xref: /linux/security/apparmor/lsm.c (revision bd628c1bed7902ec1f24ba0fe70758949146abbe)
1 /*
2  * AppArmor security module
3  *
4  * This file contains AppArmor LSM hooks.
5  *
6  * Copyright (C) 1998-2008 Novell/SUSE
7  * Copyright 2009-2010 Canonical Ltd.
8  *
9  * This program is free software; you can redistribute it and/or
10  * modify it under the terms of the GNU General Public License as
11  * published by the Free Software Foundation, version 2 of the
12  * License.
13  */
14 
15 #include <linux/lsm_hooks.h>
16 #include <linux/moduleparam.h>
17 #include <linux/mm.h>
18 #include <linux/mman.h>
19 #include <linux/mount.h>
20 #include <linux/namei.h>
21 #include <linux/ptrace.h>
22 #include <linux/ctype.h>
23 #include <linux/sysctl.h>
24 #include <linux/audit.h>
25 #include <linux/user_namespace.h>
26 #include <linux/netfilter_ipv4.h>
27 #include <linux/netfilter_ipv6.h>
28 #include <net/sock.h>
29 #include <uapi/linux/mount.h>
30 
31 #include "include/apparmor.h"
32 #include "include/apparmorfs.h"
33 #include "include/audit.h"
34 #include "include/capability.h"
35 #include "include/cred.h"
36 #include "include/file.h"
37 #include "include/ipc.h"
38 #include "include/net.h"
39 #include "include/path.h"
40 #include "include/label.h"
41 #include "include/policy.h"
42 #include "include/policy_ns.h"
43 #include "include/procattr.h"
44 #include "include/mount.h"
45 #include "include/secid.h"
46 
47 /* Flag indicating whether initialization completed */
48 int apparmor_initialized;
49 
50 DEFINE_PER_CPU(struct aa_buffers, aa_buffers);
51 
52 
53 /*
54  * LSM hook functions
55  */
56 
57 /*
58  * put the associated labels
59  */
60 static void apparmor_cred_free(struct cred *cred)
61 {
62 	aa_put_label(cred_label(cred));
63 	cred_label(cred) = NULL;
64 }
65 
66 /*
67  * allocate the apparmor part of blank credentials
68  */
69 static int apparmor_cred_alloc_blank(struct cred *cred, gfp_t gfp)
70 {
71 	cred_label(cred) = NULL;
72 	return 0;
73 }
74 
75 /*
76  * prepare new cred label for modification by prepare_cred block
77  */
78 static int apparmor_cred_prepare(struct cred *new, const struct cred *old,
79 				 gfp_t gfp)
80 {
81 	cred_label(new) = aa_get_newest_label(cred_label(old));
82 	return 0;
83 }
84 
85 /*
86  * transfer the apparmor data to a blank set of creds
87  */
88 static void apparmor_cred_transfer(struct cred *new, const struct cred *old)
89 {
90 	cred_label(new) = aa_get_newest_label(cred_label(old));
91 }
92 
93 static void apparmor_task_free(struct task_struct *task)
94 {
95 
96 	aa_free_task_ctx(task_ctx(task));
97 	task_ctx(task) = NULL;
98 }
99 
100 static int apparmor_task_alloc(struct task_struct *task,
101 			       unsigned long clone_flags)
102 {
103 	struct aa_task_ctx *new = aa_alloc_task_ctx(GFP_KERNEL);
104 
105 	if (!new)
106 		return -ENOMEM;
107 
108 	aa_dup_task_ctx(new, task_ctx(current));
109 	task_ctx(task) = new;
110 
111 	return 0;
112 }
113 
114 static int apparmor_ptrace_access_check(struct task_struct *child,
115 					unsigned int mode)
116 {
117 	struct aa_label *tracer, *tracee;
118 	int error;
119 
120 	tracer = __begin_current_label_crit_section();
121 	tracee = aa_get_task_label(child);
122 	error = aa_may_ptrace(tracer, tracee,
123 			(mode & PTRACE_MODE_READ) ? AA_PTRACE_READ
124 						  : AA_PTRACE_TRACE);
125 	aa_put_label(tracee);
126 	__end_current_label_crit_section(tracer);
127 
128 	return error;
129 }
130 
131 static int apparmor_ptrace_traceme(struct task_struct *parent)
132 {
133 	struct aa_label *tracer, *tracee;
134 	int error;
135 
136 	tracee = __begin_current_label_crit_section();
137 	tracer = aa_get_task_label(parent);
138 	error = aa_may_ptrace(tracer, tracee, AA_PTRACE_TRACE);
139 	aa_put_label(tracer);
140 	__end_current_label_crit_section(tracee);
141 
142 	return error;
143 }
144 
145 /* Derived from security/commoncap.c:cap_capget */
146 static int apparmor_capget(struct task_struct *target, kernel_cap_t *effective,
147 			   kernel_cap_t *inheritable, kernel_cap_t *permitted)
148 {
149 	struct aa_label *label;
150 	const struct cred *cred;
151 
152 	rcu_read_lock();
153 	cred = __task_cred(target);
154 	label = aa_get_newest_cred_label(cred);
155 
156 	/*
157 	 * cap_capget is stacked ahead of this and will
158 	 * initialize effective and permitted.
159 	 */
160 	if (!unconfined(label)) {
161 		struct aa_profile *profile;
162 		struct label_it i;
163 
164 		label_for_each_confined(i, label, profile) {
165 			if (COMPLAIN_MODE(profile))
166 				continue;
167 			*effective = cap_intersect(*effective,
168 						   profile->caps.allow);
169 			*permitted = cap_intersect(*permitted,
170 						   profile->caps.allow);
171 		}
172 	}
173 	rcu_read_unlock();
174 	aa_put_label(label);
175 
176 	return 0;
177 }
178 
179 static int apparmor_capable(const struct cred *cred, struct user_namespace *ns,
180 			    int cap, int audit)
181 {
182 	struct aa_label *label;
183 	int error = 0;
184 
185 	label = aa_get_newest_cred_label(cred);
186 	if (!unconfined(label))
187 		error = aa_capable(label, cap, audit);
188 	aa_put_label(label);
189 
190 	return error;
191 }
192 
193 /**
194  * common_perm - basic common permission check wrapper fn for paths
195  * @op: operation being checked
196  * @path: path to check permission of  (NOT NULL)
197  * @mask: requested permissions mask
198  * @cond: conditional info for the permission request  (NOT NULL)
199  *
200  * Returns: %0 else error code if error or permission denied
201  */
202 static int common_perm(const char *op, const struct path *path, u32 mask,
203 		       struct path_cond *cond)
204 {
205 	struct aa_label *label;
206 	int error = 0;
207 
208 	label = __begin_current_label_crit_section();
209 	if (!unconfined(label))
210 		error = aa_path_perm(op, label, path, 0, mask, cond);
211 	__end_current_label_crit_section(label);
212 
213 	return error;
214 }
215 
216 /**
217  * common_perm_cond - common permission wrapper around inode cond
218  * @op: operation being checked
219  * @path: location to check (NOT NULL)
220  * @mask: requested permissions mask
221  *
222  * Returns: %0 else error code if error or permission denied
