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/zstd.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 	DECLARE_FLEX_ARRAY(char, buffer);
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 	const struct cred *cred;
120 	int error;
121 
122 	cred = get_task_cred(child);
123 	tracee = cred_label(cred);	/* ref count on cred */
124 	tracer = __begin_current_label_crit_section();
125 	error = aa_may_ptrace(current_cred(), tracer, cred, tracee,
126 			(mode & PTRACE_MODE_READ) ? AA_PTRACE_READ
127 						  : AA_PTRACE_TRACE);
128 	__end_current_label_crit_section(tracer);
129 	put_cred(cred);
130 
131 	return error;
132 }
133 
apparmor_ptrace_traceme(struct task_struct * parent)134 static int apparmor_ptrace_traceme(struct task_struct *parent)
135 {
136 	struct aa_label *tracer, *tracee;
137 	const struct cred *cred;
138 	int error;
139 
140 	tracee = __begin_current_label_crit_section();
141 	cred = get_task_cred(parent);
142 	tracer = cred_label(cred);	/* ref count on cred */
143 	error = aa_may_ptrace(cred, tracer, current_cred(), tracee,
144 			      AA_PTRACE_TRACE);
145 	put_cred(cred);
146 	__end_current_label_crit_section(tracee);
147 
148 	return error;
149 }
150 
151 /* Derived from security/commoncap.c:cap_capget */
apparmor_capget(const struct task_struct * target,kernel_cap_t * effective,kernel_cap_t * inheritable,kernel_cap_t * permitted)152 static int apparmor_capget(const struct task_struct *target, kernel_cap_t *effective,
153 			   kernel_cap_t *inheritable, kernel_cap_t *permitted)
154 {
155 	struct aa_label *label;
156 	const struct cred *cred;
157 
158 	rcu_read_lock();
159 	cred = __task_cred(target);
160 	label = aa_get_newest_cred_label(cred);
161 
162 	/*
163 	 * cap_capget is stacked ahead of this and will
164 	 * initialize effective and permitted.
165 	 */
166 	if (!unconfined(label)) {
167 		struct aa_profile *profile;
168 		struct label_it i;
169 
170 		label_for_each_confined(i, label, profile) {
171 			struct aa_ruleset *rules;
172 			if (COMPLAIN_MODE(profile))
173 				continue;
174 			rules = list_first_entry(&profile->rules,
175 						 typeof(*rules), list);
176 			*effective = cap_intersect(*effective,
177 						   rules->caps.allow);
178 			*permitted = cap_intersect(*permitted,
179 						   rules->caps.allow);
180 		}
181 	}
182 	rcu_read_unlock();
183 	aa_put_label(label);
184 
185 	return 0;
186 }
187 
apparmor_capable(const struct cred * cred,struct user_namespace * ns,int cap,unsigned int opts)188 static int apparmor_capable(const struct cred *cred, struct user_namespace *ns,
189 			    int cap, unsigned int opts)
190 {
191 	struct aa_label *label;
192 	int error = 0;
193 
194 	label = aa_get_newest_cred_label(cred);
195 	if (!unconfined(label))
196 		error = aa_capable(cred, label, cap, opts);
197 	aa_put_label(label);
198 
199 	return error;
200 }
201 
202 /**
203  * common_perm - basic common permission check wrapper fn for paths
204  * @op: operation being checked
205  * @path: path to check permission of  (NOT NULL)
206  * @mask: requested permissions mask
207  * @cond: conditional info for the permission request  (NOT NULL)
208  *
209  * Returns: %0 else error code if error or permission denied
210  */
common_perm(const char * op,const struct path * path,u32 mask,struct path_cond * cond)211 static int common_perm(const char *op, const struct path *path, u32 mask,
212 		       struct path_cond *cond)
213 {
214 	struct aa_label *label;
215 	int error = 0;
216 
217 	label = __begin_current_label_crit_section();
218 	if (!unconfined(label))
219 		error = aa_path_perm(op, current_cred(), label, path, 0, mask,
220 				     cond);
221 	__end_current_label_crit_section(label);
222 
223 	return error;
224 }
225 
226 /**
227  * common_perm_cond - common permission wrapper around inode cond
228  * @op: operation being checked
229  * @path: location to check (NOT NULL)
230  * @mask: requested permissions mask
231  *
232  * Returns: %0 else error code if error or permission denied
233  */
common_perm_cond(const char * op,const struct path * path,u32 mask)234 static int common_perm_cond(const char *op, const struct path *path, u32 mask)
235 {
236 	vfsuid_t vfsuid = i_uid_into_vfsuid(mnt_idmap(path->mnt),
237 					    d_backing_inode(path->dentry));
238 	struct path_cond cond = {
239 		vfsuid_into_kuid(vfsuid),
240 		d_backing_inode(path->dentry)->i_mode
241 	};
242 
243 	if (!path_mediated_fs(path->dentry))
244 		return 0;
245 
246 	return common_perm(op, path, mask, &cond);
247 }
248 
249 /**
250  * common_perm_dir_dentry - common permission wrapper when path is dir, dentry
251  * @op: operation being checked
252  * @dir: directory of the dentry  (NOT NULL)
253  * @dentry: dentry to check  (NOT NULL)
254  * @mask: requested permissions mask
255  * @cond: conditional info for the permission request  (NOT NULL)
256  *
257  * Returns: %0 else error code if error or permission denied
258  */
common_perm_dir_dentry(const char * op,const struct path * dir,struct dentry * dentry,u32 mask,struct path_cond * cond)259 static int common_perm_dir_dentry(const char *op, const struct path *dir,
260 				  struct dentry *dentry, u32 mask,
261 				  struct path_cond *cond)
262 {
263 	struct path path = { .mnt = dir->mnt, .dentry = dentry };
264 
265 	return common_perm(op, &path, mask, cond);
266 }
267 
268 /**
269  * common_perm_rm - common permission wrapper for operations doing rm
270  * @op: operation being checked
271  * @dir: directory that the dentry is in  (NOT NULL)
272  * @dentry: dentry being rm'd  (NOT NULL)
273  * @mask: requested permission mask
274  *
275  * Returns: %0 else error code if error or permission denied
276  */
common_perm_rm(const char * op,const struct path * dir,struct dentry * dentry,u32 mask)277 static int common_perm_rm(const char *op, const struct path *dir,
278 			  struct dentry *dentry, u32 mask)
279 {
280 	struct inode *inode = d_backing_inode(dentry);
281 	struct path_cond cond = { };
282 	vfsuid_t vfsuid;
283 
284 	if (!inode || !path_mediated_fs(dentry))
285 		return 0;
286 
287 	vfsuid = i_uid_into_vfsuid(mnt_idmap(dir->mnt), inode);
288 	cond.uid = vfsuid_into_kuid(vfsuid);
289 	cond.mode = inode->i_mode;
290 
291 	return common_perm_dir_dentry(op, dir, dentry, mask, &cond);
292 }
293 
294 /**
295  * common_perm_create - common permission wrapper for operations doing create
296  * @op: operation being checked
297  * @dir: directory that dentry will be created in  (NOT NULL)
298  * @dentry: dentry to create   (NOT NULL)
299  * @mask: request permission mask
300  * @mode: created file mode
301  *
302  * Returns: %0 else error code if error or permission denied
303  */
common_perm_create(const char * op,const struct path * dir,struct dentry * dentry,u32 mask,umode_t mode)304 static int common_perm_create(const char *op, const struct path *dir,
305 			      struct dentry *dentry, u32 mask, umode_t mode)
306 {
307 	struct path_cond cond = { current_fsuid(), mode };
308 
309 	if (!path_mediated_fs(dir->dentry))
310 		return 0;
311 
312 	return common_perm_dir_dentry(op, dir, dentry, mask, &cond);
313 }
314 
apparmor_path_unlink(const struct path * dir,struct dentry * dentry)315 static int apparmor_path_unlink(const struct path *dir, struct dentry *dentry)
316 {
317 	return common_perm_rm(OP_UNLINK, dir, dentry, AA_MAY_DELETE);
318 }
319 
apparmor_path_mkdir(const struct path * dir,struct dentry * dentry,umode_t mode)320 static int apparmor_path_mkdir(const struct path *dir, struct dentry *dentry,
321 			       umode_t mode)
322 {
323 	return common_perm_create(OP_MKDIR, dir, dentry, AA_MAY_CREATE,
324 				  S_IFDIR);
325 }
326 
apparmor_path_rmdir(const struct path * dir,struct dentry * dentry)327 static int apparmor_path_rmdir(const struct path *dir, struct dentry *dentry)
328 {
329 	return common_perm_rm(OP_RMDIR, dir, dentry, AA_MAY_DELETE);
330 }
331 
apparmor_path_mknod(const struct path * dir,struct dentry * dentry,umode_t mode,unsigned int dev)332 static int apparmor_path_mknod(const struct path *dir, struct dentry *dentry,
333 			       umode_t mode, unsigned int dev)
334 {
335 	return common_perm_create(OP_MKNOD, dir, dentry, AA_MAY_CREATE, mode);
336 }
337 
apparmor_path_truncate(const struct path * path)338 static int apparmor_path_truncate(const struct path *path)
339 {
340 	return common_perm_cond(OP_TRUNC, path, MAY_WRITE | AA_MAY_SETATTR);
341 }
342 
apparmor_file_truncate(struct file * file)343 static int apparmor_file_truncate(struct file *file)
344 {
345 	return apparmor_path_truncate(&file->f_path);
346 }
347 
apparmor_path_symlink(const struct path * dir,struct dentry * dentry,const char * old_name)348 static int apparmor_path_symlink(const struct path *dir, struct dentry *dentry,
349 				 const char *old_name)
350 {
351 	return common_perm_create(OP_SYMLINK, dir, dentry, AA_MAY_CREATE,
352 				  S_IFLNK);
353 }
354 
apparmor_path_link(struct dentry * old_dentry,const struct path * new_dir,struct dentry * new_dentry)355 static int apparmor_path_link(struct dentry *old_dentry, const struct path *new_dir,
356 			      struct dentry *new_dentry)
357 {
358 	struct aa_label *label;
359 	int error = 0;
360 
361 	if (!path_mediated_fs(old_dentry))
362 		return 0;
363 
364 	label = begin_current_label_crit_section();
365 	if (!unconfined(label))
366 		error = aa_path_link(current_cred(), label, old_dentry, new_dir,
367 				     new_dentry);
