xref: /linux/security/apparmor/lsm.c (revision f728c17fc97aea7a33151d9ba64106291c62bb02)
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 #include <uapi/linux/lsm.h>
28 
29 #include "include/apparmor.h"
30 #include "include/apparmorfs.h"
31 #include "include/audit.h"
32 #include "include/capability.h"
33 #include "include/cred.h"
34 #include "include/file.h"
35 #include "include/ipc.h"
36 #include "include/net.h"
37 #include "include/path.h"
38 #include "include/label.h"
39 #include "include/policy.h"
40 #include "include/policy_ns.h"
41 #include "include/procattr.h"
42 #include "include/mount.h"
43 #include "include/secid.h"
44 
45 /* Flag indicating whether initialization completed */
46 int apparmor_initialized;
47 
48 union aa_buffer {
49 	struct list_head list;
50 	DECLARE_FLEX_ARRAY(char, buffer);
51 };
52 
53 struct aa_local_cache {
54 	unsigned int hold;
55 	unsigned int count;
56 	struct list_head head;
57 };
58 
59 #define RESERVE_COUNT 2
60 static int reserve_count = RESERVE_COUNT;
61 static int buffer_count;
62 
63 static LIST_HEAD(aa_global_buffers);
64 static DEFINE_SPINLOCK(aa_buffers_lock);
65 static DEFINE_PER_CPU(struct aa_local_cache, aa_local_buffers);
66 
67 /*
68  * LSM hook functions
69  */
70 
71 /*
72  * put the associated labels
73  */
74 static void apparmor_cred_free(struct cred *cred)
75 {
76 	aa_put_label(cred_label(cred));
77 	set_cred_label(cred, NULL);
78 }
79 
80 /*
81  * allocate the apparmor part of blank credentials
82  */
83 static int apparmor_cred_alloc_blank(struct cred *cred, gfp_t gfp)
84 {
85 	set_cred_label(cred, NULL);
86 	return 0;
87 }
88 
89 /*
90  * prepare new cred label for modification by prepare_cred block
91  */
92 static int apparmor_cred_prepare(struct cred *new, const struct cred *old,
93 				 gfp_t gfp)
94 {
95 	set_cred_label(new, aa_get_newest_label(cred_label(old)));
96 	return 0;
97 }
98 
99 /*
100  * transfer the apparmor data to a blank set of creds
101  */
102 static void apparmor_cred_transfer(struct cred *new, const struct cred *old)
103 {
104 	set_cred_label(new, aa_get_newest_label(cred_label(old)));
105 }
106 
107 static void apparmor_task_free(struct task_struct *task)
108 {
109 
110 	aa_free_task_ctx(task_ctx(task));
111 }
112 
113 static int apparmor_task_alloc(struct task_struct *task,
114 			       unsigned long clone_flags)
115 {
116 	struct aa_task_ctx *new = task_ctx(task);
117 
118 	aa_dup_task_ctx(new, task_ctx(current));
119 
120 	return 0;
121 }
122 
123 static int apparmor_ptrace_access_check(struct task_struct *child,
124 					unsigned int mode)
125 {
126 	struct aa_label *tracer, *tracee;
127 	const struct cred *cred;
128 	int error;
129 
130 	cred = get_task_cred(child);
131 	tracee = cred_label(cred);	/* ref count on cred */
132 	tracer = __begin_current_label_crit_section();
133 	error = aa_may_ptrace(current_cred(), tracer, cred, tracee,
134 			(mode & PTRACE_MODE_READ) ? AA_PTRACE_READ
135 						  : AA_PTRACE_TRACE);
136 	__end_current_label_crit_section(tracer);
137 	put_cred(cred);
138 
139 	return error;
140 }
141 
142 static int apparmor_ptrace_traceme(struct task_struct *parent)
143 {
144 	struct aa_label *tracer, *tracee;
145 	const struct cred *cred;
146 	int error;
147 
148 	tracee = __begin_current_label_crit_section();
149 	cred = get_task_cred(parent);
150 	tracer = cred_label(cred);	/* ref count on cred */
151 	error = aa_may_ptrace(cred, tracer, current_cred(), tracee,
152 			      AA_PTRACE_TRACE);
153 	put_cred(cred);
154 	__end_current_label_crit_section(tracee);
155 
156 	return error;
157 }
158 
159 /* Derived from security/commoncap.c:cap_capget */
160 static int apparmor_capget(const struct task_struct *target, kernel_cap_t *effective,
161 			   kernel_cap_t *inheritable, kernel_cap_t *permitted)
162 {
163 	struct aa_label *label;
164 	const struct cred *cred;
165 
166 	rcu_read_lock();
167 	cred = __task_cred(target);
168 	label = aa_get_newest_cred_label(cred);
169 
170 	/*
171 	 * cap_capget is stacked ahead of this and will
172 	 * initialize effective and permitted.
173 	 */
174 	if (!unconfined(label)) {
175 		struct aa_profile *profile;
176 		struct label_it i;
177 
178 		label_for_each_confined(i, label, profile) {
179 			struct aa_ruleset *rules;
180 			if (COMPLAIN_MODE(profile))
181 				continue;
182 			rules = list_first_entry(&profile->rules,
183 						 typeof(*rules), list);
184 			*effective = cap_intersect(*effective,
185 						   rules->caps.allow);
186 			*permitted = cap_intersect(*permitted,
187 						   rules->caps.allow);
188 		}
189 	}
190 	rcu_read_unlock();
191 	aa_put_label(label);
192 
193 	return 0;
194 }
195 
196 static int apparmor_capable(const struct cred *cred, struct user_namespace *ns,
197 			    int cap, unsigned int opts)
198 {
199 	struct aa_label *label;
200 	int error = 0;
201 
202 	label = aa_get_newest_cred_label(cred);
203 	if (!unconfined(label))
204 		error = aa_capable(cred, label, cap, opts);
205 	aa_put_label(label);
206 
207 	return error;
208 }
209 
210 /**
211  * common_perm - basic common permission check wrapper fn for paths
212  * @op: operation being checked
213  * @path: path to check permission of  (NOT NULL)
214  * @mask: requested permissions mask
215  * @cond: conditional info for the permission request  (NOT NULL)
216  *
217  * Returns: %0 else error code if error or permission denied
218  */
219 static int common_perm(const char *op, const struct path *path, u32 mask,
220 		       struct path_cond *cond)
221 {
222 	struct aa_label *label;
223 	int error = 0;
224 
225 	label = __begin_current_label_crit_section();
226 	if (!unconfined(label))
227 		error = aa_path_perm(op, current_cred(), label, path, 0, mask,
228 				     cond);
229 	__end_current_label_crit_section(label);
230 
231 	return error;
232 }
233 
234 /**
235  * common_perm_cond - common permission wrapper around inode cond
236  * @op: operation being checked
237  * @path: location to check (NOT NULL)
238  * @mask: requested permissions mask
239  *
240  * Returns: %0 else error code if error or permission denied
241  */
242 static int common_perm_cond(const char *op, const struct path *path, u32 mask)
243 {
244 	vfsuid_t vfsuid = i_uid_into_vfsuid(mnt_idmap(path->mnt),
245 					    d_backing_inode(path->dentry));
246 	struct path_cond cond = {
247 		vfsuid_into_kuid(vfsuid),
248 		d_backing_inode(path->dentry)->i_mode
249 	};
250 
251 	if (!path_mediated_fs(path->dentry))
252 		return 0;
253 
254 	return common_perm(op, path, mask, &cond);
255 }
256 
257 /**
258  * common_perm_dir_dentry - common permission wrapper when path is dir, dentry
259  * @op: operation being checked
260  * @dir: directory of the dentry  (NOT NULL)
261  * @dentry: dentry to check  (NOT NULL)
262  * @mask: requested permissions mask
263  * @cond: conditional info for the permission request  (NOT NULL)
264  *
265  * Returns: %0 else error code if error or permission denied
266  */
267 static int common_perm_dir_dentry(const char *op, const struct path *dir,
268 				  struct dentry *dentry, u32 mask,
269 				  struct path_cond *cond)
270 {
271 	struct path path = { .mnt = dir->mnt, .dentry = dentry };
272 
273 	return common_perm(op, &path, mask, cond);
274 }
275 
276 /**
277  * common_perm_rm - common permission wrapper for operations doing rm
278  * @op: operation being checked
279  * @dir: directory that the dentry is in  (NOT NULL)
280  * @dentry: dentry being rm'd  (NOT NULL)
281  * @mask: requested permission mask
282  *
283  * Returns: %0 else error code if error or permission denied
284  */
285 static int common_perm_rm(const char *op, const struct path *dir,
286 			  struct dentry *dentry, u32 mask)
287 {
288 	struct inode *inode = d_backing_inode(dentry);
289 	struct path_cond cond = { };
290 	vfsuid_t vfsuid;
291 
292 	if (!inode || !path_mediated_fs(dentry))
293 		return 0;
294 
295 	vfsuid = i_uid_into_vfsuid(mnt_idmap(dir->mnt), inode);
296 	cond.uid = vfsuid_into_kuid(vfsuid);
297 	cond.mode = inode->i_mode;
298 
299 	return common_perm_dir_dentry(op, dir, dentry, mask, &cond);
300 }
301 
302 /**
303  * common_perm_create - common permission wrapper for operations doing create
304  * @op: operation being checked
305  * @dir: directory that dentry will be created in  (NOT NULL)
306  * @dentry: dentry to create   (NOT NULL)
307  * @mask: request permission mask
308  * @mode: created file mode
309  *
310  * Returns: %0 else error code if error or permission denied
311  */
312 static int common_perm_create(const char *op, const struct path *dir,
313 			      struct dentry *dentry, u32 mask, umode_t mode)
314 {
315 	struct path_cond cond = { current_fsuid(), mode };
316 
317 	if (!path_mediated_fs(dir->dentry))
318 		return 0;
319 
320 	return common_perm_dir_dentry(op, dir, dentry, mask, &cond);
321 }
322 
323 static int apparmor_path_unlink(const struct path *dir, struct dentry *dentry)
324 {
325 	return common_perm_rm(OP_UNLINK, dir, dentry, AA_MAY_DELETE);
326 }
327 
328 static int apparmor_path_mkdir(const struct path *dir, struct dentry *dentry,
329 			       umode_t mode)
330 {
331 	return common_perm_create(OP_MKDIR, dir, dentry, AA_MAY_CREATE,
332 				  S_IFDIR);
333 }
334 
335 static int apparmor_path_rmdir(const struct path *dir, struct dentry *dentry)
336 {
337 	return common_perm_rm(OP_RMDIR, dir, dentry, AA_MAY_DELETE);
338 }
339 
340 static int apparmor_path_mknod(const struct path *dir, struct dentry *dentry,
341 			       umode_t mode, unsigned int dev)
342 {
343 	return common_perm_create(OP_MKNOD, dir, dentry, AA_MAY_CREATE, mode);
344 }