223  */
224 static int common_perm_cond(const char *op, const struct path *path, u32 mask)
225 {
226 	struct path_cond cond = { d_backing_inode(path->dentry)->i_uid,
227 				  d_backing_inode(path->dentry)->i_mode
228 	};
229 
230 	if (!path_mediated_fs(path->dentry))
231 		return 0;
232 
233 	return common_perm(op, path, mask, &cond);
234 }
235 
236 /**
237  * common_perm_dir_dentry - common permission wrapper when path is dir, dentry
238  * @op: operation being checked
239  * @dir: directory of the dentry  (NOT NULL)
240  * @dentry: dentry to check  (NOT NULL)
241  * @mask: requested permissions mask
242  * @cond: conditional info for the permission request  (NOT NULL)
243  *
244  * Returns: %0 else error code if error or permission denied
245  */
246 static int common_perm_dir_dentry(const char *op, const struct path *dir,
247 				  struct dentry *dentry, u32 mask,
248 				  struct path_cond *cond)
249 {
250 	struct path path = { .mnt = dir->mnt, .dentry = dentry };
251 
252 	return common_perm(op, &path, mask, cond);
253 }
254 
255 /**
256  * common_perm_rm - common permission wrapper for operations doing rm
257  * @op: operation being checked
258  * @dir: directory that the dentry is in  (NOT NULL)
259  * @dentry: dentry being rm'd  (NOT NULL)
260  * @mask: requested permission mask
261  *
262  * Returns: %0 else error code if error or permission denied
263  */
264 static int common_perm_rm(const char *op, const struct path *dir,
265 			  struct dentry *dentry, u32 mask)
266 {
267 	struct inode *inode = d_backing_inode(dentry);
268 	struct path_cond cond = { };
269 
270 	if (!inode || !path_mediated_fs(dentry))
271 		return 0;
272 
273 	cond.uid = inode->i_uid;
274 	cond.mode = inode->i_mode;
275 
276 	return common_perm_dir_dentry(op, dir, dentry, mask, &cond);
277 }
278 
279 /**
280  * common_perm_create - common permission wrapper for operations doing create
281  * @op: operation being checked
282  * @dir: directory that dentry will be created in  (NOT NULL)
283  * @dentry: dentry to create   (NOT NULL)
284  * @mask: request permission mask
285  * @mode: created file mode
286  *
287  * Returns: %0 else error code if error or permission denied
288  */
289 static int common_perm_create(const char *op, const struct path *dir,
290 			      struct dentry *dentry, u32 mask, umode_t mode)
291 {
292 	struct path_cond cond = { current_fsuid(), mode };
293 
294 	if (!path_mediated_fs(dir->dentry))
295 		return 0;
296 
297 	return common_perm_dir_dentry(op, dir, dentry, mask, &cond);
298 }
299 
300 static int apparmor_path_unlink(const struct path *dir, struct dentry *dentry)
301 {
302 	return common_perm_rm(OP_UNLINK, dir, dentry, AA_MAY_DELETE);
303 }
304 
305 static int apparmor_path_mkdir(const struct path *dir, struct dentry *dentry,
306 			       umode_t mode)
307 {
308 	return common_perm_create(OP_MKDIR, dir, dentry, AA_MAY_CREATE,
309 				  S_IFDIR);
310 }
311 
312 static int apparmor_path_rmdir(const struct path *dir, struct dentry *dentry)
313 {
314 	return common_perm_rm(OP_RMDIR, dir, dentry, AA_MAY_DELETE);
315 }
316 
317 static int apparmor_path_mknod(const struct path *dir, struct dentry *dentry,
318 			       umode_t mode, unsigned int dev)
319 {
320 	return common_perm_create(OP_MKNOD, dir, dentry, AA_MAY_CREATE, mode);
321 }
322 
323 static int apparmor_path_truncate(const struct path *path)
324 {
325 	return common_perm_cond(OP_TRUNC, path, MAY_WRITE | AA_MAY_SETATTR);
326 }
327 
328 static int apparmor_path_symlink(const struct path *dir, struct dentry *dentry,
329 				 const char *old_name)
330 {
331 	return common_perm_create(OP_SYMLINK, dir, dentry, AA_MAY_CREATE,
332 				  S_IFLNK);
333 }
334 
335 static int apparmor_path_link(struct dentry *old_dentry, const struct path *new_dir,
336 			      struct dentry *new_dentry)
337 {
338 	struct aa_label *label;
339 	int error = 0;
340 
341 	if (!path_mediated_fs(old_dentry))
342 		return 0;
343 
344 	label = begin_current_label_crit_section();
345 	if (!unconfined(label))
346 		error = aa_path_link(label, old_dentry, new_dir, new_dentry);
347 	end_current_label_crit_section(label);
348 
349 	return error;
350 }
351 
352 static int apparmor_path_rename(const struct path *old_dir, struct dentry *old_dentry,
353 				const struct path *new_dir, struct dentry *new_dentry)
354 {
355 	struct aa_label *label;
356 	int error = 0;
357 
358 	if (!path_mediated_fs(old_dentry))
359 		return 0;
360 
361 	label = begin_current_label_crit_section();
362 	if (!unconfined(label)) {
363 		struct path old_path = { .mnt = old_dir->mnt,
364 					 .dentry = old_dentry };
365 		struct path new_path = { .mnt = new_dir->mnt,
366 					 .dentry = new_dentry };
367 		struct path_cond cond = { d_backing_inode(old_dentry)->i_uid,
368 					  d_backing_inode(old_dentry)->i_mode
369 		};
370 
371 		error = aa_path_perm(OP_RENAME_SRC, label, &old_path, 0,
372 				     MAY_READ | AA_MAY_GETATTR | MAY_WRITE |
373 				     AA_MAY_SETATTR | AA_MAY_DELETE,
374 				     &cond);
375 		if (!error)
376 			error = aa_path_perm(OP_RENAME_DEST, label, &new_path,
377 					     0, MAY_WRITE | AA_MAY_SETATTR |
378 					     AA_MAY_CREATE, &cond);
379 
380 	}
381 	end_current_label_crit_section(label);
382 
383 	return error;
384 }
385 
386 static int apparmor_path_chmod(const struct path *path, umode_t mode)
387 {
388 	return common_perm_cond(OP_CHMOD, path, AA_MAY_CHMOD);
389 }
390 
391 static int apparmor_path_chown(const struct path *path, kuid_t uid, kgid_t gid)
392 {
393 	return common_perm_cond(OP_CHOWN, path, AA_MAY_CHOWN);
394 }
395 
396 static int apparmor_inode_getattr(const struct path *path)
397 {
398 	return common_perm_cond(OP_GETATTR, path, AA_MAY_GETATTR);
399 }
400 
401 static int apparmor_file_open(struct file *file)
402 {
403 	struct aa_file_ctx *fctx = file_ctx(file);
404 	struct aa_label *label;
405 	int error = 0;
406 
407 	if (!path_mediated_fs(file->f_path.dentry))
408 		return 0;
409 
410 	/* If in exec, permission is handled by bprm hooks.
411 	 * Cache permissions granted by the previous exec check, with
412 	 * implicit read and executable mmap which are required to
413 	 * actually execute the image.