368 	end_current_label_crit_section(label);
369 
370 	return error;
371 }
372 
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)373 static int apparmor_path_rename(const struct path *old_dir, struct dentry *old_dentry,
374 				const struct path *new_dir, struct dentry *new_dentry,
375 				const unsigned int flags)
376 {
377 	struct aa_label *label;
378 	int error = 0;
379 
380 	if (!path_mediated_fs(old_dentry))
381 		return 0;
382 	if ((flags & RENAME_EXCHANGE) && !path_mediated_fs(new_dentry))
383 		return 0;
384 
385 	label = begin_current_label_crit_section();
386 	if (!unconfined(label)) {
387 		struct mnt_idmap *idmap = mnt_idmap(old_dir->mnt);
388 		vfsuid_t vfsuid;
389 		struct path old_path = { .mnt = old_dir->mnt,
390 					 .dentry = old_dentry };
391 		struct path new_path = { .mnt = new_dir->mnt,
392 					 .dentry = new_dentry };
393 		struct path_cond cond = {
394 			.mode = d_backing_inode(old_dentry)->i_mode
395 		};
396 		vfsuid = i_uid_into_vfsuid(idmap, d_backing_inode(old_dentry));
397 		cond.uid = vfsuid_into_kuid(vfsuid);
398 
399 		if (flags & RENAME_EXCHANGE) {
400 			struct path_cond cond_exchange = {
401 				.mode = d_backing_inode(new_dentry)->i_mode,
402 			};
403 			vfsuid = i_uid_into_vfsuid(idmap, d_backing_inode(old_dentry));
404 			cond_exchange.uid = vfsuid_into_kuid(vfsuid);
405 
406 			error = aa_path_perm(OP_RENAME_SRC, current_cred(),
407 					     label, &new_path, 0,
408 					     MAY_READ | AA_MAY_GETATTR | MAY_WRITE |
409 					     AA_MAY_SETATTR | AA_MAY_DELETE,
410 					     &cond_exchange);
411 			if (!error)
412 				error = aa_path_perm(OP_RENAME_DEST, current_cred(),
413 						     label, &old_path,
414 						     0, MAY_WRITE | AA_MAY_SETATTR |
415 						     AA_MAY_CREATE, &cond_exchange);
416 		}
417 
418 		if (!error)
419 			error = aa_path_perm(OP_RENAME_SRC, current_cred(),
420 					     label, &old_path, 0,
421 					     MAY_READ | AA_MAY_GETATTR | MAY_WRITE |
422 					     AA_MAY_SETATTR | AA_MAY_DELETE,
423 					     &cond);
424 		if (!error)
425 			error = aa_path_perm(OP_RENAME_DEST, current_cred(),
426 					     label, &new_path,
427 					     0, MAY_WRITE | AA_MAY_SETATTR |
428 					     AA_MAY_CREATE, &cond);
429 
430 	}
431 	end_current_label_crit_section(label);
432 
433 	return error;
434 }
435 
apparmor_path_chmod(const struct path * path,umode_t mode)436 static int apparmor_path_chmod(const struct path *path, umode_t mode)
437 {
438 	return common_perm_cond(OP_CHMOD, path, AA_MAY_CHMOD);
439 }
440 
apparmor_path_chown(const struct path * path,kuid_t uid,kgid_t gid)441 static int apparmor_path_chown(const struct path *path, kuid_t uid, kgid_t gid)
442 {
443 	return common_perm_cond(OP_CHOWN, path, AA_MAY_CHOWN);
444 }
445 
apparmor_inode_getattr(const struct path * path)446 static int apparmor_inode_getattr(const struct path *path)
447 {
448 	return common_perm_cond(OP_GETATTR, path, AA_MAY_GETATTR);
449 }
450 
apparmor_file_open(struct file * file)451 static int apparmor_file_open(struct file *file)
452 {
453 	struct aa_file_ctx *fctx = file_ctx(file);
454 	struct aa_label *label;
455 	int error = 0;
456 
457 	if (!path_mediated_fs(file->f_path.dentry))
458 		return 0;
459 
460 	/* If in exec, permission is handled by bprm hooks.
461 	 * Cache permissions granted by the previous exec check, with
462 	 * implicit read and executable mmap which are required to
463 	 * actually execute the image.
464 	 */
465 	if (current->in_execve) {
466 		fctx->allow = MAY_EXEC | MAY_READ | AA_EXEC_MMAP;
467 		return 0;
468 	}
469 
470 	label = aa_get_newest_cred_label(file->f_cred);
471 	if (!unconfined(label)) {
472 		struct mnt_idmap *idmap = file_mnt_idmap(file);
473 		struct inode *inode = file_inode(file);
474 		vfsuid_t vfsuid;
475 		struct path_cond cond = {
476 			.mode = inode->i_mode,
477 		};
478 		vfsuid = i_uid_into_vfsuid(idmap, inode);
479 		cond.uid = vfsuid_into_kuid(vfsuid);
480 
481 		error = aa_path_perm(OP_OPEN, file->f_cred,
482 				     label, &file->f_path, 0,
483 				     aa_map_file_to_perms(file), &cond);
484 		/* todo cache full allowed permissions set and state */
485 		fctx->allow = aa_map_file_to_perms(file);
486 	}
487 	aa_put_label(label);
488 
489 	return error;
490 }
491 
apparmor_file_alloc_security(struct file * file)492 static int apparmor_file_alloc_security(struct file *file)
493 {
494 	struct aa_file_ctx *ctx = file_ctx(file);
495 	struct aa_label *label = begin_current_label_crit_section();
496 
497 	spin_lock_init(&ctx->lock);
498 	rcu_assign_pointer(ctx->label, aa_get_label(label));
499 	end_current_label_crit_section(label);
500 	return 0;
501 }
502 
apparmor_file_free_security(struct file * file)503 static void apparmor_file_free_security(struct file *file)
504 {
505 	struct aa_file_ctx *ctx = file_ctx(file);
506 
507 	if (ctx)
508 		aa_put_label(rcu_access_pointer(ctx->label));
509 }
510 
common_file_perm(const char * op,struct file * file,u32 mask,bool in_atomic)511 static int common_file_perm(const char *op, struct file *file, u32 mask,
512 			    bool in_atomic)
513 {
514 	struct aa_label *label;
515 	int error = 0;
516 
517 	/* don't reaudit files closed during inheritance */
518 	if (file->f_path.dentry == aa_null.dentry)
519 		return -EACCES;
520 
521 	label = __begin_current_label_crit_section();
522 	error = aa_file_perm(op, current_cred(), label, file, mask, in_atomic);
523 	__end_current_label_crit_section(label);
524 
525 	return error;
526 }
527 
apparmor_file_receive(struct file * file)528 static int apparmor_file_receive(struct file *file)
529 {
530 	return common_file_perm(OP_FRECEIVE, file, aa_map_file_to_perms(file),
531 				false);
532 }
533 
apparmor_file_permission(struct file * file,int mask)534 static int apparmor_file_permission(struct file *file, int mask)
535 {
536 	return common_file_perm(OP_FPERM, file, mask, false);
537 }
538 
apparmor_file_lock(struct file * file,unsigned int cmd)539 static int apparmor_file_lock(struct file *file, unsigned int cmd)
540 {
541 	u32 mask = AA_MAY_LOCK;
542 
543 	if (cmd == F_WRLCK)
544 		mask |= MAY_WRITE;
545 
546 	return common_file_perm(OP_FLOCK, file, mask, false);
547 }
548 
common_mmap(const char * op,struct file * file,unsigned long prot,unsigned long flags,bool in_atomic)549 static int common_mmap(const char *op, struct file *file, unsigned long prot,
550 		       unsigned long flags, bool in_atomic)
551 {
552 	int mask = 0;
553 
554 	if (!file || !file_ctx(file))
555 		return 0;
556 
557 	if (prot & PROT_READ)
558 		mask |= MAY_READ;
559 	/*
560 	 * Private mappings don't require write perms since they don't
561 	 * write back to the files
562 	 */
563 	if ((prot & PROT_WRITE) && !(flags & MAP_PRIVATE))
564 		mask |= MAY_WRITE;
565 	if (prot & PROT_EXEC)
566 		mask |= AA_EXEC_MMAP;
567 
568 	return common_file_perm(op, file, mask, in_atomic);
569 }
570 
apparmor_mmap_file(struct file * file,unsigned long reqprot,unsigned long prot,unsigned long flags)571 static int apparmor_mmap_file(struct file *file, unsigned long reqprot,
572 			      unsigned long prot, unsigned long flags)
573 {
574 	return common_mmap(OP_FMMAP, file, prot, flags, GFP_ATOMIC);
575 }
576 
apparmor_file_mprotect(struct vm_area_struct * vma,unsigned long reqprot,unsigned long prot)577 static int apparmor_file_mprotect(struct vm_area_struct *vma,
578 				  unsigned long reqprot, unsigned long prot)
579 {
580 	return common_mmap(OP_FMPROT, vma->vm_file, prot,
581 			   !(vma->vm_flags & VM_SHARED) ? MAP_PRIVATE : 0,
582 			   false);
583 }
584 
apparmor_sb_mount(const char * dev_name,const struct path * path,const char * type,unsigned long flags,void * data)585 static int apparmor_sb_mount(const char *dev_name, const struct path *path,
586 			     const char *type, unsigned long flags, void *data)
587 {
588 	struct aa_label *label;
589 	int error = 0;
590 
591 	/* Discard magic */
592 	if ((flags & MS_MGC_MSK) == MS_MGC_VAL)
593 		flags &= ~MS_MGC_MSK;
594 
595 	flags &= ~AA_MS_IGNORE_MASK;
596 
597 	label = __begin_current_label_crit_section();
598 	if (!unconfined(label)) {
599 		if (flags & MS_REMOUNT)
600 			error = aa_remount(current_cred(), label, path, flags,
601 					   data);
602 		else if (flags & MS_BIND)
603 			error = aa_bind_mount(current_cred(), label, path,
604 					      dev_name, flags);
605 		else if (flags & (MS_SHARED | MS_PRIVATE | MS_SLAVE |
606 				  MS_UNBINDABLE))
607 			error = aa_mount_change_type(current_cred(), label,
608 						     path, flags);
609 		else if (flags & MS_MOVE)
610 			error = aa_move_mount_old(current_cred(), label, path,
611 						  dev_name);
612 		else
613 			error = aa_new_mount(current_cred(), label, dev_name,
614 					     path, type, flags, data);
615 	}
616 	__end_current_label_crit_section(label);
617 
618 	return error;
619 }
620 
apparmor_move_mount(const struct path * from_path,const struct path * to_path)621 static int apparmor_move_mount(const struct path *from_path,
622 			       const struct path *to_path)
623 {
624 	struct aa_label *label;
625 	int error = 0;
626 
627 	label = __begin_current_label_crit_section();
628 	if (!unconfined(label))
629 		error = aa_move_mount(current_cred(), label, from_path,
630 				      to_path);
631 	__end_current_label_crit_section(label);
632 
633 	return error;
634 }
635 
apparmor_sb_umount(struct vfsmount * mnt,int flags)636 static int apparmor_sb_umount(struct vfsmount *mnt, int flags)
637 {
638 	struct aa_label *label;
