1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * AppArmor security module
4  *
5  * This file contains AppArmor LSM hooks.
6  *
7  * Copyright (C) 1998-2008 Novell/SUSE
8  * Copyright 2009-2010 Canonical Ltd.
9  */
10 
11 #include <linux/lsm_hooks.h>
12 #include <linux/moduleparam.h>
13 #include <linux/mm.h>
14 #include <linux/mman.h>
15 #include <linux/mount.h>
16 #include <linux/namei.h>
17 #include <linux/ptrace.h>
18 #include <linux/ctype.h>
19 #include <linux/sysctl.h>
20 #include <linux/audit.h>
21 #include <linux/user_namespace.h>
22 #include <linux/netfilter_ipv4.h>
23 #include <linux/netfilter_ipv6.h>
24 #include <linux/zlib.h>
25 #include <net/sock.h>
26 #include <uapi/linux/mount.h>
27 
28 #include "include/apparmor.h"
29 #include "include/apparmorfs.h"
30 #include "include/audit.h"
31 #include "include/capability.h"
32 #include "include/cred.h"
33 #include "include/file.h"
34 #include "include/ipc.h"
35 #include "include/net.h"
36 #include "include/path.h"
37 #include "include/label.h"
38 #include "include/policy.h"
39 #include "include/policy_ns.h"
40 #include "include/procattr.h"
41 #include "include/mount.h"
42 #include "include/secid.h"
43 
44 /* Flag indicating whether initialization completed */
45 int apparmor_initialized;
46 
47 union aa_buffer {
48 	struct list_head list;
49 	char buffer[1];
50 };
51 
52 #define RESERVE_COUNT 2
53 static int reserve_count = RESERVE_COUNT;
54 static int buffer_count;
55 
56 static LIST_HEAD(aa_global_buffers);
57 static DEFINE_SPINLOCK(aa_buffers_lock);
58 
59 /*
60  * LSM hook functions
61  */
62 
63 /*
64  * put the associated labels
65  */
apparmor_cred_free(struct cred * cred)66 static void apparmor_cred_free(struct cred *cred)
67 {
68 	aa_put_label(cred_label(cred));
69 	set_cred_label(cred, NULL);
70 }
71 
72 /*
73  * allocate the apparmor part of blank credentials
74  */
apparmor_cred_alloc_blank(struct cred * cred,gfp_t gfp)75 static int apparmor_cred_alloc_blank(struct cred *cred, gfp_t gfp)
76 {
77 	set_cred_label(cred, NULL);
78 	return 0;
79 }
80 
81 /*
82  * prepare new cred label for modification by prepare_cred block
83  */
apparmor_cred_prepare(struct cred * new,const struct cred * old,gfp_t gfp)84 static int apparmor_cred_prepare(struct cred *new, const struct cred *old,
85 				 gfp_t gfp)
86 {
87 	set_cred_label(new, aa_get_newest_label(cred_label(old)));
88 	return 0;
89 }
90 
91 /*
92  * transfer the apparmor data to a blank set of creds
93  */
apparmor_cred_transfer(struct cred * new,const struct cred * old)94 static void apparmor_cred_transfer(struct cred *new, const struct cred *old)
95 {
96 	set_cred_label(new, aa_get_newest_label(cred_label(old)));
97 }
98 
apparmor_task_free(struct task_struct * task)99 static void apparmor_task_free(struct task_struct *task)
100 {
101 
102 	aa_free_task_ctx(task_ctx(task));
103 }
104 
apparmor_task_alloc(struct task_struct * task,unsigned long clone_flags)105 static int apparmor_task_alloc(struct task_struct *task,
106 			       unsigned long clone_flags)
107 {
108 	struct aa_task_ctx *new = task_ctx(task);
109 
110 	aa_dup_task_ctx(new, task_ctx(current));
111 
112 	return 0;
113 }
114 
apparmor_ptrace_access_check(struct task_struct * child,unsigned int mode)115 static int apparmor_ptrace_access_check(struct task_struct *child,
116 					unsigned int mode)
117 {
118 	struct aa_label *tracer, *tracee;
119 	int error;
120 
121 	tracer = __begin_current_label_crit_section();
122 	tracee = aa_get_task_label(child);
123 	error = aa_may_ptrace(tracer, tracee,
124 			(mode & PTRACE_MODE_READ) ? AA_PTRACE_READ
125 						  : AA_PTRACE_TRACE);
126 	aa_put_label(tracee);
127 	__end_current_label_crit_section(tracer);
128 
129 	return error;
130 }
131 
apparmor_ptrace_traceme(struct task_struct * parent)132 static int apparmor_ptrace_traceme(struct task_struct *parent)
133 {
134 	struct aa_label *tracer, *tracee;
135 	int error;
136 
137 	tracee = __begin_current_label_crit_section();
138 	tracer = aa_get_task_label(parent);
139 	error = aa_may_ptrace(tracer, tracee, AA_PTRACE_TRACE);
140 	aa_put_label(tracer);
141 	__end_current_label_crit_section(tracee);
142 
143 	return error;
144 }
145 
146 /* Derived from security/commoncap.c:cap_capget */
apparmor_capget(struct task_struct * target,kernel_cap_t * effective,kernel_cap_t * inheritable,kernel_cap_t * permitted)147 static int apparmor_capget(struct task_struct *target, kernel_cap_t *effective,
148 			   kernel_cap_t *inheritable, kernel_cap_t *permitted)
149 {
150 	struct aa_label *label;
151 	const struct cred *cred;
152 
153 	rcu_read_lock();
154 	cred = __task_cred(target);
155 	label = aa_get_newest_cred_label(cred);
156 
157 	/*
158 	 * cap_capget is stacked ahead of this and will
159 	 * initialize effective and permitted.
160 	 */
161 	if (!unconfined(label)) {
162 		struct aa_profile *profile;
163 		struct label_it i;
164 
165 		label_for_each_confined(i, label, profile) {
166 			if (COMPLAIN_MODE(profile))
167 				continue;
168 			*effective = cap_intersect(*effective,
169 						   profile->caps.allow);
170 			*permitted = cap_intersect(*permitted,
171 						   profile->caps.allow);
172 		}
173 	}
174 	rcu_read_unlock();
175 	aa_put_label(label);
176 
177 	return 0;
178 }
179 
apparmor_capable(const struct cred * cred,struct user_namespace * ns,int cap,unsigned int opts)180 static int apparmor_capable(const struct cred *cred, struct user_namespace *ns,
181 			    int cap, unsigned int opts)
182 {
183 	struct aa_label *label;
184 	int error = 0;
185 
186 	label = aa_get_newest_cred_label(cred);
187 	if (!unconfined(label))
188 		error = aa_capable(label, cap, opts);
189 	aa_put_label(label);
190 
191 	return error;
192 }
193 
194 /**
195  * common_perm - basic common permission check wrapper fn for paths
196  * @op: operation being checked
197  * @path: path to check permission of  (NOT NULL)
198  * @mask: requested permissions mask
199  * @cond: conditional info for the permission request  (NOT NULL)
200  *
201  * Returns: %0 else error code if error or permission denied
202  */
common_perm(const char * op,const struct path * path,u32 mask,struct path_cond * cond)203 static int common_perm(const char *op, const struct path *path, u32 mask,
204 		       struct path_cond *cond)
205 {
206 	struct aa_label *label;
207 	int error = 0;
208 
209 	label = __begin_current_label_crit_section();
210 	if (!unconfined(label))
211 		error = aa_path_perm(op, label, path, 0, mask, cond);
212 	__end_current_label_crit_section(label);
213 
214 	return error;
215 }
216 
217 /**
218  * common_perm_cond - common permission wrapper around inode cond
219  * @op: operation being checked
220  * @path: location to check (NOT NULL)
221  * @mask: requested permissions mask
222  *
223  * Returns: %0 else error code if error or permission denied
224  */
common_perm_cond(const char * op,const struct path * path,u32 mask)225 static int common_perm_cond(const char *op, const struct path *path, u32 mask)
226 {
227 	struct user_namespace *mnt_userns = mnt_user_ns(path->mnt);
228 	struct path_cond cond = {
229 		i_uid_into_mnt(mnt_userns, d_backing_inode(path->dentry)),
230 		d_backing_inode(path->dentry)->i_mode
231 	};
232 
233 	if (!path_mediated_fs(path->dentry))
234 		return 0;
235 
236 	return common_perm(op, path, mask, &cond);
237 }
238 
239 /**
240  * common_perm_dir_dentry - common permission wrapper when path is dir, dentry
241  * @op: operation being checked
242  * @dir: directory of the dentry  (NOT NULL)
243  * @dentry: dentry to check  (NOT NULL)
244  * @mask: requested permissions mask
245  * @cond: conditional info for the permission request  (NOT NULL)