414 	 */
415 	if (current->in_execve) {
416 		fctx->allow = MAY_EXEC | MAY_READ | AA_EXEC_MMAP;
417 		return 0;
418 	}
419 
420 	label = aa_get_newest_cred_label(file->f_cred);
421 	if (!unconfined(label)) {
422 		struct inode *inode = file_inode(file);
423 		struct path_cond cond = { inode->i_uid, inode->i_mode };
424 
425 		error = aa_path_perm(OP_OPEN, label, &file->f_path, 0,
426 				     aa_map_file_to_perms(file), &cond);
427 		/* todo cache full allowed permissions set and state */
428 		fctx->allow = aa_map_file_to_perms(file);
429 	}
430 	aa_put_label(label);
431 
432 	return error;
433 }
434 
435 static int apparmor_file_alloc_security(struct file *file)
436 {
437 	int error = 0;
438 
439 	/* freed by apparmor_file_free_security */
440 	struct aa_label *label = begin_current_label_crit_section();
441 	file->f_security = aa_alloc_file_ctx(label, GFP_KERNEL);
442 	if (!file_ctx(file))
443 		error = -ENOMEM;
444 	end_current_label_crit_section(label);
445 
446 	return error;
447 }
448 
449 static void apparmor_file_free_security(struct file *file)
450 {
451 	aa_free_file_ctx(file_ctx(file));
452 }
453 
454 static int common_file_perm(const char *op, struct file *file, u32 mask)
455 {
456 	struct aa_label *label;
457 	int error = 0;
458 
459 	/* don't reaudit files closed during inheritance */
460 	if (file->f_path.dentry == aa_null.dentry)
461 		return -EACCES;
462 
463 	label = __begin_current_label_crit_section();
464 	error = aa_file_perm(op, label, file, mask);
465 	__end_current_label_crit_section(label);
466 
467 	return error;
468 }
469 
470 static int apparmor_file_receive(struct file *file)
471 {
472 	return common_file_perm(OP_FRECEIVE, file, aa_map_file_to_perms(file));
473 }
474 
475 static int apparmor_file_permission(struct file *file, int mask)
476 {
477 	return common_file_perm(OP_FPERM, file, mask);
478 }
479 
480 static int apparmor_file_lock(struct file *file, unsigned int cmd)
481 {
482 	u32 mask = AA_MAY_LOCK;
483 
484 	if (cmd == F_WRLCK)
485 		mask |= MAY_WRITE;
486 
487 	return common_file_perm(OP_FLOCK, file, mask);
488 }
489 
490 static int common_mmap(const char *op, struct file *file, unsigned long prot,
491 		       unsigned long flags)
492 {
493 	int mask = 0;
494 
495 	if (!file || !file_ctx(file))
496 		return 0;
497 
498 	if (prot & PROT_READ)
499 		mask |= MAY_READ;
500 	/*
501 	 * Private mappings don't require write perms since they don't
502 	 * write back to the files
503 	 */
504 	if ((prot & PROT_WRITE) && !(flags & MAP_PRIVATE))
505 		mask |= MAY_WRITE;
506 	if (prot & PROT_EXEC)
507 		mask |= AA_EXEC_MMAP;
508 
509 	return common_file_perm(op, file, mask);
510 }
511 
512 static int apparmor_mmap_file(struct file *file, unsigned long reqprot,
513 			      unsigned long prot, unsigned long flags)
514 {
515 	return common_mmap(OP_FMMAP, file, prot, flags);
516 }
517 
518 static int apparmor_file_mprotect(struct vm_area_struct *vma,
519 				  unsigned long reqprot, unsigned long prot)
520 {
521 	return common_mmap(OP_FMPROT, vma->vm_file, prot,
522 			   !(vma->vm_flags & VM_SHARED) ? MAP_PRIVATE : 0);
523 }
524 
525 static int apparmor_sb_mount(const char *dev_name, const struct path *path,
526 			     const char *type, unsigned long flags, void *data)
527 {
528 	struct aa_label *label;
529 	int error = 0;
530 
531 	/* Discard magic */
532 	if ((flags & MS_MGC_MSK) == MS_MGC_VAL)
533 		flags &= ~MS_MGC_MSK;
534 
535 	flags &= ~AA_MS_IGNORE_MASK;
536 
537 	label = __begin_current_label_crit_section();
538 	if (!unconfined(label)) {
539 		if (flags & MS_REMOUNT)
540 			error = aa_remount(label, path, flags, data);
541 		else if (flags & MS_BIND)
542 			error = aa_bind_mount(label, path, dev_name, flags);
543 		else if (flags & (MS_SHARED | MS_PRIVATE | MS_SLAVE |
544 				  MS_UNBINDABLE))
545 			error = aa_mount_change_type(label, path, flags);
546 		else if (flags & MS_MOVE)
547 			error = aa_move_mount(label, path, dev_name);
548 		else
549 			error = aa_new_mount(label, dev_name, path, type,
550 					     flags, data);
551 	}
552 	__end_current_label_crit_section(label);
553 
554 	return error;
555 }
556 
557 static int apparmor_sb_umount(struct vfsmount *mnt, int flags)
558 {
559 	struct aa_label *label;
560 	int error = 0;
561 
562 	label = __begin_current_label_crit_section();
563 	if (!unconfined(label))
564 		error = aa_umount(label, mnt, flags);
565 	__end_current_label_crit_section(label);
566 
567 	return error;
568 }
569 
570 static int apparmor_sb_pivotroot(const struct path *old_path,
571 				 const struct path *new_path)
572 {
573 	struct aa_label *label;
574 	int error = 0;
575 
576 	label = aa_get_current_label();
577 	if (!unconfined(label))
578 		error = aa_pivotroot(label, old_path, new_path);
579 	aa_put_label(label);
580 
581 	return error;
582 }
583 
584 static int apparmor_getprocattr(struct task_struct *task, char *name,
585 				char **value)
586 {
587 	int error = -ENOENT;
588 	/* released below */
589 	const struct cred *cred = get_task_cred(task);
590 	struct aa_task_ctx *ctx = task_ctx(current);
591 	struct aa_label *label = NULL;
592 
593 	if (strcmp(name, "current") == 0)
594 		label = aa_get_newest_label(cred_label(cred));
595 	else if (strcmp(name, "prev") == 0  && ctx->previous)
596 		label = aa_get_newest_label(ctx->previous);
597 	else if (strcmp(name, "exec") == 0 && ctx->onexec)
598 		label = aa_get_newest_label(ctx->onexec);
599 	else
600 		error = -EINVAL;
601 
602 	if (label)
603 		error = aa_getprocattr(label, value);
604 
605 	aa_put_label(label);
606 	put_cred(cred);
607 
608 	return error;
609 }
610 
611 static int apparmor_setprocattr(const char *name, void *value,
612 				size_t size)
613 {
614 	char *command, *largs = NULL, *args = value;
615 	size_t arg_size;
616 	int error;
617 	DEFINE_AUDIT_DATA(sa, LSM_AUDIT_DATA_NONE, OP_SETPROCATTR);
618 
619 	if (size == 0)
620 		return -EINVAL;
621 
622 	/* AppArmor requires that the buffer must be null terminated atm */
623 	if (args[size - 1] != '\0') {
624 		/* null terminate */
625 		largs = args = kmalloc(size + 1, GFP_KERNEL);
626 		if (!args)
627 			return -ENOMEM;
628 		memcpy(args, value, size);
629 		args[size] = '\0';
630 	}
631 
632 	error = -EINVAL;
633 	args = strim(args);
634 	command = strsep(&args, " ");
635 	if (!args)
636 		goto out;
637 	args = skip_spaces(args);
638 	if (!*args)
639 		goto out;
640 
641 	arg_size = size - (args - (largs ? largs : (char *) value));
642 	if (strcmp(name, "current") == 0) {
643 		if (strcmp(command, "changehat") == 0) {
644 			error = aa_setprocattr_changehat(args, arg_size,
645 							 AA_CHANGE_NOFLAGS);
646 		} else if (strcmp(command, "permhat") == 0) {
647 			error = aa_setprocattr_changehat(args, arg_size,
648 							 AA_CHANGE_TEST);
649 		} else if (strcmp(command, "changeprofile") == 0) {
650 			error = aa_change_profile(args, AA_CHANGE_NOFLAGS);
651 		} else if (strcmp(command, "permprofile") == 0) {
652 			error = aa_change_profile(args, AA_CHANGE_TEST);
653 		} else if (strcmp(command, "stack") == 0) {
654 			error = aa_change_profile(args, AA_CHANGE_STACK);
655 		} else
656 			goto fail;
657 	} else if (strcmp(name, "exec") == 0) {
658 		if (strcmp(command, "exec") == 0)