639 	int error = 0;
640 
641 	label = __begin_current_label_crit_section();
642 	if (!unconfined(label))
643 		error = aa_umount(current_cred(), label, mnt, flags);
644 	__end_current_label_crit_section(label);
645 
646 	return error;
647 }
648 
apparmor_sb_pivotroot(const struct path * old_path,const struct path * new_path)649 static int apparmor_sb_pivotroot(const struct path *old_path,
650 				 const struct path *new_path)
651 {
652 	struct aa_label *label;
653 	int error = 0;
654 
655 	label = aa_get_current_label();
656 	if (!unconfined(label))
657 		error = aa_pivotroot(current_cred(), label, old_path, new_path);
658 	aa_put_label(label);
659 
660 	return error;
661 }
662 
apparmor_getprocattr(struct task_struct * task,const char * name,char ** value)663 static int apparmor_getprocattr(struct task_struct *task, const char *name,
664 				char **value)
665 {
666 	int error = -ENOENT;
667 	/* released below */
668 	const struct cred *cred = get_task_cred(task);
669 	struct aa_task_ctx *ctx = task_ctx(current);
670 	struct aa_label *label = NULL;
671 
672 	if (strcmp(name, "current") == 0)
673 		label = aa_get_newest_label(cred_label(cred));
674 	else if (strcmp(name, "prev") == 0  && ctx->previous)
675 		label = aa_get_newest_label(ctx->previous);
676 	else if (strcmp(name, "exec") == 0 && ctx->onexec)
677 		label = aa_get_newest_label(ctx->onexec);
678 	else
679 		error = -EINVAL;
680 
681 	if (label)
682 		error = aa_getprocattr(label, value);
683 
684 	aa_put_label(label);
685 	put_cred(cred);
686 
687 	return error;
688 }
689 
apparmor_setprocattr(const char * name,void * value,size_t size)690 static int apparmor_setprocattr(const char *name, void *value,
691 				size_t size)
692 {
693 	char *command, *largs = NULL, *args = value;
694 	size_t arg_size;
695 	int error;
696 	DEFINE_AUDIT_DATA(ad, LSM_AUDIT_DATA_NONE, AA_CLASS_NONE,
697 			  OP_SETPROCATTR);
698 
699 	if (size == 0)
700 		return -EINVAL;
701 
702 	/* AppArmor requires that the buffer must be null terminated atm */
703 	if (args[size - 1] != '\0') {
704 		/* null terminate */
705 		largs = args = kmalloc(size + 1, GFP_KERNEL);
706 		if (!args)
707 			return -ENOMEM;
708 		memcpy(args, value, size);
709 		args[size] = '\0';
710 	}
711 
712 	error = -EINVAL;
713 	args = strim(args);
714 	command = strsep(&args, " ");
715 	if (!args)
716 		goto out;
717 	args = skip_spaces(args);
718 	if (!*args)
719 		goto out;
720 
721 	arg_size = size - (args - (largs ? largs : (char *) value));
722 	if (strcmp(name, "current") == 0) {
723 		if (strcmp(command, "changehat") == 0) {
724 			error = aa_setprocattr_changehat(args, arg_size,
725 							 AA_CHANGE_NOFLAGS);
726 		} else if (strcmp(command, "permhat") == 0) {
727 			error = aa_setprocattr_changehat(args, arg_size,
728 							 AA_CHANGE_TEST);
729 		} else if (strcmp(command, "changeprofile") == 0) {
730 			error = aa_change_profile(args, AA_CHANGE_NOFLAGS);
731 		} else if (strcmp(command, "permprofile") == 0) {
732 			error = aa_change_profile(args, AA_CHANGE_TEST);
733 		} else if (strcmp(command, "stack") == 0) {
734 			error = aa_change_profile(args, AA_CHANGE_STACK);
735 		} else
736 			goto fail;
737 	} else if (strcmp(name, "exec") == 0) {
738 		if (strcmp(command, "exec") == 0)
739 			error = aa_change_profile(args, AA_CHANGE_ONEXEC);
740 		else if (strcmp(command, "stack") == 0)
741 			error = aa_change_profile(args, (AA_CHANGE_ONEXEC |
742 							 AA_CHANGE_STACK));
743 		else
744 			goto fail;
745 	} else
746 		/* only support the "current" and "exec" process attributes */
747 		goto fail;
748 
749 	if (!error)
750 		error = size;
751 out:
752 	kfree(largs);
753 	return error;
754 
755 fail:
756 	ad.subj_label = begin_current_label_crit_section();
757 	ad.info = name;
758 	ad.error = error = -EINVAL;
759 	aa_audit_msg(AUDIT_APPARMOR_DENIED, &ad, NULL);
760 	end_current_label_crit_section(ad.subj_label);
761 	goto out;
762 }
763 
764 /**
765  * apparmor_bprm_committing_creds - do task cleanup on committing new creds
766  * @bprm: binprm for the exec  (NOT NULL)
767  */
apparmor_bprm_committing_creds(struct linux_binprm * bprm)768 static void apparmor_bprm_committing_creds(struct linux_binprm *bprm)
769 {
770 	struct aa_label *label = aa_current_raw_label();
771 	struct aa_label *new_label = cred_label(bprm->cred);
772 
773 	/* bail out if unconfined or not changing profile */
774 	if ((new_label->proxy == label->proxy) ||
775 	    (unconfined(new_label)))
776 		return;
777 
778 	aa_inherit_files(bprm->cred, current->files);
779 
780 	current->pdeath_signal = 0;
781 
782 	/* reset soft limits and set hard limits for the new label */
783 	__aa_transition_rlimits(label, new_label);
784 }
785 
786 /**
787  * apparmor_bprm_committed_creds() - do cleanup after new creds committed
788  * @bprm: binprm for the exec  (NOT NULL)
789  */
apparmor_bprm_committed_creds(struct linux_binprm * bprm)790 static void apparmor_bprm_committed_creds(struct linux_binprm *bprm)
791 {
792 	/* clear out temporary/transitional state from the context */
793 	aa_clear_task_ctx_trans(task_ctx(current));
794 
795 	return;
796 }
797 
apparmor_current_getsecid_subj(u32 * secid)798 static void apparmor_current_getsecid_subj(u32 *secid)
799 {
800 	struct aa_label *label = aa_get_current_label();
801 	*secid = label->secid;
802 	aa_put_label(label);
803 }
804 
apparmor_task_getsecid_obj(struct task_struct * p,u32 * secid)805 static void apparmor_task_getsecid_obj(struct task_struct *p, u32 *secid)
806 {
807 	struct aa_label *label = aa_get_task_label(p);
808 	*secid = label->secid;
809 	aa_put_label(label);
810 }
811 
apparmor_task_setrlimit(struct task_struct * task,unsigned int resource,struct rlimit * new_rlim)812 static int apparmor_task_setrlimit(struct task_struct *task,
813 		unsigned int resource, struct rlimit *new_rlim)
814 {
815 	struct aa_label *label = __begin_current_label_crit_section();
816 	int error = 0;
817 
818 	if (!unconfined(label))
819 		error = aa_task_setrlimit(current_cred(), label, task,
820 					  resource, new_rlim);
821 	__end_current_label_crit_section(label);
822 
823 	return error;
824 }
825 
apparmor_task_kill(struct task_struct * target,struct kernel_siginfo * info,int sig,const struct cred * cred)826 static int apparmor_task_kill(struct task_struct *target, struct kernel_siginfo *info,
827 			      int sig, const struct cred *cred)
828 {
829 	const struct cred *tc;
830 	struct aa_label *cl, *tl;
831 	int error;
832 
833 	tc = get_task_cred(target);
834 	tl = aa_get_newest_cred_label(tc);
835 	if (cred) {
836 		/*
837 		 * Dealing with USB IO specific behavior
838 		 */
839 		cl = aa_get_newest_cred_label(cred);
840 		error = aa_may_signal(cred, cl, tc, tl, sig);
841 		aa_put_label(cl);
842 	} else {
843 		cl = __begin_current_label_crit_section();
844 		error = aa_may_signal(current_cred(), cl, tc, tl, sig);
845 		__end_current_label_crit_section(cl);
846 	}
847 	aa_put_label(tl);
848 	put_cred(tc);
849 
850 	return error;
851 }
852 
853 /**
854  * apparmor_sk_alloc_security - allocate and attach the sk_security field
855  */
apparmor_sk_alloc_security(struct sock * sk,int family,gfp_t flags)856 static int apparmor_sk_alloc_security(struct sock *sk, int family, gfp_t flags)
857 {
858 	struct aa_sk_ctx *ctx;
859 
860 	ctx = kzalloc(sizeof(*ctx), flags);
861 	if (!ctx)
862 		return -ENOMEM;
863 
864 	SK_CTX(sk) = ctx;
865 
866 	return 0;
867 }
868 
869 /**
870  * apparmor_sk_free_security - free the sk_security field
871  */
apparmor_sk_free_security(struct sock * sk)872 static void apparmor_sk_free_security(struct sock *sk)
873 {
874 	struct aa_sk_ctx *ctx = SK_CTX(sk);
875 
876 	SK_CTX(sk) = NULL;
877 	aa_put_label(ctx->label);
878 	aa_put_label(ctx->peer);
879 	kfree(ctx);
880 }
881 
882 /**
883  * apparmor_sk_clone_security - clone the sk_security field
884  */
apparmor_sk_clone_security(const struct sock * sk,struct sock * newsk)885 static void apparmor_sk_clone_security(const struct sock *sk,
886 				       struct sock *newsk)
887 {
888 	struct aa_sk_ctx *ctx = SK_CTX(sk);
889 	struct aa_sk_ctx *new = SK_CTX(newsk);
890 
891 	if (new->label)
892 		aa_put_label(new->label);
893 	new->label = aa_get_label(ctx->label);
894 
895 	if (new->peer)
896 		aa_put_label(new->peer);
897 	new->peer = aa_get_label(ctx->peer);
898 }
899 
900 /**
901  * apparmor_socket_create - check perms before creating a new socket
902  */
apparmor_socket_create(int family,int type,int protocol,int kern)903 static int apparmor_socket_create(int family, int type, int protocol, int kern)
904 {
905 	struct aa_label *label;
906 	int error = 0;
907 
908 	AA_BUG(in_interrupt());
909 
910 	label = begin_current_label_crit_section();
911 	if (!(kern || unconfined(label)))
912 		error = af_select(family,
913 				  create_perm(label, family, type, protocol),
914 				  aa_af_perm(current_cred(), label,
915 					     OP_CREATE, AA_MAY_CREATE,
916 					     family, type, protocol));
917 	end_current_label_crit_section(label);
918 
919 	return error;
920 }
921 
922 /**
923  * apparmor_socket_post_create - setup the per-socket security struct
924  *
925  * Note:
926  * -   kernel sockets currently labeled unconfined but we may want to
927  *     move to a special kernel label
928  * -   socket may not have sk here if created with sock_create_lite or
929  *     sock_alloc. These should be accept cases which will be handled in
930  *     sock_graft.
