xref: /linux/security/apparmor/lsm.c (revision 9d9659b6c0ebf7dde65ebada4c67980818245913)
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 <net/sock.h>
26 
27 #include "include/apparmor.h"
28 #include "include/apparmorfs.h"
29 #include "include/audit.h"
30 #include "include/capability.h"
31 #include "include/context.h"
32 #include "include/file.h"
33 #include "include/ipc.h"
34 #include "include/path.h"
35 #include "include/policy.h"
36 #include "include/procattr.h"
37 
38 /* Flag indicating whether initialization completed */
39 int apparmor_initialized __initdata;
40 
41 /*
42  * LSM hook functions
43  */
44 
45 /*
46  * free the associated aa_task_cxt and put its profiles
47  */
48 static void apparmor_cred_free(struct cred *cred)
49 {
50 	aa_free_task_context(cred->security);
51 	cred->security = NULL;
52 }
53 
54 /*
55  * allocate the apparmor part of blank credentials
56  */
57 static int apparmor_cred_alloc_blank(struct cred *cred, gfp_t gfp)
58 {
59 	/* freed by apparmor_cred_free */
60 	struct aa_task_cxt *cxt = aa_alloc_task_context(gfp);
61 	if (!cxt)
62 		return -ENOMEM;
63 
64 	cred->security = cxt;
65 	return 0;
66 }
67 
68 /*
69  * prepare new aa_task_cxt for modification by prepare_cred block
70  */
71 static int apparmor_cred_prepare(struct cred *new, const struct cred *old,
72 				 gfp_t gfp)
73 {
74 	/* freed by apparmor_cred_free */
75 	struct aa_task_cxt *cxt = aa_alloc_task_context(gfp);
76 	if (!cxt)
77 		return -ENOMEM;
78 
79 	aa_dup_task_context(cxt, old->security);
80 	new->security = cxt;
81 	return 0;
82 }
83 
84 /*
85  * transfer the apparmor data to a blank set of creds
86  */
87 static void apparmor_cred_transfer(struct cred *new, const struct cred *old)
88 {
89 	const struct aa_task_cxt *old_cxt = old->security;
90 	struct aa_task_cxt *new_cxt = new->security;
91 
92 	aa_dup_task_context(new_cxt, old_cxt);
93 }
94 
95 static int apparmor_ptrace_access_check(struct task_struct *child,
96 					unsigned int mode)
97 {
98 	int error = cap_ptrace_access_check(child, mode);
99 	if (error)
100 		return error;
101 
102 	return aa_ptrace(current, child, mode);
103 }
104 
105 static int apparmor_ptrace_traceme(struct task_struct *parent)
106 {
107 	int error = cap_ptrace_traceme(parent);
108 	if (error)
109 		return error;
110 
111 	return aa_ptrace(parent, current, PTRACE_MODE_ATTACH);
112 }
113 
114 /* Derived from security/commoncap.c:cap_capget */
115 static int apparmor_capget(struct task_struct *target, kernel_cap_t *effective,
116 			   kernel_cap_t *inheritable, kernel_cap_t *permitted)
117 {
118 	struct aa_profile *profile;
119 	const struct cred *cred;
120 
121 	rcu_read_lock();
122 	cred = __task_cred(target);
123 	profile = aa_cred_profile(cred);
124 
125 	*effective = cred->cap_effective;
126 	*inheritable = cred->cap_inheritable;
127 	*permitted = cred->cap_permitted;
128 
129 	if (!unconfined(profile)) {
130 		*effective = cap_intersect(*effective, profile->caps.allow);
131 		*permitted = cap_intersect(*permitted, profile->caps.allow);
132 	}
133 	rcu_read_unlock();
134 
135 	return 0;
136 }
137 
138 static int apparmor_capable(struct task_struct *task, const struct cred *cred,
139 			    int cap, int audit)
140 {
141 	struct aa_profile *profile;
142 	/* cap_capable returns 0 on success, else -EPERM */
143 	int error = cap_capable(task, cred, cap, audit);
144 	if (!error) {
145 		profile = aa_cred_profile(cred);