659 			error = aa_change_profile(args, AA_CHANGE_ONEXEC);
660 		else if (strcmp(command, "stack") == 0)
661 			error = aa_change_profile(args, (AA_CHANGE_ONEXEC |
662 							 AA_CHANGE_STACK));
663 		else
664 			goto fail;
665 	} else
666 		/* only support the "current" and "exec" process attributes */
667 		goto fail;
668 
669 	if (!error)
670 		error = size;
671 out:
672 	kfree(largs);
673 	return error;
674 
675 fail:
676 	aad(&sa)->label = begin_current_label_crit_section();
677 	aad(&sa)->info = name;
678 	aad(&sa)->error = error = -EINVAL;
679 	aa_audit_msg(AUDIT_APPARMOR_DENIED, &sa, NULL);
680 	end_current_label_crit_section(aad(&sa)->label);
681 	goto out;
682 }
683 
684 /**
685  * apparmor_bprm_committing_creds - do task cleanup on committing new creds
686  * @bprm: binprm for the exec  (NOT NULL)
687  */
688 static void apparmor_bprm_committing_creds(struct linux_binprm *bprm)
689 {
690 	struct aa_label *label = aa_current_raw_label();
691 	struct aa_label *new_label = cred_label(bprm->cred);
692 
693 	/* bail out if unconfined or not changing profile */
694 	if ((new_label->proxy == label->proxy) ||
695 	    (unconfined(new_label)))
696 		return;
697 
698 	aa_inherit_files(bprm->cred, current->files);
699 
700 	current->pdeath_signal = 0;
701 
702 	/* reset soft limits and set hard limits for the new label */
703 	__aa_transition_rlimits(label, new_label);
704 }
705 
706 /**
707  * apparmor_bprm_committed_cred - do cleanup after new creds committed
708  * @bprm: binprm for the exec  (NOT NULL)
709  */
710 static void apparmor_bprm_committed_creds(struct linux_binprm *bprm)
711 {
712 	/* clear out temporary/transitional state from the context */
713 	aa_clear_task_ctx_trans(task_ctx(current));
714 
715 	return;
716 }
717 
718 static void apparmor_task_getsecid(struct task_struct *p, u32 *secid)
719 {
720 	struct aa_label *label = aa_get_task_label(p);
721 	*secid = label->secid;
722 	aa_put_label(label);
723 }
724 
725 static int apparmor_task_setrlimit(struct task_struct *task,
726 		unsigned int resource, struct rlimit *new_rlim)
727 {
728 	struct aa_label *label = __begin_current_label_crit_section();
729 	int error = 0;
730 
731 	if (!unconfined(label))
732 		error = aa_task_setrlimit(label, task, resource, new_rlim);
733 	__end_current_label_crit_section(label);
734 
735 	return error;
736 }
737 
738 static int apparmor_task_kill(struct task_struct *target, struct kernel_siginfo *info,
739 			      int sig, const struct cred *cred)
740 {
741 	struct aa_label *cl, *tl;
742 	int error;
743 
744 	if (cred) {
745 		/*
746 		 * Dealing with USB IO specific behavior
747 		 */
748 		cl = aa_get_newest_cred_label(cred);
749 		tl = aa_get_task_label(target);
750 		error = aa_may_signal(cl, tl, sig);
751 		aa_put_label(cl);
752 		aa_put_label(tl);
753 		return error;
754 	}
755 
756 	cl = __begin_current_label_crit_section();
757 	tl = aa_get_task_label(target);
758 	error = aa_may_signal(cl, tl, sig);
759 	aa_put_label(tl);
760 	__end_current_label_crit_section(cl);
761 
762 	return error;
763 }
764 
765 /**
766  * apparmor_sk_alloc_security - allocate and attach the sk_security field
767  */
768 static int apparmor_sk_alloc_security(struct sock *sk, int family, gfp_t flags)
769 {
770 	struct aa_sk_ctx *ctx;
771 
772 	ctx = kzalloc(sizeof(*ctx), flags);
773 	if (!ctx)
774 		return -ENOMEM;
775 
776 	SK_CTX(sk) = ctx;
777 
778 	return 0;
779 }
780 
781 /**
782  * apparmor_sk_free_security - free the sk_security field
783  */
784 static void apparmor_sk_free_security(struct sock *sk)
785 {
786 	struct aa_sk_ctx *ctx = SK_CTX(sk);
787 
788 	SK_CTX(sk) = NULL;
789 	aa_put_label(ctx->label);
790 	aa_put_label(ctx->peer);
791 	kfree(ctx);
792 }
793 
794 /**
795  * apparmor_clone_security - clone the sk_security field
796  */
797 static void apparmor_sk_clone_security(const struct sock *sk,
798 				       struct sock *newsk)
799 {
800 	struct aa_sk_ctx *ctx = SK_CTX(sk);
801 	struct aa_sk_ctx *new = SK_CTX(newsk);
802 
803 	new->label = aa_get_label(ctx->label);
804 	new->peer = aa_get_label(ctx->peer);
805 }
806 
807 /**
808  * apparmor_socket_create - check perms before creating a new socket
809  */
810 static int apparmor_socket_create(int family, int type, int protocol, int kern)
811 {
812 	struct aa_label *label;
813 	int error = 0;
814 
815 	AA_BUG(in_interrupt());
816 
817 	label = begin_current_label_crit_section();
818 	if (!(kern || unconfined(label)))
819 		error = af_select(family,
820 				  create_perm(label, family, type, protocol),
821 				  aa_af_perm(label, OP_CREATE, AA_MAY_CREATE,
822 					     family, type, protocol));
823 	end_current_label_crit_section(label);
824 
825 	return error;
826 }
827 
828 /**
829  * apparmor_socket_post_create - setup the per-socket security struct
830  *
831  * Note:
832  * -   kernel sockets currently labeled unconfined but we may want to
833  *     move to a special kernel label
834  * -   socket may not have sk here if created with sock_create_lite or
835  *     sock_alloc. These should be accept cases which will be handled in
836  *     sock_graft.
837  */
838 static int apparmor_socket_post_create(struct socket *sock, int family,
839 				       int type, int protocol, int kern)
840 {
841 	struct aa_label *label;
842 
843 	if (kern) {
844 		struct aa_ns *ns = aa_get_current_ns();
845 
846 		label = aa_get_label(ns_unconfined(ns));
847 		aa_put_ns(ns);
848 	} else
849 		label = aa_get_current_label();
850 
851 	if (sock->sk) {
852 		struct aa_sk_ctx *ctx = SK_CTX(sock->sk);
853 
854 		aa_put_label(ctx->label);
855 		ctx->label = aa_get_label(label);
856 	}
857 	aa_put_label(label);
858 
859 	return 0;
860 }
861 
862 /**
863  * apparmor_socket_bind - check perms before bind addr to socket
864  */
865 static int apparmor_socket_bind(struct socket *sock,
866 				struct sockaddr *address, int addrlen)
867 {
868 	AA_BUG(!sock);
869 	AA_BUG(!sock->sk);
870 	AA_BUG(!address);
871 	AA_BUG(in_interrupt());
872 
873 	return af_select(sock->sk->sk_family,
874 			 bind_perm(sock, address, addrlen),
875 			 aa_sk_perm(OP_BIND, AA_MAY_BIND, sock->sk));
876 }
877 
878 /**
879  * apparmor_socket_connect - check perms before connecting @sock to @address
880  */
881 static int apparmor_socket_connect(struct socket *sock,
882 				   struct sockaddr *address, int addrlen)
883 {
884 	AA_BUG(!sock);
885 	AA_BUG(!sock->sk);
886 	AA_BUG(!address);
887 	AA_BUG(in_interrupt());
888 
889 	return af_select(sock->sk->sk_family,
890 			 connect_perm(sock, address, addrlen),
891 			 aa_sk_perm(OP_CONNECT, AA_MAY_CONNECT, sock->sk));
892 }
893 
894 /**
895  * apparmor_socket_list - check perms before allowing listen
896  */
897 static int apparmor_socket_listen(struct socket *sock, int backlog)
898 {
899 	AA_BUG(!sock);
900 	AA_BUG(!sock->sk);
901 	AA_BUG(in_interrupt());
902 
903 	return af_select(sock->sk->sk_family,
904 			 listen_perm(sock, backlog),
905 			 aa_sk_perm(OP_LISTEN, AA_MAY_LISTEN, sock->sk));
906 }
907 
908 /**
909  * apparmor_socket_accept - check perms before accepting a new connection.
910  *
911  * Note: while @newsock is created and has some information, the accept
912  *       has not been done.