931  */
apparmor_socket_post_create(struct socket * sock,int family,int type,int protocol,int kern)932 static int apparmor_socket_post_create(struct socket *sock, int family,
933 				       int type, int protocol, int kern)
934 {
935 	struct aa_label *label;
936 
937 	if (kern) {
938 		label = aa_get_label(kernel_t);
939 	} else
940 		label = aa_get_current_label();
941 
942 	if (sock->sk) {
943 		struct aa_sk_ctx *ctx = SK_CTX(sock->sk);
944 
945 		aa_put_label(ctx->label);
946 		ctx->label = aa_get_label(label);
947 	}
948 	aa_put_label(label);
949 
950 	return 0;
951 }
952 
953 /**
954  * apparmor_socket_bind - check perms before bind addr to socket
955  */
apparmor_socket_bind(struct socket * sock,struct sockaddr * address,int addrlen)956 static int apparmor_socket_bind(struct socket *sock,
957 				struct sockaddr *address, int addrlen)
958 {
959 	AA_BUG(!sock);
960 	AA_BUG(!sock->sk);
961 	AA_BUG(!address);
962 	AA_BUG(in_interrupt());
963 
964 	return af_select(sock->sk->sk_family,
965 			 bind_perm(sock, address, addrlen),
966 			 aa_sk_perm(OP_BIND, AA_MAY_BIND, sock->sk));
967 }
968 
969 /**
970  * apparmor_socket_connect - check perms before connecting @sock to @address
971  */
apparmor_socket_connect(struct socket * sock,struct sockaddr * address,int addrlen)972 static int apparmor_socket_connect(struct socket *sock,
973 				   struct sockaddr *address, int addrlen)
974 {
975 	AA_BUG(!sock);
976 	AA_BUG(!sock->sk);
977 	AA_BUG(!address);
978 	AA_BUG(in_interrupt());
979 
980 	return af_select(sock->sk->sk_family,
981 			 connect_perm(sock, address, addrlen),
982 			 aa_sk_perm(OP_CONNECT, AA_MAY_CONNECT, sock->sk));
983 }
984 
985 /**
986  * apparmor_socket_listen - check perms before allowing listen
987  */
apparmor_socket_listen(struct socket * sock,int backlog)988 static int apparmor_socket_listen(struct socket *sock, int backlog)
989 {
990 	AA_BUG(!sock);
991 	AA_BUG(!sock->sk);
992 	AA_BUG(in_interrupt());
993 
994 	return af_select(sock->sk->sk_family,
995 			 listen_perm(sock, backlog),
996 			 aa_sk_perm(OP_LISTEN, AA_MAY_LISTEN, sock->sk));
997 }
998 
999 /**
1000  * apparmor_socket_accept - check perms before accepting a new connection.
1001  *
1002  * Note: while @newsock is created and has some information, the accept
1003  *       has not been done.
1004  */
apparmor_socket_accept(struct socket * sock,struct socket * newsock)1005 static int apparmor_socket_accept(struct socket *sock, struct socket *newsock)
1006 {
1007 	AA_BUG(!sock);
1008 	AA_BUG(!sock->sk);
1009 	AA_BUG(!newsock);
1010 	AA_BUG(in_interrupt());
1011 
1012 	return af_select(sock->sk->sk_family,
1013 			 accept_perm(sock, newsock),
1014 			 aa_sk_perm(OP_ACCEPT, AA_MAY_ACCEPT, sock->sk));
1015 }
1016 
aa_sock_msg_perm(const char * op,u32 request,struct socket * sock,struct msghdr * msg,int size)1017 static int aa_sock_msg_perm(const char *op, u32 request, struct socket *sock,
1018 			    struct msghdr *msg, int size)
1019 {
1020 	AA_BUG(!sock);
1021 	AA_BUG(!sock->sk);
1022 	AA_BUG(!msg);
1023 	AA_BUG(in_interrupt());
1024 
1025 	return af_select(sock->sk->sk_family,
1026 			 msg_perm(op, request, sock, msg, size),
1027 			 aa_sk_perm(op, request, sock->sk));
1028 }
1029 
1030 /**
1031  * apparmor_socket_sendmsg - check perms before sending msg to another socket
1032  */
apparmor_socket_sendmsg(struct socket * sock,struct msghdr * msg,int size)1033 static int apparmor_socket_sendmsg(struct socket *sock,
1034 				   struct msghdr *msg, int size)
1035 {
1036 	return aa_sock_msg_perm(OP_SENDMSG, AA_MAY_SEND, sock, msg, size);
1037 }
1038 
1039 /**
1040  * apparmor_socket_recvmsg - check perms before receiving a message
1041  */
apparmor_socket_recvmsg(struct socket * sock,struct msghdr * msg,int size,int flags)1042 static int apparmor_socket_recvmsg(struct socket *sock,
1043 				   struct msghdr *msg, int size, int flags)
1044 {
1045 	return aa_sock_msg_perm(OP_RECVMSG, AA_MAY_RECEIVE, sock, msg, size);
1046 }
1047 
1048 /* revaliation, get/set attr, shutdown */
aa_sock_perm(const char * op,u32 request,struct socket * sock)1049 static int aa_sock_perm(const char *op, u32 request, struct socket *sock)
1050 {
1051 	AA_BUG(!sock);
1052 	AA_BUG(!sock->sk);
1053 	AA_BUG(in_interrupt());
1054 
1055 	return af_select(sock->sk->sk_family,
1056 			 sock_perm(op, request, sock),
1057 			 aa_sk_perm(op, request, sock->sk));
1058 }
1059 
1060 /**
1061  * apparmor_socket_getsockname - check perms before getting the local address
1062  */
apparmor_socket_getsockname(struct socket * sock)1063 static int apparmor_socket_getsockname(struct socket *sock)
1064 {
1065 	return aa_sock_perm(OP_GETSOCKNAME, AA_MAY_GETATTR, sock);
1066 }
1067 
1068 /**
1069  * apparmor_socket_getpeername - check perms before getting remote address
1070  */
apparmor_socket_getpeername(struct socket * sock)1071 static int apparmor_socket_getpeername(struct socket *sock)
1072 {
1073 	return aa_sock_perm(OP_GETPEERNAME, AA_MAY_GETATTR, sock);
1074 }
1075 
1076 /* revaliation, get/set attr, opt */
aa_sock_opt_perm(const char * op,u32 request,struct socket * sock,int level,int optname)1077 static int aa_sock_opt_perm(const char *op, u32 request, struct socket *sock,
1078 			    int level, int optname)
1079 {
1080 	AA_BUG(!sock);
1081 	AA_BUG(!sock->sk);
1082 	AA_BUG(in_interrupt());
1083 
1084 	return af_select(sock->sk->sk_family,
1085 			 opt_perm(op, request, sock, level, optname),
1086 			 aa_sk_perm(op, request, sock->sk));
1087 }
1088 
1089 /**
1090  * apparmor_socket_getsockopt - check perms before getting socket options
1091  */
apparmor_socket_getsockopt(struct socket * sock,int level,int optname)1092 static int apparmor_socket_getsockopt(struct socket *sock, int level,
1093 				      int optname)
1094 {
1095 	return aa_sock_opt_perm(OP_GETSOCKOPT, AA_MAY_GETOPT, sock,
1096 				level, optname);
1097 }
1098 
1099 /**
1100  * apparmor_socket_setsockopt - check perms before setting socket options
1101  */
apparmor_socket_setsockopt(struct socket * sock,int level,int optname)1102 static int apparmor_socket_setsockopt(struct socket *sock, int level,
1103 				      int optname)
1104 {
1105 	return aa_sock_opt_perm(OP_SETSOCKOPT, AA_MAY_SETOPT, sock,
1106 				level, optname);
1107 }
1108 
1109 /**
1110  * apparmor_socket_shutdown - check perms before shutting down @sock conn
1111  */
apparmor_socket_shutdown(struct socket * sock,int how)1112 static int apparmor_socket_shutdown(struct socket *sock, int how)
1113 {
1114 	return aa_sock_perm(OP_SHUTDOWN, AA_MAY_SHUTDOWN, sock);
1115 }
1116 
1117 #ifdef CONFIG_NETWORK_SECMARK
1118 /**
1119  * apparmor_socket_sock_rcv_skb - check perms before associating skb to sk
1120  *
1121  * Note: can not sleep may be called with locks held
1122  *
1123  * dont want protocol specific in __skb_recv_datagram()
