;
4760 	struct sk_security_struct *sksec = sk->sk_security;
4761 	int err;
4762 
4763 	err = sock_has_perm(sk, SOCKET__CONNECT);
4764 	if (err)
4765 		return err;
4766 	if (addrlen < offsetofend(struct sockaddr, sa_family))
4767 		return -EINVAL;
4768 
4769 	/* connect(AF_UNSPEC) has special handling, as it is a documented
4770 	 * way to disconnect the socket
4771 	 */
4772 	if (address->sa_family == AF_UNSPEC)
4773 		return 0;
4774 
4775 	/*
4776 	 * If a TCP, DCCP or SCTP socket, check name_connect permission
4777 	 * for the port.
4778 	 */
4779 	if (sksec->sclass == SECCLASS_TCP_SOCKET ||
4780 	    sksec->sclass == SECCLASS_DCCP_SOCKET ||
4781 	    sksec->sclass == SECCLASS_SCTP_SOCKET) {
4782 		struct common_audit_data ad;
4783 		struct lsm_network_audit net = {0,};
4784 		struct sockaddr_in *addr4 = NULL;
4785 		struct sockaddr_in6 *addr6 = NULL;
4786 		unsigned short snum;
4787 		u32 sid, perm;
4788 
4789 		/* sctp_connectx(3) calls via selinux_sctp_bind_connect()
4790 		 * that validates multiple connect addresses. Because of this
4791 		 * need to check address->sa_family as it is possible to have
4792 		 * sk->sk_family = PF_INET6 with addr->sa_family = AF_INET.
4793 		 */
4794 		switch (address->sa_family) {
4795 		case AF_INET:
4796 			addr4 = (struct sockaddr_in *)address;
4797 			if (addrlen < sizeof(struct sockaddr_in))
4798 				return -EINVAL;
4799 			snum = ntohs(addr4->sin_port);
4800 			break;
4801 		case AF_INET6:
4802 			addr6 = (struct sockaddr_in6 *)address;
4803 			if (addrlen < SIN6_LEN_RFC2133)
4804 				return -EINVAL;
4805 			snum = ntohs(addr6->sin6_port);
4806 			break;
4807 		default:
4808 			/* Note that SCTP services expect -EINVAL, whereas
4809 			 * others expect -EAFNOSUPPORT.
4810 			 */
4811 			if (sksec->sclass == SECCLASS_SCTP_SOCKET)
4812 				return -EINVAL;
4813 			else
4814 				return -EAFNOSUPPORT;
4815 		}
4816 
4817 		err = sel_netport_sid(sk->sk_protocol, snum, &sid);
4818 		if (err)
4819 			return err;
4820 
4821 		switch (sksec->sclass) {
4822 		case SECCLASS_TCP_SOCKET:
4823 			perm = TCP_SOCKET__NAME_CONNECT;
4824 			break;
4825 		case SECCLASS_DCCP_SOCKET:
4826 			perm = DCCP_SOCKET__NAME_CONNECT;
4827 			break;
4828 		case SECCLASS_SCTP_SOCKET:
4829 			perm = SCTP_SOCKET__NAME_CONNECT;
4830 			break;
4831 		}
4832 
4833 		ad.type = LSM_AUDIT_DATA_NET;
4834 		ad.u.net = &net;
4835 		ad.u.net->dport = htons(snum);
4836 		ad.u.net->family = address->sa_family;
4837 		err = avc_has_perm(&selinux_state,
4838 				   sksec->sid, sid, sksec->sclass, perm, &ad);
4839 		if (err)
4840 			return err;
4841 	}
4842 
4843 	return 0;
4844 }
4845 
4846 /* Supports connect(2), see comments in selinux_socket_connect_helper() */
selinux_socket_connect(struct socket * sock,struct sockaddr * address,int addrlen)4847 static int selinux_socket_connect(struct socket *sock,
4848 				  struct sockaddr *address, int addrlen)
4849 {
4850 	int err;
4851 	struct sock *sk = sock->sk;
4852 
4853 	err = selinux_socket_connect_helper(sock, address, addrlen);
4854 	if (err)
4855 		return err;
4856 
4857 	return selinux_netlbl_socket_connect(sk, address);
4858 }
4859 
selinux_socket_listen(struct socket * sock,int backlog)4860 static int selinux_socket_listen(struct socket *sock, int backlog)
4861 {
4862 	return sock_has_perm(sock->sk, SOCKET__LISTEN);
4863 }
4864 
selinux_socket_accept(struct socket * sock,struct socket * newsock)4865 static int selinux_socket_accept(struct socket *sock, struct socket *newsock)
4866 {
4867 	int err;
4868 	struct inode_security_struct *isec;
4869 	struct inode_security_struct *newisec;
4870 	u16 sclass;
4871 	u32 sid;
4872 
4873 	err = sock_has_perm(sock->sk, SOCKET__ACCEPT);
4874 	if (err)
4875 		return err;
4876 
4877 	isec = inode_security_novalidate(SOCK_INODE(sock));
4878 	spin_lock(&isec->lock);
4879 	sclass = isec->sclass;
4880 	sid = isec->sid;
4881 	spin_unlock(&isec->lock);
4882 
4883 	newisec = inode_security_novalidate(SOCK_INODE(newsock));
4884 	newisec->sclass = sclass;
4885 	newisec->sid = sid;
4886 	newisec->initialized = LABEL_INITIALIZED;
4887 
4888 	return 0;
4889 }
4890 
selinux_socket_sendmsg(struct socket * sock,struct msghdr * msg,int size)4891 static int selinux_socket_sendmsg(struct socket *sock, struct msghdr *msg,
4892 				  int size)
4893 {
4894 	return sock_has_perm(sock->sk, SOCKET__WRITE);
4895 }
4896 
selinux_socket_recvmsg(struct socket * sock,struct msghdr * msg,int size,int flags)4897 static int selinux_socket_recvmsg(struct socket *sock, struct msghdr *msg,
4898 				  int size, int flags)
4899 {
4900 	return sock_has_perm(sock->sk, SOCKET__READ);
4901 }
4902 
selinux_socket_getsockname(struct socket * sock)4903 static int selinux_socket_getsockname(struct socket *sock)
4904 {
4905 	return sock_has_perm(sock->sk, SOCKET__GETATTR);
4906 }
4907 
selinux_socket_getpeername(struct socket * sock)4908 static int selinux_socket_getpeername(struct socket *sock)
4909 {
4910 	return sock_has_perm(sock->sk, SOCKET__GETATTR);
4911 }
4912 
selinux_socket_setsockopt(struct socket * sock,int level,int optname)4913 static int selinux_socket_setsockopt(struct socket *sock, int level, int optname)
4914 {
4915 	int err;
4916 
4917 	err = sock_has_perm(sock->sk, SOCKET__SETOPT);
4918 	if (err)
4919 		return err;
4920 
4921 	return selinux_netlbl_socket_setsockopt(sock, level, optname);
4922 }
4923 
selinux_socket_getsockopt(struct socket * sock,int level,int optname)4924 static int selinux_socket_getsockopt(struct socket *sock, int level,
4925 				     int optname)
4926 {
4927 	return sock_has_perm(sock->sk, SOCKET__GETOPT);
4928 }
4929 
selinux_socket_shutdown(struct socket * sock,int how)4930 static int selinux_socket_shutdown(struct socket *sock, int how)
4931 {
4932 	return sock_has_perm(sock->sk, SOCKET__SHUTDOWN);
4933 }
4934 
selinux_socket_unix_stream_connect(struct sock * sock,struct sock * other,struct sock * newsk)4935 static int selinux_socket_unix_stream_connect(struct sock *sock,
4936 					      struct sock *other,
4937 					      struct sock *newsk)
4938 {
4939 	struct sk_security_struct *sksec_sock = sock->sk_security;
4940 	struct sk_security_struct *sksec_other = other->sk_security;
4941 	struct sk_security_struct *sksec_new = newsk->sk_security;
4942 	struct common_audit_data ad;
4943 	struct lsm_network_audit net = {0,};
4944 	int err;
4945 
4946 	ad.type = LSM_AUDIT_DATA_NET;
4947 	ad.u.net = &net;
4948 	ad.u.net->sk = other;
4949 
4950 	err = avc_has_perm(&selinux_state,
4951 			   sksec_sock->sid, sksec_other->sid,
4952 			   sksec_other->sclass,
4953 			   UNIX_STREAM_SOCKET__CONNECTTO, &ad);
4954 	if (err)
4955 		return err;
4956 
4957 	/* server child socket */
4958 	sksec_new->peer_sid = sksec_sock->sid;
4959 	err = security_sid_mls_copy(&selinux_state, sksec_other->sid,
4960 				    sksec_sock->sid, &sksec_new->sid);
4961 	if (err)
4962 		return err;
4963 
4964 	/* connecting socket */
4965 	sksec_sock->peer_sid = sksec_new->sid;
4966 
4967 	return 0;
4968 }
4969 
selinux_socket_unix_may_send(struct socket * sock,struct socket * other)4970 static int selinux_socket_unix_may_send(struct socket *sock,
4971 					struct socket *other)
4972 {
4973 	struct sk_security_struct *ssec = sock->sk->sk_security;
4974 	struct sk_security_struct *osec = other->sk->sk_security;
4975 	struct common_audit_data ad;
4976 	struct lsm_network_audit net = {0,};
4977 
4978 	ad.type = LSM_AUDIT_DATA_NET;
4979 	ad.u.net = &net;
4980 	ad.u.net->sk = other->sk;
4981 
4982 	return avc_has_perm(&selinux_state,
4983 			    ssec->sid, osec->sid, osec->sclass, SOCKET__SENDTO,
4984 			    &ad);
4985 }
4986 
selinux_inet_sys_rcv_skb(struct net * ns,int ifindex,char * addrp,u16 family,u32 peer_sid,struct common_audit_data * ad)4987 static int selinux_inet_sys_rcv_skb(struct net *ns, int ifindex,
4988 				    char *addrp, u16 family, u32 peer_sid,
4989 				    struct common_audit_data *ad)
4990 {
4991 	int err;
4992 	u32 if_sid;
4993 	u32 node_sid;
4994 
4995 	err = sel_netif_sid(ns, ifindex, &if_sid);
4996 	if (err)
4997 		return err;
4998 	err = avc_has_perm(&selinux_state,
4999 			   peer_sid, if_sid,
5000 			   SECCLASS_NETIF, NETIF__INGRESS, ad);
5001 	if (err)
5002 		return err;
5003 
5004 	err = sel_netnode_sid(addrp, family, &node_sid);
5005 	if (err)
5006 		return err;
5007 	return avc_has_perm(&selinux_state,
5008 			    peer_sid, node_sid,
5009 			    SECCLASS_NODE, NODE__RECVFROM, ad);
5010 }
5011 
selinux_sock_rcv_skb_compat(struct sock * sk,struct sk_buff * skb,u16 family)5012 static int selinux_sock_rcv_skb_compat(struct sock *sk, struct sk_buff *skb,
5013 				       u16 family)
5014 {
5015 	int err = 0;
5016 	struct sk_security_struct *sksec = sk->sk_security;
5017 	u32 sk_sid = sksec->sid;
5018 	struct common_audit_data ad;
5019 	struct lsm_network_audit net = {0,};
5020 	char *addrp;
5021 
5022 	ad.type = LSM_AUDIT_DATA_NET;
5023 	ad.u.net = &net;
5024 	ad.u.net->netif = skb->skb_iif;
5025 	ad.u.net->family = family;
5026 	err = selinux_parse_skb(skb, &ad, &addrp, 1, NULL);
5027 	if (err)
5028 		return err;
5029 
5030 	if (selinux_secmark_enabled()) {
5031 		err = avc_has_perm(&selinux_state,
5032 				   sk_sid, skb->secmark, SECCLASS_PACKET,
5033 				   PACKET__RECV, &ad);
5034 		if (err)
5035 			return err;
5036 	}
5037 
5038 	err = selinux_netlbl_sock_rcv_skb(sksec, skb, family, &ad);
5039 	if (err)
5040 		return err;
5041 	err = selinux_xfrm_sock_rcv_skb(sksec->sid, skb, &ad);
5042 
5043 	return err;
5044 }
5045 
selinux_socket_sock_rcv_skb(struct sock * sk,struct sk_buff * skb)5046 static int selinux_socket_sock_rcv_skb(struct sock *sk, struct sk_buff *skb)
5047 {
5048 	int err;
5049 	struct sk_security_struct *sksec = sk->sk_security;
5050 	u16 family = sk->sk_family;
5051 	u32 sk_sid = sksec->sid;
5052 	struct common_audit_data ad;
5053 	struct lsm_network_audit net = {0,};
5054 	char *addrp;
5055 	u8 secmark_active;
5056 	u8 peerlbl_active;
5057 
5058 	if (family != PF_INET && family != PF_INET6)
5059 		return 0;
5060 
5061 	/* Handle mapped IPv4 packets arriving via IPv6 sockets */
5062 	if (family == PF_INET6 && skb->protocol == htons(ETH_P_IP))
5063 		family = PF_INET;
5064 
5065 	/* If any sort of compatibility mode is enabled then handoff processing
5066 	 * to the selinux_sock_rcv_skb_compat() function to deal with the
5067 	 * special handling.  We do this in an attempt to keep this function
5068 	 * as fast and as clean as possible. */
5069 	if (!selinux_policycap_netpeer())
5070 		return selinux_sock_rcv_skb_compat(sk, skb, family);
5071 
5072 	secmark_active = selinux_secmark_enabled();
5073 	peerlbl_active = selinux_peerlbl_enabled();
5074 	if (!secmark_active && !peerlbl_active)
5075 		return 0;
5076 
5077 	ad.type = LSM_AUDIT_DATA_NET;
5078 	ad.u.net = &net;
5079 	ad.u.net->netif = skb->skb_iif;
5080 	ad.u.net->family = family;
5081 	err = selinux_parse_skb(skb, &ad, &addrp, 1, NULL);
5082 	if (err)
5083 		return err;
5084 
5085 	if (peerlbl_active) {
5086 		u32 peer_sid;
5087 
5088 		err = selinux_skb_peerlbl_sid(skb, family, &peer_sid);
5089 		if (err)
5090 			return err;
5091 		err = selinux_inet_sys_rcv_skb(sock_net(sk), skb->skb_iif,
5092 					       addrp, family, peer_sid, &ad);
5093 		if (err) {
5094 			selinux_netlbl_err(skb, family, err, 0);
5095 			return err;
5096 		}
5097 		err = avc_has_perm(&selinux_state,
5098 				   sk_sid, peer_sid, SECCLASS_PEER,
5099 				   PEER__RECV, &ad);
5100 		if (err) {
5101 			selinux_netlbl_err(skb, family, err, 0);
5102 			return err;
5103 		}
5104 	}
5105 
5106 	if (secmark_active) {
5107 		err = avc_has_perm(&selinux_state,
5108 				   sk_sid, skb->secmark, SECCLASS_PACKET,
5109 				   PACKET__RECV, &ad);
5110 		if (err)
5111 			return err;
5112 	}
5113 
5114 	return err;
5115 }
5116 
selinux_socket_getpeersec_stream(struct socket * sock,char __user * optval,int __user * optlen,unsigned len)5117 static int selinux_socket_getpeersec_stream(struct socket *sock, char __user *optval,
5118 					    int __user *optlen, unsigned len)
5119 {
5120 	int err = 0;
5121 	char *scontext;
5122 	u32 scontext_len;
5123 	struct sk_security_struct *sksec = sock->sk->sk_security;
5124 	u32 peer_sid = SECSID_NULL;
5125 
5126 	if (sksec->sclass == SECCLASS_UNIX_STREAM_SOCKET ||
5127 	    sksec->sclass == SECCLASS_TCP_SOCKET ||