246  *
247  * Returns: %0 else error code if error or permission denied
248  */
common_perm_dir_dentry(const char * op,const struct path * dir,struct dentry * dentry,u32 mask,struct path_cond * cond)249 static int common_perm_dir_dentry(const char *op, const struct path *dir,
250 				  struct dentry *dentry, u32 mask,
251 				  struct path_cond *cond)
252 {
253 	struct path path = { .mnt = dir->mnt, .dentry = dentry };
254 
255 	return common_perm(op, &path, mask, cond);
256 }
257 
258 /**
259  * common_perm_rm - common permission wrapper for operations doing rm
260  * @op: operation being checked
261  * @dir: directory that the dentry is in  (NOT NULL)
262  * @dentry: dentry being rm'd  (NOT NULL)
263  * @mask: requested permission mask
264  *
265  * Returns: %0 else error code if error or permission denied
266  */
common_perm_rm(const char * op,const struct path * dir,struct dentry * dentry,u32 mask)267 static int common_perm_rm(const char *op, const struct path *dir,
268 			  struct dentry *dentry, u32 mask)
269 {
270 	struct inode *inode = d_backing_inode(dentry);
271 	struct user_namespace *mnt_userns = mnt_user_ns(dir->mnt);
272 	struct path_cond cond = { };
273 
274 	if (!inode || !path_mediated_fs(dentry))
275 		return 0;
276 
277 	cond.uid = i_uid_into_mnt(mnt_userns, inode);
278 	cond.mode = inode->i_mode;
279 
280 	return common_perm_dir_dentry(op, dir, dentry, mask, &cond);
281 }
282 
283 /**
284  * common_perm_create - common permission wrapper for operations doing create
285  * @op: operation being checked
286  * @dir: directory that dentry will be created in  (NOT NULL)
287  * @dentry: dentry to create   (NOT NULL)
288  * @mask: request permission mask
289  * @mode: created file mode
290  *
291  * Returns: %0 else error code if error or permission denied
292  */
common_perm_create(const char * op,const struct path * dir,struct dentry * dentry,u32 mask,umode_t mode)293 static int common_perm_create(const char *op, const struct path *dir,
294 			      struct dentry *dentry, u32 mask, umode_t mode)
295 {
296 	struct path_cond cond = { current_fsuid(), mode };
297 
298 	if (!path_mediated_fs(dir->dentry))
299 		return 0;
300 
301 	return common_perm_dir_dentry(op, dir, dentry, mask, &cond);
302 }
303 
apparmor_path_unlink(const struct path * dir,struct dentry * dentry)304 static int apparmor_path_unlink(const struct path *dir, struct dentry *dentry)
305 {
306 	return common_perm_rm(OP_UNLINK, dir, dentry, AA_MAY_DELETE);
307 }
308 
apparmor_path_mkdir(const struct path * dir,struct dentry * dentry,umode_t mode)309 static int apparmor_path_mkdir(const struct path *dir, struct dentry *dentry,
310 			       umode_t mode)
311 {
312 	return common_perm_create(OP_MKDIR, dir, dentry, AA_MAY_CREATE,
313 				  S_IFDIR);
314 }
315 
apparmor_path_rmdir(const struct path * dir,struct dentry * dentry)316 static int apparmor_path_rmdir(const struct path *dir, struct dentry *dentry)
317 {
318 	return common_perm_rm(OP_RMDIR, dir, dentry, AA_MAY_DELETE);
319 }
320 
apparmor_path_mknod(const struct path * dir,struct dentry * dentry,umode_t mode,unsigned int dev)321 static int apparmor_path_mknod(const struct path *dir, struct dentry *dentry,
322 			       umode_t mode, unsigned int dev)
323 {
324 	return common_perm_create(OP_MKNOD, dir, dentry, AA_MAY_CREATE, mode);
325 }
326 
apparmor_path_truncate(const struct path * path)327 static int apparmor_path_truncate(const struct path *path)
328 {
329 	return common_perm_cond(OP_TRUNC, path, MAY_WRITE | AA_MAY_SETATTR);
330 }
331 
apparmor_path_symlink(const struct path * dir,struct dentry * dentry,const char * old_name)332 static int apparmor_path_symlink(const struct path *dir, struct dentry *dentry,
333 				 const char *old_name)
334 {
335 	return common_perm_create(OP_SYMLINK, dir, dentry, AA_MAY_CREATE,
336 				  S_IFLNK);
337 }
338 
apparmor_path_link(struct dentry * old_dentry,const struct path * new_dir,struct dentry * new_dentry)339 static int apparmor_path_link(struct dentry *old_dentry, const struct path *new_dir,
340 			      struct dentry *new_dentry)
341 {
342 	struct aa_label *label;
343 	int error = 0;
344 
345 	if (!path_mediated_fs(old_dentry))
346 		return 0;
347 
348 	label = begin_current_label_crit_section();
349 	if (!unconfined(label))
350 		error = aa_path_link(label, old_dentry, new_dir, new_dentry);
351 	end_current_label_crit_section(label);
352 
353 	return error;
354 }
355 
apparmor_path_rename(const struct path * old_dir,struct dentry * old_dentry,const struct path * new_dir,struct dentry * new_dentry,const unsigned int flags)356 static int apparmor_path_rename(const struct path *old_dir, struct dentry *old_dentry,
357 				const struct path *new_dir, struct dentry *new_dentry,
358 				const unsigned int flags)
359 {
360 	struct aa_label *label;
361 	int error = 0;
362 
363 	if (!path_mediated_fs(old_dentry))
364 		return 0;
365 	if ((flags & RENAME_EXCHANGE) && !path_mediated_fs(new_dentry))
366 		return 0;
367 
368 	label = begin_current_label_crit_section();
369 	if (!unconfined(label)) {
370 		struct user_namespace *mnt_userns = mnt_user_ns(old_dir->mnt);
371 		struct path old_path = { .mnt = old_dir->mnt,
372 					 .dentry = old_dentry };
373 		struct path new_path = { .mnt = new_dir->mnt,
374 					 .dentry = new_dentry };
375 		struct path_cond cond = {
376 			i_uid_into_mnt(mnt_userns, d_backing_inode(old_dentry)),
377 			d_backing_inode(old_dentry)->i_mode
378 		};
379 
380 		if (flags & RENAME_EXCHANGE) {
381 			struct path_cond cond_exchange = {
382 				i_uid_into_mnt(mnt_userns, d_backing_inode(new_dentry)),
383 				d_backing_inode(new_dentry)->i_mode
384 			};
385 
386 			error = aa_path_perm(OP_RENAME_SRC, label, &new_path, 0,
387 					     MAY_READ | AA_MAY_GETATTR | MAY_WRITE |
388 					     AA_MAY_SETATTR | AA_MAY_DELETE,
389 					     &cond_exchange);
390 			if (!error)
391 				error = aa_path_perm(OP_RENAME_DEST, label, &old_path,
392 						     0, MAY_WRITE | AA_MAY_SETATTR |
393 						     AA_MAY_CREATE, &cond_exchange);
394 		}
395 
396 		if (!error)
397 			error = aa_path_perm(OP_RENAME_SRC, label, &old_path, 0,
398 					     MAY_READ | AA_MAY_GETATTR | MAY_WRITE |
399 					     AA_MAY_SETATTR | AA_MAY_DELETE,
400 					     &cond);
401 		if (!error)
402 			error = aa_path_perm(OP_RENAME_DEST, label, &new_path,
403 					     0, MAY_WRITE | AA_MAY_SETATTR |
404 					     AA_MAY_CREATE, &cond);
405 
406 	}
407 	end_current_label_crit_section(label);
408 
409 	return error;
410 }
411 
apparmor_path_chmod(const struct path * path,umode_t mode)412 static int apparmor_path_chmod(const struct path *path, umode_t mode)
413 {
414 	return common_perm_cond(OP_CHMOD, path, AA_MAY_CHMOD);
415 }
416 
apparmor_path_chown(const struct path * path,kuid_t uid,kgid_t gid)417 static int apparmor_path_chown(const struct path *path, kuid_t uid, kgid_t gid)
418 {
419 	return common_perm_cond(OP_CHOWN, path, AA_MAY_CHOWN);
420 }
421 
apparmor_inode_getattr(const struct path * path)422 static int apparmor_inode_getattr(const struct path *path)
423 {
424 	return common_perm_cond(OP_GETATTR, path, AA_MAY_GETATTR);
425 }
426 
apparmor_file_open(struct file * file)427 static int apparmor_file_open(struct file *file)
428 {
429 	struct aa_file_ctx *fctx = file_ctx(file);
430 	struct aa_label *label;
431 	int error = 0;
432 
433 	if (!path_mediated_fs(file->f_path.dentry))
434 		return 0;
435 
436 	/* If in exec, permission is handled by bprm hooks.
437 	 * Cache permissions granted by the previous exec check, with
438 	 * implicit read and executable mmap which are required to
439 	 * actually execute the image.
