xref: /openbmc/linux/security/apparmor/lsm.c (revision 1ab142d4)
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/security.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 <net/sock.h>
27 
28 #include "include/apparmor.h"
29 #include "include/apparmorfs.h"
30 #include "include/audit.h"
31 #include "include/capability.h"
32 #include "include/context.h"
33 #include "include/file.h"
34 #include "include/ipc.h"
35 #include "include/path.h"
36 #include "include/policy.h"
37 #include "include/procattr.h"
38 
39 /* Flag indicating whether initialization completed */
40 int apparmor_initialized __initdata;
41 
42 /*
43  * LSM hook functions
44  */
45 
46 /*
47  * free the associated aa_task_cxt and put its profiles
48  */
49 static void apparmor_cred_free(struct cred *cred)
50 {
51 	aa_free_task_context(cred->security);
52 	cred->security = NULL;
53 }
54 
55 /*
56  * allocate the apparmor part of blank credentials
57  */
58 static int apparmor_cred_alloc_blank(struct cred *cred, gfp_t gfp)
59 {
60 	/* freed by apparmor_cred_free */
61 	struct aa_task_cxt *cxt = aa_alloc_task_context(gfp);
62 	if (!cxt)
63 		return -ENOMEM;
64 
65 	cred->security = cxt;
66 	return 0;
67 }
68 
69 /*
70  * prepare new aa_task_cxt for modification by prepare_cred block
71  */
72 static int apparmor_cred_prepare(struct cred *new, const struct cred *old,
73 				 gfp_t gfp)
74 {
75 	/* freed by apparmor_cred_free */
76 	struct aa_task_cxt *cxt = aa_alloc_task_context(gfp);
77 	if (!cxt)
78 		return -ENOMEM;
79 
80 	aa_dup_task_context(cxt, old->security);
81 	new->security = cxt;
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 	const struct aa_task_cxt *old_cxt = old->security;
91 	struct aa_task_cxt *new_cxt = new->security;
92 
93 	aa_dup_task_context(new_cxt, old_cxt);
94 }
95 
96 static int apparmor_ptrace_access_check(struct task_struct *child,
97 					unsigned int mode)
98 {
99 	int error = cap_ptrace_access_check(child, mode);
100 	if (error)
101 		return error;
102 
103 	return aa_ptrace(current, child, mode);
104 }
105 
106 static int apparmor_ptrace_traceme(struct task_struct *parent)
107 {
108 	int error = cap_ptrace_traceme(parent);
109 	if (error)
110 		return error;
111 
112 	return aa_ptrace(parent, current, PTRACE_MODE_ATTACH);
113 }
114 
115 /* Derived from security/commoncap.c:cap_capget */
116 static int apparmor_capget(struct task_struct *target, kernel_cap_t *effective,
117 			   kernel_cap_t *inheritable, kernel_cap_t *permitted)
118 {
119 	struct aa_profile *profile;
120 	const struct cred *cred;
121 
122 	rcu_read_lock();
123 	cred = __task_cred(target);
124 	profile = aa_cred_profile(cred);
125 
126 	*effective = cred->cap_effective;
127 	*inheritable = cred->cap_inheritable;
128 	*permitted = cred->cap_permitted;
129 
130 	if (!unconfined(profile) && !COMPLAIN_MODE(profile)) {
131 		*effective = cap_intersect(*effective, profile->caps.allow);
132 		*permitted = cap_intersect(*permitted, profile->caps.allow);
133 	}
134 	rcu_read_unlock();
135 
136 	return 0;
137 }
138 
139 static int apparmor_capable(const struct cred *cred, struct user_namespace *ns,
140 			    int cap, int audit)
141 {
142 	struct aa_profile *profile;
143 	/* cap_capable returns 0 on success, else -EPERM */
144 	int error = cap_capable(cred, ns, cap, audit);
145 	if (!error) {
146 		profile = aa_cred_profile(cred);
147 		if (!unconfined(profile))
148 			error = aa_capable(current, profile, cap, audit);
149 	}
150 	return error;
151 }
152 
153 /**
154  * common_perm - basic common permission check wrapper fn for paths
155  * @op: operation being checked
156  * @path: path to check permission of  (NOT NULL)