345 
346 static int apparmor_path_truncate(const struct path *path)
347 {
348 	return common_perm_cond(OP_TRUNC, path, MAY_WRITE | AA_MAY_SETATTR);
349 }
350 
351 static int apparmor_file_truncate(struct file *file)
352 {
353 	return apparmor_path_truncate(&file->f_path);
354 }
355 
356 static int apparmor_path_symlink(const struct path *dir, struct dentry *dentry,
357 				 const char *old_name)
358 {
359 	return common_perm_create(OP_SYMLINK, dir, dentry, AA_MAY_CREATE,
360 				  S_IFLNK);
361 }
362 
363 static int apparmor_path_link(struct dentry *old_dentry, const struct path *new_dir,
364 			      struct dentry *new_dentry)
365 {
366 	struct aa_label *label;
367 	int error = 0;
368 
369 	if (!path_mediated_fs(old_dentry))
370 		return 0;
371 
372 	label = begin_current_label_crit_section();
373 	if (!unconfined(label))
374 		error = aa_path_link(current_cred(), label, old_dentry, new_dir,
375 				     new_dentry);
376 	end_current_label_crit_section(label);
377 
378 	return error;
379 }
380 
381 static int apparmor_path_rename(const struct path *old_dir, struct dentry *old_dentry,
382 				const struct path *new_dir, struct dentry *new_dentry,
383 				const unsigned int flags)
384 {
385 	struct aa_label *label;
386 	int error = 0;
387 
388 	if (!path_mediated_fs(old_dentry))
389 		return 0;
390 	if ((flags & RENAME_EXCHANGE) && !path_mediated_fs(new_dentry))
391 		return 0;
392 
393 	label = begin_current_label_crit_section();
394 	if (!unconfined(label)) {
395 		struct mnt_idmap *idmap = mnt_idmap(old_dir->mnt);
396 		vfsuid_t vfsuid;
397 		struct path old_path = { .mnt = old_dir->mnt,
398 					 .dentry = old_dentry };
399 		struct path new_path = { .mnt = new_dir->mnt,
400 					 .dentry = new_dentry };
401 		struct path_cond cond = {
402 			.mode = d_backing_inode(old_dentry)->i_mode
403 		};
404 		vfsuid = i_uid_into_vfsuid(idmap, d_backing_inode(old_dentry));
405 		cond.uid = vfsuid_into_kuid(vfsuid);
406 
407 		if (flags & RENAME_EXCHANGE) {
408 			struct path_cond cond_exchange = {
409 				.mode = d_backing_inode(new_dentry)->i_mode,
410 			};
411 			vfsuid = i_uid_into_vfsuid(idmap, d_backing_inode(old_dentry));
412 			cond_exchange.uid = vfsuid_into_kuid(vfsuid);
413 
414 			error = aa_path_perm(OP_RENAME_SRC, current_cred(),
415 					     label, &new_path, 0,
416 					     MAY_READ | AA_MAY_GETATTR | MAY_WRITE |
417 					     AA_MAY_SETATTR | AA_MAY_DELETE,
418 					     &cond_exchange);
419 			if (!error)
420 				error = aa_path_perm(OP_RENAME_DEST, current_cred(),
421 						     label, &old_path,
422 						     0, MAY_WRITE | AA_MAY_SETATTR |
423 						     AA_MAY_CREATE, &cond_exchange);
424 		}
425 
426 		if (!error)
427 			error = aa_path_perm(OP_RENAME_SRC, current_cred(),
428 					     label, &old_path, 0,
429 					     MAY_READ | AA_MAY_GETATTR | MAY_WRITE |
430 					     AA_MAY_SETATTR | AA_MAY_DELETE,
431 					     &cond);
432 		if (!error)
433 			error = aa_path_perm(OP_RENAME_DEST, current_cred(),
434 					     label, &new_path,
435 					     0, MAY_WRITE | AA_MAY_SETATTR |
436 					     AA_MAY_CREATE, &cond);
437 
438 	}
439 	end_current_label_crit_section(label);
440 
441 	return error;
442 }
443 
444 static int apparmor_path_chmod(const struct path *path, umode_t mode)
445 {
446 	return common_perm_cond(OP_CHMOD, path, AA_MAY_CHMOD);
447 }
448 
449 static int apparmor_path_chown(const struct path *path, kuid_t uid, kgid_t gid)
450 {
451 	return common_perm_cond(OP_CHOWN, path, AA_MAY_CHOWN);
452 }
453 
454 static int apparmor_inode_getattr(const struct path *path)
455 {
456 	return common_perm_cond(OP_GETATTR, path, AA_MAY_GETATTR);
457 }
458 
459 static int apparmor_file_open(struct file *file)
460 {
461 	struct aa_file_ctx *fctx = file_ctx(file);
462 	struct aa_label *label;
463 	int error = 0;
464 
465 	if (!path_mediated_fs(file->f_path.dentry))
466 		return 0;
467 
468 	/* If in exec, permission is handled by bprm hooks.
469 	 * Cache permissions granted by the previous exec check, with
470 	 * implicit read and executable mmap which are required to
471 	 * actually execute the image.
472 	 *
473 	 * Illogically, FMODE_EXEC is in f_flags, not f_mode.
474 	 */
475 	if (file->f_flags & __FMODE_EXEC) {
476 		fctx->allow = MAY_EXEC | MAY_READ | AA_EXEC_MMAP;
477 		return 0;
478 	}
479 
480 	label = aa_get_newest_cred_label(file->f_cred);
481 	if (!unconfined(label)) {
482 		struct mnt_idmap *idmap = file_mnt_idmap(file);
483 		struct inode *inode = file_inode(file);
484 		vfsuid_t vfsuid;
485 		struct path_cond cond = {
486 			.mode = inode->i_mode,
487 		};
488 		vfsuid = i_uid_into_vfsuid(idmap, inode);
489 		cond.uid = vfsuid_into_kuid(vfsuid);
490 
491 		error = aa_path_perm(OP_OPEN, file->f_cred,
492 				     label, &file->f_path, 0,
493 				     aa_map_file_to_perms(file), &cond);
494 		/* todo cache full allowed permissions set and state */
495 		fctx->allow = aa_map_file_to_perms(file);
496 	}
497 	aa_put_label(label);
498 
499 	return error;
500 }
501 
502 static int apparmor_file_alloc_security(struct file *file)
503 {
504 	struct aa_file_ctx *ctx = file_ctx(file);
505 	struct aa_label *label = begin_current_label_crit_section();
506 
507 	spin_lock_init(&ctx->lock);
508 	rcu_assign_pointer(ctx->label, aa_get_label(label));
509 	end_current_label_crit_section(label);
510 	return 0;
511 }
512 
513 static void apparmor_file_free_security(struct file *file)
514 {
515 	struct aa_file_ctx *ctx = file_ctx(file);
516 
517 	if (ctx)
518 		aa_put_label(rcu_access_pointer(ctx->label));
519 }
520 
521 static int common_file_perm(const char *op, struct file *file, u32 mask,
522 			    bool in_atomic)
523 {
524 	struct aa_label *label;
525 	int error = 0;
526 
527 	/* don't reaudit files closed during inheritance */
528 	if (file->f_path.dentry == aa_null.dentry)
529 		return -EACCES;
530 
531 	label = __begin_current_label_crit_section();
532 	error = aa_file_perm(op, current_cred(), label, file, mask, in_atomic);
533 	__end_current_label_crit_section(label);
534 
535 	return error;
536 }
537 
538 static int apparmor_file_receive(struct file *file)
539 {
540 	return common_file_perm(OP_FRECEIVE, file, aa_map_file_to_perms(file),
541 				false);
542 }
543 
544 static int apparmor_file_permission(struct file *file, int mask)
545 {
546 	return common_file_perm(OP_FPERM, file, mask, false);
547 }
548 
549 static int apparmor_file_lock(struct file *file, unsigned int cmd)
550 {
551 	u32 mask = AA_MAY_LOCK;
552 
553 	if (cmd == F_WRLCK)
554 		mask |= MAY_WRITE;
555 
556 	return common_file_perm(OP_FLOCK, file, mask, false);
557 }
558 
559 static int common_mmap(const char *op, struct file *file, unsigned long prot,
560 		       unsigned long flags, bool in_atomic)
561 {
562 	int mask = 0;
563 
564 	if (!file || !file_ctx(file))
565 		return 0;
566 
567 	if (prot & PROT_READ)
568 		mask |= MAY_READ;
569 	/*
570 	 * Private mappings don't require write perms since they don't
571 	 * write back to the files
572 	 */
573 	if ((prot & PROT_WRITE) && !(flags & MAP_PRIVATE))
574 		mask |= MAY_WRITE;
575 	if (prot & PROT_EXEC)
576 		mask |= AA_EXEC_MMAP;
577 
578 	return common_file_perm(op, file, mask, in_atomic);
579 }
580 
581 static int apparmor_mmap_file(struct file *file, unsigned long reqprot,
582 			      unsigned long prot, unsigned long flags)
583 {
584 	return common_mmap(OP_FMMAP, file, prot, flags, GFP_ATOMIC);
585 }
586 
587 static int apparmor_file_mprotect(struct vm_area_struct *vma,
588 				  unsigned long reqprot, unsigned long prot)
589 {
590 	return common_mmap(OP_FMPROT, vma->vm_file, prot,
591 			   !(vma->vm_flags & VM_SHARED) ? MAP_PRIVATE : 0,
592 			   false);
593 }
594 
595 #ifdef CONFIG_IO_URING
596 static const char *audit_uring_mask(u32 mask)
597 {
598 	if (mask & AA_MAY_CREATE_SQPOLL)
599 		return "sqpoll";
600 	if (mask & AA_MAY_OVERRIDE_CRED)
601 		return "override_creds";
602 	return "";
603 }
604 
605 static void audit_uring_cb(struct audit_buffer *ab, void *va)
606 {
607 	struct apparmor_audit_data *ad = aad_of_va(va);
608 
609 	if (ad->request & AA_URING_PERM_MASK) {
610 		audit_log_format(ab, " requested=\"%s\"",
611 				 audit_uring_mask(ad->request));
612 		if (ad->denied & AA_URING_PERM_MASK) {
613 			audit_log_format(ab, " denied=\"%s\"",
614 					 audit_uring_mask(ad->denied));
615 		}
616 	}
617 	if (ad->uring.target) {
618 		audit_log_format(ab, " tcontext=");
619 		aa_label_xaudit(ab, labels_ns(ad->subj_label),
620 				ad->uring.target,
621 				FLAGS_NONE, GFP_ATOMIC);
622 	}
623 }
624 
625 static int profile_uring(struct aa_profile *profile, u32 request,
626 			 struct aa_label *new, int cap,
627 			 struct apparmor_audit_data *ad)
628 {
629 	unsigned int state;
630 	struct aa_ruleset *rules;
631 	int error = 0;
632 
633 	AA_BUG(!profile);
634 
635 	rules = list_first_entry(&profile->rules, typeof(*rules), list);
636 	state = RULE_MEDIATES(rules, AA_CLASS_IO_URING);
637 	if (state) {
638 		struct aa_perms perms = { };
639 
640 		if (new) {
641 			aa_label_match(profile, rules, new, state,
642 				       false, request, &perms);
643 		} else {
644 			perms = *aa_lookup_perms(rules->policy, state);
645 		}
646 		aa_apply_modes_to_perms(profile, &perms);
647 		error = aa_check_perms(profile, &perms, request, ad,
648 				       audit_uring_cb);
649 	}
650 
651 	return error;
652 }
653 
654 /**
655  * apparmor_uring_override_creds - check the requested cred override
656  * @new: the target creds
657  *
658  * Check to see if the current task is allowed to override it's credentials
659  * to service an io_uring operation.