5128 	    sksec->sclass == SECCLASS_SCTP_SOCKET)
5129 		peer_sid = sksec->peer_sid;
5130 	if (peer_sid == SECSID_NULL)
5131 		return -ENOPROTOOPT;
5132 
5133 	err = security_sid_to_context(&selinux_state, peer_sid, &scontext,
5134 				      &scontext_len);
5135 	if (err)
5136 		return err;
5137 
5138 	if (scontext_len > len) {
5139 		err = -ERANGE;
5140 		goto out_len;
5141 	}
5142 
5143 	if (copy_to_user(optval, scontext, scontext_len))
5144 		err = -EFAULT;
5145 
5146 out_len:
5147 	if (put_user(scontext_len, optlen))
5148 		err = -EFAULT;
5149 	kfree(scontext);
5150 	return err;
5151 }
5152 
selinux_socket_getpeersec_dgram(struct socket * sock,struct sk_buff * skb,u32 * secid)5153 static int selinux_socket_getpeersec_dgram(struct socket *sock, struct sk_buff *skb, u32 *secid)
5154 {
5155 	u32 peer_secid = SECSID_NULL;
5156 	u16 family;
5157 	struct inode_security_struct *isec;
5158 
5159 	if (skb && skb->protocol == htons(ETH_P_IP))
5160 		family = PF_INET;
5161 	else if (skb && skb->protocol == htons(ETH_P_IPV6))
5162 		family = PF_INET6;
5163 	else if (sock)
5164 		family = sock->sk->sk_family;
5165 	else
5166 		goto out;
5167 
5168 	if (sock && family == PF_UNIX) {
5169 		isec = inode_security_novalidate(SOCK_INODE(sock));
5170 		peer_secid = isec->sid;
5171 	} else if (skb)
5172 		selinux_skb_peerlbl_sid(skb, family, &peer_secid);
5173 
5174 out:
5175 	*secid = peer_secid;
5176 	if (peer_secid == SECSID_NULL)
5177 		return -EINVAL;
5178 	return 0;
5179 }
5180 
selinux_sk_alloc_security(struct sock * sk,int family,gfp_t priority)5181 static int selinux_sk_alloc_security(struct sock *sk, int family, gfp_t priority)
5182 {
5183 	struct sk_security_struct *sksec;
5184 
5185 	sksec = kzalloc(sizeof(*sksec), priority);
5186 	if (!sksec)
5187 		return -ENOMEM;
5188 
5189 	sksec->peer_sid = SECINITSID_UNLABELED;
5190 	sksec->sid = SECINITSID_UNLABELED;
5191 	sksec->sclass = SECCLASS_SOCKET;
5192 	selinux_netlbl_sk_security_reset(sksec);
5193 	sk->sk_security = sksec;
5194 
5195 	return 0;
5196 }
5197 
selinux_sk_free_security(struct sock * sk)5198 static void selinux_sk_free_security(struct sock *sk)
5199 {
5200 	struct sk_security_struct *sksec = sk->sk_security;
5201 
5202 	sk->sk_security = NULL;
5203 	selinux_netlbl_sk_security_free(sksec);
5204 	kfree(sksec);
5205 }
5206 
selinux_sk_clone_security(const struct sock * sk,struct sock * newsk)5207 static void selinux_sk_clone_security(const struct sock *sk, struct sock *newsk)
5208 {
5209 	struct sk_security_struct *sksec = sk->sk_security;
5210 	struct sk_security_struct *newsksec = newsk->sk_security;
5211 
5212 	newsksec->sid = sksec->sid;
5213 	newsksec->peer_sid = sksec->peer_sid;
5214 	newsksec->sclass = sksec->sclass;
5215 
5216 	selinux_netlbl_sk_security_reset(newsksec);
5217 }
5218 
selinux_sk_getsecid(struct sock * sk,u32 * secid)5219 static void selinux_sk_getsecid(struct sock *sk, u32 *secid)
5220 {
5221 	if (!sk)
5222 		*secid = SECINITSID_ANY_SOCKET;
5223 	else {
5224 		struct sk_security_struct *sksec = sk->sk_security;
5225 
5226 		*secid = sksec->sid;
5227 	}
5228 }
5229 
selinux_sock_graft(struct sock * sk,struct socket * parent)5230 static void selinux_sock_graft(struct sock *sk, struct socket *parent)
5231 {
5232 	struct inode_security_struct *isec =
5233 		inode_security_novalidate(SOCK_INODE(parent));
5234 	struct sk_security_struct *sksec = sk->sk_security;
5235 
5236 	if (sk->sk_family == PF_INET || sk->sk_family == PF_INET6 ||
5237 	    sk->sk_family == PF_UNIX)
5238 		isec->sid = sksec->sid;
5239 	sksec->sclass = isec->sclass;
5240 }
5241 
5242 /*
5243  * Determines peer_secid for the asoc and updates socket's peer label
5244  * if it's the first association on the socket.
5245  */
selinux_sctp_process_new_assoc(struct sctp_association * asoc,struct sk_buff * skb)5246 static int selinux_sctp_process_new_assoc(struct sctp_association *asoc,
5247 					  struct sk_buff *skb)
5248 {
5249 	struct sock *sk = asoc->base.sk;
5250 	u16 family = sk->sk_family;
5251 	struct sk_security_struct *sksec = sk->sk_security;
5252 	struct common_audit_data ad;
5253 	struct lsm_network_audit net = {0,};
5254 	int err;
5255 
5256 	/* handle mapped IPv4 packets arriving via IPv6 sockets */
5257 	if (family == PF_INET6 && skb->protocol == htons(ETH_P_IP))
5258 		family = PF_INET;
5259 
5260 	if (selinux_peerlbl_enabled()) {
5261 		asoc->peer_secid = SECSID_NULL;
5262 
5263 		/* This will return peer_sid = SECSID_NULL if there are
5264 		 * no peer labels, see security_net_peersid_resolve().
5265 		 */
5266 		err = selinux_skb_peerlbl_sid(skb, family, &asoc->peer_secid);
5267 		if (err)
5268 			return err;
5269 
5270 		if (asoc->peer_secid == SECSID_NULL)
5271 			asoc->peer_secid = SECINITSID_UNLABELED;
5272 	} else {
5273 		asoc->peer_secid = SECINITSID_UNLABELED;
5274 	}
5275 
5276 	if (sksec->sctp_assoc_state == SCTP_ASSOC_UNSET) {
5277 		sksec->sctp_assoc_state = SCTP_ASSOC_SET;
5278 
5279 		/* Here as first association on socket. As the peer SID
5280 		 * was allowed by peer recv (and the netif/node checks),
5281 		 * then it is approved by policy and used as the primary
5282 		 * peer SID for getpeercon(3).
5283 		 */
5284 		sksec->peer_sid = asoc->peer_secid;
5285 	} else if (sksec->peer_sid != asoc->peer_secid) {
5286 		/* Other association peer SIDs are checked to enforce
5287 		 * consistency among the peer SIDs.
5288 		 */
5289 		ad.type = LSM_AUDIT_DATA_NET;
5290 		ad.u.net = &net;
5291 		ad.u.net->sk = asoc->base.sk;
5292 		err = avc_has_perm(&selinux_state,
5293 				   sksec->peer_sid, asoc->peer_secid,
5294 				   sksec->sclass, SCTP_SOCKET__ASSOCIATION,
5295 				   &ad);
5296 		if (err)
5297 			return err;
5298 	}
5299 	return 0;
5300 }
5301 
5302 /* Called whenever SCTP receives an INIT or COOKIE ECHO chunk. This
5303  * happens on an incoming connect(2), sctp_connectx(3) or
5304  * sctp_sendmsg(3) (with no association already present).
5305  */
selinux_sctp_assoc_request(struct sctp_association * asoc,struct sk_buff * skb)5306 static int selinux_sctp_assoc_request(struct sctp_association *asoc,
5307 				      struct sk_buff *skb)
5308 {
5309 	struct sk_security_struct *sksec = asoc->base.sk->sk_security;
5310 	u32 conn_sid;
5311 	int err;
5312 
5313 	if (!selinux_policycap_extsockclass())
5314 		return 0;
5315 
5316 	err = selinux_sctp_process_new_assoc(asoc, skb);
5317 	if (err)
5318 		return err;
5319 
5320 	/* Compute the MLS component for the connection and store
5321 	 * the information in asoc. This will be used by SCTP TCP type
5322 	 * sockets and peeled off connections as they cause a new
5323 	 * socket to be generated. selinux_sctp_sk_clone() will then
5324 	 * plug this into the new socket.
5325 	 */
5326 	err = selinux_conn_sid(sksec->sid, asoc->peer_secid, &conn_sid);
5327 	if (err)
5328 		return err;
5329 
5330 	asoc->secid = conn_sid;
5331 
5332 	/* Set any NetLabel labels including CIPSO/CALIPSO options. */
5333 	return selinux_netlbl_sctp_assoc_request(asoc, skb);
5334 }
5335 
5336 /* Called when SCTP receives a COOKIE ACK chunk as the final
5337  * response to an association request (initited by us).
5338  */
selinux_sctp_assoc_established(struct sctp_association * asoc,struct sk_buff * skb)5339 static int selinux_sctp_assoc_established(struct sctp_association *asoc,
5340 					  struct sk_buff *skb)
5341 {
5342 	struct sk_security_struct *sksec = asoc->base.sk->sk_security;
5343 
5344 	if (!selinux_policycap_extsockclass())
5345 		return 0;
5346 
5347 	/* Inherit secid from the parent socket - this will be picked up
5348 	 * by selinux_sctp_sk_clone() if the association gets peeled off
5349 	 * into a new socket.
5350 	 */
5351 	asoc->secid = sksec->sid;
5352 
5353 	return selinux_sctp_process_new_assoc(asoc, skb);
5354 }
5355 
5356 /* Check if sctp IPv4/IPv6 addresses are valid for binding or connecting
5357  * based on their @optname.
5358  */
selinux_sctp_bind_connect(struct sock * sk,int optname,struct sockaddr * address,int addrlen)5359 static int selinux_sctp_bind_connect(struct sock *sk, int optname,
5360 				     struct sockaddr *address,
5361 				     int addrlen)
5362 {
5363 	int len, err = 0, walk_size = 0;
5364 	void *addr_buf;
5365 	struct sockaddr *addr;
5366 	struct socket *sock;
5367 
5368 	if (!selinux_policycap_extsockclass())
5369 		return 0;
5370 
5371 	/* Process one or more addresses that may be IPv4 or IPv6 */
5372 	sock = sk->sk_socket;
5373 	addr_buf = address;
5374 
5375 	while (walk_size < addrlen) {
5376 		if (walk_size + sizeof(sa_family_t) > addrlen)
5377 			return -EINVAL;
5378 
5379 		addr = addr_buf;
5380 		switch (addr->sa_family) {
5381 		case AF_UNSPEC:
5382 		case AF_INET:
5383 			len = sizeof(struct sockaddr_in);
5384 			break;
5385 		case AF_INET6:
5386 			len = sizeof(struct sockaddr_in6);
5387 			break;
5388 		default:
5389 			return -EINVAL;
5390 		}
5391 
5392 		if (walk_size + len > addrlen)
5393 			return -EINVAL;
5394 
5395 		err = -EINVAL;
5396 		switch (optname) {
5397 		/* Bind checks */
5398 		case SCTP_PRIMARY_ADDR:
5399 		case SCTP_SET_PEER_PRIMARY_ADDR:
5400 		case SCTP_SOCKOPT_BINDX_ADD:
5401 			err = selinux_socket_bind(sock, addr, len);
5402 			break;
5403 		/* Connect checks */
5404 		case SCTP_SOCKOPT_CONNECTX:
5405 		case SCTP_PARAM_SET_PRIMARY:
5406 		case SCTP_PARAM_ADD_IP:
5407 		case SCTP_SENDMSG_CONNECT:
5408 			err = selinux_socket_connect_helper(sock, addr, len);
5409 			if (err)
5410 				return err;
5411 
5412 			/* As selinux_sctp_bind_connect() is called by the
5413 			 * SCTP protocol layer, the socket is already locked,
5414 			 * therefore selinux_netlbl_socket_connect_locked()
5415 			 * is called here. The situations handled are:
5416 			 * sctp_connectx(3), sctp_sendmsg(3), sendmsg(2),
5417 			 * whenever a new IP address is added or when a new
5418 			 * primary address is selected.
5419 			 * Note that an SCTP connect(2) call happens before
5420 			 * the SCTP protocol layer and is handled via
5421 			 * selinux_socket_connect().
5422 			 */
5423 			err = selinux_netlbl_socket_connect_locked(sk, addr);
5424 			break;
5425 		}
5426 
5427 		if (err)
5428 			return err;
5429 
5430 		addr_buf += len;
5431 		walk_size += len;
5432 	}
5433 
5434 	return 0;
5435 }
5436 
5437 /* Called whenever a new socket is created by accept(2) or sctp_peeloff(3). */
selinux_sctp_sk_clone(struct sctp_association * asoc,struct sock * sk,struct sock * newsk)5438 static void selinux_sctp_sk_clone(struct sctp_association *asoc, struct sock *sk,
5439 				  struct sock *newsk)
5440 {
5441 	struct sk_security_struct *sksec = sk->sk_security;
5442 	struct sk_security_struct *newsksec = newsk->sk_security;
5443 
5444 	/* If policy does not support SECCLASS_SCTP_SOCKET then call
5445 	 * the non-sctp clone version.
5446 	 */
5447 	if (!selinux_policycap_extsockclass())
5448 		return selinux_sk_clone_security(sk, newsk);
5449 
5450 	newsksec->sid = asoc->secid;
5451 	newsksec->peer_sid = asoc->peer_secid;
5452 	newsksec->sclass = sksec->sclass;
5453 	selinux_netlbl_sctp_sk_clone(sk, newsk);
5454 }
5455 
selinux_inet_conn_request(const struct sock * sk,struct sk_buff * skb,struct request_sock * req)5456 static int selinux_inet_conn_request(const struct sock *sk, struct sk_buff *skb,
5457 				     struct request_sock *req)
5458 {
5459 	struct sk_security_struct *sksec = sk->sk_security;
5460 	int err;
5461 	u16 family = req->rsk_ops->family;
5462 	u32 connsid;
5463 	u32 peersid;
5464 
5465 	err = selinux_skb_peerlbl_sid(skb, family, &peersid);
5466 	if (err)
5467 		return err;
5468 	err = selinux_conn_sid(sksec->sid, peersid, &connsid);
5469 	if (err)
5470 		return err;
5471 	req->secid = connsid;
5472 	req->peer_secid = peersid;
5473 
5474 	return selinux_netlbl_inet_conn_request(req, family);
5475 }
5476 
selinux_inet_csk_clone(struct sock * newsk,const struct request_sock * req)5477 static void selinux_inet_csk_clone(struct sock *newsk,
5478 				   const struct request_sock *req)
5479 {
5480 	struct sk_security_struct *newsksec = newsk->sk_security;
5481 
5482 	newsksec->sid = req->secid;
5483 	newsksec->peer_sid = req->peer_secid;
5484 	/* NOTE: Ideally, we should also get the isec->sid for the
5485 	   new socket in sync, but we don't have the isec available yet.