157  * @mask: requested permissions mask
158  * @cond: conditional info for the permission request  (NOT NULL)
159  *
160  * Returns: %0 else error code if error or permission denied
161  */
162 static int common_perm(int op, struct path *path, u32 mask,
163 		       struct path_cond *cond)
164 {
165 	struct aa_profile *profile;
166 	int error = 0;
167 
168 	profile = __aa_current_profile();
169 	if (!unconfined(profile))
170 		error = aa_path_perm(op, profile, path, 0, mask, cond);
171 
172 	return error;
173 }
174 
175 /**
176  * common_perm_dir_dentry - common permission wrapper when path is dir, dentry
177  * @op: operation being checked
178  * @dir: directory of the dentry  (NOT NULL)
179  * @dentry: dentry to check  (NOT NULL)
180  * @mask: requested permissions mask
181  * @cond: conditional info for the permission request  (NOT NULL)
182  *
183  * Returns: %0 else error code if error or permission denied
184  */
185 static int common_perm_dir_dentry(int op, struct path *dir,
186 				  struct dentry *dentry, u32 mask,
187 				  struct path_cond *cond)
188 {
189 	struct path path = { dir->mnt, dentry };
190 
191 	return common_perm(op, &path, mask, cond);
192 }
193 
194 /**
195  * common_perm_mnt_dentry - common permission wrapper when mnt, dentry
196  * @op: operation being checked
197  * @mnt: mount point of dentry (NOT NULL)
198  * @dentry: dentry to check  (NOT NULL)
199  * @mask: requested permissions mask
200  *
201  * Returns: %0 else error code if error or permission denied
202  */
203 static int common_perm_mnt_dentry(int op, struct vfsmount *mnt,
204 				  struct dentry *dentry, u32 mask)
205 {
206 	struct path path = { mnt, dentry };
207 	struct path_cond cond = { dentry->d_inode->i_uid,
208 				  dentry->d_inode->i_mode
209 	};
210 
211 	return common_perm(op, &path, mask, &cond);
212 }
213 
214 /**
215  * common_perm_rm - common permission wrapper for operations doing rm
216  * @op: operation being checked
217  * @dir: directory that the dentry is in  (NOT NULL)
218  * @dentry: dentry being rm'd  (NOT NULL)
219  * @mask: requested permission mask
220  *
221  * Returns: %0 else error code if error or permission denied
222  */
223 static int common_perm_rm(int op, struct path *dir,
224 			  struct dentry *dentry, u32 mask)
225 {
226 	struct inode *inode = dentry->d_inode;
227 	struct path_cond cond = { };
228 
229 	if (!inode || !dir->mnt || !mediated_filesystem(inode))
230 		return 0;
231 
232 	cond.uid = inode->i_uid;
233 	cond.mode = inode->i_mode;
234 
235 	return common_perm_dir_dentry(op, dir, dentry, mask, &cond);
236 }
237 
238 /**
239  * common_perm_create - common permission wrapper for operations doing create
240  * @op: operation being checked
241  * @dir: directory that dentry will be created in  (NOT NULL)
242  * @dentry: dentry to create   (NOT NULL)
243  * @mask: request permission mask
244  * @mode: created file mode
245  *
246  * Returns: %0 else error code if error or permission denied
247  */
248 static int common_perm_create(int op, struct path *dir, struct dentry *dentry,
249 			      u32 mask, umode_t mode)
250 {
251 	struct path_cond cond = { current_fsuid(), mode };
252 
253 	if (!dir->mnt || !mediated_filesystem(dir->dentry->d_inode))
254 		return 0;
255 
256 	return common_perm_dir_dentry(op, dir, dentry, mask, &cond);
257 }
258 
259 static int apparmor_path_unlink(struct path *dir, struct dentry *dentry)
260 {
261 	return common_perm_rm(OP_UNLINK, dir, dentry, AA_MAY_DELETE);
262 }
263 
264 static int apparmor_path_mkdir(struct path *dir, struct dentry *dentry,
265 			       umode_t mode)
266 {