660  */
661 static int apparmor_uring_override_creds(const struct cred *new)
662 {
663 	struct aa_profile *profile;
664 	struct aa_label *label;
665 	int error;
666 	DEFINE_AUDIT_DATA(ad, LSM_AUDIT_DATA_NONE, AA_CLASS_IO_URING,
667 			  OP_URING_OVERRIDE);
668 
669 	ad.uring.target = cred_label(new);
670 	label = __begin_current_label_crit_section();
671 	error = fn_for_each(label, profile,
672 			profile_uring(profile, AA_MAY_OVERRIDE_CRED,
673 				      cred_label(new), CAP_SYS_ADMIN, &ad));
674 	__end_current_label_crit_section(label);
675 
676 	return error;
677 }
678 
679 /**
680  * apparmor_uring_sqpoll - check if a io_uring polling thread can be created
681  *
682  * Check to see if the current task is allowed to create a new io_uring
683  * kernel polling thread.
684  */
685 static int apparmor_uring_sqpoll(void)
686 {
687 	struct aa_profile *profile;
688 	struct aa_label *label;
689 	int error;
690 	DEFINE_AUDIT_DATA(ad, LSM_AUDIT_DATA_NONE, AA_CLASS_IO_URING,
691 			  OP_URING_SQPOLL);
692 
693 	label = __begin_current_label_crit_section();
694 	error = fn_for_each(label, profile,
695 			profile_uring(profile, AA_MAY_CREATE_SQPOLL,
696 				      NULL, CAP_SYS_ADMIN, &ad));
697 	__end_current_label_crit_section(label);
698 
699 	return error;
700 }
701 #endif /* CONFIG_IO_URING */
702 
703 static int apparmor_sb_mount(const char *dev_name, const struct path *path,
704 			     const char *type, unsigned long flags, void *data)
705 {
706 	struct aa_label *label;
707 	int error = 0;
708 
709 	/* Discard magic */
710 	if ((flags & MS_MGC_MSK) == MS_MGC_VAL)
711 		flags &= ~MS_MGC_MSK;
712 
713 	flags &= ~AA_MS_IGNORE_MASK;
714 
715 	label = __begin_current_label_crit_section();
716 	if (!unconfined(label)) {
717 		if (flags & MS_REMOUNT)
718 			error = aa_remount(current_cred(), label, path, flags,
719 					   data);
720 		else if (flags & MS_BIND)
721 			error = aa_bind_mount(current_cred(), label, path,
722 					      dev_name, flags);
723 		else if (flags & (MS_SHARED | MS_PRIVATE | MS_SLAVE |
724 				  MS_UNBINDABLE))
725 			error = aa_mount_change_type(current_cred(), label,
726 						     path, flags);
727 		else if (flags & MS_MOVE)
728 			error = aa_move_mount_old(current_cred(), label, path,
729 						  dev_name);
730 		else
731 			error = aa_new_mount(current_cred(), label, dev_name,
732 					     path, type, flags, data);
733 	}
734 	__end_current_label_crit_section(label);
735 
736 	return error;
737 }
738 
739 static int apparmor_move_mount(const struct path *from_path,
740 			       const struct path *to_path)
741 {
742 	struct aa_label *label;
743 	int error = 0;
744 
745 	label = __begin_current_label_crit_section();
746 	if (!unconfined(label))
747 		error = aa_move_mount(current_cred(), label, from_path,
748 				      to_path);
749 	__end_current_label_crit_section(label);
750 
751 	return error;
752 }
753 
754 static int apparmor_sb_umount(struct vfsmount *mnt, int flags)
755 {
756 	struct aa_label *label;
757 	int error = 0;
758 
759 	label = __begin_current_label_crit_section();
760 	if (!unconfined(label))
761 		error = aa_umount(current_cred(), label, mnt, flags);
762 	__end_current_label_crit_section(label);
763 
764 	return error;
765 }
766 
767 static int apparmor_sb_pivotroot(const struct path *old_path,
768 				 const struct path *new_path)
769 {
770 	struct aa_label *label;
771 	int error = 0;
772 
773 	label = aa_get_current_label();
774 	if (!unconfined(label))
775 		error = aa_pivotroot(current_cred(), label, old_path, new_path);
776 	aa_put_label(label);
777 
778 	return error;
779 }
780 
781 static int apparmor_getselfattr(unsigned int attr, struct lsm_ctx __user *lx,
782 				size_t *size, u32 flags)
783 {
784 	int error = -ENOENT;
785 	struct aa_task_ctx *ctx = task_ctx(current);
786 	struct aa_label *label = NULL;
787 	char *value;
788 
789 	switch (attr) {
790 	case LSM_ATTR_CURRENT:
791 		label = aa_get_newest_label(cred_label(current_cred()));
792 		break;
793 	case LSM_ATTR_PREV:
794 		if (ctx->previous)
795 			label = aa_get_newest_label(ctx->previous);
796 		break;
797 	case LSM_ATTR_EXEC:
798 		if (ctx->onexec)
799 			label = aa_get_newest_label(ctx->onexec);
800 		break;
801 	default:
802 		error = -EOPNOTSUPP;
803 		break;
804 	}
805 
806 	if (label) {
807 		error = aa_getprocattr(label, &value, false);
808 		if (error > 0)
809 			error = lsm_fill_user_ctx(lx, size, value, error,
810 						  LSM_ID_APPARMOR, 0);
811 		kfree(value);
812 	}
813 
814 	aa_put_label(label);
815 
816 	if (error < 0)
817 		return error;
818 	return 1;
819 }
820 
821 static int apparmor_getprocattr(struct task_struct *task, const char *name,
822 				char **value)
823 {
824 	int error = -ENOENT;
825 	/* released below */
826 	const struct cred *cred = get_task_cred(task);
827 	struct aa_task_ctx *ctx = task_ctx(current);
828 	struct aa_label *label = NULL;
829 
830 	if (strcmp(name, "current") == 0)
831 		label = aa_get_newest_label(cred_label(cred));
832 	else if (strcmp(name, "prev") == 0  && ctx->previous)
833 		label = aa_get_newest_label(ctx->previous);
834 	else if (strcmp(name, "exec") == 0 && ctx->onexec)
835 		label = aa_get_newest_label(ctx->onexec);
836 	else
837 		error = -EINVAL;
838 
839 	if (label)
840 		error = aa_getprocattr(label, value, true);
841 
842 	aa_put_label(label);
843 	put_cred(cred);
844 
845 	return error;
846 }
847 
848 static int do_setattr(u64 attr, void *value, size_t size)
849 {
850 	char *command, *largs = NULL, *args = value;
851 	size_t arg_size;
852 	int error;
853 	DEFINE_AUDIT_DATA(ad, LSM_AUDIT_DATA_NONE, AA_CLASS_NONE,
854 			  OP_SETPROCATTR);
855 
856 	if (size == 0)
857 		return -EINVAL;
858 
859 	/* AppArmor requires that the buffer must be null terminated atm */
860 	if (args[size - 1] != '\0') {
861 		/* null terminate */
862 		largs = args = kmalloc(size + 1, GFP_KERNEL);
863 		if (!args)
864 			return -ENOMEM;
865 		memcpy(args, value, size);
866 		args[size] = '\0';
867 	}
868 
869 	error = -EINVAL;
870 	args = strim(args);
871 	command = strsep(&args, " ");
872 	if (!args)
873 		goto out;
874 	args = skip_spaces(args);
875 	if (!*args)
876 		goto out;
877 
878 	arg_size = size - (args - (largs ? largs : (char *) value));
879 	if (attr == LSM_ATTR_CURRENT) {
880 		if (strcmp(command, "changehat") == 0) {
881 			error = aa_setprocattr_changehat(args, arg_size,
882 							 AA_CHANGE_NOFLAGS);
883 		} else if (strcmp(command, "permhat") == 0) {
884 			error = aa_setprocattr_changehat(args, arg_size,
885 							 AA_CHANGE_TEST);
886 		} else if (strcmp(command, "changeprofile") == 0) {
887 			error = aa_change_profile(args, AA_CHANGE_NOFLAGS);
888 		} else if (strcmp(command, "permprofile") == 0) {
889 			error = aa_change_profile(args, AA_CHANGE_TEST);
890 		} else if (strcmp(command, "stack") == 0) {
891 			error = aa_change_profile(args, AA_CHANGE_STACK);
892 		} else
893 			goto fail;
894 	} else if (attr == LSM_ATTR_EXEC) {
895 		if (strcmp(command, "exec") == 0)
896 			error = aa_change_profile(args, AA_CHANGE_ONEXEC);
897 		else if (strcmp(command, "stack") == 0)
898 			error = aa_change_profile(args, (AA_CHANGE_ONEXEC |
899 							 AA_CHANGE_STACK));
900 		else
901 			goto fail;
902 	} else
903 		/* only support the "current" and "exec" process attributes */
904 		goto fail;
905 
906 	if (!error)
907 		error = size;
908 out:
909 	kfree(largs);
910 	return error;
911 
912 fail:
913 	ad.subj_label = begin_current_label_crit_section();
914 	if (attr == LSM_ATTR_CURRENT)
915 		ad.info = "current";
916 	else if (attr == LSM_ATTR_EXEC)
917 		ad.info = "exec";
918 	else
919 		ad.info = "invalid";
920 	ad.error = error = -EINVAL;
921 	aa_audit_msg(AUDIT_APPARMOR_DENIED, &ad, NULL);
922 	end_current_label_crit_section(ad.subj_label);
923 	goto out;
924 }
925 