440 	 */
441 	if (current->in_execve) {
442 		fctx->allow = MAY_EXEC | MAY_READ | AA_EXEC_MMAP;
443 		return 0;
444 	}
445 
446 	label = aa_get_newest_cred_label(file->f_cred);
447 	if (!unconfined(label)) {
448 		struct user_namespace *mnt_userns = file_mnt_user_ns(file);
449 		struct inode *inode = file_inode(file);
450 		struct path_cond cond = {
451 			i_uid_into_mnt(mnt_userns, inode),
452 			inode->i_mode
453 		};
454 
455 		error = aa_path_perm(OP_OPEN, label, &file->f_path, 0,
456 				     aa_map_file_to_perms(file), &cond);
457 		/* todo cache full allowed permissions set and state */
458 		fctx->allow = aa_map_file_to_perms(file);
459 	}
460 	aa_put_label(label);
461 
462 	return error;
463 }
464 
apparmor_file_alloc_security(struct file * file)465 static int apparmor_file_alloc_security(struct file *file)
466 {
467 	struct aa_file_ctx *ctx = file_ctx(file);
468 	struct aa_label *label = begin_current_label_crit_section();
469 
470 	spin_lock_init(&ctx->lock);
471 	rcu_assign_pointer(ctx->label, aa_get_label(label));
472 	end_current_label_crit_section(label);
473 	return 0;
474 }
475 
apparmor_file_free_security(struct file * file)476 static void apparmor_file_free_security(struct file *file)
477 {
478 	struct aa_file_ctx *ctx = file_ctx(file);
479 
480 	if (ctx)
481 		aa_put_label(rcu_access_pointer(ctx->label));
482 }
483 
common_file_perm(const char * op,struct file * file,u32 mask,bool in_atomic)484 static int common_file_perm(const char *op, struct file *file, u32 mask,
485 			    bool in_atomic)
486 {
487 	struct aa_label *label;
488 	int error = 0;
489 
490 	/* don't reaudit files closed during inheritance */
491 	if (file->f_path.dentry == aa_null.dentry)
492 		return -EACCES;
493 
494 	label = __begin_current_label_crit_section();
495 	error = aa_file_perm(op, label, file, mask, in_atomic);
496 	__end_current_label_crit_section(label);
497 
498 	return error;
499 }
500 
apparmor_file_receive(struct file * file)501 static int apparmor_file_receive(struct file *file)
502 {
503 	return common_file_perm(OP_FRECEIVE, file, aa_map_file_to_perms(file),
504 				false);
505 }
506 
apparmor_file_permission(struct file * file,int mask)507 static int apparmor_file_permission(struct file *file, int mask)
508 {
509 	return common_file_perm(OP_FPERM, file, mask, false);
510 }
511 
apparmor_file_lock(struct file * file,unsigned int cmd)512 static int apparmor_file_lock(struct file *file, unsigned int cmd)
513 {
514 	u32 mask = AA_MAY_LOCK;
515 
516 	if (cmd == F_WRLCK)
517 		mask |= MAY_WRITE;
518 
519 	return common_file_perm(OP_FLOCK, file, mask, false);
520 }
521 
common_mmap(const char * op,struct file * file,unsigned long prot,unsigned long flags,bool in_atomic)522 static int common_mmap(const char *op, struct file *file, unsigned long prot,
523 		       unsigned long flags, bool in_atomic)
524 {
525 	int mask = 0;
526 
527 	if (!file || !file_ctx(file))
528 		return 0;
529 
530 	if (prot & PROT_READ)
531 		mask |= MAY_READ;
532 	/*
533 	 * Private mappings don't require write perms since they don't
534 	 * write back to the files
535 	 */
536 	if ((prot & PROT_WRITE) && !(flags & MAP_PRIVATE))
537 		mask |= MAY_WRITE;
538 	if (prot & PROT_EXEC)
539 		mask |= AA_EXEC_MMAP;
540 
541 	return common_file_perm(op, file, mask, in_atomic);
542 }
543 
apparmor_mmap_file(struct file * file,unsigned long reqprot,unsigned long prot,unsigned long flags)544 static int apparmor_mmap_file(struct file *file, unsigned long reqprot,
545 			      unsigned long prot, unsigned long flags)
546 {
547 	return common_mmap(OP_FMMAP, file, prot, flags, GFP_ATOMIC);
548 }
549 
apparmor_file_mprotect(struct vm_area_struct * vma,unsigned long reqprot,unsigned long prot)550 static int apparmor_file_mprotect(struct vm_area_struct *vma,
551 				  unsigned long reqprot, unsigned long prot)
552 {
553 	return common_mmap(OP_FMPROT, vma->vm_file, prot,
554 			   !(vma->vm_flags & VM_SHARED) ? MAP_PRIVATE : 0,
555 			   false);
556 }
557 
apparmor_sb_mount(const char * dev_name,const struct path * path,const char * type,unsigned long flags,void * data)558 static int apparmor_sb_mount(const char *dev_name, const struct path *path,
559 			     const char *type, unsigned long flags, void *data)
560 {
561 	struct aa_label *label;
562 	int error = 0;
563 
564 	/* Discard magic */
565 	if ((flags & MS_MGC_MSK) == MS_MGC_VAL)
566 		flags &= ~MS_MGC_MSK;
567 
568 	flags &= ~AA_MS_IGNORE_MASK;
569 
570 	label = __begin_current_label_crit_section();
571 	if (!unconfined(label)) {
572 		if (flags & MS_REMOUNT)
573 			error = aa_remount(label, path, flags, data);
574 		else if (flags & MS_BIND)
575 			error = aa_bind_mount(label, path, dev_name, flags);
576 		else if (flags & (MS_SHARED | MS_PRIVATE | MS_SLAVE |
577 				  MS_UNBINDABLE))
578 			error = aa_mount_change_type(label, path, flags);
579 		else if (flags & MS_MOVE)
580 			error = aa_move_mount(label, path, dev_name);
581 		else
582 			error = aa_new_mount(label, dev_name, path, type,
583 					     flags, data);
584 	}
585 	__end_current_label_crit_section(label);
586 
587 	return error;
588 }
589 
apparmor_sb_umount(struct vfsmount * mnt,int flags)590 static int apparmor_sb_umount(struct vfsmount *mnt, int flags)
591 {
592 	struct aa_label *label;
593 	int error = 0;
594 
595 	label = __begin_current_label_crit_section();
596 	if (!unconfined(label))
597 		error = aa_umount(label, mnt, flags);
598 	__end_current_label_crit_section(label);
599 
600 	return error;
601 }
602 
apparmor_sb_pivotroot(const struct path * old_path,const struct path * new_path)603 static int apparmor_sb_pivotroot(const struct path *old_path,
604 				 const struct path *new_path)
605 {
606 	struct aa_label *label;
607 	int error = 0;
608 
609 	label = aa_get_current_label();
610 	if (!unconfined(label))
611 		error = aa_pivotroot(label, old_path, new_path);
612 	aa_put_label(label);
613 
614 	return error;
615 }
616 
apparmor_getprocattr(struct task_struct * task,char * name,char ** value)617 static int apparmor_getprocattr(struct task_struct *task, char *name,
618 				char **value)
619 {
620 	int error = -ENOENT;
621 	/* released below */
622 	const struct cred *cred = get_task_cred(task);
623 	struct aa_task_ctx *ctx = task_ctx(current);
624 	struct aa_label *label = NULL;
625 
626 	if (strcmp(name, "current") == 0)
627 		label = aa_get_newest_label(cred_label(cred));
628 	else if (strcmp(name, "prev") == 0  && ctx->previous)
629 		label = aa_get_newest_label(ctx->previous);
630 	else if (strcmp(name, "exec") == 0 && ctx->onexec)
631 		label = aa_get_newest_label(ctx->onexec);
632 	else
633 		error = -EINVAL;
634 
635 	if (label)
636 		error = aa_getprocattr(label, value);
637 
638 	aa_put_label(label);
639 	put_cred(cred);
640 
641 	return error;
642 }
643 
apparmor_setprocattr(const char * name,void * value,size_t size)644 static int apparmor_setprocattr(const char *name, void *value,
645 				size_t size)
646 {
647 	char *command, *largs = NULL, *args = value;
648 	size_t arg_size;
649 	int error;
650 	DEFINE_AUDIT_DATA(sa, LSM_AUDIT_DATA_NONE, OP_SETPROCATTR);
651 
652 	if (size == 0)
653 		return -EINVAL;
654 
655 	/* AppArmor requires that the buffer must be null terminated atm */
656 	if (args[size - 1] != '\0') {
657 		/* null terminate */
658 		largs = args = kmalloc(size + 1, GFP_KERNEL);
659 		if (!args)
660 			return -ENOMEM;
661 		memcpy(args, value, size);
662 		args[size] = '\0';
663 	}
664 
665 	error = -EINVAL;
666 	args = strim(args);
667 	command = strsep(&args, " ");
668 	if (!args)
669 		goto out;
670 	args = skip_spaces(args);
671 	if (!*args)
672 		goto out;
673 
674 	arg_size = size - (args - (largs ? largs : (char *) value));
675 	if (strcmp(name, "current") == 0) {
676 		if (strcmp(command, "changehat") == 0) {
677 			error = aa_setprocattr_changehat(args, arg_size,
678 							 AA_CHANGE_NOFLAGS);
679 		} else if (strcmp(command, "permhat") == 0) {
680 			error = aa_setprocattr_changehat(args, arg_size,
681 							 AA_CHANGE_TEST);
682 		} else if (strcmp(command, "changeprofile") == 0) {
683 			error = aa_change_profile(args, AA_CHANGE_NOFLAGS);
684 		} else if (strcmp(command, "permprofile") == 0) {
685 			error = aa_change_profile(args, AA_CHANGE_TEST);
686 		} else if (strcmp(command, "stack") == 0) {
687 			error = aa_change_profile(args, AA_CHANGE_STACK);
688 		} else
689 			goto fail;
690 	} else if (strcmp(name, "exec") == 0) {
691 		if (strcmp(command, "exec") == 0)