267 	return common_perm_create(OP_MKDIR, dir, dentry, AA_MAY_CREATE,
268 				  S_IFDIR);
269 }
270 
271 static int apparmor_path_rmdir(struct path *dir, struct dentry *dentry)
272 {
273 	return common_perm_rm(OP_RMDIR, dir, dentry, AA_MAY_DELETE);
274 }
275 
276 static int apparmor_path_mknod(struct path *dir, struct dentry *dentry,
277 			       umode_t mode, unsigned int dev)
278 {
279 	return common_perm_create(OP_MKNOD, dir, dentry, AA_MAY_CREATE, mode);
280 }
281 
282 static int apparmor_path_truncate(struct path *path)
283 {
284 	struct path_cond cond = { path->dentry->d_inode->i_uid,
285 				  path->dentry->d_inode->i_mode
286 	};
287 
288 	if (!path->mnt || !mediated_filesystem(path->dentry->d_inode))
289 		return 0;
290 
291 	return common_perm(OP_TRUNC, path, MAY_WRITE | AA_MAY_META_WRITE,
292 			   &cond);
293 }
294 
295 static int apparmor_path_symlink(struct path *dir, struct dentry *dentry,
296 				 const char *old_name)
297 {
298 	return common_perm_create(OP_SYMLINK, dir, dentry, AA_MAY_CREATE,
299 				  S_IFLNK);
300 }
301 
302 static int apparmor_path_link(struct dentry *old_dentry, struct path *new_dir,
303 			      struct dentry *new_dentry)
304 {
305 	struct aa_profile *profile;
306 	int error = 0;
307 
308 	if (!mediated_filesystem(old_dentry->d_inode))
309 		return 0;
310 
311 	profile = aa_current_profile();
312 	if (!unconfined(profile))
313 		error = aa_path_link(profile, old_dentry, new_dir, new_dentry);
314 	return error;
315 }
316 
317 static int apparmor_path_rename(struct path *old_dir, struct dentry *old_dentry,
318 				struct path *new_dir, struct dentry *new_dentry)
319 {
320 	struct aa_profile *profile;
321 	int error = 0;
322 
323 	if (!mediated_filesystem(old_dentry->d_inode))
324 		return 0;
325 
326 	profile = aa_current_profile();
327 	if (!unconfined(profile)) {
328 		struct path old_path = { old_dir->mnt, old_dentry };
329 		struct path new_path = { new_dir->mnt, new_dentry };
330 		struct path_cond cond = { old_dentry->d_inode->i_uid,
331 					  old_dentry->d_inode->i_mode
332 		};
333 
334 		error = aa_path_perm(OP_RENAME_SRC, profile, &old_path, 0,
335 				     MAY_READ | AA_MAY_META_READ | MAY_WRITE |
336 				     AA_MAY_META_WRITE | AA_MAY_DELETE,
337 				     &cond);
338 		if (!error)
339 			error = aa_path_perm(OP_RENAME_DEST, profile, &new_path,
340 					     0, MAY_WRITE | AA_MAY_META_WRITE |
341 					     AA_MAY_CREATE, &cond);
342 
343 	}
344 	return error;
345 }
346 
347 static int apparmor_path_chmod(struct path *path, umode_t mode)
348 {
349 	if (!mediated_filesystem(path->dentry->d_inode))
350 		return 0;
351 
352 	return common_perm_mnt_dentry(OP_CHMOD, path->mnt, path->dentry, AA_MAY_CHMOD);
353 }
354 
355 static int apparmor_path_chown(struct path *path, uid_t uid, gid_t gid)
356 {
357 	struct path_cond cond =  { path->dentry->d_inode->i_uid,
358 				   path->dentry->d_inode->i_mode
359 	};
360 
361 	if (!mediated_filesystem(path->dentry->d_inode))
362 		return 0;
363 
364 	return common_perm(OP_CHOWN, path, AA_MAY_CHOWN, &cond);
365 }
366 
367 static int apparmor_inode_getattr(struct vfsmount *mnt, struct dentry *dentry)
368 {
369 	if (!mediated_filesystem(dentry->d_inode))
370 		return 0;
371 
372 	return common_perm_mnt_dentry(OP_GETATTR, mnt, dentry,
373 				      AA_MAY_META_READ);
374 }
375 
376 static int apparmor_dentry_open(struct file *file, const struct cred *cred)
377 {
378 	struct aa_file_cxt *fcxt = file->f_security;
379 	struct aa_profile *profile;
380 	int error = 0;
381 
382 	if (!mediated_filesystem(file->f_path.dentry->d_inode))
383 		return 0;
384 
385 	/* If in exec, permission is handled by bprm hooks.