913  */
914 static int apparmor_socket_accept(struct socket *sock, struct socket *newsock)
915 {
916 	AA_BUG(!sock);
917 	AA_BUG(!sock->sk);
918 	AA_BUG(!newsock);
919 	AA_BUG(in_interrupt());
920 
921 	return af_select(sock->sk->sk_family,
922 			 accept_perm(sock, newsock),
923 			 aa_sk_perm(OP_ACCEPT, AA_MAY_ACCEPT, sock->sk));
924 }
925 
926 static int aa_sock_msg_perm(const char *op, u32 request, struct socket *sock,
927 			    struct msghdr *msg, int size)
928 {
929 	AA_BUG(!sock);
930 	AA_BUG(!sock->sk);
931 	AA_BUG(!msg);
932 	AA_BUG(in_interrupt());
933 
934 	return af_select(sock->sk->sk_family,
935 			 msg_perm(op, request, sock, msg, size),
936 			 aa_sk_perm(op, request, sock->sk));
937 }
938 
939 /**
940  * apparmor_socket_sendmsg - check perms before sending msg to another socket
941  */
942 static int apparmor_socket_sendmsg(struct socket *sock,
943 				   struct msghdr *msg, int size)
944 {
945 	return aa_sock_msg_perm(OP_SENDMSG, AA_MAY_SEND, sock, msg, size);
946 }
947 
948 /**
949  * apparmor_socket_recvmsg - check perms before receiving a message
950  */
951 static int apparmor_socket_recvmsg(struct socket *sock,
952 				   struct msghdr *msg, int size, int flags)
953 {
954 	return aa_sock_msg_perm(OP_RECVMSG, AA_MAY_RECEIVE, sock, msg, size);
955 }
956 
957 /* revaliation, get/set attr, shutdown */
958 static int aa_sock_perm(const char *op, u32 request, struct socket *sock)
959 {
960 	AA_BUG(!sock);
961 	AA_BUG(!sock->sk);
962 	AA_BUG(in_interrupt());
963 
964 	return af_select(sock->sk->sk_family,
965 			 sock_perm(op, request, sock),
966 			 aa_sk_perm(op, request, sock->sk));
967 }
968 
969 /**
970  * apparmor_socket_getsockname - check perms before getting the local address
971  */
972 static int apparmor_socket_getsockname(struct socket *sock)
973 {
974 	return aa_sock_perm(OP_GETSOCKNAME, AA_MAY_GETATTR, sock);
975 }
976 
977 /**
978  * apparmor_socket_getpeername - check perms before getting remote address
979  */
980 static int apparmor_socket_getpeername(struct socket *sock)
981 {
982 	return aa_sock_perm(OP_GETPEERNAME, AA_MAY_GETATTR, sock);
983 }
984 
985 /* revaliation, get/set attr, opt */
986 static int aa_sock_opt_perm(const char *op, u32 request, struct socket *sock,
987 			    int level, int optname)
988 {
989 	AA_BUG(!sock);
990 	AA_BUG(!sock->sk);
991 	AA_BUG(in_interrupt());
992 
993 	return af_select(sock->sk->sk_family,
994 			 opt_perm(op, request, sock, level, optname),
995 			 aa_sk_perm(op, request, sock->sk));
996 }
997 
998 /**
999  * apparmor_getsockopt - check perms before getting socket options
1000  */
1001 static int apparmor_socket_getsockopt(struct socket *sock, int level,
1002 				      int optname)
1003 {
1004 	return aa_sock_opt_perm(OP_GETSOCKOPT, AA_MAY_GETOPT, sock,
1005 				level, optname);
1006 }
1007 
1008 /**
1009  * apparmor_setsockopt - check perms before setting socket options
1010  */
1011 static int apparmor_socket_setsockopt(struct socket *sock, int level,
1012 				      int optname)
1013 {
1014 	return aa_sock_opt_perm(OP_SETSOCKOPT, AA_MAY_SETOPT, sock,
1015 				level, optname);
1016 }
1017 
1018 /**
1019  * apparmor_socket_shutdown - check perms before shutting down @sock conn
1020  */
1021 static int apparmor_socket_shutdown(struct socket *sock, int how)
1022 {
1023 	return aa_sock_perm(OP_SHUTDOWN, AA_MAY_SHUTDOWN, sock);
1024 }
1025 
1026 #ifdef CONFIG_NETWORK_SECMARK
1027 /**
1028  * apparmor_socket_sock_recv_skb - check perms before associating skb to sk
1029  *
1030  * Note: can not sleep may be called with locks held
1031  *
1032  * dont want protocol specific in __skb_recv_datagram()
1033  * to deny an incoming connection  socket_sock_rcv_skb()
1034  */
1035 static int apparmor_socket_sock_rcv_skb(struct sock *sk, struct sk_buff *skb)
1036 {
1037 	struct aa_sk_ctx *ctx = SK_CTX(sk);
1038 
1039 	if (!skb->secmark)
1040 		return 0;
1041 
1042 	return apparmor_secmark_check(ctx->label, OP_RECVMSG, AA_MAY_RECEIVE,
1043 				      skb->secmark, sk);
1044 }
1045 #endif
1046 
1047 
1048 static struct aa_label *sk_peer_label(struct sock *sk)
1049 {
1050 	struct aa_sk_ctx *ctx = SK_CTX(sk);
1051 
1052 	if (ctx->peer)
1053 		return ctx->peer;
1054 
1055 	return ERR_PTR(-ENOPROTOOPT);
1056 }
1057 
1058 /**
1059  * apparmor_socket_getpeersec_stream - get security context of peer
1060  *
1061  * Note: for tcp only valid if using ipsec or cipso on lan
1062  */
1063 static int apparmor_socket_getpeersec_stream(struct socket *sock,
1064 					     char __user *optval,
1065 					     int __user *optlen,
1066 					     unsigned int len)
1067 {
1068 	char *name;
1069 	int slen, error = 0;
1070 	struct aa_label *label;
1071 	struct aa_label *peer;
1072 
1073 	label = begin_current_label_crit_section();
1074 	peer = sk_peer_label(sock->sk);
1075 	if (IS_ERR(peer)) {
1076 		error = PTR_ERR(peer);
1077 		goto done;
1078 	}
1079 	slen = aa_label_asxprint(&name, labels_ns(label), peer,
1080 				 FLAG_SHOW_MODE | FLAG_VIEW_SUBNS |
1081 				 FLAG_HIDDEN_UNCONFINED, GFP_KERNEL);
1082 	/* don't include terminating \0 in slen, it breaks some apps */
1083 	if (slen < 0) {
1084 		error = -ENOMEM;
1085 	} else {
1086 		if (slen > len) {
1087 			error = -ERANGE;
1088 		} else if (copy_to_user(optval, name, slen)) {
1089 			error = -EFAULT;
1090 			goto out;
1091 		}
1092 		if (put_user(slen, optlen))
1093 			error = -EFAULT;
1094 out:
1095 		kfree(name);
1096 
1097 	}
1098 
1099 done:
1100 	end_current_label_crit_section(label);
1101 
1102 	return error;
1103 }
1104 
1105 /**
1106  * apparmor_socket_getpeersec_dgram - get security label of packet
1107  * @sock: the peer socket
1108  * @skb: packet data
1109  * @secid: pointer to where to put the secid of the packet
1110  *
1111  * Sets the netlabel socket state on sk from parent
1112  */
1113 static int apparmor_socket_getpeersec_dgram(struct socket *sock,
1114 					    struct sk_buff *skb, u32 *secid)
1115 
1116 {
1117 	/* TODO: requires secid support */
1118 	return -ENOPROTOOPT;
1119 }
1120 
1121 /**
1122  * apparmor_sock_graft - Initialize newly created socket
1123  * @sk: child sock
1124  * @parent: parent socket
1125  *
1126  * Note: could set off of SOCK_CTX(parent) but need to track inode and we can
1127  *       just set sk security information off of current creating process label
1128  *       Labeling of sk for accept case - probably should be sock based
1129  *       instead of task, because of the case where an implicitly labeled
1130  *       socket is shared by different tasks.