926 static int apparmor_setselfattr(unsigned int attr, struct lsm_ctx *ctx,
927 				size_t size, u32 flags)
928 {
929 	int rc;
930 
931 	if (attr != LSM_ATTR_CURRENT && attr != LSM_ATTR_EXEC)
932 		return -EOPNOTSUPP;
933 
934 	rc = do_setattr(attr, ctx->ctx, ctx->ctx_len);
935 	if (rc > 0)
936 		return 0;
937 	return rc;
938 }
939 
940 static int apparmor_setprocattr(const char *name, void *value,
941 				size_t size)
942 {
943 	int attr = lsm_name_to_attr(name);
944 
945 	if (attr)
946 		return do_setattr(attr, value, size);
947 	return -EINVAL;
948 }
949 
950 /**
951  * apparmor_bprm_committing_creds - do task cleanup on committing new creds
952  * @bprm: binprm for the exec  (NOT NULL)
953  */
954 static void apparmor_bprm_committing_creds(const struct linux_binprm *bprm)
955 {
956 	struct aa_label *label = aa_current_raw_label();
957 	struct aa_label *new_label = cred_label(bprm->cred);
958 
959 	/* bail out if unconfined or not changing profile */
960 	if ((new_label->proxy == label->proxy) ||
961 	    (unconfined(new_label)))
962 		return;
963 
964 	aa_inherit_files(bprm->cred, current->files);
965 
966 	current->pdeath_signal = 0;
967 
968 	/* reset soft limits and set hard limits for the new label */
969 	__aa_transition_rlimits(label, new_label);
970 }
971 
972 /**
973  * apparmor_bprm_committed_creds() - do cleanup after new creds committed
974  * @bprm: binprm for the exec  (NOT NULL)
975  */
976 static void apparmor_bprm_committed_creds(const struct linux_binprm *bprm)
977 {
978 	/* clear out temporary/transitional state from the context */
979 	aa_clear_task_ctx_trans(task_ctx(current));
980 
981 	return;
982 }
983 
984 static void apparmor_current_getsecid_subj(u32 *secid)
985 {
986 	struct aa_label *label = __begin_current_label_crit_section();
987 	*secid = label->secid;
988 	__end_current_label_crit_section(label);
989 }
990 
991 static void apparmor_task_getsecid_obj(struct task_struct *p, u32 *secid)
992 {
993 	struct aa_label *label = aa_get_task_label(p);
994 	*secid = label->secid;
995 	aa_put_label(label);
996 }
997 
998 static int apparmor_task_setrlimit(struct task_struct *task,
999 		unsigned int resource, struct rlimit *new_rlim)
1000 {
1001 	struct aa_label *label = __begin_current_label_crit_section();
1002 	int error = 0;
1003 
1004 	if (!unconfined(label))
1005 		error = aa_task_setrlimit(current_cred(), label, task,
1006 					  resource, new_rlim);
1007 	__end_current_label_crit_section(label);
1008 
1009 	return error;
1010 }
1011 
1012 static int apparmor_task_kill(struct task_struct *target, struct kernel_siginfo *info,
1013 			      int sig, const struct cred *cred)
1014 {
1015 	const struct cred *tc;
1016 	struct aa_label *cl, *tl;
1017 	int error;
1018 
1019 	tc = get_task_cred(target);
1020 	tl = aa_get_newest_cred_label(tc);
1021 	if (cred) {
1022 		/*
1023 		 * Dealing with USB IO specific behavior
1024 		 */
1025 		cl = aa_get_newest_cred_label(cred);
1026 		error = aa_may_signal(cred, cl, tc, tl, sig);
1027 		aa_put_label(cl);
1028 	} else {
1029 		cl = __begin_current_label_crit_section();
1030 		error = aa_may_signal(current_cred(), cl, tc, tl, sig);
1031 		__end_current_label_crit_section(cl);
1032 	}
1033 	aa_put_label(tl);
1034 	put_cred(tc);
1035 
1036 	return error;
1037 }
1038 
1039 static int apparmor_userns_create(const struct cred *cred)
1040 {
1041 	struct aa_label *label;
1042 	struct aa_profile *profile;
1043 	int error = 0;
1044 	DEFINE_AUDIT_DATA(ad, LSM_AUDIT_DATA_TASK, AA_CLASS_NS,
1045 			  OP_USERNS_CREATE);
1046 
1047 	ad.subj_cred = current_cred();
1048 
1049 	label = begin_current_label_crit_section();
1050 	if (!unconfined(label)) {
1051 		error = fn_for_each(label, profile,
1052 				    aa_profile_ns_perm(profile, &ad,
1053 						       AA_USERNS_CREATE));
1054 	}
1055 	end_current_label_crit_section(label);
1056 
1057 	return error;
1058 }
1059 
1060 static int apparmor_sk_alloc_security(struct sock *sk, int family, gfp_t flags)
1061 {
1062 	struct aa_sk_ctx *ctx;
1063 
1064 	ctx = kzalloc(sizeof(*ctx), flags);
1065 	if (!ctx)
1066 		return -ENOMEM;
1067 
1068 	sk->sk_security = ctx;
1069 
1070 	return 0;
1071 }
1072 
1073 static void apparmor_sk_free_security(struct sock *sk)
1074 {
1075 	struct aa_sk_ctx *ctx = aa_sock(sk);
1076 
1077 	sk->sk_security = NULL;
1078 	aa_put_label(ctx->label);
1079 	aa_put_label(ctx->peer);
1080 	kfree(ctx);
1081 }
1082 
1083 /**
1084  * apparmor_sk_clone_security - clone the sk_security field
1085  * @sk: sock to have security cloned
1086  * @newsk: sock getting clone
1087  */
1088 static void apparmor_sk_clone_security(const struct sock *sk,
1089 				       struct sock *newsk)
1090 {
1091 	struct aa_sk_ctx *ctx = aa_sock(sk);
1092 	struct aa_sk_ctx *new = aa_sock(newsk);
1093 
1094 	if (new->label)
1095 		aa_put_label(new->label);
1096 	new->label = aa_get_label(ctx->label);
1097 
1098 	if (new->peer)
1099 		aa_put_label(new->peer);
1100 	new->peer = aa_get_label(ctx->peer);
1101 }
1102 
1103 static int apparmor_socket_create(int family, int type, int protocol, int kern)
1104 {
1105 	struct aa_label *label;
1106 	int error = 0;
1107 
1108 	AA_BUG(in_interrupt());
1109 
1110 	label = begin_current_label_crit_section();
1111 	if (!(kern || unconfined(label)))
1112 		error = af_select(family,
1113 				  create_perm(label, family, type, protocol),
1114 				  aa_af_perm(current_cred(), label,
1115 					     OP_CREATE, AA_MAY_CREATE,
1116 					     family, type, protocol));
1117 	end_current_label_crit_section(label);
1118 
1119 	return error;
1120 }
1121 
1122 /**
1123  * apparmor_socket_post_create - setup the per-socket security struct
1124  * @sock: socket that is being setup
1125  * @family: family of socket being created
1126  * @type: type of the socket
1127  * @ptotocol: protocol of the socket
1128  * @kern: socket is a special kernel socket
1129  *
1130  * Note:
1131  * -   kernel sockets labeled kernel_t used to use unconfined
1132  * -   socket may not have sk here if created with sock_create_lite or
1133  *     sock_alloc. These should be accept cases which will be handled in
1134  *     sock_graft.
1135  */
1136 static int apparmor_socket_post_create(struct socket *sock, int family,
1137 				       int type, int protocol, int kern)
1138 {
1139 	struct aa_label *label;
1140 
1141 	if (kern) {
1142 		label = aa_get_label(kernel_t);
1143 	} else
1144 		label = aa_get_current_label();
1145 
1146 	if (sock->sk) {
1147 		struct aa_sk_ctx *ctx = aa_sock(sock->sk);
1148 
1149 		aa_put_label(ctx->label);
1150 		ctx->label = aa_get_label(label);
1151 	}
1152 	aa_put_label(label);
1153 
1154 	return 0;
1155 }
1156 
1157 static int apparmor_socket_bind(struct socket *sock,
1158 				struct sockaddr *address, int addrlen)
1159 {
1160 	AA_BUG(!sock);
1161 	AA_BUG(!sock->sk);
1162 	AA_BUG(!address);
1163 	AA_BUG(in_interrupt());
1164 
1165 	return af_select(sock->sk->sk_family,
1166 			 bind_perm(sock, address, addrlen),
1167 			 aa_sk_perm(OP_BIND, AA_MAY_BIND, sock->sk));
1168 }
1169 
1170 static int apparmor_socket_connect(struct socket *sock,
1171 				   struct sockaddr *address, int addrlen)
1172 {
1173 	AA_BUG(!sock);
1174 	AA_BUG(!sock->sk);
1175 	AA_BUG(!address);
1176 	AA_BUG(in_interrupt());
1177 
1178 	return af_select(sock->sk->sk_family,
1179 			 connect_perm(sock, address, addrlen),
1180 			 aa_sk_perm(OP_CONNECT, AA_MAY_CONNECT, sock->sk));
1181 }
1182 
1183 static int apparmor_socket_listen(struct socket *sock, int backlog)
1184 {
1185 	AA_BUG(!sock);
1186 	AA_BUG(!sock->sk);
1187 	AA_BUG(in_interrupt());
1188 
1189 	return af_select(sock->sk->sk_family,
1190 			 listen_perm(sock, backlog),
1191 			 aa_sk_perm(OP_LISTEN, AA_MAY_LISTEN, sock->sk));
1192 }
1193 
1194 /*
1195  * Note: while @newsock is created and has some information, the accept
1196  *       has not been done.