692 			error = aa_change_profile(args, AA_CHANGE_ONEXEC);
693 		else if (strcmp(command, "stack") == 0)
694 			error = aa_change_profile(args, (AA_CHANGE_ONEXEC |
695 							 AA_CHANGE_STACK));
696 		else
697 			goto fail;
698 	} else
699 		/* only support the "current" and "exec" process attributes */
700 		goto fail;
701 
702 	if (!error)
703 		error = size;
704 out:
705 	kfree(largs);
706 	return error;
707 
708 fail:
709 	aad(&sa)->label = begin_current_label_crit_section();
710 	aad(&sa)->info = name;
711 	aad(&sa)->error = error = -EINVAL;
712 	aa_audit_msg(AUDIT_APPARMOR_DENIED, &sa, NULL);
713 	end_current_label_crit_section(aad(&sa)->label);
714 	goto out;
715 }
716 
717 /**
718  * apparmor_bprm_committing_creds - do task cleanup on committing new creds
719  * @bprm: binprm for the exec  (NOT NULL)
720  */
apparmor_bprm_committing_creds(struct linux_binprm * bprm)721 static void apparmor_bprm_committing_creds(struct linux_binprm *bprm)
722 {
723 	struct aa_label *label = aa_current_raw_label();
724 	struct aa_label *new_label = cred_label(bprm->cred);
725 
726 	/* bail out if unconfined or not changing profile */
727 	if ((new_label->proxy == label->proxy) ||
728 	    (unconfined(new_label)))
729 		return;
730 
731 	aa_inherit_files(bprm->cred, current->files);
732 
733 	current->pdeath_signal = 0;
734 
735 	/* reset soft limits and set hard limits for the new label */
736 	__aa_transition_rlimits(label, new_label);
737 }
738 
739 /**
740  * apparmor_bprm_committed_cred - do cleanup after new creds committed
741  * @bprm: binprm for the exec  (NOT NULL)
742  */
apparmor_bprm_committed_creds(struct linux_binprm * bprm)743 static void apparmor_bprm_committed_creds(struct linux_binprm *bprm)
744 {
745 	/* clear out temporary/transitional state from the context */
746 	aa_clear_task_ctx_trans(task_ctx(current));
747 
748 	return;
749 }
750 
apparmor_current_getsecid_subj(u32 * secid)751 static void apparmor_current_getsecid_subj(u32 *secid)
752 {
753 	struct aa_label *label = aa_get_current_label();
754 	*secid = label->secid;
755 	aa_put_label(label);
756 }
757 
apparmor_task_getsecid_obj(struct task_struct * p,u32 * secid)758 static void apparmor_task_getsecid_obj(struct task_struct *p, u32 *secid)
759 {
760 	struct aa_label *label = aa_get_task_label(p);
761 	*secid = label->secid;
762 	aa_put_label(label);
763 }
764 
apparmor_task_setrlimit(struct task_struct * task,unsigned int resource,struct rlimit * new_rlim)765 static int apparmor_task_setrlimit(struct task_struct *task,
766 		unsigned int resource, struct rlimit *new_rlim)
767 {
768 	struct aa_label *label = __begin_current_label_crit_section();
769 	int error = 0;
770 
771 	if (!unconfined(label))
772 		error = aa_task_setrlimit(label, task, resource, new_rlim);
773 	__end_current_label_crit_section(label);
774 
775 	return error;
776 }
777 
apparmor_task_kill(struct task_struct * target,struct kernel_siginfo * info,int sig,const struct cred * cred)778 static int apparmor_task_kill(struct task_struct *target, struct kernel_siginfo *info,
779 			      int sig, const struct cred *cred)
780 {
781 	struct aa_label *cl, *tl;
782 	int error;
783 
784 	if (cred) {
785 		/*
786 		 * Dealing with USB IO specific behavior
787 		 */
788 		cl = aa_get_newest_cred_label(cred);
789 		tl = aa_get_task_label(target);
790 		error = aa_may_signal(cl, tl, sig);
791 		aa_put_label(cl);
792 		aa_put_label(tl);
793 		return error;
794 	}
795 
796 	cl = __begin_current_label_crit_section();
797 	tl = aa_get_task_label(target);
798 	error = aa_may_signal(cl, tl, sig);
799 	aa_put_label(tl);
800 	__end_current_label_crit_section(cl);
801 
802 	return error;
803 }
804 
805 /**
806  * apparmor_sk_alloc_security - allocate and attach the sk_security field
807  */
apparmor_sk_alloc_security(struct sock * sk,int family,gfp_t flags)808 static int apparmor_sk_alloc_security(struct sock *sk, int family, gfp_t flags)
809 {
810 	struct aa_sk_ctx *ctx;
811 
812 	ctx = kzalloc(sizeof(*ctx), flags);
813 	if (!ctx)
814 		return -ENOMEM;
815 
816 	SK_CTX(sk) = ctx;
817 
818 	return 0;
819 }
820 
821 /**
822  * apparmor_sk_free_security - free the sk_security field
823  */
apparmor_sk_free_security(struct sock * sk)824 static void apparmor_sk_free_security(struct sock *sk)
825 {
826 	struct aa_sk_ctx *ctx = SK_CTX(sk);
827 
828 	SK_CTX(sk) = NULL;
829 	aa_put_label(ctx->label);
830 	aa_put_label(ctx->peer);
831 	kfree(ctx);
832 }
833 
834 /**
835  * apparmor_clone_security - clone the sk_security field
836  */
apparmor_sk_clone_security(const struct sock * sk,struct sock * newsk)837 static void apparmor_sk_clone_security(const struct sock *sk,
838 				       struct sock *newsk)
839 {
840 	struct aa_sk_ctx *ctx = SK_CTX(sk);
841 	struct aa_sk_ctx *new = SK_CTX(newsk);
842 
843 	if (new->label)
844 		aa_put_label(new->label);
845 	new->label = aa_get_label(ctx->label);
846 
847 	if (new->peer)
848 		aa_put_label(new->peer);
849 	new->peer = aa_get_label(ctx->peer);
850 }
851 
852 /**
853  * apparmor_socket_create - check perms before creating a new socket
854  */
apparmor_socket_create(int family,int type,int protocol,int kern)855 static int apparmor_socket_create(int family, int type, int protocol, int kern)
856 {
857 	struct aa_label *label;
858 	int error = 0;
859 
860 	AA_BUG(in_interrupt());
861 
862 	label = begin_current_label_crit_section();
863 	if (!(kern || unconfined(label)))
864 		error = af_select(family,
865 				  create_perm(label, family, type, protocol),
866 				  aa_af_perm(label, OP_CREATE, AA_MAY_CREATE,
867 					     family, type, protocol));
868 	end_current_label_crit_section(label);
869 
870 	return error;
871 }
872 
873 /**
874  * apparmor_socket_post_create - setup the per-socket security struct
875  *
876  * Note:
877  * -   kernel sockets currently labeled unconfined but we may want to
878  *     move to a special kernel label
879  * -   socket may not have sk here if created with sock_create_lite or
880  *     sock_alloc. These should be accept cases which will be handled in
881  *     sock_graft.
882  */
apparmor_socket_post_create(struct socket * sock,int family,int type,int protocol,int kern)883 static int apparmor_socket_post_create(struct socket *sock, int family,
884 				       int type, int protocol, int kern)
885 {
886 	struct aa_label *label;
887 
888 	if (kern) {
889 		struct aa_ns *ns = aa_get_current_ns();
890 
891 		label = aa_get_label(ns_unconfined(ns));
892 		aa_put_ns(ns);
893 	} else
894 		label = aa_get_current_label();
895 
896 	if (sock->sk) {
897 		struct aa_sk_ctx *ctx = SK_CTX(sock->sk);
898 
899 		aa_put_label(ctx->label);
900 		ctx->label = aa_get_label(label);
901 	}
902 	aa_put_label(label);
903 
904 	return 0;
905 }
906 
907 /**
908  * apparmor_socket_bind - check perms before bind addr to socket
909  */
apparmor_socket_bind(struct socket * sock,struct sockaddr * address,int addrlen)910 static int apparmor_socket_bind(struct socket *sock,
911 				struct sockaddr *address, int addrlen)
912 {
913 	AA_BUG(!sock);
914 	AA_BUG(!sock->sk);
915 	AA_BUG(!address);
916 	AA_BUG(in_interrupt());
917 
918 	return af_select(sock->sk->sk_family,
919 			 bind_perm(sock, address, addrlen),
920 			 aa_sk_perm(OP_BIND, AA_MAY_BIND, sock->sk));
921 }
922 
923 /**
924  * apparmor_socket_connect - check perms before connecting @sock to @address
925  */
apparmor_socket_connect(struct socket * sock,struct sockaddr * address,int addrlen)926 static int apparmor_socket_connect(struct socket *sock,
927 				   struct sockaddr *address, int addrlen)
928 {
929 	AA_BUG(!sock);
930 	AA_BUG(!sock->sk);
931 	AA_BUG(!address);
932 	AA_BUG(in_interrupt());
933 
934 	return af_select(sock->sk->sk_family,
935 			 connect_perm(sock, address, addrlen),
936 			 aa_sk_perm(OP_CONNECT, AA_MAY_CONNECT, sock->sk));
937 }
938 
939 /**
940  * apparmor_socket_list - check perms before allowing listen
941  */
apparmor_socket_listen(struct socket * sock,int backlog)942 static int apparmor_socket_listen(struct socket *sock, int backlog)
943 {
944 	AA_BUG(!sock);
945 	AA_BUG(!sock->sk);
946 	AA_BUG(in_interrupt());
947 
948 	return af_select(sock->sk->sk_family,
949 			 listen_perm(sock, backlog),
950 			 aa_sk_perm(OP_LISTEN, AA_MAY_LISTEN, sock->sk));
951 }
952 
953 /**
954  * apparmor_socket_accept - check perms before accepting a new connection.
955  *
956  * Note: while @newsock is created and has some information, the accept
957  *       has not been done.
958  */