5486 	   So we will wait until sock_graft to do it, by which
5487 	   time it will have been created and available. */
5488 
5489 	/* We don't need to take any sort of lock here as we are the only
5490 	 * thread with access to newsksec */
5491 	selinux_netlbl_inet_csk_clone(newsk, req->rsk_ops->family);
5492 }
5493 
selinux_inet_conn_established(struct sock * sk,struct sk_buff * skb)5494 static void selinux_inet_conn_established(struct sock *sk, struct sk_buff *skb)
5495 {
5496 	u16 family = sk->sk_family;
5497 	struct sk_security_struct *sksec = sk->sk_security;
5498 
5499 	/* handle mapped IPv4 packets arriving via IPv6 sockets */
5500 	if (family == PF_INET6 && skb->protocol == htons(ETH_P_IP))
5501 		family = PF_INET;
5502 
5503 	selinux_skb_peerlbl_sid(skb, family, &sksec->peer_sid);
5504 }
5505 
selinux_secmark_relabel_packet(u32 sid)5506 static int selinux_secmark_relabel_packet(u32 sid)
5507 {
5508 	const struct task_security_struct *__tsec;
5509 	u32 tsid;
5510 
5511 	__tsec = selinux_cred(current_cred());
5512 	tsid = __tsec->sid;
5513 
5514 	return avc_has_perm(&selinux_state,
5515 			    tsid, sid, SECCLASS_PACKET, PACKET__RELABELTO,
5516 			    NULL);
5517 }
5518 
selinux_secmark_refcount_inc(void)5519 static void selinux_secmark_refcount_inc(void)
5520 {
5521 	atomic_inc(&selinux_secmark_refcount);
5522 }
5523 
selinux_secmark_refcount_dec(void)5524 static void selinux_secmark_refcount_dec(void)
5525 {
5526 	atomic_dec(&selinux_secmark_refcount);
5527 }
5528 
selinux_req_classify_flow(const struct request_sock * req,struct flowi_common * flic)5529 static void selinux_req_classify_flow(const struct request_sock *req,
5530 				      struct flowi_common *flic)
5531 {
5532 	flic->flowic_secid = req->secid;
5533 }
5534 
selinux_tun_dev_alloc_security(void ** security)5535 static int selinux_tun_dev_alloc_security(void **security)
5536 {
5537 	struct tun_security_struct *tunsec;
5538 
5539 	tunsec = kzalloc(sizeof(*tunsec), GFP_KERNEL);
5540 	if (!tunsec)
5541 		return -ENOMEM;
5542 	tunsec->sid = current_sid();
5543 
5544 	*security = tunsec;
5545 	return 0;
5546 }
5547 
selinux_tun_dev_free_security(void * security)5548 static void selinux_tun_dev_free_security(void *security)
5549 {
5550 	kfree(security);
5551 }
5552 
selinux_tun_dev_create(void)5553 static int selinux_tun_dev_create(void)
5554 {
5555 	u32 sid = current_sid();
5556 
5557 	/* we aren't taking into account the "sockcreate" SID since the socket
5558 	 * that is being created here is not a socket in the traditional sense,
5559 	 * instead it is a private sock, accessible only to the kernel, and
5560 	 * representing a wide range of network traffic spanning multiple
5561 	 * connections unlike traditional sockets - check the TUN driver to
5562 	 * get a better understanding of why this socket is special */
5563 
5564 	return avc_has_perm(&selinux_state,
5565 			    sid, sid, SECCLASS_TUN_SOCKET, TUN_SOCKET__CREATE,
5566 			    NULL);
5567 }
5568 
selinux_tun_dev_attach_queue(void * security)5569 static int selinux_tun_dev_attach_queue(void *security)
5570 {
5571 	struct tun_security_struct *tunsec = security;
5572 
5573 	return avc_has_perm(&selinux_state,
5574 			    current_sid(), tunsec->sid, SECCLASS_TUN_SOCKET,
5575 			    TUN_SOCKET__ATTACH_QUEUE, NULL);
5576 }
5577 
selinux_tun_dev_attach(struct sock * sk,void * security)5578 static int selinux_tun_dev_attach(struct sock *sk, void *security)
5579 {
5580 	struct tun_security_struct *tunsec = security;
5581 	struct sk_security_struct *sksec = sk->sk_security;
5582 
5583 	/* we don't currently perform any NetLabel based labeling here and it
5584 	 * isn't clear that we would want to do so anyway; while we could apply
5585 	 * labeling without the support of the TUN user the resulting labeled
5586 	 * traffic from the other end of the connection would almost certainly
5587 	 * cause confusion to the TUN user that had no idea network labeling
5588 	 * protocols were being used */
5589 
5590 	sksec->sid = tunsec->sid;
5591 	sksec->sclass = SECCLASS_TUN_SOCKET;
5592 
5593 	return 0;
5594 }
5595 
selinux_tun_dev_open(void * security)5596 static int selinux_tun_dev_open(void *security)
5597 {
5598 	struct tun_security_struct *tunsec = security;
5599 	u32 sid = current_sid();
5600 	int err;
5601 
5602 	err = avc_has_perm(&selinux_state,
5603 			   sid, tunsec->sid, SECCLASS_TUN_SOCKET,
5604 			   TUN_SOCKET__RELABELFROM, NULL);
5605 	if (err)
5606 		return err;
5607 	err = avc_has_perm(&selinux_state,
5608 			   sid, sid, SECCLASS_TUN_SOCKET,
5609 			   TUN_SOCKET__RELABELTO, NULL);
5610 	if (err)
5611 		return err;
5612 	tunsec->sid = sid;
5613 
5614 	return 0;
5615 }
5616 
5617 #ifdef CONFIG_NETFILTER
5618 
selinux_ip_forward(void * priv,struct sk_buff * skb,const struct nf_hook_state * state)5619 static unsigned int selinux_ip_forward(void *priv, struct sk_buff *skb,
5620 				       const struct nf_hook_state *state)
5621 {
5622 	int ifindex;
5623 	u16 family;
5624 	char *addrp;
5625 	u32 peer_sid;
5626 	struct common_audit_data ad;
5627 	struct lsm_network_audit net = {0,};
5628 	int secmark_active, peerlbl_active;
5629 
5630 	if (!selinux_policycap_netpeer())
5631 		return NF_ACCEPT;
5632 
5633 	secmark_active = selinux_secmark_enabled();
5634 	peerlbl_active = selinux_peerlbl_enabled();
5635 	if (!secmark_active && !peerlbl_active)
5636 		return NF_ACCEPT;
5637 
5638 	family = state->pf;
5639 	if (selinux_skb_peerlbl_sid(skb, family, &peer_sid) != 0)
5640 		return NF_DROP;
5641 
5642 	ifindex = state->in->ifindex;
5643 	ad.type = LSM_AUDIT_DATA_NET;
5644 	ad.u.net = &net;
5645 	ad.u.net->netif = ifindex;
5646 	ad.u.net->family = family;
5647 	if (selinux_parse_skb(skb, &ad, &addrp, 1, NULL) != 0)
5648 		return NF_DROP;
5649 
5650 	if (peerlbl_active) {
5651 		int err;
5652 
5653 		err = selinux_inet_sys_rcv_skb(state->net, ifindex,
5654 					       addrp, family, peer_sid, &ad);
5655 		if (err) {
5656 			selinux_netlbl_err(skb, family, err, 1);
5657 			return NF_DROP;
5658 		}
5659 	}
5660 
5661 	if (secmark_active)
5662 		if (avc_has_perm(&selinux_state,
5663 				 peer_sid, skb->secmark,
5664 				 SECCLASS_PACKET, PACKET__FORWARD_IN, &ad))
5665 			return NF_DROP;
5666 
5667 	if (netlbl_enabled())
5668 		/* we do this in the FORWARD path and not the POST_ROUTING
5669 		 * path because we want to make sure we apply the necessary
5670 		 * labeling before IPsec is applied so we can leverage AH
5671 		 * protection */
5672 		if (selinux_netlbl_skbuff_setsid(skb, family, peer_sid) != 0)
5673 			return NF_DROP;
5674 
5675 	return NF_ACCEPT;
5676 }
5677 
selinux_ip_output(void * priv,struct sk_buff * skb,const struct nf_hook_state * state)5678 static unsigned int selinux_ip_output(void *priv, struct sk_buff *skb,
5679 				      const struct nf_hook_state *state)
5680 {
5681 	struct sock *sk;
5682 	u32 sid;
5683 
5684 	if (!netlbl_enabled())
5685 		return NF_ACCEPT;
5686 
5687 	/* we do this in the LOCAL_OUT path and not the POST_ROUTING path
5688 	 * because we want to make sure we apply the necessary labeling
5689 	 * before IPsec is applied so we can leverage AH protection */
5690 	sk = skb->sk;
5691 	if (sk) {
5692 		struct sk_security_struct *sksec;
5693 
5694 		if (sk_listener(sk))
5695 			/* if the socket is the listening state then this
5696 			 * packet is a SYN-ACK packet which means it needs to
5697 			 * be labeled based on the connection/request_sock and
5698 			 * not the parent socket.  unfortunately, we can't
5699 			 * lookup the request_sock yet as it isn't queued on
5700 			 * the parent socket until after the SYN-ACK is sent.
5701 			 * the "solution" is to simply pass the packet as-is
5702 			 * as any IP option based labeling should be copied
5703 			 * from the initial connection request (in the IP
5704 			 * layer).  it is far from ideal, but until we get a
5705 			 * security label in the packet itself this is the
5706 			 * best we can do. */
5707 			return NF_ACCEPT;
5708 
5709 		/* standard practice, label using the parent socket */
5710 		sksec = sk->sk_security;
5711 		sid = sksec->sid;
5712 	} else
5713 		sid = SECINITSID_KERNEL;
5714 	if (selinux_netlbl_skbuff_setsid(skb, state->pf, sid) != 0)
5715 		return NF_DROP;
5716 
5717 	return NF_ACCEPT;
5718 }
5719 
5720 
selinux_ip_postroute_compat(struct sk_buff * skb,const struct nf_hook_state * state)5721 static unsigned int selinux_ip_postroute_compat(struct sk_buff *skb,
5722 					const struct nf_hook_state *state)
5723 {
5724 	struct sock *sk;
5725 	struct sk_security_struct *sksec;
5726 	struct common_audit_data ad;
5727 	struct lsm_network_audit net = {0,};
5728 	u8 proto = 0;
5729 
5730 	sk = skb_to_full_sk(skb);
5731 	if (sk == NULL)
5732 		return NF_ACCEPT;
5733 	sksec = sk->sk_security;
5734 
5735 	ad.type = LSM_AUDIT_DATA_NET;
5736 	ad.u.net = &net;
5737 	ad.u.net->netif = state->out->ifindex;
5738 	ad.u.net->family = state->pf;
5739 	if (selinux_parse_skb(skb, &ad, NULL, 0, &proto))
5740 		return NF_DROP;
5741 
5742 	if (selinux_secmark_enabled())
5743 		if (avc_has_perm(&selinux_state,
5744 				 sksec->sid, skb->secmark,
5745 				 SECCLASS_PACKET, PACKET__SEND, &ad))
5746 			return NF_DROP_ERR(-ECONNREFUSED);
5747 
5748 	if (selinux_xfrm_postroute_last(sksec->sid, skb, &ad, proto))
5749 		return NF_DROP_ERR(-ECONNREFUSED);
5750 
5751 	return NF_ACCEPT;
5752 }
5753 
selinux_ip_postroute(void * priv,struct sk_buff * skb,const struct nf_hook_state * state)5754 static unsigned int selinux_ip_postroute(void *priv,
5755 					 struct sk_buff *skb,
5756 					 const struct nf_hook_state *state)
5757 {
5758 	u16 family;
5759 	u32 secmark_perm;
5760 	u32 peer_sid;
5761 	int ifindex;
5762 	struct sock *sk;
5763 	struct common_audit_data ad;
5764 	struct lsm_network_audit net = {0,};
5765 	char *addrp;
5766 	int secmark_active, peerlbl_active;
5767 
5768 	/* If any sort of compatibility mode is enabled then handoff processing
5769 	 * to the selinux_ip_postroute_compat() function to deal with the
5770 	 * special handling.  We do this in an attempt to keep this function
5771 	 * as fast and as clean as possible. */
5772 	if (!selinux_policycap_netpeer())
5773 		return selinux_ip_postroute_compat(skb, state);
5774 
5775 	secmark_active = selinux_secmark_enabled();
5776 	peerlbl_active = selinux_peerlbl_enabled();
5777 	if (!secmark_active && !peerlbl_active)
5778 		return NF_ACCEPT;
5779 
5780 	sk = skb_to_full_sk(skb);
5781 
5782 #ifdef CONFIG_XFRM
5783 	/* If skb->dst->xfrm is non-NULL then the packet is undergoing an IPsec
5784 	 * packet transformation so allow the packet to pass without any checks
5785 	 * since we'll have another chance to perform access control checks
5786 	 * when the packet is on it's final way out.
5787 	 * NOTE: there appear to be some IPv6 multicast cases where skb->dst
5788 	 *       is NULL, in this case go ahead and apply access control.