1197  */
1198 static int apparmor_socket_accept(struct socket *sock, struct socket *newsock)
1199 {
1200 	AA_BUG(!sock);
1201 	AA_BUG(!sock->sk);
1202 	AA_BUG(!newsock);
1203 	AA_BUG(in_interrupt());
1204 
1205 	return af_select(sock->sk->sk_family,
1206 			 accept_perm(sock, newsock),
1207 			 aa_sk_perm(OP_ACCEPT, AA_MAY_ACCEPT, sock->sk));
1208 }
1209 
1210 static int aa_sock_msg_perm(const char *op, u32 request, struct socket *sock,
1211 			    struct msghdr *msg, int size)
1212 {
1213 	AA_BUG(!sock);
1214 	AA_BUG(!sock->sk);
1215 	AA_BUG(!msg);
1216 	AA_BUG(in_interrupt());
1217 
1218 	return af_select(sock->sk->sk_family,
1219 			 msg_perm(op, request, sock, msg, size),
1220 			 aa_sk_perm(op, request, sock->sk));
1221 }
1222 
1223 static int apparmor_socket_sendmsg(struct socket *sock,
1224 				   struct msghdr *msg, int size)
1225 {
1226 	return aa_sock_msg_perm(OP_SENDMSG, AA_MAY_SEND, sock, msg, size);
1227 }
1228 
1229 static int apparmor_socket_recvmsg(struct socket *sock,
1230 				   struct msghdr *msg, int size, int flags)
1231 {
1232 	return aa_sock_msg_perm(OP_RECVMSG, AA_MAY_RECEIVE, sock, msg, size);
1233 }
1234 
1235 /* revaliation, get/set attr, shutdown */
1236 static int aa_sock_perm(const char *op, u32 request, struct socket *sock)
1237 {
1238 	AA_BUG(!sock);
1239 	AA_BUG(!sock->sk);
1240 	AA_BUG(in_interrupt());
1241 
1242 	return af_select(sock->sk->sk_family,
1243 			 sock_perm(op, request, sock),
1244 			 aa_sk_perm(op, request, sock->sk));
1245 }
1246 
1247 static int apparmor_socket_getsockname(struct socket *sock)
1248 {
1249 	return aa_sock_perm(OP_GETSOCKNAME, AA_MAY_GETATTR, sock);
1250 }
1251 
1252 static int apparmor_socket_getpeername(struct socket *sock)
1253 {
1254 	return aa_sock_perm(OP_GETPEERNAME, AA_MAY_GETATTR, sock);
1255 }
1256 
1257 /* revaliation, get/set attr, opt */
1258 static int aa_sock_opt_perm(const char *op, u32 request, struct socket *sock,
1259 			    int level, int optname)
1260 {
1261 	AA_BUG(!sock);
1262 	AA_BUG(!sock->sk);
1263 	AA_BUG(in_interrupt());
1264 
1265 	return af_select(sock->sk->sk_family,
1266 			 opt_perm(op, request, sock, level, optname),
1267 			 aa_sk_perm(op, request, sock->sk));
1268 }
1269 
1270 static int apparmor_socket_getsockopt(struct socket *sock, int level,
1271 				      int optname)
1272 {
1273 	return aa_sock_opt_perm(OP_GETSOCKOPT, AA_MAY_GETOPT, sock,
1274 				level, optname);
1275 }
1276 
1277 static int apparmor_socket_setsockopt(struct socket *sock, int level,
1278 				      int optname)
1279 {
1280 	return aa_sock_opt_perm(OP_SETSOCKOPT, AA_MAY_SETOPT, sock,
1281 				level, optname);
1282 }
1283 
1284 static int apparmor_socket_shutdown(struct socket *sock, int how)
1285 {
1286 	return aa_sock_perm(OP_SHUTDOWN, AA_MAY_SHUTDOWN, sock);
1287 }
1288 
1289 #ifdef CONFIG_NETWORK_SECMARK
1290 /**
1291  * apparmor_socket_sock_rcv_skb - check perms before associating skb to sk
1292  * @sk: sk to associate @skb with
1293  * @skb: skb to check for perms
1294  *
1295  * Note: can not sleep may be called with locks held
1296  *
1297  * dont want protocol specific in __skb_recv_datagram()
1298  * to deny an incoming connection  socket_sock_rcv_skb()
1299  */
1300 static int apparmor_socket_sock_rcv_skb(struct sock *sk, struct sk_buff *skb)
1301 {
1302 	struct aa_sk_ctx *ctx = aa_sock(sk);
1303 
1304 	if (!skb->secmark)
1305 		return 0;
1306 
1307 	return apparmor_secmark_check(ctx->label, OP_RECVMSG, AA_MAY_RECEIVE,
1308 				      skb->secmark, sk);
1309 }
1310 #endif
1311 
1312 
1313 static struct aa_label *sk_peer_label(struct sock *sk)
1314 {
1315 	struct aa_sk_ctx *ctx = aa_sock(sk);
1316 
1317 	if (ctx->peer)
1318 		return ctx->peer;
1319 
1320 	return ERR_PTR(-ENOPROTOOPT);
1321 }
1322 
1323 /**
1324  * apparmor_socket_getpeersec_stream - get security context of peer
1325  * @sock: socket that we are trying to get the peer context of
1326  * @optval: output - buffer to copy peer name to
1327  * @optlen: output - size of copied name in @optval
1328  * @len: size of @optval buffer
1329  * Returns: 0 on success, -errno of failure
1330  *
1331  * Note: for tcp only valid if using ipsec or cipso on lan
1332  */
1333 static int apparmor_socket_getpeersec_stream(struct socket *sock,
1334 					     sockptr_t optval, sockptr_t optlen,
1335 					     unsigned int len)
1336 {
1337 	char *name = NULL;
1338 	int slen, error = 0;
1339 	struct aa_label *label;
1340 	struct aa_label *peer;
1341 
1342 	label = begin_current_label_crit_section();
1343 	peer = sk_peer_label(sock->sk);
1344 	if (IS_ERR(peer)) {
1345 		error = PTR_ERR(peer);
1346 		goto done;
1347 	}
1348 	slen = aa_label_asxprint(&name, labels_ns(label), peer,
1349 				 FLAG_SHOW_MODE | FLAG_VIEW_SUBNS |
1350 				 FLAG_HIDDEN_UNCONFINED, GFP_KERNEL);
1351 	/* don't include terminating \0 in slen, it breaks some apps */
1352 	if (slen < 0) {
1353 		error = -ENOMEM;
1354 		goto done;
1355 	}
1356 	if (slen > len) {
1357 		error = -ERANGE;
1358 		goto done_len;
1359 	}
1360 
1361 	if (copy_to_sockptr(optval, name, slen))
1362 		error = -EFAULT;
1363 done_len:
1364 	if (copy_to_sockptr(optlen, &slen, sizeof(slen)))
1365 		error = -EFAULT;
1366 done:
1367 	end_current_label_crit_section(label);
1368 	kfree(name);
1369 	return error;
1370 }
1371 
1372 /**
1373  * apparmor_socket_getpeersec_dgram - get security label of packet
1374  * @sock: the peer socket
1375  * @skb: packet data
1376  * @secid: pointer to where to put the secid of the packet
1377  *
1378  * Sets the netlabel socket state on sk from parent
1379  */
1380 static int apparmor_socket_getpeersec_dgram(struct socket *sock,
1381 					    struct sk_buff *skb, u32 *secid)
1382 
1383 {
1384 	/* TODO: requires secid support */
1385 	return -ENOPROTOOPT;
1386 }
1387 
1388 /**
1389  * apparmor_sock_graft - Initialize newly created socket
1390  * @sk: child sock
1391  * @parent: parent socket
1392  *
1393  * Note: could set off of SOCK_CTX(parent) but need to track inode and we can
1394  *       just set sk security information off of current creating process label
1395  *       Labeling of sk for accept case - probably should be sock based
1396  *       instead of task, because of the case where an implicitly labeled
1397  *       socket is shared by different tasks.
1398  */
1399 static void apparmor_sock_graft(struct sock *sk, struct socket *parent)
1400 {
1401 	struct aa_sk_ctx *ctx = aa_sock(sk);
1402 
1403 	if (!ctx->label)
1404 		ctx->label = aa_get_current_label();
1405 }
1406 
1407 #ifdef CONFIG_NETWORK_SECMARK
1408 static int apparmor_inet_conn_request(const struct sock *sk, struct sk_buff *skb,
1409 				      struct request_sock *req)
1410 {
1411 	struct aa_sk_ctx *ctx = aa_sock(sk);
1412 
1413 	if (!skb->secmark)
1414 		return 0;
1415 
1416 	return apparmor_secmark_check(ctx->label, OP_CONNECT, AA_MAY_CONNECT,
1417 				      skb->secmark, sk);
1418 }
1419 #endif
1420 
1421 /*
1422  * The cred blob is a pointer to, not an instance of, an aa_label.
1423  */
1424 struct lsm_blob_sizes apparmor_blob_sizes __ro_after_init = {
1425 	.lbs_cred = sizeof(struct aa_label *),
1426 	.lbs_file = sizeof(struct aa_file_ctx),
1427 	.lbs_task = sizeof(struct aa_task_ctx),
1428 };
1429 
1430 static const struct lsm_id apparmor_lsmid = {
1431 	.name = "apparmor",
1432 	.id = LSM_ID_APPARMOR,
1433 };
1434 
1435 static struct security_hook_list apparmor_hooks[] __ro_after_init = {
1436 	LSM_HOOK_INIT(ptrace_access_check, apparmor_ptrace_access_check),
1437 	LSM_HOOK_INIT(ptrace_traceme, apparmor_ptrace_traceme),
1438 	LSM_HOOK_INIT(capget, apparmor_capget),
1439 	LSM_HOOK_INIT(capable, apparmor_capable),
1440 
1441 	LSM_HOOK_INIT(move_mount, apparmor_move_mount),
1442 	LSM_HOOK_INIT(sb_mount, apparmor_sb_mount),
1443 	LSM_HOOK_INIT(sb_umount, apparmor_sb_umount),
1444 	LSM_HOOK_INIT(sb_pivotroot, apparmor_sb_pivotroot),
1445 
1446 	LSM_HOOK_INIT(path_link, apparmor_path_link),
1447 	LSM_HOOK_INIT(path_unlink, apparmor_path_unlink),
1448 	LSM_HOOK_INIT(path_symlink, apparmor_path_symlink),
1449 	LSM_HOOK_INIT(path_mkdir, apparmor_path_mkdir),
1450 	LSM_HOOK_INIT(path_rmdir, apparmor_path_rmdir),
1451 	LSM_HOOK_INIT(path_mknod, apparmor_path_mknod),
1452 	LSM_HOOK_INIT(path_rename, apparmor_path_rename),
1453 	LSM_HOOK_INIT(path_chmod, apparmor_path_chmod),
1454 	LSM_HOOK_INIT(path_chown, apparmor_path_chown),
1455 	LSM_HOOK_INIT(path_truncate, apparmor_path_truncate),
1456 	LSM_HOOK_INIT(inode_getattr, apparmor_inode_getattr),
1457 
1458 	LSM_HOOK_INIT(file_open, apparmor_file_open),
1459 	LSM_HOOK_INIT(file_receive, apparmor_file_receive),
1460 	LSM_HOOK_INIT(file_permission, apparmor_file_permission),
1461 	LSM_HOOK_INIT(file_alloc_security, apparmor_file_alloc_security),
1462 	LSM_HOOK_INIT(file_free_security, apparmor_file_free_security),
1463 	LSM_HOOK_INIT(mmap_file, apparmor_mmap_file),
1464 	LSM_HOOK_INIT(file_mprotect, apparmor_file_mprotect),
1465 	LSM_HOOK_INIT(file_lock, apparmor_file_lock),
1466 	LSM_HOOK_INIT(file_truncate, apparmor_file_truncate),
1467 
1468 	LSM_HOOK_INIT(getselfattr, apparmor_getselfattr),
1469 	LSM_HOOK_INIT(setselfattr, apparmor_setselfattr),
1470 	LSM_HOOK_INIT(getprocattr, apparmor_getprocattr),
1471 	LSM_HOOK_INIT(setprocattr, apparmor_setprocattr),
1472 
1473 	LSM_HOOK_INIT(sk_alloc_security, apparmor_sk_alloc_security),
1474 	LSM_HOOK_INIT(sk_free_security, apparmor_sk_free_security),
1475 	LSM_HOOK_INIT(sk_clone_security, apparmor_sk_clone_security),
1476 
1477 	LSM_HOOK_INIT(socket_create, apparmor_socket_create),
1478 	LSM_HOOK_INIT(socket_post_create, apparmor_socket_post_create),
1479 	LSM_HOOK_INIT(socket_bind, apparmor_socket_bind),
1480 	LSM_HOOK_INIT(socket_connect, apparmor_socket_connect),
1481 	LSM_HOOK_INIT(socket_listen, apparmor_socket_listen),
1482 	LSM_HOOK_INIT(socket_accept, apparmor_socket_accept),
1483 	LSM_HOOK_INIT(socket_sendmsg, apparmor_socket_sendmsg),
1484 	LSM_HOOK_INIT(socket_recvmsg, apparmor_socket_recvmsg),
1485 	LSM_HOOK_INIT(socket_getsockname, apparmor_socket_getsockname),
1486 	LSM_HOOK_INIT(socket_getpeername, apparmor_socket_getpeername),
1487 	LSM_HOOK_INIT(socket_getsockopt, apparmor_socket_getsockopt),
1488 	LSM_HOOK_INIT(socket_setsockopt, apparmor_socket_setsockopt),
1489 	LSM_HOOK_INIT(socket_shutdown, apparmor_socket_shutdown),
1490 #ifdef CONFIG_NETWORK_SECMARK
1491 	LSM_HOOK_INIT(socket_sock_rcv_skb, apparmor_socket_sock_rcv_skb),
1492 #endif
1493 	LSM_HOOK_INIT(socket_getpeersec_stream,
1494 		      apparmor_socket_getpeersec_stream),