1131  */
1132 static void apparmor_sock_graft(struct sock *sk, struct socket *parent)
1133 {
1134 	struct aa_sk_ctx *ctx = SK_CTX(sk);
1135 
1136 	if (!ctx->label)
1137 		ctx->label = aa_get_current_label();
1138 }
1139 
1140 #ifdef CONFIG_NETWORK_SECMARK
1141 static int apparmor_inet_conn_request(struct sock *sk, struct sk_buff *skb,
1142 				      struct request_sock *req)
1143 {
1144 	struct aa_sk_ctx *ctx = SK_CTX(sk);
1145 
1146 	if (!skb->secmark)
1147 		return 0;
1148 
1149 	return apparmor_secmark_check(ctx->label, OP_CONNECT, AA_MAY_CONNECT,
1150 				      skb->secmark, sk);
1151 }
1152 #endif
1153 
1154 static struct security_hook_list apparmor_hooks[] __lsm_ro_after_init = {
1155 	LSM_HOOK_INIT(ptrace_access_check, apparmor_ptrace_access_check),
1156 	LSM_HOOK_INIT(ptrace_traceme, apparmor_ptrace_traceme),
1157 	LSM_HOOK_INIT(capget, apparmor_capget),
1158 	LSM_HOOK_INIT(capable, apparmor_capable),
1159 
1160 	LSM_HOOK_INIT(sb_mount, apparmor_sb_mount),
1161 	LSM_HOOK_INIT(sb_umount, apparmor_sb_umount),
1162 	LSM_HOOK_INIT(sb_pivotroot, apparmor_sb_pivotroot),
1163 
1164 	LSM_HOOK_INIT(path_link, apparmor_path_link),
1165 	LSM_HOOK_INIT(path_unlink, apparmor_path_unlink),
1166 	LSM_HOOK_INIT(path_symlink, apparmor_path_symlink),
1167 	LSM_HOOK_INIT(path_mkdir, apparmor_path_mkdir),
1168 	LSM_HOOK_INIT(path_rmdir, apparmor_path_rmdir),
1169 	LSM_HOOK_INIT(path_mknod, apparmor_path_mknod),
1170 	LSM_HOOK_INIT(path_rename, apparmor_path_rename),
1171 	LSM_HOOK_INIT(path_chmod, apparmor_path_chmod),
1172 	LSM_HOOK_INIT(path_chown, apparmor_path_chown),
1173 	LSM_HOOK_INIT(path_truncate, apparmor_path_truncate),
1174 	LSM_HOOK_INIT(inode_getattr, apparmor_inode_getattr),
1175 
1176 	LSM_HOOK_INIT(file_open, apparmor_file_open),
1177 	LSM_HOOK_INIT(file_receive, apparmor_file_receive),
1178 	LSM_HOOK_INIT(file_permission, apparmor_file_permission),
1179 	LSM_HOOK_INIT(file_alloc_security, apparmor_file_alloc_security),
1180 	LSM_HOOK_INIT(file_free_security, apparmor_file_free_security),
1181 	LSM_HOOK_INIT(mmap_file, apparmor_mmap_file),
1182 	LSM_HOOK_INIT(file_mprotect, apparmor_file_mprotect),
1183 	LSM_HOOK_INIT(file_lock, apparmor_file_lock),
1184 
1185 	LSM_HOOK_INIT(getprocattr, apparmor_getprocattr),
1186 	LSM_HOOK_INIT(setprocattr, apparmor_setprocattr),
1187 
1188 	LSM_HOOK_INIT(sk_alloc_security, apparmor_sk_alloc_security),
1189 	LSM_HOOK_INIT(sk_free_security, apparmor_sk_free_security),
1190 	LSM_HOOK_INIT(sk_clone_security, apparmor_sk_clone_security),
1191 
1192 	LSM_HOOK_INIT(socket_create, apparmor_socket_create),
1193 	LSM_HOOK_INIT(socket_post_create, apparmor_socket_post_create),
1194 	LSM_HOOK_INIT(socket_bind, apparmor_socket_bind),
1195 	LSM_HOOK_INIT(socket_connect, apparmor_socket_connect),
1196 	LSM_HOOK_INIT(socket_listen, apparmor_socket_listen),
1197 	LSM_HOOK_INIT(socket_accept, apparmor_socket_accept),
1198 	LSM_HOOK_INIT(socket_sendmsg, apparmor_socket_sendmsg),
1199 	LSM_HOOK_INIT(socket_recvmsg, apparmor_socket_recvmsg),
1200 	LSM_HOOK_INIT(socket_getsockname, apparmor_socket_getsockname),
1201 	LSM_HOOK_INIT(socket_getpeername, apparmor_socket_getpeername),
1202 	LSM_HOOK_INIT(socket_getsockopt, apparmor_socket_getsockopt),
1203 	LSM_HOOK_INIT(socket_setsockopt, apparmor_socket_setsockopt),
1204 	LSM_HOOK_INIT(socket_shutdown, apparmor_socket_shutdown),
1205 #ifdef CONFIG_NETWORK_SECMARK
1206 	LSM_HOOK_INIT(socket_sock_rcv_skb, apparmor_socket_sock_rcv_skb),
1207 #endif
1208 	LSM_HOOK_INIT(socket_getpeersec_stream,
1209 		      apparmor_socket_getpeersec_stream),
1210 	LSM_HOOK_INIT(socket_getpeersec_dgram,
1211 		      apparmor_socket_getpeersec_dgram),
1212 	LSM_HOOK_INIT(sock_graft, apparmor_sock_graft),
1213 #ifdef CONFIG_NETWORK_SECMARK
1214 	LSM_HOOK_INIT(inet_conn_request, apparmor_inet_conn_request),
1215 #endif
1216 
1217 	LSM_HOOK_INIT(cred_alloc_blank, apparmor_cred_alloc_blank),
1218 	LSM_HOOK_INIT(cred_free, apparmor_cred_free),
1219 	LSM_HOOK_INIT(cred_prepare, apparmor_cred_prepare),
1220 	LSM_HOOK_INIT(cred_transfer, apparmor_cred_transfer),
1221 
1222 	LSM_HOOK_INIT(bprm_set_creds, apparmor_bprm_set_creds),
1223 	LSM_HOOK_INIT(bprm_committing_creds, apparmor_bprm_committing_creds),
1224 	LSM_HOOK_INIT(bprm_committed_creds, apparmor_bprm_committed_creds),
1225 
1226 	LSM_HOOK_INIT(task_free, apparmor_task_free),
1227 	LSM_HOOK_INIT(task_alloc, apparmor_task_alloc),
1228 	LSM_HOOK_INIT(task_getsecid, apparmor_task_getsecid),
1229 	LSM_HOOK_INIT(task_setrlimit, apparmor_task_setrlimit),
1230 	LSM_HOOK_INIT(task_kill, apparmor_task_kill),
1231 
1232 #ifdef CONFIG_AUDIT
1233 	LSM_HOOK_INIT(audit_rule_init, aa_audit_rule_init),
1234 	LSM_HOOK_INIT(audit_rule_known, aa_audit_rule_known),
1235 	LSM_HOOK_INIT(audit_rule_match, aa_audit_rule_match),
1236 	LSM_HOOK_INIT(audit_rule_free, aa_audit_rule_free),
1237 #endif
1238 
1239 	LSM_HOOK_INIT(secid_to_secctx, apparmor_secid_to_secctx),
1240 	LSM_HOOK_INIT(secctx_to_secid, apparmor_secctx_to_secid),
1241 	LSM_HOOK_INIT(release_secctx, apparmor_release_secctx),
1242 };
1243 
1244 /*
1245  * AppArmor sysfs module parameters
1246  */
1247 
1248 static int param_set_aabool(const char *val, const struct kernel_param *kp);
1249 static int param_get_aabool(char *buffer, const struct kernel_param *kp);
1250 #define param_check_aabool param_check_bool
1251 static const struct kernel_param_ops param_ops_aabool = {
1252 	.flags = KERNEL_PARAM_OPS_FL_NOARG,
1253 	.set = param_set_aabool,
1254 	.get = param_get_aabool
1255 };
1256 
1257 static int param_set_aauint(const char *val, const struct kernel_param *kp);
1258 static int param_get_aauint(char *buffer, const struct kernel_param *kp);
1259 #define param_check_aauint param_check_uint
1260 static const struct kernel_param_ops param_ops_aauint = {
1261 	.set = param_set_aauint,
1262 	.get = param_get_aauint
1263 };
1264 
1265 static int param_set_aalockpolicy(const char *val, const struct kernel_param *kp);
1266 static int param_get_aalockpolicy(char *buffer, const struct kernel_param *kp);
1267 #define param_check_aalockpolicy param_check_bool
1268 static const struct kernel_param_ops param_ops_aalockpolicy = {
1269 	.flags = KERNEL_PARAM_OPS_FL_NOARG,
1270 	.set = param_set_aalockpolicy,
1271 	.get = param_get_aalockpolicy
1272 };
1273 
1274 static int param_set_audit(const char *val, const struct kernel_param *kp);
1275 static int param_get_audit(char *buffer, const struct kernel_param *kp);
1276 
1277 static int param_set_mode(const char *val, const struct kernel_param *kp);
1278 static int param_get_mode(char *buffer, const struct kernel_param *kp);
1279 
1280 /* Flag values, also controllable via /sys/module/apparmor/parameters
1281  * We define special types as we want to do additional mediation.