386 	 * Cache permissions granted by the previous exec check, with
387 	 * implicit read and executable mmap which are required to
388 	 * actually execute the image.
389 	 */
390 	if (current->in_execve) {
391 		fcxt->allow = MAY_EXEC | MAY_READ | AA_EXEC_MMAP;
392 		return 0;
393 	}
394 
395 	profile = aa_cred_profile(cred);
396 	if (!unconfined(profile)) {
397 		struct inode *inode = file->f_path.dentry->d_inode;
398 		struct path_cond cond = { inode->i_uid, inode->i_mode };
399 
400 		error = aa_path_perm(OP_OPEN, profile, &file->f_path, 0,
401 				     aa_map_file_to_perms(file), &cond);
402 		/* todo cache full allowed permissions set and state */
403 		fcxt->allow = aa_map_file_to_perms(file);
404 	}
405 
406 	return error;
407 }
408 
409 static int apparmor_file_alloc_security(struct file *file)
410 {
411 	/* freed by apparmor_file_free_security */
412 	file->f_security = aa_alloc_file_context(GFP_KERNEL);
413 	if (!file->f_security)
414 		return -ENOMEM;
415 	return 0;
416 
417 }
418 
419 static void apparmor_file_free_security(struct file *file)
420 {
421 	struct aa_file_cxt *cxt = file->f_security;
422 
423 	aa_free_file_context(cxt);
424 }
425 
426 static int common_file_perm(int op, struct file *file, u32 mask)
427 {
428 	struct aa_file_cxt *fcxt = file->f_security;
429 	struct aa_profile *profile, *fprofile = aa_cred_profile(file->f_cred);
430 	int error = 0;
431 
432 	BUG_ON(!fprofile);
433 
434 	if (!file->f_path.mnt ||
435 	    !mediated_filesystem(file->f_path.dentry->d_inode))
436 		return 0;
437 
438 	profile = __aa_current_profile();
439 
440 	/* revalidate access, if task is unconfined, or the cached cred
441 	 * doesn't match or if the request is for more permissions than
442 	 * was granted.
443 	 *
444 	 * Note: the test for !unconfined(fprofile) is to handle file
445 	 *       delegation from unconfined tasks
446 	 */
447 	if (!unconfined(profile) && !unconfined(fprofile) &&
448 	    ((fprofile != profile) || (mask & ~fcxt->allow)))
449 		error = aa_file_perm(op, profile, file, mask);
450 
451 	return error;
452 }
453 
454 static int apparmor_file_permission(struct file *file, int mask)
455 {
456 	return common_file_perm(OP_FPERM, file, mask);
457 }
458 
459 static int apparmor_file_lock(struct file *file, unsigned int cmd)
460 {
461 	u32 mask = AA_MAY_LOCK;
462 
463 	if (cmd == F_WRLCK)
464 		mask |= MAY_WRITE;
465 
466 	return common_file_perm(OP_FLOCK, file, mask);
467 }
468 
469 static int common_mmap(int op, struct file *file, unsigned long prot,
470 		       unsigned long flags)
471 {
472 	struct dentry *dentry;
473 	int mask = 0;
474 
475 	if (!file || !file->f_security)
476 		return 0;
477 
478 	if (prot & PROT_READ)
479 		mask |= MAY_READ;
480 	/*
481 	 * Private mappings don't require write perms since they don't
482 	 * write back to the files
483 	 */
484 	if ((prot & PROT_WRITE) && !(flags & MAP_PRIVATE))
485 		mask |= MAY_WRITE;
486 	if (prot & PROT_EXEC)
487 		mask |= AA_EXEC_MMAP;
488 
489 	dentry = file->f_path.dentry;
490 	return common_file_perm(op, file, mask);
491 }
492 
493 static int apparmor_file_mmap(struct file *file, unsigned long reqprot,
494 			      unsigned long prot, unsigned long flags,
495 			      unsigned long addr, unsigned long addr_only)
496 {
497 	int rc = 0;
498 
499 	/* do DAC check */
500 	rc = cap_file_mmap(file, reqprot, prot, flags, addr, addr_only);
501 	if (rc || addr_only)
502 		return rc;
503 