apparmor_socket_accept(struct socket * sock,struct socket * newsock)959 static int apparmor_socket_accept(struct socket *sock, struct socket *newsock)
960 {
961 	AA_BUG(!sock);
962 	AA_BUG(!sock->sk);
963 	AA_BUG(!newsock);
964 	AA_BUG(in_interrupt());
965 
966 	return af_select(sock->sk->sk_family,
967 			 accept_perm(sock, newsock),
968 			 aa_sk_perm(OP_ACCEPT, AA_MAY_ACCEPT, sock->sk));
969 }
970 
aa_sock_msg_perm(const char * op,u32 request,struct socket * sock,struct msghdr * msg,int size)971 static int aa_sock_msg_perm(const char *op, u32 request, struct socket *sock,
972 			    struct msghdr *msg, int size)
973 {
974 	AA_BUG(!sock);
975 	AA_BUG(!sock->sk);
976 	AA_BUG(!msg);
977 	AA_BUG(in_interrupt());
978 
979 	return af_select(sock->sk->sk_family,
980 			 msg_perm(op, request, sock, msg, size),
981 			 aa_sk_perm(op, request, sock->sk));
982 }
983 
984 /**
985  * apparmor_socket_sendmsg - check perms before sending msg to another socket
986  */
apparmor_socket_sendmsg(struct socket * sock,struct msghdr * msg,int size)987 static int apparmor_socket_sendmsg(struct socket *sock,
988 				   struct msghdr *msg, int size)
989 {
990 	return aa_sock_msg_perm(OP_SENDMSG, AA_MAY_SEND, sock, msg, size);
991 }
992 
993 /**
994  * apparmor_socket_recvmsg - check perms before receiving a message
995  */
apparmor_socket_recvmsg(struct socket * sock,struct msghdr * msg,int size,int flags)996 static int apparmor_socket_recvmsg(struct socket *sock,
997 				   struct msghdr *msg, int size, int flags)
998 {
999 	return aa_sock_msg_perm(OP_RECVMSG, AA_MAY_RECEIVE, sock, msg, size);
1000 }
1001 
1002 /* revaliation, get/set attr, shutdown */
aa_sock_perm(const char * op,u32 request,struct socket * sock)1003 static int aa_sock_perm(const char *op, u32 request, struct socket *sock)
1004 {
1005 	AA_BUG(!sock);
1006 	AA_BUG(!sock->sk);
1007 	AA_BUG(in_interrupt());
1008 
1009 	return af_select(sock->sk->sk_family,
1010 			 sock_perm(op, request, sock),
1011 			 aa_sk_perm(op, request, sock->sk));
1012 }
1013 
1014 /**
1015  * apparmor_socket_getsockname - check perms before getting the local address
1016  */
apparmor_socket_getsockname(struct socket * sock)1017 static int apparmor_socket_getsockname(struct socket *sock)
1018 {
1019 	return aa_sock_perm(OP_GETSOCKNAME, AA_MAY_GETATTR, sock);
1020 }
1021 
1022 /**
1023  * apparmor_socket_getpeername - check perms before getting remote address
1024  */
apparmor_socket_getpeername(struct socket * sock)1025 static int apparmor_socket_getpeername(struct socket *sock)
1026 {
1027 	return aa_sock_perm(OP_GETPEERNAME, AA_MAY_GETATTR, sock);
1028 }
1029 
1030 /* revaliation, get/set attr, opt */
aa_sock_opt_perm(const char * op,u32 request,struct socket * sock,int level,int optname)1031 static int aa_sock_opt_perm(const char *op, u32 request, struct socket *sock,
1032 			    int level, int optname)
1033 {
1034 	AA_BUG(!sock);
1035 	AA_BUG(!sock->sk);
1036 	AA_BUG(in_interrupt());
1037 
1038 	return af_select(sock->sk->sk_family,
1039 			 opt_perm(op, request, sock, level, optname),
1040 			 aa_sk_perm(op, request, sock->sk));
1041 }
1042 
1043 /**
1044  * apparmor_getsockopt - check perms before getting socket options
1045  */
apparmor_socket_getsockopt(struct socket * sock,int level,int optname)1046 static int apparmor_socket_getsockopt(struct socket *sock, int level,
1047 				      int optname)
1048 {
1049 	return aa_sock_opt_perm(OP_GETSOCKOPT, AA_MAY_GETOPT, sock,
1050 				level, optname);
1051 }
1052 
1053 /**
1054  * apparmor_setsockopt - check perms before setting socket options
1055  */
apparmor_socket_setsockopt(struct socket * sock,int level,int optname)1056 static int apparmor_socket_setsockopt(struct socket *sock, int level,
1057 				      int optname)
1058 {
1059 	return aa_sock_opt_perm(OP_SETSOCKOPT, AA_MAY_SETOPT, sock,
1060 				level, optname);
1061 }
1062 
1063 /**
1064  * apparmor_socket_shutdown - check perms before shutting down @sock conn
1065  */
apparmor_socket_shutdown(struct socket * sock,int how)1066 static int apparmor_socket_shutdown(struct socket *sock, int how)
1067 {
1068 	return aa_sock_perm(OP_SHUTDOWN, AA_MAY_SHUTDOWN, sock);
1069 }
1070 
1071 #ifdef CONFIG_NETWORK_SECMARK
1072 /**
1073  * apparmor_socket_sock_recv_skb - check perms before associating skb to sk
1074  *
1075  * Note: can not sleep may be called with locks held
1076  *
1077  * dont want protocol specific in __skb_recv_datagram()
1078  * to deny an incoming connection  socket_sock_rcv_skb()
1079  */
apparmor_socket_sock_rcv_skb(struct sock * sk,struct sk_buff * skb)1080 static int apparmor_socket_sock_rcv_skb(struct sock *sk, struct sk_buff *skb)
1081 {
1082 	struct aa_sk_ctx *ctx = SK_CTX(sk);
1083 
1084 	if (!skb->secmark)
1085 		return 0;
1086 
1087 	return apparmor_secmark_check(ctx->label, OP_RECVMSG, AA_MAY_RECEIVE,
1088 				      skb->secmark, sk);
1089 }
1090 #endif
1091 
1092 
sk_peer_label(struct sock * sk)1093 static struct aa_label *sk_peer_label(struct sock *sk)
1094 {
1095 	struct aa_sk_ctx *ctx = SK_CTX(sk);
1096 
1097 	if (ctx->peer)
1098 		return ctx->peer;
1099 
1100 	return ERR_PTR(-ENOPROTOOPT);
1101 }
1102 
1103 /**
1104  * apparmor_socket_getpeersec_stream - get security context of peer
1105  *
1106  * Note: for tcp only valid if using ipsec or cipso on lan
1107  */
apparmor_socket_getpeersec_stream(struct socket * sock,char __user * optval,int __user * optlen,unsigned int len)1108 static int apparmor_socket_getpeersec_stream(struct socket *sock,
1109 					     char __user *optval,
1110 					     int __user *optlen,
1111 					     unsigned int len)
1112 {
1113 	char *name;
1114 	int slen, error = 0;
1115 	struct aa_label *label;
1116 	struct aa_label *peer;
1117 
1118 	label = begin_current_label_crit_section();
1119 	peer = sk_peer_label(sock->sk);
1120 	if (IS_ERR(peer)) {
1121 		error = PTR_ERR(peer);
1122 		goto done;
1123 	}
1124 	slen = aa_label_asxprint(&name, labels_ns(label), peer,
1125 				 FLAG_SHOW_MODE | FLAG_VIEW_SUBNS |
1126 				 FLAG_HIDDEN_UNCONFINED, GFP_KERNEL);
1127 	/* don't include terminating \0 in slen, it breaks some apps */
1128 	if (slen < 0) {
1129 		error = -ENOMEM;
1130 	} else {
1131 		if (slen > len) {
1132 			error = -ERANGE;
1133 		} else if (copy_to_user(optval, name, slen)) {
1134 			error = -EFAULT;
1135 			goto out;
1136 		}
1137 		if (put_user(slen, optlen))
1138 			error = -EFAULT;
1139 out:
1140 		kfree(name);
1141 
1142 	}
1143 
1144 done:
1145 	end_current_label_crit_section(label);
1146 
1147 	return error;
1148 }
1149 
1150 /**
1151  * apparmor_socket_getpeersec_dgram - get security label of packet
1152  * @sock: the peer socket
1153  * @skb: packet data
1154  * @secid: pointer to where to put the secid of the packet
1155  *
1156  * Sets the netlabel socket state on sk from parent
1157  */
apparmor_socket_getpeersec_dgram(struct socket * sock,struct sk_buff * skb,u32 * secid)1158 static int apparmor_socket_getpeersec_dgram(struct socket *sock,
1159 					    struct sk_buff *skb, u32 *secid)
1160 
1161 {
1162 	/* TODO: requires secid support */
1163 	return -ENOPROTOOPT;
1164 }
1165 
1166 /**
1167  * apparmor_sock_graft - Initialize newly created socket
1168  * @sk: child sock
1169  * @parent: parent socket
1170  *
1171  * Note: could set off of SOCK_CTX(parent) but need to track inode and we can
1172  *       just set sk security information off of current creating process label
1173  *       Labeling of sk for accept case - probably should be sock based
1174  *       instead of task, because of the case where an implicitly labeled
1175  *       socket is shared by different tasks.
1176  */
apparmor_sock_graft(struct sock * sk,struct socket * parent)1177 static void apparmor_sock_graft(struct sock *sk, struct socket *parent)
1178 {
1179 	struct aa_sk_ctx *ctx = SK_CTX(sk);
1180 
1181 	if (!ctx->label)
1182 		ctx->label = aa_get_current_label();
1183 }
1184 
1185 #ifdef CONFIG_NETWORK_SECMARK
apparmor_inet_conn_request(const struct sock * sk,struct sk_buff * skb,struct request_sock * req)1186 static int apparmor_inet_conn_request(const struct sock *sk, struct sk_buff *skb,
1187 				      struct request_sock *req)
1188 {
1189 	struct aa_sk_ctx *ctx = SK_CTX(sk);
1190 
1191 	if (!skb->secmark)
1192 		return 0;
1193 
1194 	return apparmor_secmark_check(ctx->label, OP_CONNECT, AA_MAY_CONNECT,
1195 				      skb->secmark, sk);
1196 }
1197 #endif
1198 
1199 /*
1200  * The cred blob is a pointer to, not an instance of, an aa_task_ctx.