5789 	 * NOTE: if this is a local socket (skb->sk != NULL) that is in the
5790 	 *       TCP listening state we cannot wait until the XFRM processing
5791 	 *       is done as we will miss out on the SA label if we do;
5792 	 *       unfortunately, this means more work, but it is only once per
5793 	 *       connection. */
5794 	if (skb_dst(skb) != NULL && skb_dst(skb)->xfrm != NULL &&
5795 	    !(sk && sk_listener(sk)))
5796 		return NF_ACCEPT;
5797 #endif
5798 
5799 	family = state->pf;
5800 	if (sk == NULL) {
5801 		/* Without an associated socket the packet is either coming
5802 		 * from the kernel or it is being forwarded; check the packet
5803 		 * to determine which and if the packet is being forwarded
5804 		 * query the packet directly to determine the security label. */
5805 		if (skb->skb_iif) {
5806 			secmark_perm = PACKET__FORWARD_OUT;
5807 			if (selinux_skb_peerlbl_sid(skb, family, &peer_sid))
5808 				return NF_DROP;
5809 		} else {
5810 			secmark_perm = PACKET__SEND;
5811 			peer_sid = SECINITSID_KERNEL;
5812 		}
5813 	} else if (sk_listener(sk)) {
5814 		/* Locally generated packet but the associated socket is in the
5815 		 * listening state which means this is a SYN-ACK packet.  In
5816 		 * this particular case the correct security label is assigned
5817 		 * to the connection/request_sock but unfortunately we can't
5818 		 * query the request_sock as it isn't queued on the parent
5819 		 * socket until after the SYN-ACK packet is sent; the only
5820 		 * viable choice is to regenerate the label like we do in
5821 		 * selinux_inet_conn_request().  See also selinux_ip_output()
5822 		 * for similar problems. */
5823 		u32 skb_sid;
5824 		struct sk_security_struct *sksec;
5825 
5826 		sksec = sk->sk_security;
5827 		if (selinux_skb_peerlbl_sid(skb, family, &skb_sid))
5828 			return NF_DROP;
5829 		/* At this point, if the returned skb peerlbl is SECSID_NULL
5830 		 * and the packet has been through at least one XFRM
5831 		 * transformation then we must be dealing with the "final"
5832 		 * form of labeled IPsec packet; since we've already applied
5833 		 * all of our access controls on this packet we can safely
5834 		 * pass the packet. */
5835 		if (skb_sid == SECSID_NULL) {
5836 			switch (family) {
5837 			case PF_INET:
5838 				if (IPCB(skb)->flags & IPSKB_XFRM_TRANSFORMED)
5839 					return NF_ACCEPT;
5840 				break;
5841 			case PF_INET6:
5842 				if (IP6CB(skb)->flags & IP6SKB_XFRM_TRANSFORMED)
5843 					return NF_ACCEPT;
5844 				break;
5845 			default:
5846 				return NF_DROP_ERR(-ECONNREFUSED);
5847 			}
5848 		}
5849 		if (selinux_conn_sid(sksec->sid, skb_sid, &peer_sid))
5850 			return NF_DROP;
5851 		secmark_perm = PACKET__SEND;
5852 	} else {
5853 		/* Locally generated packet, fetch the security label from the
5854 		 * associated socket. */
5855 		struct sk_security_struct *sksec = sk->sk_security;
5856 		peer_sid = sksec->sid;
5857 		secmark_perm = PACKET__SEND;
5858 	}
5859 
5860 	ifindex = state->out->ifindex;
5861 	ad.type = LSM_AUDIT_DATA_NET;
5862 	ad.u.net = &net;
5863 	ad.u.net->netif = ifindex;
5864 	ad.u.net->family = family;
5865 	if (selinux_parse_skb(skb, &ad, &addrp, 0, NULL))
5866 		return NF_DROP;
5867 
5868 	if (secmark_active)
5869 		if (avc_has_perm(&selinux_state,
5870 				 peer_sid, skb->secmark,
5871 				 SECCLASS_PACKET, secmark_perm, &ad))
5872 			return NF_DROP_ERR(-ECONNREFUSED);
5873 
5874 	if (peerlbl_active) {
5875 		u32 if_sid;
5876 		u32 node_sid;
5877 
5878 		if (sel_netif_sid(state->net, ifindex, &if_sid))
5879 			return NF_DROP;
5880 		if (avc_has_perm(&selinux_state,
5881 				 peer_sid, if_sid,
5882 				 SECCLASS_NETIF, NETIF__EGRESS, &ad))
5883 			return NF_DROP_ERR(-ECONNREFUSED);
5884 
5885 		if (sel_netnode_sid(addrp, family, &node_sid))
5886 			return NF_DROP;
5887 		if (avc_has_perm(&selinux_state,
5888 				 peer_sid, node_sid,
5889 				 SECCLASS_NODE, NODE__SENDTO, &ad))
5890 			return NF_DROP_ERR(-ECONNREFUSED);
5891 	}
5892 
5893 	return NF_ACCEPT;
5894 }
5895 #endif	/* CONFIG_NETFILTER */
5896 
selinux_netlink_send(struct sock * sk,struct sk_buff * skb)5897 static int selinux_netlink_send(struct sock *sk, struct sk_buff *skb)
5898 {
5899 	int rc = 0;
5900 	unsigned int msg_len;
5901 	unsigned int data_len = skb->len;
5902 	unsigned char *data = skb->data;
5903 	struct nlmsghdr *nlh;
5904 	struct sk_security_struct *sksec = sk->sk_security;
5905 	u16 sclass = sksec->sclass;
5906 	u32 perm;
5907 
5908 	while (data_len >= nlmsg_total_size(0)) {
5909 		nlh = (struct nlmsghdr *)data;
5910 
5911 		/* NOTE: the nlmsg_len field isn't reliably set by some netlink
5912 		 *       users which means we can't reject skb's with bogus
5913 		 *       length fields; our solution is to follow what
5914 		 *       netlink_rcv_skb() does and simply skip processing at
5915 		 *       messages with length fields that are clearly junk
5916 		 */
5917 		if (nlh->nlmsg_len < NLMSG_HDRLEN || nlh->nlmsg_len > data_len)
5918 			return 0;
5919 
5920 		rc = selinux_nlmsg_lookup(sclass, nlh->nlmsg_type, &perm);
5921 		if (rc == 0) {
5922 			rc = sock_has_perm(sk, perm);
5923 			if (rc)
5924 				return rc;
5925 		} else if (rc == -EINVAL) {
5926 			/* -EINVAL is a missing msg/perm mapping */
5927 			pr_warn_ratelimited("SELinux: unrecognized netlink"
5928 				" message: protocol=%hu nlmsg_type=%hu sclass=%s"
5929 				" pid=%d comm=%s\n",
5930 				sk->sk_protocol, nlh->nlmsg_type,
5931 				secclass_map[sclass - 1].name,
5932 				task_pid_nr(current), current->comm);
5933 			if (enforcing_enabled(&selinux_state) &&
5934 			    !security_get_allow_unknown(&selinux_state))
5935 				return rc;
5936 			rc = 0;
5937 		} else if (rc == -ENOENT) {
5938 			/* -ENOENT is a missing socket/class mapping, ignore */
5939 			rc = 0;
5940 		} else {
5941 			return rc;
5942 		}
5943 
5944 		/* move to the next message after applying netlink padding */
5945 		msg_len = NLMSG_ALIGN(nlh->nlmsg_len);
5946 		if (msg_len >= data_len)
5947 			return 0;
5948 		data_len -= msg_len;
5949 		data += msg_len;
5950 	}
5951 
5952 	return rc;
5953 }
5954 
ipc_init_security(struct ipc_security_struct * isec,u16 sclass)5955 static void ipc_init_security(struct ipc_security_struct *isec, u16 sclass)
5956 {
5957 	isec->sclass = sclass;
5958 	isec->sid = current_sid();
5959 }
5960 
ipc_has_perm(struct kern_ipc_perm * ipc_perms,u32 perms)5961 static int ipc_has_perm(struct kern_ipc_perm *ipc_perms,
5962 			u32 perms)
5963 {
5964 	struct ipc_security_struct *isec;
5965 	struct common_audit_data ad;
5966 	u32 sid = current_sid();
5967 
5968 	isec = selinux_ipc(ipc_perms);
5969 
5970 	ad.type = LSM_AUDIT_DATA_IPC;
5971 	ad.u.ipc_id = ipc_perms->key;
5972 
5973 	return avc_has_perm(&selinux_state,
5974 			    sid, isec->sid, isec->sclass, perms, &ad);
5975 }
5976 
selinux_msg_msg_alloc_security(struct msg_msg * msg)5977 static int selinux_msg_msg_alloc_security(struct msg_msg *msg)
5978 {
5979 	struct msg_security_struct *msec;
5980 
5981 	msec = selinux_msg_msg(msg);
5982 	msec->sid = SECINITSID_UNLABELED;
5983 
5984 	return 0;
5985 }
5986 
5987 /* message queue security operations */
selinux_msg_queue_alloc_security(struct kern_ipc_perm * msq)5988 static int selinux_msg_queue_alloc_security(struct kern_ipc_perm *msq)
5989 {
5990 	struct ipc_security_struct *isec;
5991 	struct common_audit_data ad;
5992 	u32 sid = current_sid();
5993 	int rc;
5994 
5995 	isec = selinux_ipc(msq);
5996 	ipc_init_security(isec, SECCLASS_MSGQ);
5997 
5998 	ad.type = LSM_AUDIT_DATA_IPC;
5999 	ad.u.ipc_id = msq->key;
6000 
6001 	rc = avc_has_perm(&selinux_state,
6002 			  sid, isec->sid, SECCLASS_MSGQ,
6003 			  MSGQ__CREATE, &ad);
6004 	return rc;
6005 }
6006 
selinux_msg_queue_associate(struct kern_ipc_perm * msq,int msqflg)6007 static int selinux_msg_queue_associate(struct kern_ipc_perm *msq, int msqflg)
6008 {
6009 	struct ipc_security_struct *isec;
6010 	struct common_audit_data ad;
6011 	u32 sid = current_sid();
6012 
6013 	isec = selinux_ipc(msq);
6014 
6015 	ad.type = LSM_AUDIT_DATA_IPC;
6016 	ad.u.ipc_id = msq->key;
6017 
6018 	return avc_has_perm(&selinux_state,
6019 			    sid, isec->sid, SECCLASS_MSGQ,
6020 			    MSGQ__ASSOCIATE, &ad);
6021 }
6022 
selinux_msg_queue_msgctl(struct kern_ipc_perm * msq,int cmd)6023 static int selinux_msg_queue_msgctl(struct kern_ipc_perm *msq, int cmd)
6024 {
6025 	int err;
6026 	int perms;
6027 
6028 	switch (cmd) {
6029 	case IPC_INFO:
6030 	case MSG_INFO:
6031 		/* No specific object, just general system-wide information. */
6032 		return avc_has_perm(&selinux_state,
6033 				    current_sid(), SECINITSID_KERNEL,
6034 				    SECCLASS_SYSTEM, SYSTEM__IPC_INFO, NULL);
6035 	case IPC_STAT:
6036 	case MSG_STAT:
6037 	case MSG_STAT_ANY:
6038 		perms = MSGQ__GETATTR | MSGQ__ASSOCIATE;
6039 		break;
6040 	case IPC_SET:
6041 		perms = MSGQ__SETATTR;
6042 		break;
6043 	case IPC_RMID:
6044 		perms = MSGQ__DESTROY;
6045 		break;
6046 	default:
6047 		return 0;
6048 	}
6049 
6050 	err = ipc_has_perm(msq, perms);
6051 	return err;
6052 }
6053 
selinux_msg_queue_msgsnd(struct kern_ipc_perm * msq,struct msg_msg * msg,int msqflg)6054 static int selinux_msg_queue_msgsnd(struct kern_ipc_perm *msq, struct msg_msg *msg, int msqflg)
6055 {
6056 	struct ipc_security_struct *isec;
6057 	struct msg_security_struct *msec;
6058 	struct common_audit_data ad;
6059 	u32 sid = current_sid();
6060 	int rc;
6061 
6062 	isec = selinux_ipc(msq);
6063 	msec = selinux_msg_msg(msg);
6064 
6065 	/*
6066 	 * First time through, need to assign label to the message
6067 	 */
6068 	if (msec->sid == SECINITSID_UNLABELED) {
6069 		/*
6070 		 * Compute new sid based on current process and
6071 		 * message queue this message will be stored in
6072 		 */
6073 		rc = security_transition_sid(&selinux_state, sid, isec->sid,
6074 					     SECCLASS_MSG, NULL, &msec->sid);
6075 		if (rc)
6076 			return rc;
6077 	}
6078 
6079 	ad.type = LSM_AUDIT_DATA_IPC;
6080 	ad.u.ipc_id = msq->key;
6081 
6082 	/* Can this process write to the queue? */
6083 	rc = avc_has_perm(&selinux_state,
6084 			  sid, isec->sid, SECCLASS_MSGQ,
6085 			  MSGQ__WRITE, &ad);
6086 	if (!rc)
6087 		/* Can this process send the message */
6088 		rc = avc_has_perm(&selinux_state,
6089 				  sid, msec->sid, SECCLASS_MSG,
6090 				  MSG__SEND, &ad);
6091 	if (!rc)
6092 		/* Can the message be put in the queue? */
6093 		rc = avc_has_perm(&selinux_state,
6094 				  msec->sid, isec->sid, SECCLASS_MSGQ,
6095 				  MSGQ__ENQUEUE, &ad);
6096 
6097 	return rc;
6098 }
6099 
selinux_msg_queue_msgrcv(struct kern_ipc_perm * msq,struct msg_msg * msg,struct task_struct * target,long type,int mode)6100 static int selinux_msg_queue_msgrcv(struct kern_ipc_perm *msq, struct msg_msg *msg,
6101 				    struct task_struct *target,
6102 				    long type, int mode)
6103 {
6104 	struct ipc_security_struct *isec;
6105 	struct msg_security_struct *msec;
6106 	struct common_audit_data ad;
6107 	u32 sid = task_sid_obj(target);
6108 	int rc;
6109 
6110 	isec = selinux_ipc(msq);
6111 	msec = selinux_msg_msg(msg);
6112 
6113 	ad.type = LSM_AUDIT_DATA_IPC;
6114 	ad.u.ipc_id = msq->key;
6115 
6116 	rc = avc_has_perm(&selinux_state,
6117 			  sid, isec->sid,
6118 			  SECCLASS_MSGQ, MSGQ__READ, &ad);
6119 	if (!rc)
6120 		rc = avc_has_perm(&selinux_state,
6121 				  sid, msec->sid,
6122 				  SECCLASS_MSG, MSG__RECEIVE, &ad);
6123 	return rc;
6124 }
6125 
6126 /* Shared Memory security operations */