1495 	LSM_HOOK_INIT(socket_getpeersec_dgram,
1496 		      apparmor_socket_getpeersec_dgram),
1497 	LSM_HOOK_INIT(sock_graft, apparmor_sock_graft),
1498 #ifdef CONFIG_NETWORK_SECMARK
1499 	LSM_HOOK_INIT(inet_conn_request, apparmor_inet_conn_request),
1500 #endif
1501 
1502 	LSM_HOOK_INIT(cred_alloc_blank, apparmor_cred_alloc_blank),
1503 	LSM_HOOK_INIT(cred_free, apparmor_cred_free),
1504 	LSM_HOOK_INIT(cred_prepare, apparmor_cred_prepare),
1505 	LSM_HOOK_INIT(cred_transfer, apparmor_cred_transfer),
1506 
1507 	LSM_HOOK_INIT(bprm_creds_for_exec, apparmor_bprm_creds_for_exec),
1508 	LSM_HOOK_INIT(bprm_committing_creds, apparmor_bprm_committing_creds),
1509 	LSM_HOOK_INIT(bprm_committed_creds, apparmor_bprm_committed_creds),
1510 
1511 	LSM_HOOK_INIT(task_free, apparmor_task_free),
1512 	LSM_HOOK_INIT(task_alloc, apparmor_task_alloc),
1513 	LSM_HOOK_INIT(current_getsecid_subj, apparmor_current_getsecid_subj),
1514 	LSM_HOOK_INIT(task_getsecid_obj, apparmor_task_getsecid_obj),
1515 	LSM_HOOK_INIT(task_setrlimit, apparmor_task_setrlimit),
1516 	LSM_HOOK_INIT(task_kill, apparmor_task_kill),
1517 	LSM_HOOK_INIT(userns_create, apparmor_userns_create),
1518 
1519 #ifdef CONFIG_AUDIT
1520 	LSM_HOOK_INIT(audit_rule_init, aa_audit_rule_init),
1521 	LSM_HOOK_INIT(audit_rule_known, aa_audit_rule_known),
1522 	LSM_HOOK_INIT(audit_rule_match, aa_audit_rule_match),
1523 	LSM_HOOK_INIT(audit_rule_free, aa_audit_rule_free),
1524 #endif
1525 
1526 	LSM_HOOK_INIT(secid_to_secctx, apparmor_secid_to_secctx),
1527 	LSM_HOOK_INIT(secctx_to_secid, apparmor_secctx_to_secid),
1528 	LSM_HOOK_INIT(release_secctx, apparmor_release_secctx),
1529 
1530 #ifdef CONFIG_IO_URING
1531 	LSM_HOOK_INIT(uring_override_creds, apparmor_uring_override_creds),
1532 	LSM_HOOK_INIT(uring_sqpoll, apparmor_uring_sqpoll),
1533 #endif
1534 };
1535 
1536 /*
1537  * AppArmor sysfs module parameters
1538  */
1539 
1540 static int param_set_aabool(const char *val, const struct kernel_param *kp);
1541 static int param_get_aabool(char *buffer, const struct kernel_param *kp);
1542 #define param_check_aabool param_check_bool
1543 static const struct kernel_param_ops param_ops_aabool = {
1544 	.flags = KERNEL_PARAM_OPS_FL_NOARG,
1545 	.set = param_set_aabool,
1546 	.get = param_get_aabool
1547 };
1548 
1549 static int param_set_aauint(const char *val, const struct kernel_param *kp);
1550 static int param_get_aauint(char *buffer, const struct kernel_param *kp);
1551 #define param_check_aauint param_check_uint
1552 static const struct kernel_param_ops param_ops_aauint = {
1553 	.set = param_set_aauint,
1554 	.get = param_get_aauint
1555 };
1556 
1557 static int param_set_aacompressionlevel(const char *val,
1558 					const struct kernel_param *kp);
1559 static int param_get_aacompressionlevel(char *buffer,
1560 					const struct kernel_param *kp);
1561 #define param_check_aacompressionlevel param_check_int
1562 static const struct kernel_param_ops param_ops_aacompressionlevel = {
1563 	.set = param_set_aacompressionlevel,
1564 	.get = param_get_aacompressionlevel
1565 };
1566 
1567 static int param_set_aalockpolicy(const char *val, const struct kernel_param *kp);
1568 static int param_get_aalockpolicy(char *buffer, const struct kernel_param *kp);
1569 #define param_check_aalockpolicy param_check_bool
1570 static const struct kernel_param_ops param_ops_aalockpolicy = {
1571 	.flags = KERNEL_PARAM_OPS_FL_NOARG,
1572 	.set = param_set_aalockpolicy,
1573 	.get = param_get_aalockpolicy
1574 };
1575 
1576 static int param_set_audit(const char *val, const struct kernel_param *kp);
1577 static int param_get_audit(char *buffer, const struct kernel_param *kp);
1578 
1579 static int param_set_mode(const char *val, const struct kernel_param *kp);
1580 static int param_get_mode(char *buffer, const struct kernel_param *kp);
1581 
1582 /* Flag values, also controllable via /sys/module/apparmor/parameters
1583  * We define special types as we want to do additional mediation.
1584  */
1585 
1586 /* AppArmor global enforcement switch - complain, enforce, kill */
1587 enum profile_mode aa_g_profile_mode = APPARMOR_ENFORCE;
1588 module_param_call(mode, param_set_mode, param_get_mode,
1589 		  &aa_g_profile_mode, S_IRUSR | S_IWUSR);
1590 
1591 /* whether policy verification hashing is enabled */
1592 bool aa_g_hash_policy = IS_ENABLED(CONFIG_SECURITY_APPARMOR_HASH_DEFAULT);
1593 #ifdef CONFIG_SECURITY_APPARMOR_HASH
1594 module_param_named(hash_policy, aa_g_hash_policy, aabool, S_IRUSR | S_IWUSR);
1595 #endif
1596 
1597 /* whether policy exactly as loaded is retained for debug and checkpointing */
1598 bool aa_g_export_binary = IS_ENABLED(CONFIG_SECURITY_APPARMOR_EXPORT_BINARY);
1599 #ifdef CONFIG_SECURITY_APPARMOR_EXPORT_BINARY
1600 module_param_named(export_binary, aa_g_export_binary, aabool, 0600);
1601 #endif
1602 
1603 /* policy loaddata compression level */
1604 int aa_g_rawdata_compression_level = AA_DEFAULT_CLEVEL;
1605 module_param_named(rawdata_compression_level, aa_g_rawdata_compression_level,
1606 		   aacompressionlevel, 0400);
1607 
1608 /* Debug mode */
1609 bool aa_g_debug = IS_ENABLED(CONFIG_SECURITY_APPARMOR_DEBUG_MESSAGES);
1610 module_param_named(debug, aa_g_debug, aabool, S_IRUSR | S_IWUSR);
1611 
1612 /* Audit mode */
1613 enum audit_mode aa_g_audit;
1614 module_param_call(audit, param_set_audit, param_get_audit,
1615 		  &aa_g_audit, S_IRUSR | S_IWUSR);
1616 
1617 /* Determines if audit header is included in audited messages.  This
1618  * provides more context if the audit daemon is not running
1619  */
1620 bool aa_g_audit_header = true;
1621 module_param_named(audit_header, aa_g_audit_header, aabool,
1622 		   S_IRUSR | S_IWUSR);
1623 
1624 /* lock out loading/removal of policy
1625  * TODO: add in at boot loading of policy, which is the only way to
1626  *       load policy, if lock_policy is set
1627  */
1628 bool aa_g_lock_policy;
1629 module_param_named(lock_policy, aa_g_lock_policy, aalockpolicy,
1630 		   S_IRUSR | S_IWUSR);
1631 
1632 /* Syscall logging mode */
1633 bool aa_g_logsyscall;
1634 module_param_named(logsyscall, aa_g_logsyscall, aabool, S_IRUSR | S_IWUSR);
1635 
1636 /* Maximum pathname length before accesses will start getting rejected */
1637 unsigned int aa_g_path_max = 2 * PATH_MAX;
1638 module_param_named(path_max, aa_g_path_max, aauint, S_IRUSR);
1639 
1640 /* Determines how paranoid loading of policy is and how much verification
1641  * on the loaded policy is done.
1642  * DEPRECATED: read only as strict checking of load is always done now
1643  * that none root users (user namespaces) can load policy.
1644  */
1645 bool aa_g_paranoid_load = IS_ENABLED(CONFIG_SECURITY_APPARMOR_PARANOID_LOAD);
1646 module_param_named(paranoid_load, aa_g_paranoid_load, aabool, S_IRUGO);
1647 
1648 static int param_get_aaintbool(char *buffer, const struct kernel_param *kp);
1649 static int param_set_aaintbool(const char *val, const struct kernel_param *kp);
1650 #define param_check_aaintbool param_check_int
1651 static const struct kernel_param_ops param_ops_aaintbool = {
1652 	.set = param_set_aaintbool,
1653 	.get = param_get_aaintbool
1654 };
1655 /* Boot time disable flag */
1656 static int apparmor_enabled __ro_after_init = 1;
1657 module_param_named(enabled, apparmor_enabled, aaintbool, 0444);
1658 
1659 static int __init apparmor_enabled_setup(char *str)
1660 {
1661 	unsigned long enabled;
1662 	int error = kstrtoul(str, 0, &enabled);
1663 	if (!error)
1664 		apparmor_enabled = enabled ? 1 : 0;
1665 	return 1;
1666 }
1667 
1668 __setup("apparmor=", apparmor_enabled_setup);
1669 
1670 /* set global flag turning off the ability to load policy */
1671 static int param_set_aalockpolicy(const char *val, const struct kernel_param *kp)
1672 {
1673 	if (!apparmor_enabled)
1674 		return -EINVAL;
1675 	if (apparmor_initialized && !aa_current_policy_admin_capable(NULL))
1676 		return -EPERM;
1677 	return param_set_bool(val, kp);
1678 }
1679 
1680 static int param_get_aalockpolicy(char *buffer, const struct kernel_param *kp)
1681 {
1682 	if (!apparmor_enabled)
1683 		return -EINVAL;
1684 	if (apparmor_initialized && !aa_current_policy_view_capable(NULL))
1685 		return -EPERM;
1686 	return param_get_bool(buffer, kp);
1687 }
1688 
1689 static int param_set_aabool(const char *val, const struct kernel_param *kp)
1690 {
1691 	if (!apparmor_enabled)
1692 		return -EINVAL;
1693 	if (apparmor_initialized && !aa_current_policy_admin_capable(NULL))
1694 		return -EPERM;
1695 	return param_set_bool(val, kp);
1696 }
1697 
1698 static int param_get_aabool(char *buffer, const struct kernel_param *kp)
1699 {
1700 	if (!apparmor_enabled)
1701 		return -EINVAL;
1702 	if (apparmor_initialized && !aa_current_policy_view_capable(NULL))
1703 		return -EPERM;
1704 	return param_get_bool(buffer, kp);
1705 }
1706 
1707 static int param_set_aauint(const char *val, const struct kernel_param *kp)
1708 {
1709 	int error;
1710 
1711 	if (!apparmor_enabled)
1712 		return -EINVAL;
1713 	/* file is ro but enforce 2nd line check */
1714 	if (apparmor_initialized)
1715 		return -EPERM;
1716 
1717 	error = param_set_uint(val, kp);
1718 	aa_g_path_max = max_t(uint32_t, aa_g_path_max, sizeof(union aa_buffer));
1719 	pr_info("AppArmor: buffer size set to %d bytes\n", aa_g_path_max);
1720 
1721 	return error;
1722 }
1723 
1724 static int param_get_aauint(char *buffer, const struct kernel_param *kp)
1725 {
1726 	if (!apparmor_enabled)
1727 		return -EINVAL;
1728 	if (apparmor_initialized && !aa_current_policy_view_capable(NULL))
1729 		return -EPERM;
1730 	return param_get_uint(buffer, kp);
1731 }
1732 
1733 /* Can only be set before AppArmor is initialized (i.e. on boot cmdline). */
1734 static int param_set_aaintbool(const char *val, const struct kernel_param *kp)
1735 {
1736 	struct kernel_param kp_local;
1737 	bool value;
1738 	int error;
1739 
1740 	if (apparmor_initialized)
1741 		return -EPERM;
1742 
1743 	/* Create local copy, with arg pointing to bool type. */
1744 	value = !!*((int *)kp->arg);
1745 	memcpy(&kp_local, kp, sizeof(kp_local));
1746 	kp_local.arg = &value;
1747 
1748 	error = param_set_bool(val, &kp_local);
1749 	if (!error)
1750 		*((int *)kp->arg) = *((bool *)kp_local.arg);
1751 	return error;
1752 }
1753 
1754 /*
1755  * To avoid changing /sys/module/apparmor/parameters/enabled from Y/N to
1756  * 1/0, this converts the "int that is actually bool" back to bool for
1757  * display in the /sys filesystem, while keeping it "int" for the LSM
1758  * infrastructure.