504 	return common_mmap(OP_FMMAP, file, prot, flags);
505 }
506 
507 static int apparmor_file_mprotect(struct vm_area_struct *vma,
508 				  unsigned long reqprot, unsigned long prot)
509 {
510 	return common_mmap(OP_FMPROT, vma->vm_file, prot,
511 			   !(vma->vm_flags & VM_SHARED) ? MAP_PRIVATE : 0);
512 }
513 
514 static int apparmor_getprocattr(struct task_struct *task, char *name,
515 				char **value)
516 {
517 	int error = -ENOENT;
518 	struct aa_profile *profile;
519 	/* released below */
520 	const struct cred *cred = get_task_cred(task);
521 	struct aa_task_cxt *cxt = cred->security;
522 	profile = aa_cred_profile(cred);
523 
524 	if (strcmp(name, "current") == 0)
525 		error = aa_getprocattr(aa_newest_version(cxt->profile),
526 				       value);
527 	else if (strcmp(name, "prev") == 0  && cxt->previous)
528 		error = aa_getprocattr(aa_newest_version(cxt->previous),
529 				       value);
530 	else if (strcmp(name, "exec") == 0 && cxt->onexec)
531 		error = aa_getprocattr(aa_newest_version(cxt->onexec),
532 				       value);
533 	else
534 		error = -EINVAL;
535 
536 	put_cred(cred);
537 
538 	return error;
539 }
540 
541 static int apparmor_setprocattr(struct task_struct *task, char *name,
542 				void *value, size_t size)
543 {
544 	char *command, *args = value;
545 	size_t arg_size;
546 	int error;
547 
548 	if (size == 0)
549 		return -EINVAL;
550 	/* args points to a PAGE_SIZE buffer, AppArmor requires that
551 	 * the buffer must be null terminated or have size <= PAGE_SIZE -1
552 	 * so that AppArmor can null terminate them
553 	 */
554 	if (args[size - 1] != '\0') {
555 		if (size == PAGE_SIZE)
556 			return -EINVAL;
557 		args[size] = '\0';
558 	}
559 
560 	/* task can only write its own attributes */
561 	if (current != task)
562 		return -EACCES;
563 
564 	args = value;
565 	args = strim(args);
566 	command = strsep(&args, " ");
567 	if (!args)
568 		return -EINVAL;
569 	args = skip_spaces(args);
570 	if (!*args)
571 		return -EINVAL;
572 
573 	arg_size = size - (args - (char *) value);
574 	if (strcmp(name, "current") == 0) {
575 		if (strcmp(command, "changehat") == 0) {
576 			error = aa_setprocattr_changehat(args, arg_size,
577 							 !AA_DO_TEST);
578 		} else if (strcmp(command, "permhat") == 0) {
579 			error = aa_setprocattr_changehat(args, arg_size,
580 							 AA_DO_TEST);
581 		} else if (strcmp(command, "changeprofile") == 0) {
582 			error = aa_setprocattr_changeprofile(args, !AA_ONEXEC,
583 							     !AA_DO_TEST);
584 		} else if (strcmp(command, "permprofile") == 0) {
585 			error = aa_setprocattr_changeprofile(args, !AA_ONEXEC,
586 							     AA_DO_TEST);
587 		} else if (strcmp(command, "permipc") == 0) {
588 			error = aa_setprocattr_permipc(args);
589 		} else {
590 			struct common_audit_data sa;
591 			COMMON_AUDIT_DATA_INIT(&sa, NONE);
592 			sa.aad.op = OP_SETPROCATTR;
593 			sa.aad.info = name;
594 			sa.aad.error = -EINVAL;
595 			return aa_audit(AUDIT_APPARMOR_DENIED,
596 					__aa_current_profile(), GFP_KERNEL,
597 					&sa, NULL);
598 		}
599 	} else if (strcmp(name, "exec") == 0) {
600 		error = aa_setprocattr_changeprofile(args, AA_ONEXEC,
601 						     !AA_DO_TEST);
602 	} else {
603 		/* only support the "current" and "exec" process attributes */
604 		return -EINVAL;
605 	}
606 	if (!error)
607 		error = size;
608 	return error;
609 }
610 
611 static int apparmor_task_setrlimit(struct task_struct *task,
612 		unsigned int resource, struct rlimit *new_rlim)