selinux_shm_alloc_security(struct kern_ipc_perm * shp)6127 static int selinux_shm_alloc_security(struct kern_ipc_perm *shp)
6128 {
6129 	struct ipc_security_struct *isec;
6130 	struct common_audit_data ad;
6131 	u32 sid = current_sid();
6132 	int rc;
6133 
6134 	isec = selinux_ipc(shp);
6135 	ipc_init_security(isec, SECCLASS_SHM);
6136 
6137 	ad.type = LSM_AUDIT_DATA_IPC;
6138 	ad.u.ipc_id = shp->key;
6139 
6140 	rc = avc_has_perm(&selinux_state,
6141 			  sid, isec->sid, SECCLASS_SHM,
6142 			  SHM__CREATE, &ad);
6143 	return rc;
6144 }
6145 
selinux_shm_associate(struct kern_ipc_perm * shp,int shmflg)6146 static int selinux_shm_associate(struct kern_ipc_perm *shp, int shmflg)
6147 {
6148 	struct ipc_security_struct *isec;
6149 	struct common_audit_data ad;
6150 	u32 sid = current_sid();
6151 
6152 	isec = selinux_ipc(shp);
6153 
6154 	ad.type = LSM_AUDIT_DATA_IPC;
6155 	ad.u.ipc_id = shp->key;
6156 
6157 	return avc_has_perm(&selinux_state,
6158 			    sid, isec->sid, SECCLASS_SHM,
6159 			    SHM__ASSOCIATE, &ad);
6160 }
6161 
6162 /* Note, at this point, shp is locked down */
selinux_shm_shmctl(struct kern_ipc_perm * shp,int cmd)6163 static int selinux_shm_shmctl(struct kern_ipc_perm *shp, int cmd)
6164 {
6165 	int perms;
6166 	int err;
6167 
6168 	switch (cmd) {
6169 	case IPC_INFO:
6170 	case SHM_INFO:
6171 		/* No specific object, just general system-wide information. */
6172 		return avc_has_perm(&selinux_state,
6173 				    current_sid(), SECINITSID_KERNEL,
6174 				    SECCLASS_SYSTEM, SYSTEM__IPC_INFO, NULL);
6175 	case IPC_STAT:
6176 	case SHM_STAT:
6177 	case SHM_STAT_ANY:
6178 		perms = SHM__GETATTR | SHM__ASSOCIATE;
6179 		break;
6180 	case IPC_SET:
6181 		perms = SHM__SETATTR;
6182 		break;
6183 	case SHM_LOCK:
6184 	case SHM_UNLOCK:
6185 		perms = SHM__LOCK;
6186 		break;
6187 	case IPC_RMID:
6188 		perms = SHM__DESTROY;
6189 		break;
6190 	default:
6191 		return 0;
6192 	}
6193 
6194 	err = ipc_has_perm(shp, perms);
6195 	return err;
6196 }
6197 
selinux_shm_shmat(struct kern_ipc_perm * shp,char __user * shmaddr,int shmflg)6198 static int selinux_shm_shmat(struct kern_ipc_perm *shp,
6199 			     char __user *shmaddr, int shmflg)
6200 {
6201 	u32 perms;
6202 
6203 	if (shmflg & SHM_RDONLY)
6204 		perms = SHM__READ;
6205 	else
6206 		perms = SHM__READ | SHM__WRITE;
6207 
6208 	return ipc_has_perm(shp, perms);
6209 }
6210 
6211 /* Semaphore security operations */
selinux_sem_alloc_security(struct kern_ipc_perm * sma)6212 static int selinux_sem_alloc_security(struct kern_ipc_perm *sma)
6213 {
6214 	struct ipc_security_struct *isec;
6215 	struct common_audit_data ad;
6216 	u32 sid = current_sid();
6217 	int rc;
6218 
6219 	isec = selinux_ipc(sma);
6220 	ipc_init_security(isec, SECCLASS_SEM);
6221 
6222 	ad.type = LSM_AUDIT_DATA_IPC;
6223 	ad.u.ipc_id = sma->key;
6224 
6225 	rc = avc_has_perm(&selinux_state,
6226 			  sid, isec->sid, SECCLASS_SEM,
6227 			  SEM__CREATE, &ad);
6228 	return rc;
6229 }
6230 
selinux_sem_associate(struct kern_ipc_perm * sma,int semflg)6231 static int selinux_sem_associate(struct kern_ipc_perm *sma, int semflg)
6232 {
6233 	struct ipc_security_struct *isec;
6234 	struct common_audit_data ad;
6235 	u32 sid = current_sid();
6236 
6237 	isec = selinux_ipc(sma);
6238 
6239 	ad.type = LSM_AUDIT_DATA_IPC;
6240 	ad.u.ipc_id = sma->key;
6241 
6242 	return avc_has_perm(&selinux_state,
6243 			    sid, isec->sid, SECCLASS_SEM,
6244 			    SEM__ASSOCIATE, &ad);
6245 }
6246 
6247 /* Note, at this point, sma is locked down */
selinux_sem_semctl(struct kern_ipc_perm * sma,int cmd)6248 static int selinux_sem_semctl(struct kern_ipc_perm *sma, int cmd)
6249 {
6250 	int err;
6251 	u32 perms;
6252 
6253 	switch (cmd) {
6254 	case IPC_INFO:
6255 	case SEM_INFO:
6256 		/* No specific object, just general system-wide information. */
6257 		return avc_has_perm(&selinux_state,
6258 				    current_sid(), SECINITSID_KERNEL,
6259 				    SECCLASS_SYSTEM, SYSTEM__IPC_INFO, NULL);
6260 	case GETPID:
6261 	case GETNCNT:
6262 	case GETZCNT:
6263 		perms = SEM__GETATTR;
6264 		break;
6265 	case GETVAL:
6266 	case GETALL:
6267 		perms = SEM__READ;
6268 		break;
6269 	case SETVAL:
6270 	case SETALL:
6271 		perms = SEM__WRITE;
6272 		break;
6273 	case IPC_RMID:
6274 		perms = SEM__DESTROY;
6275 		break;
6276 	case IPC_SET:
6277 		perms = SEM__SETATTR;
6278 		break;
6279 	case IPC_STAT:
6280 	case SEM_STAT:
6281 	case SEM_STAT_ANY:
6282 		perms = SEM__GETATTR | SEM__ASSOCIATE;
6283 		break;
6284 	default:
6285 		return 0;
6286 	}
6287 
6288 	err = ipc_has_perm(sma, perms);
6289 	return err;
6290 }
6291 
selinux_sem_semop(struct kern_ipc_perm * sma,struct sembuf * sops,unsigned nsops,int alter)6292 static int selinux_sem_semop(struct kern_ipc_perm *sma,
6293 			     struct sembuf *sops, unsigned nsops, int alter)
6294 {
6295 	u32 perms;
6296 
6297 	if (alter)
6298 		perms = SEM__READ | SEM__WRITE;
6299 	else
6300 		perms = SEM__READ;
6301 
6302 	return ipc_has_perm(sma, perms);
6303 }
6304 
selinux_ipc_permission(struct kern_ipc_perm * ipcp,short flag)6305 static int selinux_ipc_permission(struct kern_ipc_perm *ipcp, short flag)
6306 {
6307 	u32 av = 0;
6308 
6309 	av = 0;
6310 	if (flag & S_IRUGO)
6311 		av |= IPC__UNIX_READ;
6312 	if (flag & S_IWUGO)
6313 		av |= IPC__UNIX_WRITE;
6314 
6315 	if (av == 0)
6316 		return 0;
6317 
6318 	return ipc_has_perm(ipcp, av);
6319 }
6320 
selinux_ipc_getsecid(struct kern_ipc_perm * ipcp,u32 * secid)6321 static void selinux_ipc_getsecid(struct kern_ipc_perm *ipcp, u32 *secid)
6322 {
6323 	struct ipc_security_struct *isec = selinux_ipc(ipcp);
6324 	*secid = isec->sid;
6325 }
6326 
selinux_d_instantiate(struct dentry * dentry,struct inode * inode)6327 static void selinux_d_instantiate(struct dentry *dentry, struct inode *inode)
6328 {
6329 	if (inode)
6330 		inode_doinit_with_dentry(inode, dentry);
6331 }
6332 
selinux_getprocattr(struct task_struct * p,char * name,char ** value)6333 static int selinux_getprocattr(struct task_struct *p,
6334 			       char *name, char **value)
6335 {
6336 	const struct task_security_struct *__tsec;
6337 	u32 sid;
6338 	int error;
6339 	unsigned len;
6340 
6341 	rcu_read_lock();
6342 	__tsec = selinux_cred(__task_cred(p));
6343 
6344 	if (current != p) {
6345 		error = avc_has_perm(&selinux_state,
6346 				     current_sid(), __tsec->sid,
6347 				     SECCLASS_PROCESS, PROCESS__GETATTR, NULL);
6348 		if (error)
6349 			goto bad;
6350 	}
6351 
6352 	if (!strcmp(name, "current"))
6353 		sid = __tsec->sid;
6354 	else if (!strcmp(name, "prev"))
6355 		sid = __tsec->osid;
6356 	else if (!strcmp(name, "exec"))
6357 		sid = __tsec->exec_sid;
6358 	else if (!strcmp(name, "fscreate"))
6359 		sid = __tsec->create_sid;
6360 	else if (!strcmp(name, "keycreate"))
6361 		sid = __tsec->keycreate_sid;
6362 	else if (!strcmp(name, "sockcreate"))
6363 		sid = __tsec->sockcreate_sid;
6364 	else {
6365 		error = -EINVAL;
6366 		goto bad;
6367 	}
6368 	rcu_read_unlock();
6369 
6370 	if (!sid)
6371 		return 0;
6372 
6373 	error = security_sid_to_context(&selinux_state, sid, value, &len);
6374 	if (error)
6375 		return error;
6376 	return len;
6377 
6378 bad:
6379 	rcu_read_unlock();
6380 	return error;
6381 }
6382 
selinux_setprocattr(const char * name,void * value,size_t size)6383 static int selinux_setprocattr(const char *name, void *value, size_t size)
6384 {
6385 	struct task_security_struct *tsec;
6386 	struct cred *new;
6387 	u32 mysid = current_sid(), sid = 0, ptsid;
6388 	int error;
6389 	char *str = value;
6390 
6391 	/*
6392 	 * Basic control over ability to set these attributes at all.
6393 	 */
6394 	if (!strcmp(name, "exec"))
6395 		error = avc_has_perm(&selinux_state,
6396 				     mysid, mysid, SECCLASS_PROCESS,
6397 				     PROCESS__SETEXEC, NULL);
6398 	else if (!strcmp(name, "fscreate"))
6399 		error = avc_has_perm(&selinux_state,
6400 				     mysid, mysid, SECCLASS_PROCESS,
6401 				     PROCESS__SETFSCREATE, NULL);
6402 	else if (!strcmp(name, "keycreate"))
6403 		error = avc_has_perm(&selinux_state,
6404 				     mysid, mysid, SECCLASS_PROCESS,
6405 				     PROCESS__SETKEYCREATE, NULL);
6406 	else if (!strcmp(name, "sockcreate"))
6407 		error = avc_has_perm(&selinux_state,
6408 				     mysid, mysid, SECCLASS_PROCESS,
6409 				     PROCESS__SETSOCKCREATE, NULL);
6410 	else if (!strcmp(name, "current"))
6411 		error = avc_has_perm(&selinux_state,
6412 				     mysid, mysid, SECCLASS_PROCESS,
6413 				     PROCESS__SETCURRENT, NULL);
6414 	else
6415 		error = -EINVAL;
6416 	if (error)
6417 		return error;
6418 
6419 	/* Obtain a SID for the context, if one was specified. */
6420 	if (size && str[0] && str[0] != '\n') {
6421 		if (str[size-1] == '\n') {
6422 			str[size-1] = 0;
6423 			size--;
6424 		}
6425 		error = security_context_to_sid(&selinux_state, value, size,
6426 						&sid, GFP_KERNEL);
6427 		if (error == -EINVAL && !strcmp(name, "fscreate")) {
6428 			if (!has_cap_mac_admin(true)) {
6429 				struct audit_buffer *ab;
6430 				size_t audit_size;
6431 
6432 				/* We strip a nul only if it is at the end, otherwise the
6433 				 * context contains a nul and we should audit that */
6434 				if (str[size - 1] == '\0')
6435 					audit_size = size - 1;
6436 				else
6437 					audit_size = size;
6438 				ab = audit_log_start(audit_context(),
6439 						     GFP_ATOMIC,
6440 						     AUDIT_SELINUX_ERR);
6441 				if (!ab)
6442 					return error;
6443 				audit_log_format(ab, "op=fscreate invalid_context=");
6444 				audit_log_n_untrustedstring(ab, value, audit_size);
6445 				audit_log_end(ab);
6446 
6447 				return error;
6448 			}
6449 			error = security_context_to_sid_force(
6450 						      &selinux_state,
6451 						      value, size, &sid);
6452 		}
6453 		if (error)
6454 			return error;
6455 	}
6456 
6457 	new = prepare_creds();
6458 	if (!new)
6459 		return -ENOMEM;
6460 
6461 	/* Permission checking based on the specified context is
6462 	   performed during the actual operation (execve,
6463 	   open/mkdir/...), when we know the full context of the
6464 	   operation.  See selinux_bprm_creds_for_exec for the execve
6465 	   checks and may_create for the file creation checks. The
6466 	   operation will then fail if the context is not permitted. */
6467 	tsec = selinux_cred(new);
6468 	if (!strcmp(name, "exec")) {
6469 		tsec->exec_sid = sid;
6470 	} else if (!strcmp(name, "fscreate")) {
6471 		tsec->create_sid = sid;
6472 	} else if (!strcmp(name, "keycreate")) {
6473 		if (sid) {
6474 			error = avc_has_perm(&selinux_state, mysid, sid,
6475 					     SECCLASS_KEY, KEY__CREATE, NULL);
6476 			if (error)
6477 				goto abort_change;
6478 		}
6479 		tsec->keycreate_sid = sid;
6480 	} else if (!strcmp(name, "sockcreate")) {
6481 		tsec->sockcreate_sid = sid;
6482 	} else if (!strcmp(name, "current")) {
6483 		error = -EINVAL;
6484 		if (sid == 0)
6485 			goto abort_change;
6486 
6487 		/* Only allow single threaded processes to change context */
6488 		if (!current_is_single_threaded()) {
6489 			error = security_bounded_transition(&selinux_state,
6490 							    tsec->sid, sid);
6491 			if (error)
6492 				goto abort_change;
6493 		}
6494 
6495 		/* Check permissions for the transition. */
6496 		error = avc_has_perm(&selinux_state,
6497 				     tsec->sid, sid, SECCLASS_PROCESS,
6498 				     PROCESS__DYNTRANSITION, NULL);
6499 		if (error)
6500 			goto abort_change;
6501 
6502 		/* Check for ptracing, and update the task SID if ok.