1201  */
1202 struct lsm_blob_sizes apparmor_blob_sizes __lsm_ro_after_init = {
1203 	.lbs_cred = sizeof(struct aa_task_ctx *),
1204 	.lbs_file = sizeof(struct aa_file_ctx),
1205 	.lbs_task = sizeof(struct aa_task_ctx),
1206 };
1207 
1208 static struct security_hook_list apparmor_hooks[] __lsm_ro_after_init = {
1209 	LSM_HOOK_INIT(ptrace_access_check, apparmor_ptrace_access_check),
1210 	LSM_HOOK_INIT(ptrace_traceme, apparmor_ptrace_traceme),
1211 	LSM_HOOK_INIT(capget, apparmor_capget),
1212 	LSM_HOOK_INIT(capable, apparmor_capable),
1213 
1214 	LSM_HOOK_INIT(sb_mount, apparmor_sb_mount),
1215 	LSM_HOOK_INIT(sb_umount, apparmor_sb_umount),
1216 	LSM_HOOK_INIT(sb_pivotroot, apparmor_sb_pivotroot),
1217 
1218 	LSM_HOOK_INIT(path_link, apparmor_path_link),
1219 	LSM_HOOK_INIT(path_unlink, apparmor_path_unlink),
1220 	LSM_HOOK_INIT(path_symlink, apparmor_path_symlink),
1221 	LSM_HOOK_INIT(path_mkdir, apparmor_path_mkdir),
1222 	LSM_HOOK_INIT(path_rmdir, apparmor_path_rmdir),
1223 	LSM_HOOK_INIT(path_mknod, apparmor_path_mknod),
1224 	LSM_HOOK_INIT(path_rename, apparmor_path_rename),
1225 	LSM_HOOK_INIT(path_chmod, apparmor_path_chmod),
1226 	LSM_HOOK_INIT(path_chown, apparmor_path_chown),
1227 	LSM_HOOK_INIT(path_truncate, apparmor_path_truncate),
1228 	LSM_HOOK_INIT(inode_getattr, apparmor_inode_getattr),
1229 
1230 	LSM_HOOK_INIT(file_open, apparmor_file_open),
1231 	LSM_HOOK_INIT(file_receive, apparmor_file_receive),
1232 	LSM_HOOK_INIT(file_permission, apparmor_file_permission),
1233 	LSM_HOOK_INIT(file_alloc_security, apparmor_file_alloc_security),
1234 	LSM_HOOK_INIT(file_free_security, apparmor_file_free_security),
1235 	LSM_HOOK_INIT(mmap_file, apparmor_mmap_file),
1236 	LSM_HOOK_INIT(file_mprotect, apparmor_file_mprotect),
1237 	LSM_HOOK_INIT(file_lock, apparmor_file_lock),
1238 
1239 	LSM_HOOK_INIT(getprocattr, apparmor_getprocattr),
1240 	LSM_HOOK_INIT(setprocattr, apparmor_setprocattr),
1241 
1242 	LSM_HOOK_INIT(sk_alloc_security, apparmor_sk_alloc_security),
1243 	LSM_HOOK_INIT(sk_free_security, apparmor_sk_free_security),
1244 	LSM_HOOK_INIT(sk_clone_security, apparmor_sk_clone_security),
1245 
1246 	LSM_HOOK_INIT(socket_create, apparmor_socket_create),
1247 	LSM_HOOK_INIT(socket_post_create, apparmor_socket_post_create),
1248 	LSM_HOOK_INIT(socket_bind, apparmor_socket_bind),
1249 	LSM_HOOK_INIT(socket_connect, apparmor_socket_connect),
1250 	LSM_HOOK_INIT(socket_listen, apparmor_socket_listen),
1251 	LSM_HOOK_INIT(socket_accept, apparmor_socket_accept),
1252 	LSM_HOOK_INIT(socket_sendmsg, apparmor_socket_sendmsg),
1253 	LSM_HOOK_INIT(socket_recvmsg, apparmor_socket_recvmsg),
1254 	LSM_HOOK_INIT(socket_getsockname, apparmor_socket_getsockname),
1255 	LSM_HOOK_INIT(socket_getpeername, apparmor_socket_getpeername),
1256 	LSM_HOOK_INIT(socket_getsockopt, apparmor_socket_getsockopt),
1257 	LSM_HOOK_INIT(socket_setsockopt, apparmor_socket_setsockopt),
1258 	LSM_HOOK_INIT(socket_shutdown, apparmor_socket_shutdown),
1259 #ifdef CONFIG_NETWORK_SECMARK
1260 	LSM_HOOK_INIT(socket_sock_rcv_skb, apparmor_socket_sock_rcv_skb),
1261 #endif
1262 	LSM_HOOK_INIT(socket_getpeersec_stream,
1263 		      apparmor_socket_getpeersec_stream),
1264 	LSM_HOOK_INIT(socket_getpeersec_dgram,
1265 		      apparmor_socket_getpeersec_dgram),
1266 	LSM_HOOK_INIT(sock_graft, apparmor_sock_graft),
1267 #ifdef CONFIG_NETWORK_SECMARK
1268 	LSM_HOOK_INIT(inet_conn_request, apparmor_inet_conn_request),
1269 #endif
1270 
1271 	LSM_HOOK_INIT(cred_alloc_blank, apparmor_cred_alloc_blank),
1272 	LSM_HOOK_INIT(cred_free, apparmor_cred_free),
1273 	LSM_HOOK_INIT(cred_prepare, apparmor_cred_prepare),
1274 	LSM_HOOK_INIT(cred_transfer, apparmor_cred_transfer),
1275 
1276 	LSM_HOOK_INIT(bprm_creds_for_exec, apparmor_bprm_creds_for_exec),
1277 	LSM_HOOK_INIT(bprm_committing_creds, apparmor_bprm_committing_creds),
1278 	LSM_HOOK_INIT(bprm_committed_creds, apparmor_bprm_committed_creds),
1279 
1280 	LSM_HOOK_INIT(task_free, apparmor_task_free),
1281 	LSM_HOOK_INIT(task_alloc, apparmor_task_alloc),
1282 	LSM_HOOK_INIT(current_getsecid_subj, apparmor_current_getsecid_subj),
1283 	LSM_HOOK_INIT(task_getsecid_obj, apparmor_task_getsecid_obj),
1284 	LSM_HOOK_INIT(task_setrlimit, apparmor_task_setrlimit),
1285 	LSM_HOOK_INIT(task_kill, apparmor_task_kill),
1286 
1287 #ifdef CONFIG_AUDIT
1288 	LSM_HOOK_INIT(audit_rule_init, aa_audit_rule_init),
1289 	LSM_HOOK_INIT(audit_rule_known, aa_audit_rule_known),
1290 	LSM_HOOK_INIT(audit_rule_match, aa_audit_rule_match),
1291 	LSM_HOOK_INIT(audit_rule_free, aa_audit_rule_free),
1292 #endif
1293 
1294 	LSM_HOOK_INIT(secid_to_secctx, apparmor_secid_to_secctx),
1295 	LSM_HOOK_INIT(secctx_to_secid, apparmor_secctx_to_secid),
1296 	LSM_HOOK_INIT(release_secctx, apparmor_release_secctx),
1297 };
1298 
1299 /*
1300  * AppArmor sysfs module parameters
1301  */
1302 
1303 static int param_set_aabool(const char *val, const struct kernel_param *kp);
1304 static int param_get_aabool(char *buffer, const struct kernel_param *kp);
1305 #define param_check_aabool param_check_bool
1306 static const struct kernel_param_ops param_ops_aabool = {
1307 	.flags = KERNEL_PARAM_OPS_FL_NOARG,
1308 	.set = param_set_aabool,
1309 	.get = param_get_aabool
1310 };
1311 
1312 static int param_set_aauint(const char *val, const struct kernel_param *kp);
1313 static int param_get_aauint(char *buffer, const struct kernel_param *kp);
1314 #define param_check_aauint param_check_uint
1315 static const struct kernel_param_ops param_ops_aauint = {
1316 	.set = param_set_aauint,
1317 	.get = param_get_aauint
1318 };
1319 
1320 static int param_set_aacompressionlevel(const char *val,
1321 					const struct kernel_param *kp);
1322 static int param_get_aacompressionlevel(char *buffer,
1323 					const struct kernel_param *kp);
1324 #define param_check_aacompressionlevel param_check_int
1325 static const struct kernel_param_ops param_ops_aacompressionlevel = {
1326 	.set = param_set_aacompressionlevel,
1327 	.get = param_get_aacompressionlevel
1328 };
1329 
1330 static int param_set_aalockpolicy(const char *val, const struct kernel_param *kp);
1331 static int param_get_aalockpolicy(char *buffer, const struct kernel_param *kp);
1332 #define param_check_aalockpolicy param_check_bool
1333 static const struct kernel_param_ops param_ops_aalockpolicy = {
1334 	.flags = KERNEL_PARAM_OPS_FL_NOARG,
1335 	.set = param_set_aalockpolicy,
1336 	.get = param_get_aalockpolicy
1337 };
1338 
1339 static int param_set_audit(const char *val, const struct kernel_param *kp);
1340 static int param_get_audit(char *buffer, const struct kernel_param *kp);
1341 
1342 static int param_set_mode(const char *val, const struct kernel_param *kp);
1343 static int param_get_mode(char *buffer, const struct kernel_param *kp);
1344 
1345 /* Flag values, also controllable via /sys/module/apparmor/parameters
1346  * We define special types as we want to do additional mediation.
1347  */
1348 
1349 /* AppArmor global enforcement switch - complain, enforce, kill */
1350 enum profile_mode aa_g_profile_mode = APPARMOR_ENFORCE;
1351 module_param_call(mode, param_set_mode, param_get_mode,
1352 		  &aa_g_profile_mode, S_IRUSR | S_IWUSR);
1353 
1354 /* whether policy verification hashing is enabled */
1355 bool aa_g_hash_policy = IS_ENABLED(CONFIG_SECURITY_APPARMOR_HASH_DEFAULT);
1356 #ifdef CONFIG_SECURITY_APPARMOR_HASH
1357 module_param_named(hash_policy, aa_g_hash_policy, aabool, S_IRUSR | S_IWUSR);
1358 #endif
1359 
1360 /* policy loaddata compression level */
1361 int aa_g_rawdata_compression_level = Z_DEFAULT_COMPRESSION;
1362 module_param_named(rawdata_compression_level, aa_g_rawdata_compression_level,
1363 		   aacompressionlevel, 0400);
1364 
1365 /* Debug mode */
1366 bool aa_g_debug = IS_ENABLED(CONFIG_SECURITY_APPARMOR_DEBUG_MESSAGES);
1367 module_param_named(debug, aa_g_debug, aabool, S_IRUSR | S_IWUSR);
1368 
1369 /* Audit mode */
1370 enum audit_mode aa_g_audit;
1371 module_param_call(audit, param_set_audit, param_get_audit,
1372 		  &aa_g_audit, S_IRUSR | S_IWUSR);
1373 
1374 /* Determines if audit header is included in audited messages.  This
1375  * provides more context if the audit daemon is not running
1376  */
1377 bool aa_g_audit_header = true;
1378 module_param_named(audit_header, aa_g_audit_header, aabool,
1379 		   S_IRUSR | S_IWUSR);
1380 
1381 /* lock out loading/removal of policy
1382  * TODO: add in at boot loading of policy, which is the only way to
1383  *       load policy, if lock_policy is set
1384  */
1385 bool aa_g_lock_policy;
1386 module_param_named(lock_policy, aa_g_lock_policy, aalockpolicy,
1387 		   S_IRUSR | S_IWUSR);
1388 
1389 /* Syscall logging mode */
1390 bool aa_g_logsyscall;
1391 module_param_named(logsyscall, aa_g_logsyscall, aabool, S_IRUSR | S_IWUSR);
1392 
1393 /* Maximum pathname length before accesses will start getting rejected */
1394 unsigned int aa_g_path_max = 2 * PATH_MAX;
1395 module_param_named(path_max, aa_g_path_max, aauint, S_IRUSR);
1396 
1397 /* Determines how paranoid loading of policy is and how much verification
1398  * on the loaded policy is done.
1399  * DEPRECATED: read only as strict checking of load is always done now
1400  * that none root users (user namespaces) can load policy.