1124  * to deny an incoming connection  socket_sock_rcv_skb()
1125  */
apparmor_socket_sock_rcv_skb(struct sock * sk,struct sk_buff * skb)1126 static int apparmor_socket_sock_rcv_skb(struct sock *sk, struct sk_buff *skb)
1127 {
1128 	struct aa_sk_ctx *ctx = SK_CTX(sk);
1129 
1130 	if (!skb->secmark)
1131 		return 0;
1132 
1133 	return apparmor_secmark_check(ctx->label, OP_RECVMSG, AA_MAY_RECEIVE,
1134 				      skb->secmark, sk);
1135 }
1136 #endif
1137 
1138 
sk_peer_label(struct sock * sk)1139 static struct aa_label *sk_peer_label(struct sock *sk)
1140 {
1141 	struct aa_sk_ctx *ctx = SK_CTX(sk);
1142 
1143 	if (ctx->peer)
1144 		return ctx->peer;
1145 
1146 	return ERR_PTR(-ENOPROTOOPT);
1147 }
1148 
1149 /**
1150  * apparmor_socket_getpeersec_stream - get security context of peer
1151  *
1152  * Note: for tcp only valid if using ipsec or cipso on lan
1153  */
apparmor_socket_getpeersec_stream(struct socket * sock,sockptr_t optval,sockptr_t optlen,unsigned int len)1154 static int apparmor_socket_getpeersec_stream(struct socket *sock,
1155 					     sockptr_t optval, sockptr_t optlen,
1156 					     unsigned int len)
1157 {
1158 	char *name = NULL;
1159 	int slen, error = 0;
1160 	struct aa_label *label;
1161 	struct aa_label *peer;
1162 
1163 	label = begin_current_label_crit_section();
1164 	peer = sk_peer_label(sock->sk);
1165 	if (IS_ERR(peer)) {
1166 		error = PTR_ERR(peer);
1167 		goto done;
1168 	}
1169 	slen = aa_label_asxprint(&name, labels_ns(label), peer,
1170 				 FLAG_SHOW_MODE | FLAG_VIEW_SUBNS |
1171 				 FLAG_HIDDEN_UNCONFINED, GFP_KERNEL);
1172 	/* don't include terminating \0 in slen, it breaks some apps */
1173 	if (slen < 0) {
1174 		error = -ENOMEM;
1175 		goto done;
1176 	}
1177 	if (slen > len) {
1178 		error = -ERANGE;
1179 		goto done_len;
1180 	}
1181 
1182 	if (copy_to_sockptr(optval, name, slen))
1183 		error = -EFAULT;
1184 done_len:
1185 	if (copy_to_sockptr(optlen, &slen, sizeof(slen)))
1186 		error = -EFAULT;
1187 done:
1188 	end_current_label_crit_section(label);
1189 	kfree(name);
1190 	return error;
1191 }
1192 
1193 /**
1194  * apparmor_socket_getpeersec_dgram - get security label of packet
1195  * @sock: the peer socket
1196  * @skb: packet data
1197  * @secid: pointer to where to put the secid of the packet
1198  *
1199  * Sets the netlabel socket state on sk from parent
1200  */
apparmor_socket_getpeersec_dgram(struct socket * sock,struct sk_buff * skb,u32 * secid)1201 static int apparmor_socket_getpeersec_dgram(struct socket *sock,
1202 					    struct sk_buff *skb, u32 *secid)
1203 
1204 {
1205 	/* TODO: requires secid support */
1206 	return -ENOPROTOOPT;
1207 }
1208 
1209 /**
1210  * apparmor_sock_graft - Initialize newly created socket
1211  * @sk: child sock
1212  * @parent: parent socket
1213  *
1214  * Note: could set off of SOCK_CTX(parent) but need to track inode and we can
1215  *       just set sk security information off of current creating process label
1216  *       Labeling of sk for accept case - probably should be sock based
1217  *       instead of task, because of the case where an implicitly labeled
1218  *       socket is shared by different tasks.
1219  */
apparmor_sock_graft(struct sock * sk,struct socket * parent)1220 static void apparmor_sock_graft(struct sock *sk, struct socket *parent)
1221 {
1222 	struct aa_sk_ctx *ctx = SK_CTX(sk);
1223 
1224 	if (!ctx->label)
1225 		ctx->label = aa_get_current_label();
1226 }
1227 
1228 #ifdef CONFIG_NETWORK_SECMARK
apparmor_inet_conn_request(const struct sock * sk,struct sk_buff * skb,struct request_sock * req)1229 static int apparmor_inet_conn_request(const struct sock *sk, struct sk_buff *skb,
1230 				      struct request_sock *req)
1231 {
1232 	struct aa_sk_ctx *ctx = SK_CTX(sk);
1233 
1234 	if (!skb->secmark)
1235 		return 0;
1236 
1237 	return apparmor_secmark_check(ctx->label, OP_CONNECT, AA_MAY_CONNECT,
1238 				      skb->secmark, sk);
1239 }
1240 #endif
1241 
1242 /*
1243  * The cred blob is a pointer to, not an instance of, an aa_label.
1244  */
1245 struct lsm_blob_sizes apparmor_blob_sizes __ro_after_init = {
1246 	.lbs_cred = sizeof(struct aa_label *),
1247 	.lbs_file = sizeof(struct aa_file_ctx),
1248 	.lbs_task = sizeof(struct aa_task_ctx),
1249 };
1250 
1251 static struct security_hook_list apparmor_hooks[] __ro_after_init = {
1252 	LSM_HOOK_INIT(ptrace_access_check, apparmor_ptrace_access_check),
1253 	LSM_HOOK_INIT(ptrace_traceme, apparmor_ptrace_traceme),
1254 	LSM_HOOK_INIT(capget, apparmor_capget),
1255 	LSM_HOOK_INIT(capable, apparmor_capable),
1256 
1257 	LSM_HOOK_INIT(move_mount, apparmor_move_mount),
1258 	LSM_HOOK_INIT(sb_mount, apparmor_sb_mount),
1259 	LSM_HOOK_INIT(sb_umount, apparmor_sb_umount),
1260 	LSM_HOOK_INIT(sb_pivotroot, apparmor_sb_pivotroot),
1261 
1262 	LSM_HOOK_INIT(path_link, apparmor_path_link),
1263 	LSM_HOOK_INIT(path_unlink, apparmor_path_unlink),
1264 	LSM_HOOK_INIT(path_symlink, apparmor_path_symlink),
1265 	LSM_HOOK_INIT(path_mkdir, apparmor_path_mkdir),
1266 	LSM_HOOK_INIT(path_rmdir, apparmor_path_rmdir),
1267 	LSM_HOOK_INIT(path_mknod, apparmor_path_mknod),
1268 	LSM_HOOK_INIT(path_rename, apparmor_path_rename),
1269 	LSM_HOOK_INIT(path_chmod, apparmor_path_chmod),
1270 	LSM_HOOK_INIT(path_chown, apparmor_path_chown),
1271 	LSM_HOOK_INIT(path_truncate, apparmor_path_truncate),
1272 	LSM_HOOK_INIT(inode_getattr, apparmor_inode_getattr),
1273 
1274 	LSM_HOOK_INIT(file_open, apparmor_file_open),
1275 	LSM_HOOK_INIT(file_receive, apparmor_file_receive),
1276 	LSM_HOOK_INIT(file_permission, apparmor_file_permission),
1277 	LSM_HOOK_INIT(file_alloc_security, apparmor_file_alloc_security),
1278 	LSM_HOOK_INIT(file_free_security, apparmor_file_free_security),
1279 	LSM_HOOK_INIT(mmap_file, apparmor_mmap_file),
1280 	LSM_HOOK_INIT(file_mprotect, apparmor_file_mprotect),
1281 	LSM_HOOK_INIT(file_lock, apparmor_file_lock),
1282 	LSM_HOOK_INIT(file_truncate, apparmor_file_truncate),
1283 
1284 	LSM_HOOK_INIT(getprocattr, apparmor_getprocattr),
1285 	LSM_HOOK_INIT(setprocattr, apparmor_setprocattr),
1286 
1287 	LSM_HOOK_INIT(sk_alloc_security, apparmor_sk_alloc_security),
1288 	LSM_HOOK_INIT(sk_free_security, apparmor_sk_free_security),
1289 	LSM_HOOK_INIT(sk_clone_security, apparmor_sk_clone_security),
1290 
1291 	LSM_HOOK_INIT(socket_create, apparmor_socket_create),
1292 	LSM_HOOK_INIT(socket_post_create, apparmor_socket_post_create),
1293 	LSM_HOOK_INIT(socket_bind, apparmor_socket_bind),
1294 	LSM_HOOK_INIT(socket_connect, apparmor_socket_connect),
1295 	LSM_HOOK_INIT(socket_listen, apparmor_socket_listen),
1296 	LSM_HOOK_INIT(socket_accept, apparmor_socket_accept),
1297 	LSM_HOOK_INIT(socket_sendmsg, apparmor_socket_sendmsg),
1298 	LSM_HOOK_INIT(socket_recvmsg, apparmor_socket_recvmsg),
1299 	LSM_HOOK_INIT(socket_getsockname, apparmor_socket_getsockname),