6503 		   Otherwise, leave SID unchanged and fail. */
6504 		ptsid = ptrace_parent_sid();
6505 		if (ptsid != 0) {
6506 			error = avc_has_perm(&selinux_state,
6507 					     ptsid, sid, SECCLASS_PROCESS,
6508 					     PROCESS__PTRACE, NULL);
6509 			if (error)
6510 				goto abort_change;
6511 		}
6512 
6513 		tsec->sid = sid;
6514 	} else {
6515 		error = -EINVAL;
6516 		goto abort_change;
6517 	}
6518 
6519 	commit_creds(new);
6520 	return size;
6521 
6522 abort_change:
6523 	abort_creds(new);
6524 	return error;
6525 }
6526 
selinux_ismaclabel(const char * name)6527 static int selinux_ismaclabel(const char *name)
6528 {
6529 	return (strcmp(name, XATTR_SELINUX_SUFFIX) == 0);
6530 }
6531 
selinux_secid_to_secctx(u32 secid,char ** secdata,u32 * seclen)6532 static int selinux_secid_to_secctx(u32 secid, char **secdata, u32 *seclen)
6533 {
6534 	return security_sid_to_context(&selinux_state, secid,
6535 				       secdata, seclen);
6536 }
6537 
selinux_secctx_to_secid(const char * secdata,u32 seclen,u32 * secid)6538 static int selinux_secctx_to_secid(const char *secdata, u32 seclen, u32 *secid)
6539 {
6540 	return security_context_to_sid(&selinux_state, secdata, seclen,
6541 				       secid, GFP_KERNEL);
6542 }
6543 
selinux_release_secctx(char * secdata,u32 seclen)6544 static void selinux_release_secctx(char *secdata, u32 seclen)
6545 {
6546 	kfree(secdata);
6547 }
6548 
selinux_inode_invalidate_secctx(struct inode * inode)6549 static void selinux_inode_invalidate_secctx(struct inode *inode)
6550 {
6551 	struct inode_security_struct *isec = selinux_inode(inode);
6552 
6553 	spin_lock(&isec->lock);
6554 	isec->initialized = LABEL_INVALID;
6555 	spin_unlock(&isec->lock);
6556 }
6557 
6558 /*
6559  *	called with inode->i_mutex locked
6560  */
selinux_inode_notifysecctx(struct inode * inode,void * ctx,u32 ctxlen)6561 static int selinux_inode_notifysecctx(struct inode *inode, void *ctx, u32 ctxlen)
6562 {
6563 	int rc = selinux_inode_setsecurity(inode, XATTR_SELINUX_SUFFIX,
6564 					   ctx, ctxlen, 0);
6565 	/* Do not return error when suppressing label (SBLABEL_MNT not set). */
6566 	return rc == -EOPNOTSUPP ? 0 : rc;
6567 }
6568 
6569 /*
6570  *	called with inode->i_mutex locked
6571  */
selinux_inode_setsecctx(struct dentry * dentry,void * ctx,u32 ctxlen)6572 static int selinux_inode_setsecctx(struct dentry *dentry, void *ctx, u32 ctxlen)
6573 {
6574 	return __vfs_setxattr_noperm(&init_user_ns, dentry, XATTR_NAME_SELINUX,
6575 				     ctx, ctxlen, 0);
6576 }
6577 
selinux_inode_getsecctx(struct inode * inode,void ** ctx,u32 * ctxlen)6578 static int selinux_inode_getsecctx(struct inode *inode, void **ctx, u32 *ctxlen)
6579 {
6580 	int len = 0;
6581 	len = selinux_inode_getsecurity(&init_user_ns, inode,
6582 					XATTR_SELINUX_SUFFIX, ctx, true);
6583 	if (len < 0)
6584 		return len;
6585 	*ctxlen = len;
6586 	return 0;
6587 }
6588 #ifdef CONFIG_KEYS
6589 
selinux_key_alloc(struct key * k,const struct cred * cred,unsigned long flags)6590 static int selinux_key_alloc(struct key *k, const struct cred *cred,
6591 			     unsigned long flags)
6592 {
6593 	const struct task_security_struct *tsec;
6594 	struct key_security_struct *ksec;
6595 
6596 	ksec = kzalloc(sizeof(struct key_security_struct), GFP_KERNEL);
6597 	if (!ksec)
6598 		return -ENOMEM;
6599 
6600 	tsec = selinux_cred(cred);
6601 	if (tsec->keycreate_sid)
6602 		ksec->sid = tsec->keycreate_sid;
6603 	else
6604 		ksec->sid = tsec->sid;
6605 
6606 	k->security = ksec;
6607 	return 0;
6608 }
6609 
selinux_key_free(struct key * k)6610 static void selinux_key_free(struct key *k)
6611 {
6612 	struct key_security_struct *ksec = k->security;
6613 
6614 	k->security = NULL;
6615 	kfree(ksec);
6616 }
6617 
selinux_key_permission(key_ref_t key_ref,const struct cred * cred,enum key_need_perm need_perm)6618 static int selinux_key_permission(key_ref_t key_ref,
6619 				  const struct cred *cred,
6620 				  enum key_need_perm need_perm)
6621 {
6622 	struct key *key;
6623 	struct key_security_struct *ksec;
6624 	u32 perm, sid;
6625 
6626 	switch (need_perm) {
6627 	case KEY_NEED_VIEW:
6628 		perm = KEY__VIEW;
6629 		break;
6630 	case KEY_NEED_READ:
6631 		perm = KEY__READ;
6632 		break;
6633 	case KEY_NEED_WRITE:
6634 		perm = KEY__WRITE;
6635 		break;
6636 	case KEY_NEED_SEARCH:
6637 		perm = KEY__SEARCH;
6638 		break;
6639 	case KEY_NEED_LINK:
6640 		perm = KEY__LINK;
6641 		break;
6642 	case KEY_NEED_SETATTR:
6643 		perm = KEY__SETATTR;
6644 		break;
6645 	case KEY_NEED_UNLINK:
6646 	case KEY_SYSADMIN_OVERRIDE:
6647 	case KEY_AUTHTOKEN_OVERRIDE:
6648 	case KEY_DEFER_PERM_CHECK:
6649 		return 0;
6650 	default:
6651 		WARN_ON(1);
6652 		return -EPERM;
6653 
6654 	}
6655 
6656 	sid = cred_sid(cred);
6657 	key = key_ref_to_ptr(key_ref);
6658 	ksec = key->security;
6659 
6660 	return avc_has_perm(&selinux_state,
6661 			    sid, ksec->sid, SECCLASS_KEY, perm, NULL);
6662 }
6663 
selinux_key_getsecurity(struct key * key,char ** _buffer)6664 static int selinux_key_getsecurity(struct key *key, char **_buffer)
6665 {
6666 	struct key_security_struct *ksec = key->security;
6667 	char *context = NULL;
6668 	unsigned len;
6669 	int rc;
6670 
6671 	rc = security_sid_to_context(&selinux_state, ksec->sid,
6672 				     &context, &len);
6673 	if (!rc)
6674 		rc = len;
6675 	*_buffer = context;
6676 	return rc;
6677 }
6678 
6679 #ifdef CONFIG_KEY_NOTIFICATIONS
selinux_watch_key(struct key * key)6680 static int selinux_watch_key(struct key *key)
6681 {
6682 	struct key_security_struct *ksec = key->security;
6683 	u32 sid = current_sid();
6684 
6685 	return avc_has_perm(&selinux_state,
6686 			    sid, ksec->sid, SECCLASS_KEY, KEY__VIEW, NULL);
6687 }
6688 #endif
6689 #endif
6690 
6691 #ifdef CONFIG_SECURITY_INFINIBAND
selinux_ib_pkey_access(void * ib_sec,u64 subnet_prefix,u16 pkey_val)6692 static int selinux_ib_pkey_access(void *ib_sec, u64 subnet_prefix, u16 pkey_val)
6693 {
6694 	struct common_audit_data ad;
6695 	int err;
6696 	u32 sid = 0;
6697 	struct ib_security_struct *sec = ib_sec;
6698 	struct lsm_ibpkey_audit ibpkey;
6699 
6700 	err = sel_ib_pkey_sid(subnet_prefix, pkey_val, &sid);
6701 	if (err)
6702 		return err;
6703 
6704 	ad.type = LSM_AUDIT_DATA_IBPKEY;
6705 	ibpkey.subnet_prefix = subnet_prefix;
6706 	ibpkey.pkey = pkey_val;
6707 	ad.u.ibpkey = &ibpkey;
6708 	return avc_has_perm(&selinux_state,
6709 			    sec->sid, sid,
6710 			    SECCLASS_INFINIBAND_PKEY,
6711 			    INFINIBAND_PKEY__ACCESS, &ad);
6712 }
6713 
selinux_ib_endport_manage_subnet(void * ib_sec,const char * dev_name,u8 port_num)6714 static int selinux_ib_endport_manage_subnet(void *ib_sec, const char *dev_name,
6715 					    u8 port_num)
6716 {
6717 	struct common_audit_data ad;
6718 	int err;
6719 	u32 sid = 0;
6720 	struct ib_security_struct *sec = ib_sec;
6721 	struct lsm_ibendport_audit ibendport;
6722 
6723 	err = security_ib_endport_sid(&selinux_state, dev_name, port_num,
6724 				      &sid);
6725 
6726 	if (err)
6727 		return err;
6728 
6729 	ad.type = LSM_AUDIT_DATA_IBENDPORT;
6730 	ibendport.dev_name = dev_name;
6731 	ibendport.port = port_num;
6732 	ad.u.ibendport = &ibendport;
6733 	return avc_has_perm(&selinux_state,
6734 			    sec->sid, sid,
6735 			    SECCLASS_INFINIBAND_ENDPORT,
6736 			    INFINIBAND_ENDPORT__MANAGE_SUBNET, &ad);
6737 }
6738 
selinux_ib_alloc_security(void ** ib_sec)6739 static int selinux_ib_alloc_security(void **ib_sec)
6740 {
6741 	struct ib_security_struct *sec;
6742 
6743 	sec = kzalloc(sizeof(*sec), GFP_KERNEL);
6744 	if (!sec)
6745 		return -ENOMEM;
6746 	sec->sid = current_sid();
6747 
6748 	*ib_sec = sec;
6749 	return 0;
6750 }
6751 
selinux_ib_free_security(void * ib_sec)6752 static void selinux_ib_free_security(void *ib_sec)
6753 {
6754 	kfree(ib_sec);
6755 }
6756 #endif
6757 
6758 #ifdef CONFIG_BPF_SYSCALL
selinux_bpf(int cmd,union bpf_attr * attr,unsigned int size)6759 static int selinux_bpf(int cmd, union bpf_attr *attr,
6760 				     unsigned int size)
6761 {
6762 	u32 sid = current_sid();
6763 	int ret;
6764 
6765 	switch (cmd) {
6766 	case BPF_MAP_CREATE:
6767 		ret = avc_has_perm(&selinux_state,
6768 				   sid, sid, SECCLASS_BPF, BPF__MAP_CREATE,
6769 				   NULL);
6770 		break;
6771 	case BPF_PROG_LOAD:
6772 		ret = avc_has_perm(&selinux_state,
6773 				   sid, sid, SECCLASS_BPF, BPF__PROG_LOAD,
6774 				   NULL);
6775 		break;
6776 	default:
6777 		ret = 0;
6778 		break;
6779 	}
6780 
6781 	return ret;
6782 }
6783 
bpf_map_fmode_to_av(fmode_t fmode)6784 static u32 bpf_map_fmode_to_av(fmode_t fmode)
6785 {
6786 	u32 av = 0;
6787 
6788 	if (fmode & FMODE_READ)
6789 		av |= BPF__MAP_READ;
6790 	if (fmode & FMODE_WRITE)
6791 		av |= BPF__MAP_WRITE;
6792 	return av;
6793 }
6794 
6795 /* This function will check the file pass through unix socket or binder to see
6796  * if it is a bpf related object. And apply correspinding checks on the bpf
6797  * object based on the type. The bpf maps and programs, not like other files and
6798  * socket, are using a shared anonymous inode inside the kernel as their inode.
6799  * So checking that inode cannot identify if the process have privilege to
6800  * access the bpf object and that's why we have to add this additional check in
6801  * selinux_file_receive and selinux_binder_transfer_files.
6802  */
bpf_fd_pass(struct file * file,u32 sid)6803 static int bpf_fd_pass(struct file *file, u32 sid)
6804 {
6805 	struct bpf_security_struct *bpfsec;
6806 	struct bpf_prog *prog;
6807 	struct bpf_map *map;
6808 	int ret;
6809 
6810 	if (file->f_op == &bpf_map_fops) {
6811 		map = file->private_data;
6812 		bpfsec = map->security;
6813 		ret = avc_has_perm(&selinux_state,
6814 				   sid, bpfsec->sid, SECCLASS_BPF,
6815 				   bpf_map_fmode_to_av(file->f_mode), NULL);
6816 		if (ret)
6817 			return ret;
6818 	} else if (file->f_op == &bpf_prog_fops) {
6819 		prog = file->private_data;
6820 		bpfsec = prog->aux->security;
6821 		ret = avc_has_perm(&selinux_state,
6822 				   sid, bpfsec->sid, SECCLASS_BPF,
6823 				   BPF__PROG_RUN, NULL);
6824 		if (ret)
6825 			return ret;
6826 	}
6827 	return 0;
6828 }
6829 
selinux_bpf_map(struct bpf_map * map,fmode_t fmode)6830 static int selinux_bpf_map(struct bpf_map *map, fmode_t fmode)
6831 {
6832 	u32 sid = current_sid();
6833 	struct bpf_security_struct *bpfsec;
6834 
6835 	bpfsec = map->security;
6836 	return avc_has_perm(&selinux_state,
6837 			    sid, bpfsec->sid, SECCLASS_BPF,
6838 			    bpf_map_fmode_to_av(fmode), NULL);
6839 }
6840 
selinux_bpf_prog(struct bpf_prog * prog)6841 static int selinux_bpf_prog(struct bpf_prog *prog)
6842 {
6843 	u32 sid = current_sid();
6844 	struct bpf_security_struct *bpfsec;
6845 
6846 	bpfsec = prog->aux->security;
6847 	return avc_has_perm(&selinux_state,
6848 			    sid, bpfsec->sid, SECCLASS_BPF,
6849 			    BPF__PROG_RUN, NULL);
6850 }
6851 
selinux_bpf_map_alloc(struct bpf_map * map)6852 static int selinux_bpf_map_alloc(struct bpf_map *map)
6853 {
6854 	struct bpf_security_struct *bpfsec;
6855 
6856 	bpfsec = kzalloc(sizeof(*bpfsec), GFP_KERNEL);
6857 	if (!bpfsec)
6858 		return -ENOMEM;
6859 
6860 	bpfsec->sid = current_sid();
6861 	map->security = bpfsec;
6862 
6863 	return 0;
6864 }
6865 
selinux_bpf_map_free(struct bpf_map * map)6866 static void selinux_bpf_map_free(struct bpf_map *map)
6867 {
6868 	struct bpf_security_struct *bpfsec = map->security;
6869 
6870 	map->security = NULL;
6871 	kfree(bpfsec);
6872 }
6873 
selinux_bpf_prog_alloc(struct bpf_prog_aux * aux)6874 static int selinux_bpf_prog_alloc(struct bpf_prog_aux *aux)
6875 {
6876 	struct bpf_security_struct *bpfsec;
6877 
6878 	bpfsec = kzalloc(sizeof(*bpfsec), GFP_KERNEL);
6879 	if (!bpfsec)
6880 		return -ENOMEM;
6881 
6882 	bpfsec->sid = current_sid();
6883 	aux->security = bpfsec;
6884 
6885 	return 0;
6886 }
6887 
selinux_bpf_prog_free(struct bpf_prog_aux * aux)6888 static void selinux_bpf_prog_free(struct bpf_prog_aux *aux)
6889 {
6890 	struct bpf_security_struct *bpfsec = aux->security;
6891 
6892 	aux->security = NULL;
6893 	kfree(bpfsec);
6894 }
6895 #endif
6896 
6897 struct lsm_blob_sizes selinux_blob_sizes __lsm_ro_after_init = {
6898 	.lbs_cred = sizeof(struct task_security_struct),
6899 	.lbs_file = sizeof(struct file_security_struct),
6900 	.lbs_inode = sizeof(struct inode_security_struct),
6901 	.lbs_ipc = sizeof(struct ipc_security_struct),
6902 	.lbs_msg_msg = sizeof(struct msg_security_struct),
6903 	.lbs_superblock = sizeof(struct superblock_security_struct),
6904 };
6905 
6906 #ifdef CONFIG_PERF_EVENTS
selinux_perf_event_open(struct perf_event_attr * attr,int type)6907 static int selinux_perf_event_open(struct perf_event_attr *attr, int type)
6908 {
6909 	u32 requested, sid = current_sid();
6910 
6911 	if (type == PERF_SECURITY_OPEN)
6912 		requested = PERF_EVENT__OPEN;
6913 	else if (type == PERF_SECURITY_CPU)
6914 		requested = PERF_EVENT__CPU;
6915 	else if (type == PERF_SECURITY_KERNEL)
6916 		requested = PERF_EVENT__KERNEL;
6917 	else if (type == PERF_SECURITY_TRACEPOINT)
6918 		requested = PERF_EVENT__TRACEPOINT;
6919 	else
6920 		return -EINVAL;
6921 
6922 	return avc_has_perm(&selinux_state, sid, sid, SECCLASS_PERF_EVENT,
6923 			    requested, NULL);
6924 }
6925 
selinux_perf_event_alloc(struct perf_event * event)6926 static int selinux_perf_event_alloc(struct perf_event *event)
6927 {
6928 	struct perf_event_security_struct *perfsec;
6929 
6930 	perfsec = kzalloc(sizeof(*perfsec), GFP_KERNEL);
6931 	if (!perfsec)
6932 		return -ENOMEM;
6933 
6934 	perfsec->sid = current_sid();
6935 	event->security = perfsec;
6936 
6937 	return 0;
6938 }
6939 
selinux_perf_event_free(struct perf_event * event)6940 static void selinux_perf_event_free(struct perf_event *event)
6941 {
6942 	struct perf_event_security_struct *perfsec = event->security;
6943 
6944 	event->security = NULL;
6945 	kfree(perfsec);
6946 }
6947 
selinux_perf_event_read(struct perf_event * event)6948 static int selinux_perf_event_read(struct perf_event *event)
6949 {
6950 	struct perf_event_security_struct *perfsec = event->security;
6951 	u32 sid = current_sid();
6952 
6953 	return avc_has_perm(&selinux_state, sid, perfsec->sid,
6954 			    SECCLASS_PERF_EVENT, PERF_EVENT__READ, NULL);
6955 }
6956 
selinux_perf_event_write(struct perf_event * event)6957 static int selinux_perf_event_write(struct perf_event *event)
6958 {
6959 	struct perf_event_security_struct *perfsec = event->security;
6960 	u32 sid = current_sid();
6961 
6962 	return avc_has_perm(&selinux_state, sid, perfsec->sid,
6963 			    SECCLASS_PERF_EVENT, PERF_EVENT__WRITE, NULL);
6964 }
6965 #endif
6966 
6967 #ifdef CONFIG_IO_URING
6968 /**
6969  * selinux_uring_override_creds - check the requested cred override
6970  * @new: the target creds
6971  *
6972  * Check to see if the current task is allowed to override it's credentials
6973  * to service an io_uring operation.
6974  */
selinux_uring_override_creds(const struct cred * new)6975 static int selinux_uring_override_creds(const struct cred *new)
6976 {
6977 	return avc_has_perm(&selinux_state, current_sid(), cred_sid(new),
6978 			    SECCLASS_IO_URING, IO_URING__OVERRIDE_CREDS, NULL);
6979 }
6980 
6981 /**
6982  * selinux_uring_sqpoll - check if a io_uring polling thread can be created
6983  *
6984  * Check to see if the current task is allowed to create a new io_uring
6985  * kernel polling thread.