146 		if (!unconfined(profile))
147 			error = aa_capable(task, profile, cap, audit);
148 	}
149 	return error;
150 }
151 
152 /**
153  * common_perm - basic common permission check wrapper fn for paths
154  * @op: operation being checked
155  * @path: path to check permission of  (NOT NULL)
156  * @mask: requested permissions mask
157  * @cond: conditional info for the permission request  (NOT NULL)
158  *
159  * Returns: %0 else error code if error or permission denied
160  */
161 static int common_perm(int op, struct path *path, u32 mask,
162 		       struct path_cond *cond)
163 {
164 	struct aa_profile *profile;
165 	int error = 0;
166 
167 	profile = __aa_current_profile();
168 	if (!unconfined(profile))
169 		error = aa_path_perm(op, profile, path, 0, mask, cond);
170 
171 	return error;
172 }
173 
174 /**
175  * common_perm_dir_dentry - common permission wrapper when path is dir, dentry
176  * @op: operation being checked
177  * @dir: directory of the dentry  (NOT NULL)
178  * @dentry: dentry to check  (NOT NULL)
179  * @mask: requested permissions mask
180  * @cond: conditional info for the permission request  (NOT NULL)
181  *
182  * Returns: %0 else error code if error or permission denied
183  */
184 static int common_perm_dir_dentry(int op, struct path *dir,
185 				  struct dentry *dentry, u32 mask,
186 				  struct path_cond *cond)
187 {
188 	struct path path = { dir->mnt, dentry };
189 
190 	return common_perm(op, &path, mask, cond);
191 }
192 
193 /**
194  * common_perm_mnt_dentry - common permission wrapper when mnt, dentry
195  * @op: operation being checked
196  * @mnt: mount point of dentry (NOT NULL)
197  * @dentry: dentry to check  (NOT NULL)
198  * @mask: requested permissions mask
199  *
200  * Returns: %0 else error code if error or permission denied
201  */
202 static int common_perm_mnt_dentry(int op, struct vfsmount *mnt,
203 				  struct dentry *dentry, u32 mask)
204 {
205 	struct path path = { mnt, dentry };
206 	struct path_cond cond = { dentry->d_inode->i_uid,
207 				  dentry->d_inode->i_mode
208 	};
209 
210 	return common_perm(op, &path, mask, &cond);
211 }
212 
213 /**
214  * common_perm_rm - common permission wrapper for operations doing rm
215  * @op: operation being checked
216  * @dir: directory that the dentry is in  (NOT NULL)
217  * @dentry: dentry being rm'd  (NOT NULL)
218  * @mask: requested permission mask
219  *
220  * Returns: %0 else error code if error or permission denied
221  */
222 static int common_perm_rm(int op, struct path *dir,
223 			  struct dentry *dentry, u32 mask)
224 {
225 	struct inode *inode = dentry->d_inode;
226 	struct path_cond cond = { };
227 
228 	if (!inode || !dir->mnt || !mediated_filesystem(inode))
229 		return 0;
230 
231 	cond.uid = inode->i_uid;
232 	cond.mode = inode->i_mode;
233 
234 	return common_perm_dir_dentry(op, dir, dentry, mask, &cond);
235 }
236 
237 /**
238  * common_perm_create - common permission wrapper for operations doing create
239  * @op: operation being checked
240  * @dir: directory that dentry will be created in  (NOT NULL)
241  * @dentry: dentry to create   (NOT NULL)
242  * @mask: request permission mask
243  * @mode: created file mode
244  *
245  * Returns: %0 else error code if error or permission denied
246  */
247 static int common_perm_create(int op, struct path *dir, struct dentry *dentry,
248 			      u32 mask, umode_t mode)
249 {
250 	struct path_cond cond = { current_fsuid(), mode };