613 {
614 	struct aa_profile *profile = __aa_current_profile();
615 	int error = 0;
616 
617 	if (!unconfined(profile))
618 		error = aa_task_setrlimit(profile, task, resource, new_rlim);
619 
620 	return error;
621 }
622 
623 static struct security_operations apparmor_ops = {
624 	.name =				"apparmor",
625 
626 	.ptrace_access_check =		apparmor_ptrace_access_check,
627 	.ptrace_traceme =		apparmor_ptrace_traceme,
628 	.capget =			apparmor_capget,
629 	.capable =			apparmor_capable,
630 
631 	.path_link =			apparmor_path_link,
632 	.path_unlink =			apparmor_path_unlink,
633 	.path_symlink =			apparmor_path_symlink,
634 	.path_mkdir =			apparmor_path_mkdir,
635 	.path_rmdir =			apparmor_path_rmdir,
636 	.path_mknod =			apparmor_path_mknod,
637 	.path_rename =			apparmor_path_rename,
638 	.path_chmod =			apparmor_path_chmod,
639 	.path_chown =			apparmor_path_chown,
640 	.path_truncate =		apparmor_path_truncate,
641 	.dentry_open =			apparmor_dentry_open,
642 	.inode_getattr =                apparmor_inode_getattr,
643 
644 	.file_permission =		apparmor_file_permission,
645 	.file_alloc_security =		apparmor_file_alloc_security,
646 	.file_free_security =		apparmor_file_free_security,
647 	.file_mmap =			apparmor_file_mmap,
648 	.file_mprotect =		apparmor_file_mprotect,
649 	.file_lock =			apparmor_file_lock,
650 
651 	.getprocattr =			apparmor_getprocattr,
652 	.setprocattr =			apparmor_setprocattr,
653 
654 	.cred_alloc_blank =		apparmor_cred_alloc_blank,
655 	.cred_free =			apparmor_cred_free,
656 	.cred_prepare =			apparmor_cred_prepare,
657 	.cred_transfer =		apparmor_cred_transfer,
658 
659 	.bprm_set_creds =		apparmor_bprm_set_creds,
660 	.bprm_committing_creds =	apparmor_bprm_committing_creds,
661 	.bprm_committed_creds =		apparmor_bprm_committed_creds,
662 	.bprm_secureexec =		apparmor_bprm_secureexec,
663 
664 	.task_setrlimit =		apparmor_task_setrlimit,
665 };
666 
667 /*
668  * AppArmor sysfs module parameters
669  */
670 
671 static int param_set_aabool(const char *val, const struct kernel_param *kp);
672 static int param_get_aabool(char *buffer, const struct kernel_param *kp);
673 #define param_check_aabool param_check_bool
674 static struct kernel_param_ops param_ops_aabool = {
675 	.set = param_set_aabool,
676 	.get = param_get_aabool
677 };
678 
679 static int param_set_aauint(const char *val, const struct kernel_param *kp);
680 static int param_get_aauint(char *buffer, const struct kernel_param *kp);
681 #define param_check_aauint param_check_uint
682 static struct kernel_param_ops param_ops_aauint = {
683 	.set = param_set_aauint,
684 	.get = param_get_aauint
685 };
686 
687 static int param_set_aalockpolicy(const char *val, const struct kernel_param *kp);
688 static int param_get_aalockpolicy(char *buffer, const struct kernel_param *kp);
689 #define param_check_aalockpolicy param_check_bool
690 static struct kernel_param_ops param_ops_aalockpolicy = {
691 	.set = param_set_aalockpolicy,
692 	.get = param_get_aalockpolicy
693 };
694 
695 static int param_set_audit(const char *val, struct kernel_param *kp);
696 static int param_get_audit(char *buffer, struct kernel_param *kp);
697 
698 static int param_set_mode(const char *val, struct kernel_param *kp);
699 static int param_get_mode(char *buffer, struct kernel_param *kp);
700 
701 /* Flag values, also controllable via /sys/module/apparmor/parameters
702  * We define special types as we want to do additional mediation.