6986  */
selinux_uring_sqpoll(void)6987 static int selinux_uring_sqpoll(void)
6988 {
6989 	int sid = current_sid();
6990 
6991 	return avc_has_perm(&selinux_state, sid, sid,
6992 			    SECCLASS_IO_URING, IO_URING__SQPOLL, NULL);
6993 }
6994 
6995 /**
6996  * selinux_uring_cmd - check if IORING_OP_URING_CMD is allowed
6997  * @ioucmd: the io_uring command structure
6998  *
6999  * Check to see if the current domain is allowed to execute an
7000  * IORING_OP_URING_CMD against the device/file specified in @ioucmd.
7001  *
7002  */
selinux_uring_cmd(struct io_uring_cmd * ioucmd)7003 static int selinux_uring_cmd(struct io_uring_cmd *ioucmd)
7004 {
7005 	struct file *file = ioucmd->file;
7006 	struct inode *inode = file_inode(file);
7007 	struct inode_security_struct *isec = selinux_inode(inode);
7008 	struct common_audit_data ad;
7009 
7010 	ad.type = LSM_AUDIT_DATA_FILE;
7011 	ad.u.file = file;
7012 
7013 	return avc_has_perm(&selinux_state, current_sid(), isec->sid,
7014 			    SECCLASS_IO_URING, IO_URING__CMD, &ad);
7015 }
7016 #endif /* CONFIG_IO_URING */
7017 
7018 /*
7019  * IMPORTANT NOTE: When adding new hooks, please be careful to keep this order:
7020  * 1. any hooks that don't belong to (2.) or (3.) below,
7021  * 2. hooks that both access structures allocated by other hooks, and allocate
7022  *    structures that can be later accessed by other hooks (mostly "cloning"
7023  *    hooks),
7024  * 3. hooks that only allocate structures that can be later accessed by other
7025  *    hooks ("allocating" hooks).
7026  *
7027  * Please follow block comment delimiters in the list to keep this order.
7028  *
7029  * This ordering is needed for SELinux runtime disable to work at least somewhat
7030  * safely. Breaking the ordering rules above might lead to NULL pointer derefs
7031  * when disabling SELinux at runtime.
7032  */
7033 static struct security_hook_list selinux_hooks[] __lsm_ro_after_init = {
7034 	LSM_HOOK_INIT(binder_set_context_mgr, selinux_binder_set_context_mgr),
7035 	LSM_HOOK_INIT(binder_transaction, selinux_binder_transaction),
7036 	LSM_HOOK_INIT(binder_transfer_binder, selinux_binder_transfer_binder),
7037 	LSM_HOOK_INIT(binder_transfer_file, selinux_binder_transfer_file),
7038 
7039 	LSM_HOOK_INIT(ptrace_access_check, selinux_ptrace_access_check),
7040 	LSM_HOOK_INIT(ptrace_traceme, selinux_ptrace_traceme),
7041 	LSM_HOOK_INIT(capget, selinux_capget),
7042 	LSM_HOOK_INIT(capset, selinux_capset),
7043 	LSM_HOOK_INIT(capable, selinux_capable),
7044 	LSM_HOOK_INIT(quotactl, selinux_quotactl),
7045 	LSM_HOOK_INIT(quota_on, selinux_quota_on),
7046 	LSM_HOOK_INIT(syslog, selinux_syslog),
7047 	LSM_HOOK_INIT(vm_enough_memory, selinux_vm_enough_memory),
7048 
7049 	LSM_HOOK_INIT(netlink_send, selinux_netlink_send),
7050 
7051 	LSM_HOOK_INIT(bprm_creds_for_exec, selinux_bprm_creds_for_exec),
7052 	LSM_HOOK_INIT(bprm_committing_creds, selinux_bprm_committing_creds),
7053 	LSM_HOOK_INIT(bprm_committed_creds, selinux_bprm_committed_creds),
7054 
7055 	LSM_HOOK_INIT(sb_free_mnt_opts, selinux_free_mnt_opts),
7056 	LSM_HOOK_INIT(sb_mnt_opts_compat, selinux_sb_mnt_opts_compat),
7057 	LSM_HOOK_INIT(sb_remount, selinux_sb_remount),
7058 	LSM_HOOK_INIT(sb_kern_mount, selinux_sb_kern_mount),
7059 	LSM_HOOK_INIT(sb_show_options, selinux_sb_show_options),
7060 	LSM_HOOK_INIT(sb_statfs, selinux_sb_statfs),
7061 	LSM_HOOK_INIT(sb_mount, selinux_mount),
7062 	LSM_HOOK_INIT(sb_umount, selinux_umount),
7063 	LSM_HOOK_INIT(sb_set_mnt_opts, selinux_set_mnt_opts),
7064 	LSM_HOOK_INIT(sb_clone_mnt_opts, selinux_sb_clone_mnt_opts),
7065 
7066 	LSM_HOOK_INIT(move_mount, selinux_move_mount),
7067 
7068 	LSM_HOOK_INIT(dentry_init_security, selinux_dentry_init_security),
7069 	LSM_HOOK_INIT(dentry_create_files_as, selinux_dentry_create_files_as),
7070 
7071 	LSM_HOOK_INIT(inode_free_security, selinux_inode_free_security),
7072 	LSM_HOOK_INIT(inode_init_security, selinux_inode_init_security),
7073 	LSM_HOOK_INIT(inode_init_security_anon, selinux_inode_init_security_anon),
7074 	LSM_HOOK_INIT(inode_create, selinux_inode_create),
7075 	LSM_HOOK_INIT(inode_link, selinux_inode_link),
7076 	LSM_HOOK_INIT(inode_unlink, selinux_inode_unlink),
7077 	LSM_HOOK_INIT(inode_symlink, selinux_inode_symlink),
7078 	LSM_HOOK_INIT(inode_mkdir, selinux_inode_mkdir),
7079 	LSM_HOOK_INIT(inode_rmdir, selinux_inode_rmdir),
7080 	LSM_HOOK_INIT(inode_mknod, selinux_inode_mknod),
7081 	LSM_HOOK_INIT(inode_rename, selinux_inode_rename),
7082 	LSM_HOOK_INIT(inode_readlink, selinux_inode_readlink),
7083 	LSM_HOOK_INIT(inode_follow_link, selinux_inode_follow_link),
7084 	LSM_HOOK_INIT(inode_permission, selinux_inode_permission),
7085 	LSM_HOOK_INIT(inode_setattr, selinux_inode_setattr),
7086 	LSM_HOOK_INIT(inode_getattr, selinux_inode_getattr),
7087 	LSM_HOOK_INIT(inode_setxattr, selinux_inode_setxattr),
7088 	LSM_HOOK_INIT(inode_post_setxattr, selinux_inode_post_setxattr),
7089 	LSM_HOOK_INIT(inode_getxattr, selinux_inode_getxattr),
7090 	LSM_HOOK_INIT(inode_listxattr, selinux_inode_listxattr),
7091 	LSM_HOOK_INIT(inode_removexattr, selinux_inode_removexattr),
7092 	LSM_HOOK_INIT(inode_getsecurity, selinux_inode_getsecurity),
7093 	LSM_HOOK_INIT(inode_setsecurity, selinux_inode_setsecurity),
7094 	LSM_HOOK_INIT(inode_listsecurity, selinux_inode_listsecurity),
7095 	LSM_HOOK_INIT(inode_getsecid, selinux_inode_getsecid),
7096 	LSM_HOOK_INIT(inode_copy_up, selinux_inode_copy_up),
7097 	LSM_HOOK_INIT(inode_copy_up_xattr, selinux_inode_copy_up_xattr),
7098 	LSM_HOOK_INIT(path_notify, selinux_path_notify),
7099 
7100 	LSM_HOOK_INIT(kernfs_init_security, selinux_kernfs_init_security),
7101 
7102 	LSM_HOOK_INIT(file_permission, selinux_file_permission),
7103 	LSM_HOOK_INIT(file_alloc_security, selinux_file_alloc_security),
7104 	LSM_HOOK_INIT(file_ioctl, selinux_file_ioctl),
7105 	LSM_HOOK_INIT(mmap_file, selinux_mmap_file),
7106 	LSM_HOOK_INIT(mmap_addr, selinux_mmap_addr),
7107 	LSM_HOOK_INIT(file_mprotect, selinux_file_mprotect),
7108 	LSM_HOOK_INIT(file_lock, selinux_file_lock),
7109 	LSM_HOOK_INIT(file_fcntl, selinux_file_fcntl),
7110 	LSM_HOOK_INIT(file_set_fowner, selinux_file_set_fowner),
7111 	LSM_HOOK_INIT(file_send_sigiotask, selinux_file_send_sigiotask),
7112 	LSM_HOOK_INIT(file_receive, selinux_file_receive),
7113 
7114 	LSM_HOOK_INIT(file_open, selinux_file_open),
7115 
7116 	LSM_HOOK_INIT(task_alloc, selinux_task_alloc),
7117 	LSM_HOOK_INIT(cred_prepare, selinux_cred_prepare),
7118 	LSM_HOOK_INIT(cred_transfer, selinux_cred_transfer),
7119 	LSM_HOOK_INIT(cred_getsecid, selinux_cred_getsecid),
7120 	LSM_HOOK_INIT(kernel_act_as, selinux_kernel_act_as),
7121 	LSM_HOOK_INIT(kernel_create_files_as, selinux_kernel_create_files_as),
7122 	LSM_HOOK_INIT(kernel_module_request, selinux_kernel_module_request),
7123 	LSM_HOOK_INIT(kernel_load_data, selinux_kernel_load_data),
7124 	LSM_HOOK_INIT(kernel_read_file, selinux_kernel_read_file),
7125 	LSM_HOOK_INIT(task_setpgid, selinux_task_setpgid),
7126 	LSM_HOOK_INIT(task_getpgid, selinux_task_getpgid),
7127 	LSM_HOOK_INIT(task_getsid, selinux_task_getsid),
7128 	LSM_HOOK_INIT(current_getsecid_subj, selinux_current_getsecid_subj),
7129 	LSM_HOOK_INIT(task_getsecid_obj, selinux_task_getsecid_obj),
7130 	LSM_HOOK_INIT(task_setnice, selinux_task_setnice),
7131 	LSM_HOOK_INIT(task_setioprio, selinux_task_setioprio),
7132 	LSM_HOOK_INIT(task_getioprio, selinux_task_getioprio),
7133 	LSM_HOOK_INIT(task_prlimit, selinux_task_prlimit),
7134 	LSM_HOOK_INIT(task_setrlimit, selinux_task_setrlimit),
7135 	LSM_HOOK_INIT(task_setscheduler, selinux_task_setscheduler),
7136 	LSM_HOOK_INIT(task_getscheduler, selinux_task_getscheduler),
7137 	LSM_HOOK_INIT(task_movememory, selinux_task_movememory),
7138 	LSM_HOOK_INIT(task_kill, selinux_task_kill),
7139 	LSM_HOOK_INIT(task_to_inode, selinux_task_to_inode),
7140 
7141 	LSM_HOOK_INIT(ipc_permission, selinux_ipc_permission),
7142 	LSM_HOOK_INIT(ipc_getsecid, selinux_ipc_getsecid),
7143 
7144 	LSM_HOOK_INIT(msg_queue_associate, selinux_msg_queue_associate),
7145 	LSM_HOOK_INIT(msg_queue_msgctl, selinux_msg_queue_msgctl),
7146 	LSM_HOOK_INIT(msg_queue_msgsnd, selinux_msg_queue_msgsnd),
7147 	LSM_HOOK_INIT(msg_queue_msgrcv, selinux_msg_queue_msgrcv),
7148 
7149 	LSM_HOOK_INIT(shm_associate, selinux_shm_associate),
7150 	LSM_HOOK_INIT(shm_shmctl, selinux_shm_shmctl),
7151 	LSM_HOOK_INIT(shm_shmat, selinux_shm_shmat),
7152 
7153 	LSM_HOOK_INIT(sem_associate, selinux_sem_associate),
7154 	LSM_HOOK_INIT(sem_semctl, selinux_sem_semctl),
7155 	LSM_HOOK_INIT(sem_semop, selinux_sem_semop),
7156 
7157 	LSM_HOOK_INIT(d_instantiate, selinux_d_instantiate),
7158 
7159 	LSM_HOOK_INIT(getprocattr, selinux_getprocattr),
7160 	LSM_HOOK_INIT(setprocattr, selinux_setprocattr),
7161 
7162 	LSM_HOOK_INIT(ismaclabel, selinux_ismaclabel),
7163 	LSM_HOOK_INIT(secctx_to_secid, selinux_secctx_to_secid),
7164 	LSM_HOOK_INIT(release_secctx, selinux_release_secctx),
7165 	LSM_HOOK_INIT(inode_invalidate_secctx, selinux_inode_invalidate_secctx),
7166 	LSM_HOOK_INIT(inode_notifysecctx, selinux_inode_notifysecctx),
7167 	LSM_HOOK_INIT(inode_setsecctx, selinux_inode_setsecctx),
7168 
7169 	LSM_HOOK_INIT(unix_stream_connect, selinux_socket_unix_stream_connect),
7170 	LSM_HOOK_INIT(unix_may_send, selinux_socket_unix_may_send),
7171 
7172 	LSM_HOOK_INIT(socket_create, selinux_socket_create),
7173 	LSM_HOOK_INIT(socket_post_create, selinux_socket_post_create),
7174 	LSM_HOOK_INIT(socket_socketpair, selinux_socket_socketpair),
7175 	LSM_HOOK_INIT(socket_bind, selinux_socket_bind),
7176 	LSM_HOOK_INIT(socket_connect, selinux_socket_connect),
7177 	LSM_HOOK_INIT(socket_listen, selinux_socket_listen),
7178 	LSM_HOOK_INIT(socket_accept, selinux_socket_accept),
7179 	LSM_HOOK_INIT(socket_sendmsg, selinux_socket_sendmsg),
7180 	LSM_HOOK_INIT(socket_recvmsg, selinux_socket_recvmsg),
7181 	LSM_HOOK_INIT(socket_getsockname, selinux_socket_getsockname),
7182 	LSM_HOOK_INIT(socket_getpeername, selinux_socket_getpeername),
7183 	LSM_HOOK_INIT(socket_getsockopt, selinux_socket_getsockopt),
7184 	LSM_HOOK_INIT(socket_setsockopt, selinux_socket_setsockopt),
7185 	LSM_HOOK_INIT(socket_shutdown, selinux_socket_shutdown),
7186 	LSM_HOOK_INIT(socket_sock_rcv_skb, selinux_socket_sock_rcv_skb),
7187 	LSM_HOOK_INIT(socket_getpeersec_stream,
7188 			selinux_socket_getpeersec_stream),
7189 	LSM_HOOK_INIT(socket_getpeersec_dgram, selinux_socket_getpeersec_dgram),
7190 	LSM_HOOK_INIT(sk_free_security, selinux_sk_free_security),
7191 	LSM_HOOK_INIT(sk_clone_security, selinux_sk_clone_security),
7192 	LSM_HOOK_INIT(sk_getsecid, selinux_sk_getsecid),
7193 	LSM_HOOK_INIT(sock_graft, selinux_sock_graft),
7194 	LSM_HOOK_INIT(sctp_assoc_request, selinux_sctp_assoc_request),
7195 	LSM_HOOK_INIT(sctp_sk_clone, selinux_sctp_sk_clone),
7196 	LSM_HOOK_INIT(sctp_bind_connect, selinux_sctp_bind_connect),
7197 	LSM_HOOK_INIT(sctp_assoc_established, selinux_sctp_assoc_established),
7198 	LSM_HOOK_INIT(inet_conn_request, selinux_inet_conn_request),
7199 	LSM_HOOK_INIT(inet_csk_clone, selinux_inet_csk_clone),