1282  */
1283 
1284 /* AppArmor global enforcement switch - complain, enforce, kill */
1285 enum profile_mode aa_g_profile_mode = APPARMOR_ENFORCE;
1286 module_param_call(mode, param_set_mode, param_get_mode,
1287 		  &aa_g_profile_mode, S_IRUSR | S_IWUSR);
1288 
1289 /* whether policy verification hashing is enabled */
1290 bool aa_g_hash_policy = IS_ENABLED(CONFIG_SECURITY_APPARMOR_HASH_DEFAULT);
1291 #ifdef CONFIG_SECURITY_APPARMOR_HASH
1292 module_param_named(hash_policy, aa_g_hash_policy, aabool, S_IRUSR | S_IWUSR);
1293 #endif
1294 
1295 /* Debug mode */
1296 bool aa_g_debug = IS_ENABLED(CONFIG_SECURITY_APPARMOR_DEBUG_MESSAGES);
1297 module_param_named(debug, aa_g_debug, aabool, S_IRUSR | S_IWUSR);
1298 
1299 /* Audit mode */
1300 enum audit_mode aa_g_audit;
1301 module_param_call(audit, param_set_audit, param_get_audit,
1302 		  &aa_g_audit, S_IRUSR | S_IWUSR);
1303 
1304 /* Determines if audit header is included in audited messages.  This
1305  * provides more context if the audit daemon is not running
1306  */
1307 bool aa_g_audit_header = true;
1308 module_param_named(audit_header, aa_g_audit_header, aabool,
1309 		   S_IRUSR | S_IWUSR);
1310 
1311 /* lock out loading/removal of policy
1312  * TODO: add in at boot loading of policy, which is the only way to
1313  *       load policy, if lock_policy is set
1314  */
1315 bool aa_g_lock_policy;
1316 module_param_named(lock_policy, aa_g_lock_policy, aalockpolicy,
1317 		   S_IRUSR | S_IWUSR);
1318 
1319 /* Syscall logging mode */
1320 bool aa_g_logsyscall;
1321 module_param_named(logsyscall, aa_g_logsyscall, aabool, S_IRUSR | S_IWUSR);
1322 
1323 /* Maximum pathname length before accesses will start getting rejected */
1324 unsigned int aa_g_path_max = 2 * PATH_MAX;
1325 module_param_named(path_max, aa_g_path_max, aauint, S_IRUSR);
1326 
1327 /* Determines how paranoid loading of policy is and how much verification
1328  * on the loaded policy is done.
1329  * DEPRECATED: read only as strict checking of load is always done now
1330  * that none root users (user namespaces) can load policy.
1331  */
1332 bool aa_g_paranoid_load = true;
1333 module_param_named(paranoid_load, aa_g_paranoid_load, aabool, S_IRUGO);
1334 
1335 /* Boot time disable flag */
1336 static bool apparmor_enabled = CONFIG_SECURITY_APPARMOR_BOOTPARAM_VALUE;
1337 module_param_named(enabled, apparmor_enabled, bool, S_IRUGO);
1338 
1339 static int __init apparmor_enabled_setup(char *str)
1340 {
1341 	unsigned long enabled;
1342 	int error = kstrtoul(str, 0, &enabled);
1343 	if (!error)
1344 		apparmor_enabled = enabled ? 1 : 0;
1345 	return 1;
1346 }
1347 
1348 __setup("apparmor=", apparmor_enabled_setup);
1349 
1350 /* set global flag turning off the ability to load policy */
1351 static int param_set_aalockpolicy(const char *val, const struct kernel_param *kp)
1352 {
1353 	if (!apparmor_enabled)
1354 		return -EINVAL;
1355 	if (apparmor_initialized && !policy_admin_capable(NULL))
1356 		return -EPERM;
1357 	return param_set_bool(val, kp);
1358 }
1359 
1360 static int param_get_aalockpolicy(char *buffer, const struct kernel_param *kp)
1361 {
1362 	if (!apparmor_enabled)
1363 		return -EINVAL;
1364 	if (apparmor_initialized && !policy_view_capable(NULL))
1365 		return -EPERM;
1366 	return param_get_bool(buffer, kp);
1367 }
1368 
1369 static int param_set_aabool(const char *val, const struct kernel_param *kp)
1370 {
1371 	if (!apparmor_enabled)
1372 		return -EINVAL;
1373 	if (apparmor_initialized && !policy_admin_capable(NULL))
1374 		return -EPERM;
1375 	return param_set_bool(val, kp);
1376 }
1377 
1378 static int param_get_aabool(char *buffer, const struct kernel_param *kp)
1379 {
1380 	if (!apparmor_enabled)
1381 		return -EINVAL;
1382 	if (apparmor_initialized && !policy_view_capable(NULL))
1383 		return -EPERM;
1384 	return param_get_bool(buffer, kp);
1385 }
1386 
1387 static int param_set_aauint(const char *val, const struct kernel_param *kp)
1388 {
1389 	int error;
1390 
1391 	if (!apparmor_enabled)
1392 		return -EINVAL;
1393 	/* file is ro but enforce 2nd line check */
1394 	if (apparmor_initialized)
1395 		return -EPERM;
1396 
1397 	error = param_set_uint(val, kp);
1398 	pr_info("AppArmor: buffer size set to %d bytes\n", aa_g_path_max);
1399 
1400 	return error;
1401 }
1402 
1403 static int param_get_aauint(char *buffer, const struct kernel_param *kp)
1404 {
1405 	if (!apparmor_enabled)
1406 		return -EINVAL;
1407 	if (apparmor_initialized && !policy_view_capable(NULL))
1408 		return -EPERM;
1409 	return param_get_uint(buffer, kp);
1410 }
1411 
1412 static int param_get_audit(char *buffer, const struct kernel_param *kp)
1413 {
1414 	if (!apparmor_enabled)
1415 		return -EINVAL;
1416 	if (apparmor_initialized && !policy_view_capable(NULL))
1417 		return -EPERM;
1418 	return sprintf(buffer, "%s", audit_mode_names[aa_g_audit]);
1419 }
1420 
1421 static int param_set_audit(const char *val, const struct kernel_param *kp)
1422 {
1423 	int i;
1424 
1425 	if (!apparmor_enabled)
1426 		return -EINVAL;
1427 	if (!val)
1428 		return -EINVAL;
1429 	if (apparmor_initialized && !policy_admin_capable(NULL))
1430 		return -EPERM;
1431 
1432 	i = match_string(audit_mode_names, AUDIT_MAX_INDEX, val);
1433 	if (i < 0)
1434 		return -EINVAL;
1435 
1436 	aa_g_audit = i;
1437 	return 0;
1438 }
1439 
1440 static int param_get_mode(char *buffer, const struct kernel_param *kp)
1441 {
1442 	if (!apparmor_enabled)
1443 		return -EINVAL;
1444 	if (apparmor_initialized && !policy_view_capable(NULL))
1445 		return -EPERM;
1446 
1447 	return sprintf(buffer, "%s", aa_profile_mode_names[aa_g_profile_mode]);
1448 }
1449 
1450 static int param_set_mode(const char *val, const struct kernel_param *kp)
1451 {
1452 	int i;
1453 
1454 	if (!apparmor_enabled)
1455 		return -EINVAL;
1456 	if (!val)
1457 		return -EINVAL;
1458 	if (apparmor_initialized && !policy_admin_capable(NULL))
1459 		return -EPERM;
1460 
1461 	i = match_string(aa_profile_mode_names, APPARMOR_MODE_NAMES_MAX_INDEX,
1462 			 val);
1463 	if (i < 0)
1464 		return -EINVAL;
1465 
1466 	aa_g_profile_mode = i;
1467 	return 0;
1468 }
1469 
1470 /*
1471  * AppArmor init functions
1472  */
1473 
1474 /**
1475  * set_init_ctx - set a task context and profile on the first task.