703  */
704 
705 /* AppArmor global enforcement switch - complain, enforce, kill */
706 enum profile_mode aa_g_profile_mode = APPARMOR_ENFORCE;
707 module_param_call(mode, param_set_mode, param_get_mode,
708 		  &aa_g_profile_mode, S_IRUSR | S_IWUSR);
709 
710 /* Debug mode */
711 bool aa_g_debug;
712 module_param_named(debug, aa_g_debug, aabool, S_IRUSR | S_IWUSR);
713 
714 /* Audit mode */
715 enum audit_mode aa_g_audit;
716 module_param_call(audit, param_set_audit, param_get_audit,
717 		  &aa_g_audit, S_IRUSR | S_IWUSR);
718 
719 /* Determines if audit header is included in audited messages.  This
720  * provides more context if the audit daemon is not running
721  */
722 bool aa_g_audit_header = 1;
723 module_param_named(audit_header, aa_g_audit_header, aabool,
724 		   S_IRUSR | S_IWUSR);
725 
726 /* lock out loading/removal of policy
727  * TODO: add in at boot loading of policy, which is the only way to
728  *       load policy, if lock_policy is set
729  */
730 bool aa_g_lock_policy;
731 module_param_named(lock_policy, aa_g_lock_policy, aalockpolicy,
732 		   S_IRUSR | S_IWUSR);
733 
734 /* Syscall logging mode */
735 bool aa_g_logsyscall;
736 module_param_named(logsyscall, aa_g_logsyscall, aabool, S_IRUSR | S_IWUSR);
737 
738 /* Maximum pathname length before accesses will start getting rejected */
739 unsigned int aa_g_path_max = 2 * PATH_MAX;
740 module_param_named(path_max, aa_g_path_max, aauint, S_IRUSR | S_IWUSR);
741 
742 /* Determines how paranoid loading of policy is and how much verification
743  * on the loaded policy is done.
744  */
745 bool aa_g_paranoid_load = 1;
746 module_param_named(paranoid_load, aa_g_paranoid_load, aabool,
747 		   S_IRUSR | S_IWUSR);
748 
749 /* Boot time disable flag */
750 static bool apparmor_enabled = CONFIG_SECURITY_APPARMOR_BOOTPARAM_VALUE;
751 module_param_named(enabled, apparmor_enabled, aabool, S_IRUSR);
752 
753 static int __init apparmor_enabled_setup(char *str)
754 {
755 	unsigned long enabled;
756 	int error = strict_strtoul(str, 0, &enabled);
757 	if (!error)
758 		apparmor_enabled = enabled ? 1 : 0;
759 	return 1;
760 }
761 
762 __setup("apparmor=", apparmor_enabled_setup);
763 
764 /* set global flag turning off the ability to load policy */
765 static int param_set_aalockpolicy(const char *val, const struct kernel_param *kp)
766 {
767 	if (!capable(CAP_MAC_ADMIN))
768 		return -EPERM;
769 	if (aa_g_lock_policy)
770 		return -EACCES;
771 	return param_set_bool(val, kp);
772 }
773 
774 static int param_get_aalockpolicy(char *buffer, const struct kernel_param *kp)
775 {
776 	if (!capable(CAP_MAC_ADMIN))
777 		return -EPERM;
778 	return param_get_bool(buffer, kp);
779 }
780 
781 static int param_set_aabool(const char *val, const struct kernel_param *kp)
782 {
783 	if (!capable(CAP_MAC_ADMIN))
784 		return -EPERM;
785 	return param_set_bool(val, kp);
786 }
787 
788 static int param_get_aabool(char *buffer, const struct kernel_param *kp)
789 {
790 	if (!capable(CAP_MAC_ADMIN))
791 		return -EPERM;
792 	return param_get_bool(buffer, kp);
793 }
794 
795 static int param_set_aauint(const char *val, const struct kernel_param *kp)
796 {
797 	if (!capable(CAP_MAC_ADMIN))
798 		return -EPERM;
799 	return param_set_uint(val, kp);
800 }
801 
802 static int param_get_aauint(char *buffer, const struct kernel_param *kp)
803 {
804 	if (!capable(CAP_MAC_ADMIN))
805 		return -EPERM;
806 	return param_get_uint(buffer, kp);