7200 	LSM_HOOK_INIT(inet_conn_established, selinux_inet_conn_established),
7201 	LSM_HOOK_INIT(secmark_relabel_packet, selinux_secmark_relabel_packet),
7202 	LSM_HOOK_INIT(secmark_refcount_inc, selinux_secmark_refcount_inc),
7203 	LSM_HOOK_INIT(secmark_refcount_dec, selinux_secmark_refcount_dec),
7204 	LSM_HOOK_INIT(req_classify_flow, selinux_req_classify_flow),
7205 	LSM_HOOK_INIT(tun_dev_free_security, selinux_tun_dev_free_security),
7206 	LSM_HOOK_INIT(tun_dev_create, selinux_tun_dev_create),
7207 	LSM_HOOK_INIT(tun_dev_attach_queue, selinux_tun_dev_attach_queue),
7208 	LSM_HOOK_INIT(tun_dev_attach, selinux_tun_dev_attach),
7209 	LSM_HOOK_INIT(tun_dev_open, selinux_tun_dev_open),
7210 #ifdef CONFIG_SECURITY_INFINIBAND
7211 	LSM_HOOK_INIT(ib_pkey_access, selinux_ib_pkey_access),
7212 	LSM_HOOK_INIT(ib_endport_manage_subnet,
7213 		      selinux_ib_endport_manage_subnet),
7214 	LSM_HOOK_INIT(ib_free_security, selinux_ib_free_security),
7215 #endif
7216 #ifdef CONFIG_SECURITY_NETWORK_XFRM
7217 	LSM_HOOK_INIT(xfrm_policy_free_security, selinux_xfrm_policy_free),
7218 	LSM_HOOK_INIT(xfrm_policy_delete_security, selinux_xfrm_policy_delete),
7219 	LSM_HOOK_INIT(xfrm_state_free_security, selinux_xfrm_state_free),
7220 	LSM_HOOK_INIT(xfrm_state_delete_security, selinux_xfrm_state_delete),
7221 	LSM_HOOK_INIT(xfrm_policy_lookup, selinux_xfrm_policy_lookup),
7222 	LSM_HOOK_INIT(xfrm_state_pol_flow_match,
7223 			selinux_xfrm_state_pol_flow_match),
7224 	LSM_HOOK_INIT(xfrm_decode_session, selinux_xfrm_decode_session),
7225 #endif
7226 
7227 #ifdef CONFIG_KEYS
7228 	LSM_HOOK_INIT(key_free, selinux_key_free),
7229 	LSM_HOOK_INIT(key_permission, selinux_key_permission),
7230 	LSM_HOOK_INIT(key_getsecurity, selinux_key_getsecurity),
7231 #ifdef CONFIG_KEY_NOTIFICATIONS
7232 	LSM_HOOK_INIT(watch_key, selinux_watch_key),
7233 #endif
7234 #endif
7235 
7236 #ifdef CONFIG_AUDIT
7237 	LSM_HOOK_INIT(audit_rule_known, selinux_audit_rule_known),
7238 	LSM_HOOK_INIT(audit_rule_match, selinux_audit_rule_match),
7239 	LSM_HOOK_INIT(audit_rule_free, selinux_audit_rule_free),
7240 #endif
7241 
7242 #ifdef CONFIG_BPF_SYSCALL
7243 	LSM_HOOK_INIT(bpf, selinux_bpf),
7244 	LSM_HOOK_INIT(bpf_map, selinux_bpf_map),
7245 	LSM_HOOK_INIT(bpf_prog, selinux_bpf_prog),
7246 	LSM_HOOK_INIT(bpf_map_free_security, selinux_bpf_map_free),
7247 	LSM_HOOK_INIT(bpf_prog_free_security, selinux_bpf_prog_free),
7248 #endif
7249 
7250 #ifdef CONFIG_PERF_EVENTS
7251 	LSM_HOOK_INIT(perf_event_open, selinux_perf_event_open),
7252 	LSM_HOOK_INIT(perf_event_free, selinux_perf_event_free),
7253 	LSM_HOOK_INIT(perf_event_read, selinux_perf_event_read),
7254 	LSM_HOOK_INIT(perf_event_write, selinux_perf_event_write),
7255 #endif
7256 
7257 #ifdef CONFIG_IO_URING
7258 	LSM_HOOK_INIT(uring_override_creds, selinux_uring_override_creds),
7259 	LSM_HOOK_INIT(uring_sqpoll, selinux_uring_sqpoll),
7260 	LSM_HOOK_INIT(uring_cmd, selinux_uring_cmd),
7261 #endif
7262 
7263 	/*
7264 	 * PUT "CLONING" (ACCESSING + ALLOCATING) HOOKS HERE
7265 	 */
7266 	LSM_HOOK_INIT(fs_context_dup, selinux_fs_context_dup),
7267 	LSM_HOOK_INIT(fs_context_parse_param, selinux_fs_context_parse_param),
7268 	LSM_HOOK_INIT(sb_eat_lsm_opts, selinux_sb_eat_lsm_opts),
7269 #ifdef CONFIG_SECURITY_NETWORK_XFRM
7270 	LSM_HOOK_INIT(xfrm_policy_clone_security, selinux_xfrm_policy_clone),
7271 #endif
7272 
7273 	/*
7274 	 * PUT "ALLOCATING" HOOKS HERE
7275 	 */
7276 	LSM_HOOK_INIT(msg_msg_alloc_security, selinux_msg_msg_alloc_security),
7277 	LSM_HOOK_INIT(msg_queue_alloc_security,
7278 		      selinux_msg_queue_alloc_security),
7279 	LSM_HOOK_INIT(shm_alloc_security, selinux_shm_alloc_security),
7280 	LSM_HOOK_INIT(sb_alloc_security, selinux_sb_alloc_security),
7281 	LSM_HOOK_INIT(inode_alloc_security, selinux_inode_alloc_security),
7282 	LSM_HOOK_INIT(sem_alloc_security, selinux_sem_alloc_security),
7283 	LSM_HOOK_INIT(secid_to_secctx, selinux_secid_to_secctx),
7284 	LSM_HOOK_INIT(inode_getsecctx, selinux_inode_getsecctx),
7285 	LSM_HOOK_INIT(sk_alloc_security, selinux_sk_alloc_security),
7286 	LSM_HOOK_INIT(tun_dev_alloc_security, selinux_tun_dev_alloc_security),
7287 #ifdef CONFIG_SECURITY_INFINIBAND
7288 	LSM_HOOK_INIT(ib_alloc_security, selinux_ib_alloc_security),
7289 #endif
7290 #ifdef CONFIG_SECURITY_NETWORK_XFRM
7291 	LSM_HOOK_INIT(xfrm_policy_alloc_security, selinux_xfrm_policy_alloc),
7292 	LSM_HOOK_INIT(xfrm_state_alloc, selinux_xfrm_state_alloc),
7293 	LSM_HOOK_INIT(xfrm_state_alloc_acquire,
7294 		      selinux_xfrm_state_alloc_acquire),
7295 #endif
7296 #ifdef CONFIG_KEYS
7297 	LSM_HOOK_INIT(key_alloc, selinux_key_alloc),
7298 #endif
7299 #ifdef CONFIG_AUDIT
7300 	LSM_HOOK_INIT(audit_rule_init, selinux_audit_rule_init),
7301 #endif
7302 #ifdef CONFIG_BPF_SYSCALL
7303 	LSM_HOOK_INIT(bpf_map_alloc_security, selinux_bpf_map_alloc),
7304 	LSM_HOOK_INIT(bpf_prog_alloc_security, selinux_bpf_prog_alloc),
7305 #endif
7306 #ifdef CONFIG_PERF_EVENTS
7307 	LSM_HOOK_INIT(perf_event_alloc, selinux_perf_event_alloc),
7308 #endif
7309 };
7310 
selinux_init(void)7311 static __init int selinux_init(void)
7312 {
7313 	pr_info("SELinux:  Initializing.\n");
7314 
7315 	memset(&selinux_state, 0, sizeof(selinux_state));
7316 	enforcing_set(&selinux_state, selinux_enforcing_boot);
7317 	if (CONFIG_SECURITY_SELINUX_CHECKREQPROT_VALUE)
7318 		pr_err("SELinux: CONFIG_SECURITY_SELINUX_CHECKREQPROT_VALUE is non-zero.  This is deprecated and will be rejected in a future kernel release.\n");
7319 	checkreqprot_set(&selinux_state, selinux_checkreqprot_boot);
7320 	selinux_avc_init(&selinux_state.avc);
7321 	mutex_init(&selinux_state.status_lock);
7322 	mutex_init(&selinux_state.policy_mutex);
7323 
7324 	/* Set the security state for the initial task. */
7325 	cred_init_security();
7326 
7327 	default_noexec = !(VM_DATA_DEFAULT_FLAGS & VM_EXEC);
7328 
7329 	avc_init();
7330 
7331 	avtab_cache_init();
7332 
7333 	ebitmap_cache_init();
7334 
7335 	hashtab_cache_init();
7336 
7337 	security_add_hooks(selinux_hooks, ARRAY_SIZE(selinux_hooks), "selinux");
7338 
7339 	if (avc_add_callback(selinux_netcache_avc_callback, AVC_CALLBACK_RESET))
7340 		panic("SELinux: Unable to register AVC netcache callback\n");
7341 
7342 	if (avc_add_callback(selinux_lsm_notifier_avc_callback, AVC_CALLBACK_RESET))
7343 		panic("SELinux: Unable to register AVC LSM notifier callback\n");
7344 
7345 	if (selinux_enforcing_boot)
7346 		pr_debug("SELinux:  Starting in enforcing mode\n");
7347 	else
7348 		pr_debug("SELinux:  Starting in permissive mode\n");
7349 
7350 	fs_validate_description("selinux", selinux_fs_parameters);
7351 
7352 	return 0;
7353 }
7354 
delayed_superblock_init(struct super_block * sb,void * unused)7355 static void delayed_superblock_init(struct super_block *sb, void *unused)
7356 {
7357 	selinux_set_mnt_opts(sb, NULL, 0, NULL);
7358 }
7359 
selinux_complete_init(void)7360 void selinux_complete_init(void)
7361 {
7362 	pr_debug("SELinux:  Completing initialization.\n");
7363 
7364 	/* Set up any superblocks initialized prior to the policy load. */
7365 	pr_debug("SELinux:  Setting up existing superblocks.\n");
7366 	iterate_supers(delayed_superblock_init, NULL);
7367 }
7368 
7369 /* SELinux requires early initialization in order to label
7370    all processes and objects when they are created. */
7371 DEFINE_LSM(selinux) = {
7372 	.name = "selinux",
7373 	.flags = LSM_FLAG_LEGACY_MAJOR | LSM_FLAG_EXCLUSIVE,
7374 	.enabled = &selinux_enabled_boot,
7375 	.blobs = &selinux_blob_sizes,
7376 	.init = selinux_init,
7377 };
7378 
7379 #if defined(CONFIG_NETFILTER)
7380 
7381 static const struct nf_hook_ops selinux_nf_ops[] = {
7382 	{
7383 		.hook =		selinux_ip_postroute,
7384 		.pf =		NFPROTO_IPV4,
7385 		.hooknum =	NF_INET_POST_ROUTING,
7386 		.priority =	NF_IP_PRI_SELINUX_LAST,
7387 	},
7388 	{
7389 		.hook =		selinux_ip_forward,
7390 		.pf =		NFPROTO_IPV4,
7391 		.hooknum =	NF_INET_FORWARD,
7392 		.priority =	NF_IP_PRI_SELINUX_FIRST,
7393 	},
7394 	{
7395 		.hook =		selinux_ip_output,
7396 		.pf =		NFPROTO_IPV4,
7397 		.hooknum =	NF_INET_LOCAL_OUT,
7398 		.priority =	NF_IP_PRI_SELINUX_FIRST,
7399 	},
7400 #if IS_ENABLED(CONFIG_IPV6)
7401 	{
7402 		.hook =		selinux_ip_postroute,
7403 		.pf =		NFPROTO_IPV6,
7404 		.hooknum =	NF_INET_POST_ROUTING,
7405 		.priority =	NF_IP6_PRI_SELINUX_LAST,
7406 	},
7407 	{
7408 		.hook =		selinux_ip_forward,
7409 		.pf =		NFPROTO_IPV6,
7410 		.hooknum =	NF_INET_FORWARD,
7411 		.priority =	NF_IP6_PRI_SELINUX_FIRST,
7412 	},
7413 	{
7414 		.hook =		selinux_ip_output,
7415 		.pf =		NFPROTO_IPV6,
7416 		.hooknum =	NF_INET_LOCAL_OUT,
7417 		.priority =	NF_IP6_PRI_SELINUX_FIRST,
7418 	},
7419 #endif	/* IPV6 */
7420 };
7421 
selinux_nf_register(struct net * net)7422 static int __net_init selinux_nf_register(struct net *net)
7423 {
7424 	return nf_register_net_hooks(net, selinux_nf_ops,
7425 				     ARRAY_SIZE(selinux_nf_ops));
7426 }
7427 
selinux_nf_unregister(struct net * net)7428 static void __net_exit selinux_nf_unregister(struct net *net)
7429 {
7430 	nf_unregister_net_hooks(net, selinux_nf_ops,
7431 				ARRAY_SIZE(selinux_nf_ops));
7432 }
7433 
7434 static struct pernet_operations selinux_net_ops = {
7435 	.init = selinux_nf_register,
7436 	.exit = selinux_nf_unregister,
7437 };
7438 
selinux_nf_ip_init(void)7439 static int __init selinux_nf_ip_init(void)
7440 {
7441 	int err;
7442 
7443 	if (!selinux_enabled_boot)
7444 		return 0;
7445 
7446 	pr_debug("SELinux:  Registering netfilter hooks\n");
7447 
7448 	err = register_pernet_subsys(&selinux_net_ops);
7449 	if (err)
7450 		panic("SELinux: register_pernet_subsys: error %d\n", err);
7451 
7452 	return 0;
7453 }
7454 __initcall(selinux_nf_ip_init);
7455 
7456 #ifdef CONFIG_SECURITY_SELINUX_DISABLE
selinux_nf_ip_exit(void)7457 static void selinux_nf_ip_exit(void)
7458 {
7459 	pr_debug("SELinux:  Unregistering netfilter hooks\n");
7460 
7461 	unregister_pernet_subsys(&selinux_net_ops);
7462 }
7463 #endif
7464 
7465 #else /* CONFIG_NETFILTER */
7466 
7467 #ifdef CONFIG_SECURITY_SELINUX_DISABLE
7468 #define selinux_nf_ip_exit()
7469 #endif
7470 
7471 #endif /* CONFIG_NETFILTER */
7472 
7473 #ifdef CONFIG_SECURITY_SELINUX_DISABLE
selinux_disable(struct selinux_state * state)7474 int selinux_disable(struct selinux_state *state)
7475 {
7476 	if (selinux_initialized(state)) {
7477 		/* Not permitted after initial policy load. */
7478 		return -EINVAL;
7479 	}
7480 
7481 	if (selinux_disabled(state)) {
7482 		/* Only do this once. */
7483 		return -EINVAL;
7484 	}
7485 
7486 	selinux_mark_disabled(state);
7487 
7488 	pr_info("SELinux:  Disabled at runtime.\n");
7489 
7490 	/*
7491 	 * Unregister netfilter hooks.
7492 	 * Must be done before security_delete_hooks() to avoid breaking
7493 	 * runtime disable.
7494 	 */
7495 	selinux_nf_ip_exit();
7496 
7497 	security_delete_hooks(selinux_hooks, ARRAY_SIZE(selinux_hooks));
7498 
7499 	/* Try to destroy the avc node cache */
7500 	avc_disable();
7501 
7502 	/* Unregister selinuxfs. */
7503 	exit_sel_fs();
7504 
7505 	return 0;
7506 }
7507 #endif
7508