1300 	LSM_HOOK_INIT(socket_getpeername, apparmor_socket_getpeername),
1301 	LSM_HOOK_INIT(socket_getsockopt, apparmor_socket_getsockopt),
1302 	LSM_HOOK_INIT(socket_setsockopt, apparmor_socket_setsockopt),
1303 	LSM_HOOK_INIT(socket_shutdown, apparmor_socket_shutdown),
1304 #ifdef CONFIG_NETWORK_SECMARK
1305 	LSM_HOOK_INIT(socket_sock_rcv_skb, apparmor_socket_sock_rcv_skb),
1306 #endif
1307 	LSM_HOOK_INIT(socket_getpeersec_stream,
1308 		      apparmor_socket_getpeersec_stream),
1309 	LSM_HOOK_INIT(socket_getpeersec_dgram,
1310 		      apparmor_socket_getpeersec_dgram),
1311 	LSM_HOOK_INIT(sock_graft, apparmor_sock_graft),
1312 #ifdef CONFIG_NETWORK_SECMARK
1313 	LSM_HOOK_INIT(inet_conn_request, apparmor_inet_conn_request),
1314 #endif
1315 
1316 	LSM_HOOK_INIT(cred_alloc_blank, apparmor_cred_alloc_blank),
1317 	LSM_HOOK_INIT(cred_free, apparmor_cred_free),
1318 	LSM_HOOK_INIT(cred_prepare, apparmor_cred_prepare),
1319 	LSM_HOOK_INIT(cred_transfer, apparmor_cred_transfer),
1320 
1321 	LSM_HOOK_INIT(bprm_creds_for_exec, apparmor_bprm_creds_for_exec),
1322 	LSM_HOOK_INIT(bprm_committing_creds, apparmor_bprm_committing_creds),
1323 	LSM_HOOK_INIT(bprm_committed_creds, apparmor_bprm_committed_creds),
1324 
1325 	LSM_HOOK_INIT(task_free, apparmor_task_free),
1326 	LSM_HOOK_INIT(task_alloc, apparmor_task_alloc),
1327 	LSM_HOOK_INIT(current_getsecid_subj, apparmor_current_getsecid_subj),
1328 	LSM_HOOK_INIT(task_getsecid_obj, apparmor_task_getsecid_obj),
1329 	LSM_HOOK_INIT(task_setrlimit, apparmor_task_setrlimit),
1330 	LSM_HOOK_INIT(task_kill, apparmor_task_kill),
1331 
1332 #ifdef CONFIG_AUDIT
1333 	LSM_HOOK_INIT(audit_rule_init, aa_audit_rule_init),
1334 	LSM_HOOK_INIT(audit_rule_known, aa_audit_rule_known),
1335 	LSM_HOOK_INIT(audit_rule_match, aa_audit_rule_match),
1336 	LSM_HOOK_INIT(audit_rule_free, aa_audit_rule_free),
1337 #endif
1338 
1339 	LSM_HOOK_INIT(secid_to_secctx, apparmor_secid_to_secctx),
1340 	LSM_HOOK_INIT(secctx_to_secid, apparmor_secctx_to_secid),
1341 	LSM_HOOK_INIT(release_secctx, apparmor_release_secctx),
1342 };
1343 
1344 /*
1345  * AppArmor sysfs module parameters
1346  */
1347 
1348 static int param_set_aabool(const char *val, const struct kernel_param *kp);
1349 static int param_get_aabool(char *buffer, const struct kernel_param *kp);
1350 #define param_check_aabool param_check_bool
1351 static const struct kernel_param_ops param_ops_aabool = {
1352 	.flags = KERNEL_PARAM_OPS_FL_NOARG,
1353 	.set = param_set_aabool,
1354 	.get = param_get_aabool
1355 };
1356 
1357 static int param_set_aauint(const char *val, const struct kernel_param *kp);
1358 static int param_get_aauint(char *buffer, const struct kernel_param *kp);
1359 #define param_check_aauint param_check_uint
1360 static const struct kernel_param_ops param_ops_aauint = {
1361 	.set = param_set_aauint,
1362 	.get = param_get_aauint
1363 };
1364 
1365 static int param_set_aacompressionlevel(const char *val,
1366 					const struct kernel_param *kp);
1367 static int param_get_aacompressionlevel(char *buffer,
1368 					const struct kernel_param *kp);
1369 #define param_check_aacompressionlevel param_check_int
1370 static const struct kernel_param_ops param_ops_aacompressionlevel = {
1371 	.set = param_set_aacompressionlevel,
1372 	.get = param_get_aacompressionlevel
1373 };
1374 
1375 static int param_set_aalockpolicy(const char *val, const struct kernel_param *kp);
1376 static int param_get_aalockpolicy(char *buffer, const struct kernel_param *kp);
1377 #define param_check_aalockpolicy param_check_bool
1378 static const struct kernel_param_ops param_ops_aalockpolicy = {
1379 	.flags = KERNEL_PARAM_OPS_FL_NOARG,
1380 	.set = param_set_aalockpolicy,
1381 	.get = param_get_aalockpolicy
1382 };
1383 
1384 static int param_set_audit(const char *val, const struct kernel_param *kp);
1385 static int param_get_audit(char *buffer, const struct kernel_param *kp);
1386 
1387 static int param_set_mode(const char *val, const struct kernel_param *kp);
1388 static int param_get_mode(char *buffer, const struct kernel_param *kp);
1389 
1390 /* Flag values, also controllable via /sys/module/apparmor/parameters
1391  * We define special types as we want to do additional mediation.
1392  */
1393 
1394 /* AppArmor global enforcement switch - complain, enforce, kill */
1395 enum profile_mode aa_g_profile_mode = APPARMOR_ENFORCE;
1396 module_param_call(mode, param_set_mode, param_get_mode,
1397 		  &aa_g_profile_mode, S_IRUSR | S_IWUSR);
1398 
1399 /* whether policy verification hashing is enabled */
1400 bool aa_g_hash_policy = IS_ENABLED(CONFIG_SECURITY_APPARMOR_HASH_DEFAULT);
1401 #ifdef CONFIG_SECURITY_APPARMOR_HASH
1402 module_param_named(hash_policy, aa_g_hash_policy, aabool, S_IRUSR | S_IWUSR);
1403 #endif
1404 
1405 /* whether policy exactly as loaded is retained for debug and checkpointing */
1406 bool aa_g_export_binary = IS_ENABLED(CONFIG_SECURITY_APPARMOR_EXPORT_BINARY);
1407 #ifdef CONFIG_SECURITY_APPARMOR_EXPORT_BINARY
1408 module_param_named(export_binary, aa_g_export_binary, aabool, 0600);
1409 #endif
1410 
1411 /* policy loaddata compression level */
1412 int aa_g_rawdata_compression_level = AA_DEFAULT_CLEVEL;
1413 module_param_named(rawdata_compression_level, aa_g_rawdata_compression_level,
1414 		   aacompressionlevel, 0400);
1415 
1416 /* Debug mode */
1417 bool aa_g_debug = IS_ENABLED(CONFIG_SECURITY_APPARMOR_DEBUG_MESSAGES);
1418 module_param_named(debug, aa_g_debug, aabool, S_IRUSR | S_IWUSR);
1419 
1420 /* Audit mode */
1421 enum audit_mode aa_g_audit;
1422 module_param_call(audit, param_set_audit, param_get_audit,
1423 		  &aa_g_audit, S_IRUSR | S_IWUSR);
1424 
1425 /* Determines if audit header is included in audited messages.  This
1426  * provides more context if the audit daemon is not running
1427  */
1428 bool aa_g_audit_header = true;
1429 module_param_named(audit_header, aa_g_audit_header, aabool,
1430 		   S_IRUSR | S_IWUSR);
1431 
1432 /* lock out loading/removal of policy
1433  * TODO: add in at boot loading of policy, which is the only way to
1434  *       load policy, if lock_policy is set
1435  */
1436 bool aa_g_lock_policy;
1437 module_param_named(lock_policy, aa_g_lock_policy, aalockpolicy,
1438 		   S_IRUSR | S_IWUSR);
1439 
1440 /* Syscall logging mode */
1441 bool aa_g_logsyscall;
1442 module_param_named(logsyscall, aa_g_logsyscall, aabool, S_IRUSR | S_IWUSR);
1443 
1444 /* Maximum pathname length before accesses will start getting rejected */
1445 unsigned int aa_g_path_max = 2 * PATH_MAX;
1446 module_param_named(path_max, aa_g_path_max, aauint, S_IRUSR);
1447 
1448 /* Determines how paranoid loading of policy is and how much verification
1449  * on the loaded policy is done.
1450  * DEPRECATED: read only as strict checking of load is always done now
1451  * that none root users (user namespaces) can load policy.