1759  */
1760 static int param_get_aaintbool(char *buffer, const struct kernel_param *kp)
1761 {
1762 	struct kernel_param kp_local;
1763 	bool value;
1764 
1765 	/* Create local copy, with arg pointing to bool type. */
1766 	value = !!*((int *)kp->arg);
1767 	memcpy(&kp_local, kp, sizeof(kp_local));
1768 	kp_local.arg = &value;
1769 
1770 	return param_get_bool(buffer, &kp_local);
1771 }
1772 
1773 static int param_set_aacompressionlevel(const char *val,
1774 					const struct kernel_param *kp)
1775 {
1776 	int error;
1777 
1778 	if (!apparmor_enabled)
1779 		return -EINVAL;
1780 	if (apparmor_initialized)
1781 		return -EPERM;
1782 
1783 	error = param_set_int(val, kp);
1784 
1785 	aa_g_rawdata_compression_level = clamp(aa_g_rawdata_compression_level,
1786 					       AA_MIN_CLEVEL, AA_MAX_CLEVEL);
1787 	pr_info("AppArmor: policy rawdata compression level set to %d\n",
1788 		aa_g_rawdata_compression_level);
1789 
1790 	return error;
1791 }
1792 
1793 static int param_get_aacompressionlevel(char *buffer,
1794 					const struct kernel_param *kp)
1795 {
1796 	if (!apparmor_enabled)
1797 		return -EINVAL;
1798 	if (apparmor_initialized && !aa_current_policy_view_capable(NULL))
1799 		return -EPERM;
1800 	return param_get_int(buffer, kp);
1801 }
1802 
1803 static int param_get_audit(char *buffer, const struct kernel_param *kp)
1804 {
1805 	if (!apparmor_enabled)
1806 		return -EINVAL;
1807 	if (apparmor_initialized && !aa_current_policy_view_capable(NULL))
1808 		return -EPERM;
1809 	return sprintf(buffer, "%s", audit_mode_names[aa_g_audit]);
1810 }
1811 
1812 static int param_set_audit(const char *val, const struct kernel_param *kp)
1813 {
1814 	int i;
1815 
1816 	if (!apparmor_enabled)
1817 		return -EINVAL;
1818 	if (!val)
1819 		return -EINVAL;
1820 	if (apparmor_initialized && !aa_current_policy_admin_capable(NULL))
1821 		return -EPERM;
1822 
1823 	i = match_string(audit_mode_names, AUDIT_MAX_INDEX, val);
1824 	if (i < 0)
1825 		return -EINVAL;
1826 
1827 	aa_g_audit = i;
1828 	return 0;
1829 }
1830 
1831 static int param_get_mode(char *buffer, const struct kernel_param *kp)
1832 {
1833 	if (!apparmor_enabled)
1834 		return -EINVAL;
1835 	if (apparmor_initialized && !aa_current_policy_view_capable(NULL))
1836 		return -EPERM;
1837 
1838 	return sprintf(buffer, "%s", aa_profile_mode_names[aa_g_profile_mode]);
1839 }
1840 
1841 static int param_set_mode(const char *val, const struct kernel_param *kp)
1842 {
1843 	int i;
1844 
1845 	if (!apparmor_enabled)
1846 		return -EINVAL;
1847 	if (!val)
1848 		return -EINVAL;
1849 	if (apparmor_initialized && !aa_current_policy_admin_capable(NULL))
1850 		return -EPERM;
1851 
1852 	i = match_string(aa_profile_mode_names, APPARMOR_MODE_NAMES_MAX_INDEX,
1853 			 val);
1854 	if (i < 0)
1855 		return -EINVAL;
1856 
1857 	aa_g_profile_mode = i;
1858 	return 0;
1859 }
1860 
1861 char *aa_get_buffer(bool in_atomic)
1862 {
1863 	union aa_buffer *aa_buf;
1864 	struct aa_local_cache *cache;
1865 	bool try_again = true;
1866 	gfp_t flags = (GFP_KERNEL | __GFP_RETRY_MAYFAIL | __GFP_NOWARN);
1867 
1868 	/* use per cpu cached buffers first */
1869 	cache = get_cpu_ptr(&aa_local_buffers);
1870 	if (!list_empty(&cache->head)) {
1871 		aa_buf = list_first_entry(&cache->head, union aa_buffer, list);
1872 		list_del(&aa_buf->list);
1873 		cache->hold--;
1874 		cache->count--;
1875 		put_cpu_ptr(&aa_local_buffers);
1876 		return &aa_buf->buffer[0];
1877 	}
1878 	put_cpu_ptr(&aa_local_buffers);
1879 
1880 	if (!spin_trylock(&aa_buffers_lock)) {
1881 		cache = get_cpu_ptr(&aa_local_buffers);
1882 		cache->hold += 1;
1883 		put_cpu_ptr(&aa_local_buffers);
1884 		spin_lock(&aa_buffers_lock);
1885 	} else {
1886 		cache = get_cpu_ptr(&aa_local_buffers);
1887 		put_cpu_ptr(&aa_local_buffers);
1888 	}
1889 retry:
1890 	if (buffer_count > reserve_count ||
1891 	    (in_atomic && !list_empty(&aa_global_buffers))) {
1892 		aa_buf = list_first_entry(&aa_global_buffers, union aa_buffer,
1893 					  list);
1894 		list_del(&aa_buf->list);
1895 		buffer_count--;
1896 		spin_unlock(&aa_buffers_lock);
1897 		return aa_buf->buffer;
1898 	}
1899 	if (in_atomic) {
1900 		/*
1901 		 * out of reserve buffers and in atomic context so increase
1902 		 * how many buffers to keep in reserve
1903 		 */
1904 		reserve_count++;
1905 		flags = GFP_ATOMIC;
1906 	}
1907 	spin_unlock(&aa_buffers_lock);
1908 
1909 	if (!in_atomic)
1910 		might_sleep();
1911 	aa_buf = kmalloc(aa_g_path_max, flags);
1912 	if (!aa_buf) {
1913 		if (try_again) {
1914 			try_again = false;
1915 			spin_lock(&aa_buffers_lock);
1916 			goto retry;
1917 		}
1918 		pr_warn_once("AppArmor: Failed to allocate a memory buffer.\n");
1919 		return NULL;
1920 	}
1921 	return aa_buf->buffer;
1922 }
1923 
1924 void aa_put_buffer(char *buf)
1925 {
1926 	union aa_buffer *aa_buf;
1927 	struct aa_local_cache *cache;
1928 
1929 	if (!buf)
1930 		return;
1931 	aa_buf = container_of(buf, union aa_buffer, buffer[0]);
1932 
1933 	cache = get_cpu_ptr(&aa_local_buffers);
1934 	if (!cache->hold) {
1935 		put_cpu_ptr(&aa_local_buffers);
1936 
1937 		if (spin_trylock(&aa_buffers_lock)) {
1938 			/* put back on global list */
1939 			list_add(&aa_buf->list, &aa_global_buffers);
1940 			buffer_count++;
1941 			spin_unlock(&aa_buffers_lock);
1942 			cache = get_cpu_ptr(&aa_local_buffers);
1943 			put_cpu_ptr(&aa_local_buffers);
1944 			return;
1945 		}
1946 		/* contention on global list, fallback to percpu */
1947 		cache = get_cpu_ptr(&aa_local_buffers);
1948 		cache->hold += 1;
1949 	}
1950 
1951 	/* cache in percpu list */
1952 	list_add(&aa_buf->list, &cache->head);
1953 	cache->count++;
1954 	put_cpu_ptr(&aa_local_buffers);
1955 }
1956 
1957 /*
1958  * AppArmor init functions
1959  */
1960 
1961 /**
1962  * set_init_ctx - set a task context and profile on the first task.
1963  *
1964  * TODO: allow setting an alternate profile than unconfined
1965  */
1966 static int __init set_init_ctx(void)
1967 {
1968 	struct cred *cred = (__force struct cred *)current->real_cred;
1969 
1970 	set_cred_label(cred, aa_get_label(ns_unconfined(root_ns)));
1971 
1972 	return 0;
1973 }
1974 
1975 static void destroy_buffers(void)
1976 {
1977 	union aa_buffer *aa_buf;
1978 
1979 	spin_lock(&aa_buffers_lock);
1980 	while (!list_empty(&aa_global_buffers)) {
1981 		aa_buf = list_first_entry(&aa_global_buffers, union aa_buffer,
1982 					 list);
1983 		list_del(&aa_buf->list);
1984 		spin_unlock(&aa_buffers_lock);
1985 		kfree(aa_buf);
1986 		spin_lock(&aa_buffers_lock);
1987 	}
1988 	spin_unlock(&aa_buffers_lock);
1989 }
1990 
1991 static int __init alloc_buffers(void)
1992 {
1993 	union aa_buffer *aa_buf;
1994 	int i, num;
1995 
1996 	/*
1997 	 * per cpu set of cached allocated buffers used to help reduce
1998 	 * lock contention
1999 	 */
2000 	for_each_possible_cpu(i) {
2001 		per_cpu(aa_local_buffers, i).hold = 0;
2002 		per_cpu(aa_local_buffers, i).count = 0;
2003 		INIT_LIST_HEAD(&per_cpu(aa_local_buffers, i).head);
2004 	}
2005 	/*
2006 	 * A function may require two buffers at once. Usually the buffers are
2007 	 * used for a short period of time and are shared. On UP kernel buffers
2008 	 * two should be enough, with more CPUs it is possible that more
2009 	 * buffers will be used simultaneously. The preallocated pool may grow.