1401  */
1402 bool aa_g_paranoid_load = true;
1403 module_param_named(paranoid_load, aa_g_paranoid_load, aabool, S_IRUGO);
1404 
1405 static int param_get_aaintbool(char *buffer, const struct kernel_param *kp);
1406 static int param_set_aaintbool(const char *val, const struct kernel_param *kp);
1407 #define param_check_aaintbool param_check_int
1408 static const struct kernel_param_ops param_ops_aaintbool = {
1409 	.set = param_set_aaintbool,
1410 	.get = param_get_aaintbool
1411 };
1412 /* Boot time disable flag */
1413 static int apparmor_enabled __lsm_ro_after_init = 1;
1414 module_param_named(enabled, apparmor_enabled, aaintbool, 0444);
1415 
apparmor_enabled_setup(char * str)1416 static int __init apparmor_enabled_setup(char *str)
1417 {
1418 	unsigned long enabled;
1419 	int error = kstrtoul(str, 0, &enabled);
1420 	if (!error)
1421 		apparmor_enabled = enabled ? 1 : 0;
1422 	return 1;
1423 }
1424 
1425 __setup("apparmor=", apparmor_enabled_setup);
1426 
1427 /* set global flag turning off the ability to load policy */
param_set_aalockpolicy(const char * val,const struct kernel_param * kp)1428 static int param_set_aalockpolicy(const char *val, const struct kernel_param *kp)
1429 {
1430 	if (!apparmor_enabled)
1431 		return -EINVAL;
1432 	if (apparmor_initialized && !aa_current_policy_admin_capable(NULL))
1433 		return -EPERM;
1434 	return param_set_bool(val, kp);
1435 }
1436 
param_get_aalockpolicy(char * buffer,const struct kernel_param * kp)1437 static int param_get_aalockpolicy(char *buffer, const struct kernel_param *kp)
1438 {
1439 	if (!apparmor_enabled)
1440 		return -EINVAL;
1441 	if (apparmor_initialized && !aa_current_policy_view_capable(NULL))
1442 		return -EPERM;
1443 	return param_get_bool(buffer, kp);
1444 }
1445 
param_set_aabool(const char * val,const struct kernel_param * kp)1446 static int param_set_aabool(const char *val, const struct kernel_param *kp)
1447 {
1448 	if (!apparmor_enabled)
1449 		return -EINVAL;
1450 	if (apparmor_initialized && !aa_current_policy_admin_capable(NULL))
1451 		return -EPERM;
1452 	return param_set_bool(val, kp);
1453 }
1454 
param_get_aabool(char * buffer,const struct kernel_param * kp)1455 static int param_get_aabool(char *buffer, const struct kernel_param *kp)
1456 {
1457 	if (!apparmor_enabled)
1458 		return -EINVAL;
1459 	if (apparmor_initialized && !aa_current_policy_view_capable(NULL))
1460 		return -EPERM;
1461 	return param_get_bool(buffer, kp);
1462 }
1463 
param_set_aauint(const char * val,const struct kernel_param * kp)1464 static int param_set_aauint(const char *val, const struct kernel_param *kp)
1465 {
1466 	int error;
1467 
1468 	if (!apparmor_enabled)
1469 		return -EINVAL;
1470 	/* file is ro but enforce 2nd line check */
1471 	if (apparmor_initialized)
1472 		return -EPERM;
1473 
1474 	error = param_set_uint(val, kp);
1475 	aa_g_path_max = max_t(uint32_t, aa_g_path_max, sizeof(union aa_buffer));
1476 	pr_info("AppArmor: buffer size set to %d bytes\n", aa_g_path_max);
1477 
1478 	return error;
1479 }
1480 
param_get_aauint(char * buffer,const struct kernel_param * kp)1481 static int param_get_aauint(char *buffer, const struct kernel_param *kp)
1482 {
1483 	if (!apparmor_enabled)
1484 		return -EINVAL;
1485 	if (apparmor_initialized && !aa_current_policy_view_capable(NULL))
1486 		return -EPERM;
1487 	return param_get_uint(buffer, kp);
1488 }
1489 
1490 /* Can only be set before AppArmor is initialized (i.e. on boot cmdline). */
param_set_aaintbool(const char * val,const struct kernel_param * kp)1491 static int param_set_aaintbool(const char *val, const struct kernel_param *kp)
1492 {
1493 	struct kernel_param kp_local;
1494 	bool value;
1495 	int error;
1496 
1497 	if (apparmor_initialized)
1498 		return -EPERM;
1499 
1500 	/* Create local copy, with arg pointing to bool type. */
1501 	value = !!*((int *)kp->arg);
1502 	memcpy(&kp_local, kp, sizeof(kp_local));
1503 	kp_local.arg = &value;
1504 
1505 	error = param_set_bool(val, &kp_local);
1506 	if (!error)
1507 		*((int *)kp->arg) = *((bool *)kp_local.arg);
1508 	return error;
1509 }
1510 
1511 /*
1512  * To avoid changing /sys/module/apparmor/parameters/enabled from Y/N to
1513  * 1/0, this converts the "int that is actually bool" back to bool for
1514  * display in the /sys filesystem, while keeping it "int" for the LSM
1515  * infrastructure.
1516  */
param_get_aaintbool(char * buffer,const struct kernel_param * kp)1517 static int param_get_aaintbool(char *buffer, const struct kernel_param *kp)
1518 {
1519 	struct kernel_param kp_local;
1520 	bool value;
1521 
1522 	/* Create local copy, with arg pointing to bool type. */
1523 	value = !!*((int *)kp->arg);
1524 	memcpy(&kp_local, kp, sizeof(kp_local));
1525 	kp_local.arg = &value;
1526 
1527 	return param_get_bool(buffer, &kp_local);
1528 }
1529 
param_set_aacompressionlevel(const char * val,const struct kernel_param * kp)1530 static int param_set_aacompressionlevel(const char *val,
1531 					const struct kernel_param *kp)
1532 {
1533 	int error;
1534 
1535 	if (!apparmor_enabled)
1536 		return -EINVAL;
1537 	if (apparmor_initialized)
1538 		return -EPERM;
1539 
1540 	error = param_set_int(val, kp);
1541 
1542 	aa_g_rawdata_compression_level = clamp(aa_g_rawdata_compression_level,
1543 					       Z_NO_COMPRESSION,
1544 					       Z_BEST_COMPRESSION);
1545 	pr_info("AppArmor: policy rawdata compression level set to %u\n",
1546 		aa_g_rawdata_compression_level);
1547 
1548 	return error;
1549 }
1550 
param_get_aacompressionlevel(char * buffer,const struct kernel_param * kp)1551 static int param_get_aacompressionlevel(char *buffer,
1552 					const struct kernel_param *kp)
1553 {
1554 	if (!apparmor_enabled)
1555 		return -EINVAL;
1556 	if (apparmor_initialized && !aa_current_policy_view_capable(NULL))
1557 		return -EPERM;
1558 	return param_get_int(buffer, kp);
1559 }
1560 
param_get_audit(char * buffer,const struct kernel_param * kp)1561 static int param_get_audit(char *buffer, const struct kernel_param *kp)
1562 {
1563 	if (!apparmor_enabled)
1564 		return -EINVAL;
1565 	if (apparmor_initialized && !aa_current_policy_view_capable(NULL))
1566 		return -EPERM;
1567 	return sprintf(buffer, "%s", audit_mode_names[aa_g_audit]);
1568 }
1569 
param_set_audit(const char * val,const struct kernel_param * kp)1570 static int param_set_audit(const char *val, const struct kernel_param *kp)
1571 {
1572 	int i;
1573 
1574 	if (!apparmor_enabled)
1575 		return -EINVAL;
1576 	if (!val)
1577 		return -EINVAL;
1578 	if (apparmor_initialized && !aa_current_policy_admin_capable(NULL))
1579 		return -EPERM;
1580 
1581 	i = match_string(audit_mode_names, AUDIT_MAX_INDEX, val);
1582 	if (i < 0)
1583 		return -EINVAL;
1584 
1585 	aa_g_audit = i;
1586 	return 0;
1587 }
1588 
param_get_mode(char * buffer,const struct kernel_param * kp)1589 static int param_get_mode(char *buffer, const struct kernel_param *kp)
1590 {
1591 	if (!apparmor_enabled)
1592 		return -EINVAL;
1593 	if (apparmor_initialized && !aa_current_policy_view_capable(NULL))
1594 		return -EPERM;
1595 
1596 	return sprintf(buffer, "%s", aa_profile_mode_names[aa_g_profile_mode]);
1597 }
1598 
param_set_mode(const char * val,const struct kernel_param * kp)1599 static int param_set_mode(const char *val, const struct kernel_param *kp)
1600 {
1601 	int i;
1602 
1603 	if (!apparmor_enabled)
1604 		return -EINVAL;
1605 	if (!val)
1606 		return -EINVAL;
1607 	if (apparmor_initialized && !aa_current_policy_admin_capable(NULL))
1608 		return -EPERM;
1609 
1610 	i = match_string(aa_profile_mode_names, APPARMOR_MODE_NAMES_MAX_INDEX,
1611 			 val);
1612 	if (i < 0)
1613 		return -EINVAL;
1614 
1615 	aa_g_profile_mode = i;
1616 	return 0;
1617 }
1618 
aa_get_buffer(bool in_atomic)1619 char *aa_get_buffer(bool in_atomic)
1620 {
1621 	union aa_buffer *aa_buf;
1622 	bool try_again = true;
1623 	gfp_t flags = (GFP_KERNEL | __GFP_RETRY_MAYFAIL | __GFP_NOWARN);
1624 
1625 retry:
1626 	spin_lock(&aa_buffers_lock);
1627 	if (buffer_count > reserve_count ||
1628 	    (in_atomic && !list_empty(&aa_global_buffers))) {
1629 		aa_buf = list_first_entry(&aa_global_buffers, union aa_buffer,
1630 					  list);
1631 		list_del(&aa_buf->list);
1632 		buffer_count--;
1633 		spin_unlock(&aa_buffers_lock);
1634 		return &aa_buf->buffer[0];
1635 	}
1636 	if (in_atomic) {
1637 		/*
1638 		 * out of reserve buffers and in atomic context so increase
1639 		 * how many buffers to keep in reserve
1640 		 */
1641 		reserve_count++;
1642 		flags = GFP_ATOMIC;
1643 	}
1644 	spin_unlock(&aa_buffers_lock);
1645 
1646 	if (!in_atomic)
1647 		might_sleep();
1648 	aa_buf = kmalloc(aa_g_path_max, flags);
1649 	if (!aa_buf) {
1650 		if (try_again) {
1651 			try_again = false;
1652 			goto retry;
1653 		}
1654 		pr_warn_once("AppArmor: Failed to allocate a memory buffer.\n");
1655 		return NULL;
1656 	}
1657 	return &aa_buf->buffer[0];
1658 }
1659 
aa_put_buffer(char * buf)1660 void aa_put_buffer(char *buf)
1661 {
1662 	union aa_buffer *aa_buf;
1663 
1664 	if (!buf)
1665 		return;
1666 	aa_buf = container_of(buf, union aa_buffer, buffer[0]);
1667 
1668 	spin_lock(&aa_buffers_lock);
1669 	list_add(&aa_buf->list, &aa_global_buffers);
1670 	buffer_count++;
1671 	spin_unlock(&aa_buffers_lock);
1672 }
1673 
1674 /*
1675  * AppArmor init functions
1676  */
1677 
1678 /**
1679  * set_init_ctx - set a task context and profile on the first task.