1452  */
1453 bool aa_g_paranoid_load = IS_ENABLED(CONFIG_SECURITY_APPARMOR_PARANOID_LOAD);
1454 module_param_named(paranoid_load, aa_g_paranoid_load, aabool, S_IRUGO);
1455 
1456 static int param_get_aaintbool(char *buffer, const struct kernel_param *kp);
1457 static int param_set_aaintbool(const char *val, const struct kernel_param *kp);
1458 #define param_check_aaintbool param_check_int
1459 static const struct kernel_param_ops param_ops_aaintbool = {
1460 	.set = param_set_aaintbool,
1461 	.get = param_get_aaintbool
1462 };
1463 /* Boot time disable flag */
1464 static int apparmor_enabled __ro_after_init = 1;
1465 module_param_named(enabled, apparmor_enabled, aaintbool, 0444);
1466 
apparmor_enabled_setup(char * str)1467 static int __init apparmor_enabled_setup(char *str)
1468 {
1469 	unsigned long enabled;
1470 	int error = kstrtoul(str, 0, &enabled);
1471 	if (!error)
1472 		apparmor_enabled = enabled ? 1 : 0;
1473 	return 1;
1474 }
1475 
1476 __setup("apparmor=", apparmor_enabled_setup);
1477 
1478 /* set global flag turning off the ability to load policy */
param_set_aalockpolicy(const char * val,const struct kernel_param * kp)1479 static int param_set_aalockpolicy(const char *val, const struct kernel_param *kp)
1480 {
1481 	if (!apparmor_enabled)
1482 		return -EINVAL;
1483 	if (apparmor_initialized && !aa_current_policy_admin_capable(NULL))
1484 		return -EPERM;
1485 	return param_set_bool(val, kp);
1486 }
1487 
param_get_aalockpolicy(char * buffer,const struct kernel_param * kp)1488 static int param_get_aalockpolicy(char *buffer, const struct kernel_param *kp)
1489 {
1490 	if (!apparmor_enabled)
1491 		return -EINVAL;
1492 	if (apparmor_initialized && !aa_current_policy_view_capable(NULL))
1493 		return -EPERM;
1494 	return param_get_bool(buffer, kp);
1495 }
1496 
param_set_aabool(const char * val,const struct kernel_param * kp)1497 static int param_set_aabool(const char *val, const struct kernel_param *kp)
1498 {
1499 	if (!apparmor_enabled)
1500 		return -EINVAL;
1501 	if (apparmor_initialized && !aa_current_policy_admin_capable(NULL))
1502 		return -EPERM;
1503 	return param_set_bool(val, kp);
1504 }
1505 
param_get_aabool(char * buffer,const struct kernel_param * kp)1506 static int param_get_aabool(char *buffer, const struct kernel_param *kp)
1507 {
1508 	if (!apparmor_enabled)
1509 		return -EINVAL;
1510 	if (apparmor_initialized && !aa_current_policy_view_capable(NULL))
1511 		return -EPERM;
1512 	return param_get_bool(buffer, kp);
1513 }
1514 
param_set_aauint(const char * val,const struct kernel_param * kp)1515 static int param_set_aauint(const char *val, const struct kernel_param *kp)
1516 {
1517 	int error;
1518 
1519 	if (!apparmor_enabled)
1520 		return -EINVAL;
1521 	/* file is ro but enforce 2nd line check */
1522 	if (apparmor_initialized)
1523 		return -EPERM;
1524 
1525 	error = param_set_uint(val, kp);
1526 	aa_g_path_max = max_t(uint32_t, aa_g_path_max, sizeof(union aa_buffer));
1527 	pr_info("AppArmor: buffer size set to %d bytes\n", aa_g_path_max);
1528 
1529 	return error;
1530 }
1531 
param_get_aauint(char * buffer,const struct kernel_param * kp)1532 static int param_get_aauint(char *buffer, const struct kernel_param *kp)
1533 {
1534 	if (!apparmor_enabled)
1535 		return -EINVAL;
1536 	if (apparmor_initialized && !aa_current_policy_view_capable(NULL))
1537 		return -EPERM;
1538 	return param_get_uint(buffer, kp);
1539 }
1540 
1541 /* Can only be set before AppArmor is initialized (i.e. on boot cmdline). */
param_set_aaintbool(const char * val,const struct kernel_param * kp)1542 static int param_set_aaintbool(const char *val, const struct kernel_param *kp)
1543 {
1544 	struct kernel_param kp_local;
1545 	bool value;
1546 	int error;
1547 
1548 	if (apparmor_initialized)
1549 		return -EPERM;
1550 
1551 	/* Create local copy, with arg pointing to bool type. */
1552 	value = !!*((int *)kp->arg);
1553 	memcpy(&kp_local, kp, sizeof(kp_local));
1554 	kp_local.arg = &value;
1555 
1556 	error = param_set_bool(val, &kp_local);
1557 	if (!error)
1558 		*((int *)kp->arg) = *((bool *)kp_local.arg);
1559 	return error;
1560 }
1561 
1562 /*
1563  * To avoid changing /sys/module/apparmor/parameters/enabled from Y/N to
1564  * 1/0, this converts the "int that is actually bool" back to bool for
1565  * display in the /sys filesystem, while keeping it "int" for the LSM
1566  * infrastructure.
1567  */
param_get_aaintbool(char * buffer,const struct kernel_param * kp)1568 static int param_get_aaintbool(char *buffer, const struct kernel_param *kp)
1569 {
1570 	struct kernel_param kp_local;
1571 	bool value;
1572 
1573 	/* Create local copy, with arg pointing to bool type. */
1574 	value = !!*((int *)kp->arg);
1575 	memcpy(&kp_local, kp, sizeof(kp_local));
1576 	kp_local.arg = &value;
1577 
1578 	return param_get_bool(buffer, &kp_local);
1579 }
1580 
param_set_aacompressionlevel(const char * val,const struct kernel_param * kp)1581 static int param_set_aacompressionlevel(const char *val,
1582 					const struct kernel_param *kp)
1583 {
1584 	int error;
1585 
1586 	if (!apparmor_enabled)
1587 		return -EINVAL;
1588 	if (apparmor_initialized)
1589 		return -EPERM;
1590 
1591 	error = param_set_int(val, kp);
1592 
1593 	aa_g_rawdata_compression_level = clamp(aa_g_rawdata_compression_level,
1594 					       AA_MIN_CLEVEL, AA_MAX_CLEVEL);
1595 	pr_info("AppArmor: policy rawdata compression level set to %d\n",
1596 		aa_g_rawdata_compression_level);
1597 
1598 	return error;
1599 }
1600 
param_get_aacompressionlevel(char * buffer,const struct kernel_param * kp)1601 static int param_get_aacompressionlevel(char *buffer,
1602 					const struct kernel_param *kp)
1603 {
1604 	if (!apparmor_enabled)
1605 		return -EINVAL;
1606 	if (apparmor_initialized && !aa_current_policy_view_capable(NULL))
1607 		return -EPERM;
1608 	return param_get_int(buffer, kp);
1609 }
1610 
param_get_audit(char * buffer,const struct kernel_param * kp)1611 static int param_get_audit(char *buffer, const struct kernel_param *kp)
1612 {
1613 	if (!apparmor_enabled)
1614 		return -EINVAL;
1615 	if (apparmor_initialized && !aa_current_policy_view_capable(NULL))
1616 		return -EPERM;
1617 	return sprintf(buffer, "%s", audit_mode_names[aa_g_audit]);
1618 }
1619 
param_set_audit(const char * val,const struct kernel_param * kp)1620 static int param_set_audit(const char *val, const struct kernel_param *kp)
1621 {
1622 	int i;
1623 
1624 	if (!apparmor_enabled)
1625 		return -EINVAL;
1626 	if (!val)
1627 		return -EINVAL;
1628 	if (apparmor_initialized && !aa_current_policy_admin_capable(NULL))
1629 		return -EPERM;
1630 
1631 	i = match_string(audit_mode_names, AUDIT_MAX_INDEX, val);
1632 	if (i < 0)
1633 		return -EINVAL;
1634 
1635 	aa_g_audit = i;
1636 	return 0;
1637 }
1638 
param_get_mode(char * buffer,const struct kernel_param * kp)1639 static int param_get_mode(char *buffer, const struct kernel_param *kp)
1640 {
1641 	if (!apparmor_enabled)
1642 		return -EINVAL;
1643 	if (apparmor_initialized && !aa_current_policy_view_capable(NULL))
1644 		return -EPERM;
1645 
1646 	return sprintf(buffer, "%s", aa_profile_mode_names[aa_g_profile_mode]);
1647 }
1648 
param_set_mode(const char * val,const struct kernel_param * kp)1649 static int param_set_mode(const char *val, const struct kernel_param *kp)
1650 {
1651 	int i;
1652 
1653 	if (!apparmor_enabled)
1654 		return -EINVAL;
1655 	if (!val)
1656 		return -EINVAL;
1657 	if (apparmor_initialized && !aa_current_policy_admin_capable(NULL))
1658 		return -EPERM;
1659 
1660 	i = match_string(aa_profile_mode_names, APPARMOR_MODE_NAMES_MAX_INDEX,
1661 			 val);
1662 	if (i < 0)
1663 		return -EINVAL;
1664 
1665 	aa_g_profile_mode = i;
1666 	return 0;
1667 }
1668 
aa_get_buffer(bool in_atomic)1669 char *aa_get_buffer(bool in_atomic)
1670 {
1671 	union aa_buffer *aa_buf;
1672 	bool try_again = true;
1673 	gfp_t flags = (GFP_KERNEL | __GFP_RETRY_MAYFAIL | __GFP_NOWARN);
1674 
1675 retry:
1676 	spin_lock(&aa_buffers_lock);
1677 	if (buffer_count > reserve_count ||
1678 	    (in_atomic && !list_empty(&aa_global_buffers))) {
1679 		aa_buf = list_first_entry(&aa_global_buffers, union aa_buffer,
1680 					  list);
1681 		list_del(&aa_buf->list);
1682 		buffer_count--;
1683 		spin_unlock(&aa_buffers_lock);
1684 		return aa_buf->buffer;
1685 	}
1686 	if (in_atomic) {
1687 		/*
1688 		 * out of reserve buffers and in atomic context so increase
1689 		 * how many buffers to keep in reserve
1690 		 */
1691 		reserve_count++;
1692 		flags = GFP_ATOMIC;
1693 	}
1694 	spin_unlock(&aa_buffers_lock);
1695 
1696 	if (!in_atomic)
1697 		might_sleep();
1698 	aa_buf = kmalloc(aa_g_path_max, flags);
1699 	if (!aa_buf) {
1700 		if (try_again) {
1701 			try_again = false;
1702 			goto retry;
1703 		}
1704 		pr_warn_once("AppArmor: Failed to allocate a memory buffer.\n");
1705 		return NULL;
1706 	}
1707 	return aa_buf->buffer;
1708 }
1709 
aa_put_buffer(char * buf)1710 void aa_put_buffer(char *buf)
1711 {
1712 	union aa_buffer *aa_buf;
1713 
1714 	if (!buf)
1715 		return;
1716 	aa_buf = container_of(buf, union aa_buffer, buffer[0]);
1717 
1718 	spin_lock(&aa_buffers_lock);
1719 	list_add(&aa_buf->list, &aa_global_buffers);
1720 	buffer_count++;
1721 	spin_unlock(&aa_buffers_lock);
1722 }
1723 
1724 /*
1725  * AppArmor init functions
1726  */
1727 
1728 /**
1729  * set_init_ctx - set a task context and profile on the first task.