807 }
808 
809 static int param_get_audit(char *buffer, struct kernel_param *kp)
810 {
811 	if (!capable(CAP_MAC_ADMIN))
812 		return -EPERM;
813 
814 	if (!apparmor_enabled)
815 		return -EINVAL;
816 
817 	return sprintf(buffer, "%s", audit_mode_names[aa_g_audit]);
818 }
819 
820 static int param_set_audit(const char *val, struct kernel_param *kp)
821 {
822 	int i;
823 	if (!capable(CAP_MAC_ADMIN))
824 		return -EPERM;
825 
826 	if (!apparmor_enabled)
827 		return -EINVAL;
828 
829 	if (!val)
830 		return -EINVAL;
831 
832 	for (i = 0; i < AUDIT_MAX_INDEX; i++) {
833 		if (strcmp(val, audit_mode_names[i]) == 0) {
834 			aa_g_audit = i;
835 			return 0;
836 		}
837 	}
838 
839 	return -EINVAL;
840 }
841 
842 static int param_get_mode(char *buffer, struct kernel_param *kp)
843 {
844 	if (!capable(CAP_MAC_ADMIN))
845 		return -EPERM;
846 
847 	if (!apparmor_enabled)
848 		return -EINVAL;
849 
850 	return sprintf(buffer, "%s", profile_mode_names[aa_g_profile_mode]);
851 }
852 
853 static int param_set_mode(const char *val, struct kernel_param *kp)
854 {
855 	int i;
856 	if (!capable(CAP_MAC_ADMIN))
857 		return -EPERM;
858 
859 	if (!apparmor_enabled)
860 		return -EINVAL;
861 
862 	if (!val)
863 		return -EINVAL;
864 
865 	for (i = 0; i < APPARMOR_NAMES_MAX_INDEX; i++) {
866 		if (strcmp(val, profile_mode_names[i]) == 0) {
867 			aa_g_profile_mode = i;
868 			return 0;
869 		}
870 	}
871 
872 	return -EINVAL;
873 }
874 
875 /*
876  * AppArmor init functions
877  */
878 
879 /**
880  * set_init_cxt - set a task context and profile on the first task.
881  *
882  * TODO: allow setting an alternate profile than unconfined
883  */
884 static int __init set_init_cxt(void)
885 {
886 	struct cred *cred = (struct cred *)current->real_cred;
887 	struct aa_task_cxt *cxt;
888 
889 	cxt = aa_alloc_task_context(GFP_KERNEL);
890 	if (!cxt)
891 		return -ENOMEM;
892 
893 	cxt->profile = aa_get_profile(root_ns->unconfined);
894 	cred->security = cxt;
895 
896 	return 0;
897 }
898 
899 static int __init apparmor_init(void)
900 {
901 	int error;
902 
903 	if (!apparmor_enabled || !security_module_enable(&apparmor_ops)) {
904 		aa_info_message("AppArmor disabled by boot time parameter");
905 		apparmor_enabled = 0;
906 		return 0;
907 	}
908 
909 	error = aa_alloc_root_ns();
910 	if (error) {
911 		AA_ERROR("Unable to allocate default profile namespace\n");
912 		goto alloc_out;
913 	}
914 
915 	error = set_init_cxt();
916 	if (error) {
917 		AA_ERROR("Failed to set context on init task\n");
918 		goto register_security_out;
919 	}
920 
921 	error = register_security(&apparmor_ops);
922 	if (error) {
923 		AA_ERROR("Unable to register AppArmor\n");
924 		goto set_init_cxt_out;
925 	}
926 
927 	/* Report that AppArmor successfully initialized */
928 	apparmor_initialized = 1;
929 	if (aa_g_profile_mode == APPARMOR_COMPLAIN)
930 		aa_info_message("AppArmor initialized: complain mode enabled");
931 	else if (aa_g_profile_mode == APPARMOR_KILL)
932 		aa_info_message("AppArmor initialized: kill mode enabled");
933 	else
934 		aa_info_message("AppArmor initialized");
935 
936 	return error;
937 
938 set_init_cxt_out:
939 	aa_free_task_context(current->real_cred->security);
940 
941 register_security_out:
942 	aa_free_root_ns();
943 
944 alloc_out:
945 	aa_destroy_aafs();
946 
947 	apparmor_enabled = 0;
948 	return error;
949 }
950 
951 security_initcall(apparmor_init);
952