1680  *
1681  * TODO: allow setting an alternate profile than unconfined
1682  */
set_init_ctx(void)1683 static int __init set_init_ctx(void)
1684 {
1685 	struct cred *cred = (__force struct cred *)current->real_cred;
1686 
1687 	set_cred_label(cred, aa_get_label(ns_unconfined(root_ns)));
1688 
1689 	return 0;
1690 }
1691 
destroy_buffers(void)1692 static void destroy_buffers(void)
1693 {
1694 	union aa_buffer *aa_buf;
1695 
1696 	spin_lock(&aa_buffers_lock);
1697 	while (!list_empty(&aa_global_buffers)) {
1698 		aa_buf = list_first_entry(&aa_global_buffers, union aa_buffer,
1699 					 list);
1700 		list_del(&aa_buf->list);
1701 		spin_unlock(&aa_buffers_lock);
1702 		kfree(aa_buf);
1703 		spin_lock(&aa_buffers_lock);
1704 	}
1705 	spin_unlock(&aa_buffers_lock);
1706 }
1707 
alloc_buffers(void)1708 static int __init alloc_buffers(void)
1709 {
1710 	union aa_buffer *aa_buf;
1711 	int i, num;
1712 
1713 	/*
1714 	 * A function may require two buffers at once. Usually the buffers are
1715 	 * used for a short period of time and are shared. On UP kernel buffers
1716 	 * two should be enough, with more CPUs it is possible that more
1717 	 * buffers will be used simultaneously. The preallocated pool may grow.
1718 	 * This preallocation has also the side-effect that AppArmor will be
1719 	 * disabled early at boot if aa_g_path_max is extremly high.
1720 	 */
1721 	if (num_online_cpus() > 1)
1722 		num = 4 + RESERVE_COUNT;
1723 	else
1724 		num = 2 + RESERVE_COUNT;
1725 
1726 	for (i = 0; i < num; i++) {
1727 
1728 		aa_buf = kmalloc(aa_g_path_max, GFP_KERNEL |
1729 				 __GFP_RETRY_MAYFAIL | __GFP_NOWARN);
1730 		if (!aa_buf) {
1731 			destroy_buffers();
1732 			return -ENOMEM;
1733 		}
1734 		aa_put_buffer(&aa_buf->buffer[0]);
1735 	}
1736 	return 0;
1737 }
1738 
1739 #ifdef CONFIG_SYSCTL
apparmor_dointvec(struct ctl_table * table,int write,void * buffer,size_t * lenp,loff_t * ppos)1740 static int apparmor_dointvec(struct ctl_table *table, int write,
1741 			     void *buffer, size_t *lenp, loff_t *ppos)
1742 {
1743 	if (!aa_current_policy_admin_capable(NULL))
1744 		return -EPERM;
1745 	if (!apparmor_enabled)
1746 		return -EINVAL;
1747 
1748 	return proc_dointvec(table, write, buffer, lenp, ppos);
1749 }
1750 
1751 static struct ctl_path apparmor_sysctl_path[] = {
1752 	{ .procname = "kernel", },
1753 	{ }
1754 };
1755 
1756 static struct ctl_table apparmor_sysctl_table[] = {
1757 	{
1758 		.procname       = "unprivileged_userns_apparmor_policy",
1759 		.data           = &unprivileged_userns_apparmor_policy,
1760 		.maxlen         = sizeof(int),
1761 		.mode           = 0600,
1762 		.proc_handler   = apparmor_dointvec,
1763 	},
1764 	{ }
1765 };
1766 
apparmor_init_sysctl(void)1767 static int __init apparmor_init_sysctl(void)
1768 {
1769 	return register_sysctl_paths(apparmor_sysctl_path,
1770 				     apparmor_sysctl_table) ? 0 : -ENOMEM;
1771 }
1772 #else
apparmor_init_sysctl(void)1773 static inline int apparmor_init_sysctl(void)
1774 {
1775 	return 0;
1776 }
1777 #endif /* CONFIG_SYSCTL */
1778 
1779 #if defined(CONFIG_NETFILTER) && defined(CONFIG_NETWORK_SECMARK)
apparmor_ip_postroute(void * priv,struct sk_buff * skb,const struct nf_hook_state * state)1780 static unsigned int apparmor_ip_postroute(void *priv,
1781 					  struct sk_buff *skb,
1782 					  const struct nf_hook_state *state)
1783 {
1784 	struct aa_sk_ctx *ctx;
1785 	struct sock *sk;
1786 
1787 	if (!skb->secmark)
1788 		return NF_ACCEPT;
1789 
1790 	sk = skb_to_full_sk(skb);
1791 	if (sk == NULL)
1792 		return NF_ACCEPT;
1793 
1794 	ctx = SK_CTX(sk);
1795 	if (!apparmor_secmark_check(ctx->label, OP_SENDMSG, AA_MAY_SEND,
1796 				    skb->secmark, sk))
1797 		return NF_ACCEPT;
1798 
1799 	return NF_DROP_ERR(-ECONNREFUSED);
1800 
1801 }
1802 
1803 static const struct nf_hook_ops apparmor_nf_ops[] = {
1804 	{
1805 		.hook =         apparmor_ip_postroute,
1806 		.pf =           NFPROTO_IPV4,
1807 		.hooknum =      NF_INET_POST_ROUTING,
1808 		.priority =     NF_IP_PRI_SELINUX_FIRST,
1809 	},
1810 #if IS_ENABLED(CONFIG_IPV6)
1811 	{
1812 		.hook =         apparmor_ip_postroute,
1813 		.pf =           NFPROTO_IPV6,
1814 		.hooknum =      NF_INET_POST_ROUTING,
1815 		.priority =     NF_IP6_PRI_SELINUX_FIRST,
1816 	},
1817 #endif
1818 };
1819 
apparmor_nf_register(struct net * net)1820 static int __net_init apparmor_nf_register(struct net *net)
1821 {
1822 	int ret;
1823 
1824 	ret = nf_register_net_hooks(net, apparmor_nf_ops,
1825 				    ARRAY_SIZE(apparmor_nf_ops));
1826 	return ret;
1827 }
1828 
apparmor_nf_unregister(struct net * net)1829 static void __net_exit apparmor_nf_unregister(struct net *net)
1830 {
1831 	nf_unregister_net_hooks(net, apparmor_nf_ops,
1832 				ARRAY_SIZE(apparmor_nf_ops));
1833 }
1834 
1835 static struct pernet_operations apparmor_net_ops = {
1836 	.init = apparmor_nf_register,
1837 	.exit = apparmor_nf_unregister,
1838 };
1839 
apparmor_nf_ip_init(void)1840 static int __init apparmor_nf_ip_init(void)
1841 {
1842 	int err;
1843 
1844 	if (!apparmor_enabled)
1845 		return 0;
1846 
1847 	err = register_pernet_subsys(&apparmor_net_ops);
1848 	if (err)
1849 		panic("Apparmor: register_pernet_subsys: error %d\n", err);
1850 
1851 	return 0;
1852 }
1853 __initcall(apparmor_nf_ip_init);
1854 #endif
1855 
apparmor_init(void)1856 static int __init apparmor_init(void)
1857 {
1858 	int error;
1859 
1860 	aa_secids_init();
1861 
1862 	error = aa_setup_dfa_engine();
1863 	if (error) {
1864 		AA_ERROR("Unable to setup dfa engine\n");
1865 		goto alloc_out;
1866 	}
1867 
1868 	error = aa_alloc_root_ns();
1869 	if (error) {
1870 		AA_ERROR("Unable to allocate default profile namespace\n");
1871 		goto alloc_out;
1872 	}
1873 
1874 	error = apparmor_init_sysctl();
1875 	if (error) {
1876 		AA_ERROR("Unable to register sysctls\n");
1877 		goto alloc_out;
1878 
1879 	}
1880 
1881 	error = alloc_buffers();
1882 	if (error) {
1883 		AA_ERROR("Unable to allocate work buffers\n");
1884 		goto alloc_out;
1885 	}
1886 
1887 	error = set_init_ctx();
1888 	if (error) {
1889 		AA_ERROR("Failed to set context on init task\n");
1890 		aa_free_root_ns();
1891 		goto buffers_out;
1892 	}
1893 	security_add_hooks(apparmor_hooks, ARRAY_SIZE(apparmor_hooks),
1894 				"apparmor");
1895 
1896 	/* Report that AppArmor successfully initialized */
1897 	apparmor_initialized = 1;
1898 	if (aa_g_profile_mode == APPARMOR_COMPLAIN)
1899 		aa_info_message("AppArmor initialized: complain mode enabled");
1900 	else if (aa_g_profile_mode == APPARMOR_KILL)
1901 		aa_info_message("AppArmor initialized: kill mode enabled");
1902 	else
1903 		aa_info_message("AppArmor initialized");
1904 
1905 	return error;
1906 
1907 buffers_out:
1908 	destroy_buffers();
1909 alloc_out:
1910 	aa_destroy_aafs();
1911 	aa_teardown_dfa_engine();
1912 
1913 	apparmor_enabled = false;
1914 	return error;
1915 }
1916 
1917 DEFINE_LSM(apparmor) = {
1918 	.name = "apparmor",
1919 	.flags = LSM_FLAG_LEGACY_MAJOR | LSM_FLAG_EXCLUSIVE,
1920 	.enabled = &apparmor_enabled,
1921 	.blobs = &apparmor_blob_sizes,
1922 	.init = apparmor_init,
1923 };
1924