1730  *
1731  * TODO: allow setting an alternate profile than unconfined
1732  */
set_init_ctx(void)1733 static int __init set_init_ctx(void)
1734 {
1735 	struct cred *cred = (__force struct cred *)current->real_cred;
1736 
1737 	set_cred_label(cred, aa_get_label(ns_unconfined(root_ns)));
1738 
1739 	return 0;
1740 }
1741 
destroy_buffers(void)1742 static void destroy_buffers(void)
1743 {
1744 	union aa_buffer *aa_buf;
1745 
1746 	spin_lock(&aa_buffers_lock);
1747 	while (!list_empty(&aa_global_buffers)) {
1748 		aa_buf = list_first_entry(&aa_global_buffers, union aa_buffer,
1749 					 list);
1750 		list_del(&aa_buf->list);
1751 		spin_unlock(&aa_buffers_lock);
1752 		kfree(aa_buf);
1753 		spin_lock(&aa_buffers_lock);
1754 	}
1755 	spin_unlock(&aa_buffers_lock);
1756 }
1757 
alloc_buffers(void)1758 static int __init alloc_buffers(void)
1759 {
1760 	union aa_buffer *aa_buf;
1761 	int i, num;
1762 
1763 	/*
1764 	 * A function may require two buffers at once. Usually the buffers are
1765 	 * used for a short period of time and are shared. On UP kernel buffers
1766 	 * two should be enough, with more CPUs it is possible that more
1767 	 * buffers will be used simultaneously. The preallocated pool may grow.
1768 	 * This preallocation has also the side-effect that AppArmor will be
1769 	 * disabled early at boot if aa_g_path_max is extremly high.
1770 	 */
1771 	if (num_online_cpus() > 1)
1772 		num = 4 + RESERVE_COUNT;
1773 	else
1774 		num = 2 + RESERVE_COUNT;
1775 
1776 	for (i = 0; i < num; i++) {
1777 
1778 		aa_buf = kmalloc(aa_g_path_max, GFP_KERNEL |
1779 				 __GFP_RETRY_MAYFAIL | __GFP_NOWARN);
1780 		if (!aa_buf) {
1781 			destroy_buffers();
1782 			return -ENOMEM;
1783 		}
1784 		aa_put_buffer(aa_buf->buffer);
1785 	}
1786 	return 0;
1787 }
1788 
1789 #ifdef CONFIG_SYSCTL
apparmor_dointvec(struct ctl_table * table,int write,void * buffer,size_t * lenp,loff_t * ppos)1790 static int apparmor_dointvec(struct ctl_table *table, int write,
1791 			     void *buffer, size_t *lenp, loff_t *ppos)
1792 {
1793 	if (!aa_current_policy_admin_capable(NULL))
1794 		return -EPERM;
1795 	if (!apparmor_enabled)
1796 		return -EINVAL;
1797 
1798 	return proc_dointvec(table, write, buffer, lenp, ppos);
1799 }
1800 
1801 static struct ctl_table apparmor_sysctl_table[] = {
1802 	{
1803 		.procname       = "unprivileged_userns_apparmor_policy",
1804 		.data           = &unprivileged_userns_apparmor_policy,
1805 		.maxlen         = sizeof(int),
1806 		.mode           = 0600,
1807 		.proc_handler   = apparmor_dointvec,
1808 	},
1809 	{
1810 		.procname       = "apparmor_display_secid_mode",
1811 		.data           = &apparmor_display_secid_mode,
1812 		.maxlen         = sizeof(int),
1813 		.mode           = 0600,
1814 		.proc_handler   = apparmor_dointvec,
1815 	},
1816 
1817 	{ }
1818 };
1819 
apparmor_init_sysctl(void)1820 static int __init apparmor_init_sysctl(void)
1821 {
1822 	return register_sysctl("kernel", apparmor_sysctl_table) ? 0 : -ENOMEM;
1823 }
1824 #else
apparmor_init_sysctl(void)1825 static inline int apparmor_init_sysctl(void)
1826 {
1827 	return 0;
1828 }
1829 #endif /* CONFIG_SYSCTL */
1830 
1831 #if defined(CONFIG_NETFILTER) && defined(CONFIG_NETWORK_SECMARK)
apparmor_ip_postroute(void * priv,struct sk_buff * skb,const struct nf_hook_state * state)1832 static unsigned int apparmor_ip_postroute(void *priv,
1833 					  struct sk_buff *skb,
1834 					  const struct nf_hook_state *state)
1835 {
1836 	struct aa_sk_ctx *ctx;
1837 	struct sock *sk;
1838 
1839 	if (!skb->secmark)
1840 		return NF_ACCEPT;
1841 
1842 	sk = skb_to_full_sk(skb);
1843 	if (sk == NULL)
1844 		return NF_ACCEPT;
1845 
1846 	ctx = SK_CTX(sk);
1847 	if (!apparmor_secmark_check(ctx->label, OP_SENDMSG, AA_MAY_SEND,
1848 				    skb->secmark, sk))
1849 		return NF_ACCEPT;
1850 
1851 	return NF_DROP_ERR(-ECONNREFUSED);
1852 
1853 }
1854 
1855 static const struct nf_hook_ops apparmor_nf_ops[] = {
1856 	{
1857 		.hook =         apparmor_ip_postroute,
1858 		.pf =           NFPROTO_IPV4,
1859 		.hooknum =      NF_INET_POST_ROUTING,
1860 		.priority =     NF_IP_PRI_SELINUX_FIRST,
1861 	},
1862 #if IS_ENABLED(CONFIG_IPV6)
1863 	{
1864 		.hook =         apparmor_ip_postroute,
1865 		.pf =           NFPROTO_IPV6,
1866 		.hooknum =      NF_INET_POST_ROUTING,
1867 		.priority =     NF_IP6_PRI_SELINUX_FIRST,
1868 	},
1869 #endif
1870 };
1871 
apparmor_nf_register(struct net * net)1872 static int __net_init apparmor_nf_register(struct net *net)
1873 {
1874 	return nf_register_net_hooks(net, apparmor_nf_ops,
1875 				    ARRAY_SIZE(apparmor_nf_ops));
1876 }
1877 
apparmor_nf_unregister(struct net * net)1878 static void __net_exit apparmor_nf_unregister(struct net *net)
1879 {
1880 	nf_unregister_net_hooks(net, apparmor_nf_ops,
1881 				ARRAY_SIZE(apparmor_nf_ops));
1882 }
1883 
1884 static struct pernet_operations apparmor_net_ops = {
1885 	.init = apparmor_nf_register,
1886 	.exit = apparmor_nf_unregister,
1887 };
1888 
apparmor_nf_ip_init(void)1889 static int __init apparmor_nf_ip_init(void)
1890 {
1891 	int err;
1892 
1893 	if (!apparmor_enabled)
1894 		return 0;
1895 
1896 	err = register_pernet_subsys(&apparmor_net_ops);
1897 	if (err)
1898 		panic("Apparmor: register_pernet_subsys: error %d\n", err);
1899 
1900 	return 0;
1901 }
1902 __initcall(apparmor_nf_ip_init);
1903 #endif
1904 
apparmor_init(void)1905 static int __init apparmor_init(void)
1906 {
1907 	int error;
1908 
1909 	error = aa_setup_dfa_engine();
1910 	if (error) {
1911 		AA_ERROR("Unable to setup dfa engine\n");
1912 		goto alloc_out;
1913 	}
1914 
1915 	error = aa_alloc_root_ns();
1916 	if (error) {
1917 		AA_ERROR("Unable to allocate default profile namespace\n");
1918 		goto alloc_out;
1919 	}
1920 
1921 	error = apparmor_init_sysctl();
1922 	if (error) {
1923 		AA_ERROR("Unable to register sysctls\n");
1924 		goto alloc_out;
1925 
1926 	}
1927 
1928 	error = alloc_buffers();
1929 	if (error) {
1930 		AA_ERROR("Unable to allocate work buffers\n");
1931 		goto alloc_out;
1932 	}
1933 
1934 	error = set_init_ctx();
1935 	if (error) {
1936 		AA_ERROR("Failed to set context on init task\n");
1937 		aa_free_root_ns();
1938 		goto buffers_out;
1939 	}
1940 	security_add_hooks(apparmor_hooks, ARRAY_SIZE(apparmor_hooks),
1941 				"apparmor");
1942 
1943 	/* Report that AppArmor successfully initialized */
1944 	apparmor_initialized = 1;
1945 	if (aa_g_profile_mode == APPARMOR_COMPLAIN)
1946 		aa_info_message("AppArmor initialized: complain mode enabled");
1947 	else if (aa_g_profile_mode == APPARMOR_KILL)
1948 		aa_info_message("AppArmor initialized: kill mode enabled");
1949 	else
1950 		aa_info_message("AppArmor initialized");
1951 
1952 	return error;
1953 
1954 buffers_out:
1955 	destroy_buffers();
1956 alloc_out:
1957 	aa_destroy_aafs();
1958 	aa_teardown_dfa_engine();
1959 
1960 	apparmor_enabled = false;
1961 	return error;
1962 }
1963 
1964 DEFINE_LSM(apparmor) = {
1965 	.name = "apparmor",
1966 	.flags = LSM_FLAG_LEGACY_MAJOR | LSM_FLAG_EXCLUSIVE,
1967 	.enabled = &apparmor_enabled,
1968 	.blobs = &apparmor_blob_sizes,
1969 	.init = apparmor_init,
1970 };
1971