1476  *
1477  * TODO: allow setting an alternate profile than unconfined
1478  */
1479 static int __init set_init_ctx(void)
1480 {
1481 	struct cred *cred = (struct cred *)current->real_cred;
1482 	struct aa_task_ctx *ctx;
1483 
1484 	ctx = aa_alloc_task_ctx(GFP_KERNEL);
1485 	if (!ctx)
1486 		return -ENOMEM;
1487 
1488 	cred_label(cred) = aa_get_label(ns_unconfined(root_ns));
1489 	task_ctx(current) = ctx;
1490 
1491 	return 0;
1492 }
1493 
1494 static void destroy_buffers(void)
1495 {
1496 	u32 i, j;
1497 
1498 	for_each_possible_cpu(i) {
1499 		for_each_cpu_buffer(j) {
1500 			kfree(per_cpu(aa_buffers, i).buf[j]);
1501 			per_cpu(aa_buffers, i).buf[j] = NULL;
1502 		}
1503 	}
1504 }
1505 
1506 static int __init alloc_buffers(void)
1507 {
1508 	u32 i, j;
1509 
1510 	for_each_possible_cpu(i) {
1511 		for_each_cpu_buffer(j) {
1512 			char *buffer;
1513 
1514 			if (cpu_to_node(i) > num_online_nodes())
1515 				/* fallback to kmalloc for offline nodes */
1516 				buffer = kmalloc(aa_g_path_max, GFP_KERNEL);
1517 			else
1518 				buffer = kmalloc_node(aa_g_path_max, GFP_KERNEL,
1519 						      cpu_to_node(i));
1520 			if (!buffer) {
1521 				destroy_buffers();
1522 				return -ENOMEM;
1523 			}
1524 			per_cpu(aa_buffers, i).buf[j] = buffer;
1525 		}
1526 	}
1527 
1528 	return 0;
1529 }
1530 
1531 #ifdef CONFIG_SYSCTL
1532 static int apparmor_dointvec(struct ctl_table *table, int write,
1533 			     void __user *buffer, size_t *lenp, loff_t *ppos)
1534 {
1535 	if (!policy_admin_capable(NULL))
1536 		return -EPERM;
1537 	if (!apparmor_enabled)
1538 		return -EINVAL;
1539 
1540 	return proc_dointvec(table, write, buffer, lenp, ppos);
1541 }
1542 
1543 static struct ctl_path apparmor_sysctl_path[] = {
1544 	{ .procname = "kernel", },
1545 	{ }
1546 };
1547 
1548 static struct ctl_table apparmor_sysctl_table[] = {
1549 	{
1550 		.procname       = "unprivileged_userns_apparmor_policy",
1551 		.data           = &unprivileged_userns_apparmor_policy,
1552 		.maxlen         = sizeof(int),
1553 		.mode           = 0600,
1554 		.proc_handler   = apparmor_dointvec,
1555 	},
1556 	{ }
1557 };
1558 
1559 static int __init apparmor_init_sysctl(void)
1560 {
1561 	return register_sysctl_paths(apparmor_sysctl_path,
1562 				     apparmor_sysctl_table) ? 0 : -ENOMEM;
1563 }
1564 #else
1565 static inline int apparmor_init_sysctl(void)
1566 {
1567 	return 0;
1568 }
1569 #endif /* CONFIG_SYSCTL */
1570 
1571 #if defined(CONFIG_NETFILTER) && defined(CONFIG_NETWORK_SECMARK)
1572 static unsigned int apparmor_ip_postroute(void *priv,
1573 					  struct sk_buff *skb,
1574 					  const struct nf_hook_state *state)
1575 {
1576 	struct aa_sk_ctx *ctx;
1577 	struct sock *sk;
1578 
1579 	if (!skb->secmark)
1580 		return NF_ACCEPT;
1581 
1582 	sk = skb_to_full_sk(skb);
1583 	if (sk == NULL)
1584 		return NF_ACCEPT;
1585 
1586 	ctx = SK_CTX(sk);
1587 	if (!apparmor_secmark_check(ctx->label, OP_SENDMSG, AA_MAY_SEND,
1588 				    skb->secmark, sk))
1589 		return NF_ACCEPT;
1590 
1591 	return NF_DROP_ERR(-ECONNREFUSED);
1592 
1593 }
1594 
1595 static unsigned int apparmor_ipv4_postroute(void *priv,
1596 					    struct sk_buff *skb,
1597 					    const struct nf_hook_state *state)
1598 {
1599 	return apparmor_ip_postroute(priv, skb, state);
1600 }
1601 
1602 static unsigned int apparmor_ipv6_postroute(void *priv,
1603 					    struct sk_buff *skb,
1604 					    const struct nf_hook_state *state)
1605 {
1606 	return apparmor_ip_postroute(priv, skb, state);
1607 }
1608 
1609 static const struct nf_hook_ops apparmor_nf_ops[] = {
1610 	{
1611 		.hook =         apparmor_ipv4_postroute,
1612 		.pf =           NFPROTO_IPV4,
1613 		.hooknum =      NF_INET_POST_ROUTING,
1614 		.priority =     NF_IP_PRI_SELINUX_FIRST,
1615 	},
1616 #if IS_ENABLED(CONFIG_IPV6)
1617 	{
1618 		.hook =         apparmor_ipv6_postroute,
1619 		.pf =           NFPROTO_IPV6,
1620 		.hooknum =      NF_INET_POST_ROUTING,
1621 		.priority =     NF_IP6_PRI_SELINUX_FIRST,
1622 	},
1623 #endif
1624 };
1625 
1626 static int __net_init apparmor_nf_register(struct net *net)
1627 {
1628 	int ret;
1629 
1630 	ret = nf_register_net_hooks(net, apparmor_nf_ops,
1631 				    ARRAY_SIZE(apparmor_nf_ops));
1632 	return ret;
1633 }
1634 
1635 static void __net_exit apparmor_nf_unregister(struct net *net)
1636 {
1637 	nf_unregister_net_hooks(net, apparmor_nf_ops,
1638 				ARRAY_SIZE(apparmor_nf_ops));
1639 }
1640 
1641 static struct pernet_operations apparmor_net_ops = {
1642 	.init = apparmor_nf_register,
1643 	.exit = apparmor_nf_unregister,
1644 };
1645 
1646 static int __init apparmor_nf_ip_init(void)
1647 {
1648 	int err;
1649 
1650 	if (!apparmor_enabled)
1651 		return 0;
1652 
1653 	err = register_pernet_subsys(&apparmor_net_ops);
1654 	if (err)
1655 		panic("Apparmor: register_pernet_subsys: error %d\n", err);
1656 
1657 	return 0;
1658 }
1659 __initcall(apparmor_nf_ip_init);
1660 #endif
1661 
1662 static int __init apparmor_init(void)
1663 {
1664 	int error;
1665 
1666 	if (!apparmor_enabled || !security_module_enable("apparmor")) {
1667 		aa_info_message("AppArmor disabled by boot time parameter");
1668 		apparmor_enabled = false;
1669 		return 0;
1670 	}
1671 
1672 	aa_secids_init();
1673 
1674 	error = aa_setup_dfa_engine();
1675 	if (error) {
1676 		AA_ERROR("Unable to setup dfa engine\n");
1677 		goto alloc_out;
1678 	}
1679 
1680 	error = aa_alloc_root_ns();
1681 	if (error) {
1682 		AA_ERROR("Unable to allocate default profile namespace\n");
1683 		goto alloc_out;
1684 	}
1685 
1686 	error = apparmor_init_sysctl();
1687 	if (error) {
1688 		AA_ERROR("Unable to register sysctls\n");
1689 		goto alloc_out;
1690 
1691 	}
1692 
1693 	error = alloc_buffers();
1694 	if (error) {
1695 		AA_ERROR("Unable to allocate work buffers\n");
1696 		goto buffers_out;
1697 	}
1698 
1699 	error = set_init_ctx();
1700 	if (error) {
1701 		AA_ERROR("Failed to set context on init task\n");
1702 		aa_free_root_ns();
1703 		goto buffers_out;
1704 	}
1705 	security_add_hooks(apparmor_hooks, ARRAY_SIZE(apparmor_hooks),
1706 				"apparmor");
1707 
1708 	/* Report that AppArmor successfully initialized */
1709 	apparmor_initialized = 1;
1710 	if (aa_g_profile_mode == APPARMOR_COMPLAIN)
1711 		aa_info_message("AppArmor initialized: complain mode enabled");
1712 	else if (aa_g_profile_mode == APPARMOR_KILL)
1713 		aa_info_message("AppArmor initialized: kill mode enabled");
1714 	else
1715 		aa_info_message("AppArmor initialized");
1716 
1717 	return error;
1718 
1719 buffers_out:
1720 	destroy_buffers();
1721 
1722 alloc_out:
1723 	aa_destroy_aafs();
1724 	aa_teardown_dfa_engine();
1725 
1726 	apparmor_enabled = false;
1727 	return error;
1728 }
1729 
1730 DEFINE_LSM(apparmor) = {
1731 	.name = "apparmor",
1732 	.init = apparmor_init,
1733 };
1734