2010 	 * This preallocation has also the side-effect that AppArmor will be
2011 	 * disabled early at boot if aa_g_path_max is extremly high.
2012 	 */
2013 	if (num_online_cpus() > 1)
2014 		num = 4 + RESERVE_COUNT;
2015 	else
2016 		num = 2 + RESERVE_COUNT;
2017 
2018 	for (i = 0; i < num; i++) {
2019 
2020 		aa_buf = kmalloc(aa_g_path_max, GFP_KERNEL |
2021 				 __GFP_RETRY_MAYFAIL | __GFP_NOWARN);
2022 		if (!aa_buf) {
2023 			destroy_buffers();
2024 			return -ENOMEM;
2025 		}
2026 		aa_put_buffer(aa_buf->buffer);
2027 	}
2028 	return 0;
2029 }
2030 
2031 #ifdef CONFIG_SYSCTL
2032 static int apparmor_dointvec(struct ctl_table *table, int write,
2033 			     void *buffer, size_t *lenp, loff_t *ppos)
2034 {
2035 	if (!aa_current_policy_admin_capable(NULL))
2036 		return -EPERM;
2037 	if (!apparmor_enabled)
2038 		return -EINVAL;
2039 
2040 	return proc_dointvec(table, write, buffer, lenp, ppos);
2041 }
2042 
2043 static struct ctl_table apparmor_sysctl_table[] = {
2044 #ifdef CONFIG_USER_NS
2045 	{
2046 		.procname       = "unprivileged_userns_apparmor_policy",
2047 		.data           = &unprivileged_userns_apparmor_policy,
2048 		.maxlen         = sizeof(int),
2049 		.mode           = 0600,
2050 		.proc_handler   = apparmor_dointvec,
2051 	},
2052 #endif /* CONFIG_USER_NS */
2053 	{
2054 		.procname       = "apparmor_display_secid_mode",
2055 		.data           = &apparmor_display_secid_mode,
2056 		.maxlen         = sizeof(int),
2057 		.mode           = 0600,
2058 		.proc_handler   = apparmor_dointvec,
2059 	},
2060 	{
2061 		.procname       = "apparmor_restrict_unprivileged_unconfined",
2062 		.data           = &aa_unprivileged_unconfined_restricted,
2063 		.maxlen         = sizeof(int),
2064 		.mode           = 0600,
2065 		.proc_handler   = apparmor_dointvec,
2066 	},
2067 	{ }
2068 };
2069 
2070 static int __init apparmor_init_sysctl(void)
2071 {
2072 	return register_sysctl("kernel", apparmor_sysctl_table) ? 0 : -ENOMEM;
2073 }
2074 #else
2075 static inline int apparmor_init_sysctl(void)
2076 {
2077 	return 0;
2078 }
2079 #endif /* CONFIG_SYSCTL */
2080 
2081 #if defined(CONFIG_NETFILTER) && defined(CONFIG_NETWORK_SECMARK)
2082 static unsigned int apparmor_ip_postroute(void *priv,
2083 					  struct sk_buff *skb,
2084 					  const struct nf_hook_state *state)
2085 {
2086 	struct aa_sk_ctx *ctx;
2087 	struct sock *sk;
2088 
2089 	if (!skb->secmark)
2090 		return NF_ACCEPT;
2091 
2092 	sk = skb_to_full_sk(skb);
2093 	if (sk == NULL)
2094 		return NF_ACCEPT;
2095 
2096 	ctx = aa_sock(sk);
2097 	if (!apparmor_secmark_check(ctx->label, OP_SENDMSG, AA_MAY_SEND,
2098 				    skb->secmark, sk))
2099 		return NF_ACCEPT;
2100 
2101 	return NF_DROP_ERR(-ECONNREFUSED);
2102 
2103 }
2104 
2105 static const struct nf_hook_ops apparmor_nf_ops[] = {
2106 	{
2107 		.hook =         apparmor_ip_postroute,
2108 		.pf =           NFPROTO_IPV4,
2109 		.hooknum =      NF_INET_POST_ROUTING,
2110 		.priority =     NF_IP_PRI_SELINUX_FIRST,
2111 	},
2112 #if IS_ENABLED(CONFIG_IPV6)
2113 	{
2114 		.hook =         apparmor_ip_postroute,
2115 		.pf =           NFPROTO_IPV6,
2116 		.hooknum =      NF_INET_POST_ROUTING,
2117 		.priority =     NF_IP6_PRI_SELINUX_FIRST,
2118 	},
2119 #endif
2120 };
2121 
2122 static int __net_init apparmor_nf_register(struct net *net)
2123 {
2124 	return nf_register_net_hooks(net, apparmor_nf_ops,
2125 				    ARRAY_SIZE(apparmor_nf_ops));
2126 }
2127 
2128 static void __net_exit apparmor_nf_unregister(struct net *net)
2129 {
2130 	nf_unregister_net_hooks(net, apparmor_nf_ops,
2131 				ARRAY_SIZE(apparmor_nf_ops));
2132 }
2133 
2134 static struct pernet_operations apparmor_net_ops = {
2135 	.init = apparmor_nf_register,
2136 	.exit = apparmor_nf_unregister,
2137 };
2138 
2139 static int __init apparmor_nf_ip_init(void)
2140 {
2141 	int err;
2142 
2143 	if (!apparmor_enabled)
2144 		return 0;
2145 
2146 	err = register_pernet_subsys(&apparmor_net_ops);
2147 	if (err)
2148 		panic("Apparmor: register_pernet_subsys: error %d\n", err);
2149 
2150 	return 0;
2151 }
2152 __initcall(apparmor_nf_ip_init);
2153 #endif
2154 
2155 static char nulldfa_src[] = {
2156 	#include "nulldfa.in"
2157 };
2158 static struct aa_dfa *nulldfa;
2159 
2160 static char stacksplitdfa_src[] = {
2161 	#include "stacksplitdfa.in"
2162 };
2163 struct aa_dfa *stacksplitdfa;
2164 struct aa_policydb *nullpdb;
2165 
2166 static int __init aa_setup_dfa_engine(void)
2167 {
2168 	int error = -ENOMEM;
2169 
2170 	nullpdb = aa_alloc_pdb(GFP_KERNEL);
2171 	if (!nullpdb)
2172 		return -ENOMEM;
2173 
2174 	nulldfa = aa_dfa_unpack(nulldfa_src, sizeof(nulldfa_src),
2175 			    TO_ACCEPT1_FLAG(YYTD_DATA32) |
2176 			    TO_ACCEPT2_FLAG(YYTD_DATA32));
2177 	if (IS_ERR(nulldfa)) {
2178 		error = PTR_ERR(nulldfa);
2179 		goto fail;
2180 	}
2181 	nullpdb->dfa = aa_get_dfa(nulldfa);
2182 	nullpdb->perms = kcalloc(2, sizeof(struct aa_perms), GFP_KERNEL);
2183 	if (!nullpdb->perms)
2184 		goto fail;
2185 	nullpdb->size = 2;
2186 
2187 	stacksplitdfa = aa_dfa_unpack(stacksplitdfa_src,
2188 				      sizeof(stacksplitdfa_src),
2189 				      TO_ACCEPT1_FLAG(YYTD_DATA32) |
2190 				      TO_ACCEPT2_FLAG(YYTD_DATA32));
2191 	if (IS_ERR(stacksplitdfa)) {
2192 		error = PTR_ERR(stacksplitdfa);
2193 		goto fail;
2194 	}
2195 
2196 	return 0;
2197 
2198 fail:
2199 	aa_put_pdb(nullpdb);
2200 	aa_put_dfa(nulldfa);
2201 	nullpdb = NULL;
2202 	nulldfa = NULL;
2203 	stacksplitdfa = NULL;
2204 
2205 	return error;
2206 }
2207 
2208 static void __init aa_teardown_dfa_engine(void)
2209 {
2210 	aa_put_dfa(stacksplitdfa);
2211 	aa_put_dfa(nulldfa);
2212 	aa_put_pdb(nullpdb);
2213 	nullpdb = NULL;
2214 	stacksplitdfa = NULL;
2215 	nulldfa = NULL;
2216 }
2217 
2218 static int __init apparmor_init(void)
2219 {
2220 	int error;
2221 
2222 	error = aa_setup_dfa_engine();
2223 	if (error) {
2224 		AA_ERROR("Unable to setup dfa engine\n");
2225 		goto alloc_out;
2226 	}
2227 
2228 	error = aa_alloc_root_ns();
2229 	if (error) {
2230 		AA_ERROR("Unable to allocate default profile namespace\n");
2231 		goto alloc_out;
2232 	}
2233 
2234 	error = apparmor_init_sysctl();
2235 	if (error) {
2236 		AA_ERROR("Unable to register sysctls\n");
2237 		goto alloc_out;
2238 
2239 	}
2240 
2241 	error = alloc_buffers();
2242 	if (error) {
2243 		AA_ERROR("Unable to allocate work buffers\n");
2244 		goto alloc_out;
2245 	}
2246 
2247 	error = set_init_ctx();
2248 	if (error) {
2249 		AA_ERROR("Failed to set context on init task\n");
2250 		aa_free_root_ns();
2251 		goto buffers_out;
2252 	}
2253 	security_add_hooks(apparmor_hooks, ARRAY_SIZE(apparmor_hooks),
2254 				&apparmor_lsmid);
2255 
2256 	/* Report that AppArmor successfully initialized */
2257 	apparmor_initialized = 1;
2258 	if (aa_g_profile_mode == APPARMOR_COMPLAIN)
2259 		aa_info_message("AppArmor initialized: complain mode enabled");
2260 	else if (aa_g_profile_mode == APPARMOR_KILL)
2261 		aa_info_message("AppArmor initialized: kill mode enabled");
2262 	else
2263 		aa_info_message("AppArmor initialized");
2264 
2265 	return error;
2266 
2267 buffers_out:
2268 	destroy_buffers();
2269 alloc_out:
2270 	aa_destroy_aafs();
2271 	aa_teardown_dfa_engine();
2272 
2273 	apparmor_enabled = false;
2274 	return error;
2275 }
2276 
2277 DEFINE_LSM(apparmor) = {
2278 	.name = "apparmor",
2279 	.flags = LSM_FLAG_LEGACY_MAJOR | LSM_FLAG_EXCLUSIVE,
2280 	.enabled = &apparmor_enabled,
2281 	.blobs = &apparmor_blob_sizes,
2282 	.init = apparmor_init,
2283 };
2284