251 
252 	if (!dir->mnt || !mediated_filesystem(dir->dentry->d_inode))
253 		return 0;
254 
255 	return common_perm_dir_dentry(op, dir, dentry, mask, &cond);
256 }
257 
258 static int apparmor_path_unlink(struct path *dir, struct dentry *dentry)
259 {
260 	return common_perm_rm(OP_UNLINK, dir, dentry, AA_MAY_DELETE);
261 }
262 
263 static int apparmor_path_mkdir(struct path *dir, struct dentry *dentry,
264 			       int mode)
265 {
266 	return common_perm_create(OP_MKDIR, dir, dentry, AA_MAY_CREATE,
267 				  S_IFDIR);
268 }
269 
270 static int apparmor_path_rmdir(struct path *dir, struct dentry *dentry)
271 {
272 	return common_perm_rm(OP_RMDIR, dir, dentry, AA_MAY_DELETE);
273 }
274 
275 static int apparmor_path_mknod(struct path *dir, struct dentry *dentry,
276 			       int mode, unsigned int dev)
277 {
278 	return common_perm_create(OP_MKNOD, dir, dentry, AA_MAY_CREATE, mode);
279 }
280 
281 static int apparmor_path_truncate(struct path *path)
282 {
283 	struct path_cond cond = { path->dentry->d_inode->i_uid,
284 				  path->dentry->d_inode->i_mode
285 	};
286 
287 	if (!path->mnt || !mediated_filesystem(path->dentry->d_inode))
288 		return 0;
289 
290 	return common_perm(OP_TRUNC, path, MAY_WRITE | AA_MAY_META_WRITE,
291 			   &cond);
292 }
293 
294 static int apparmor_path_symlink(struct path *dir, struct dentry *dentry,
295 				 const char *old_name)
296 {
297 	return common_perm_create(OP_SYMLINK, dir, dentry, AA_MAY_CREATE,
298 				  S_IFLNK);
299 }
300 
301 static int apparmor_path_link(struct dentry *old_dentry, struct path *new_dir,
302 			      struct dentry *new_dentry)
303 {
304 	struct aa_profile *profile;
305 	int error = 0;
306 
307 	if (!mediated_filesystem(old_dentry->d_inode))
308 		return 0;
309 
310 	profile = aa_current_profile();
311 	if (!unconfined(profile))
312 		error = aa_path_link(profile, old_dentry, new_dir, new_dentry);
313 	return error;
314 }
315 
316 static int apparmor_path_rename(struct path *old_dir, struct dentry *old_dentry,
317 				struct path *new_dir, struct dentry *new_dentry)
318 {
319 	struct aa_profile *profile;
320 	int error = 0;
321 
322 	if (!mediated_filesystem(old_dentry->d_inode))
323 		return 0;
324 
325 	profile = aa_current_profile();
326 	if (!unconfined(profile)) {
327 		struct path old_path = { old_dir->mnt, old_dentry };
328 		struct path new_path = { new_dir->mnt, new_dentry };
329 		struct path_cond cond = { old_dentry->d_inode->i_uid,
330 					  old_dentry->d_inode->i_mode
331 		};
332 
333 		error = aa_path_perm(OP_RENAME_SRC, profile, &old_path, 0,
334 				     MAY_READ | AA_MAY_META_READ | MAY_WRITE |
335 				     AA_MAY_META_WRITE | AA_MAY_DELETE,
336 				     &cond);
337 		if (!error)
338 			error = aa_path_perm(OP_RENAME_DEST, profile, &new_path,
339 					     0, MAY_WRITE | AA_MAY_META_WRITE |
340 					     AA_MAY_CREATE, &cond);
341 
342 	}
343 	return error;
344 }
345 
346 static int apparmor_path_chmod(struct dentry *dentry, struct vfsmount *mnt,
347 			       mode_t mode)
348 {
349 	if (!mediated_filesystem(dentry->d_inode))
350 		return 0;
351 
352 	return common_perm_mnt_dentry(OP_CHMOD, mnt, 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, NULL, GFP_KERNEL,
596 					&sa, NULL);
597 		}
598 	} else if (strcmp(name, "exec") == 0) {
599 		error = aa_setprocattr_changeprofile(args, AA_ONEXEC,
600 						     !AA_DO_TEST);
601 	} else {
602 		/* only support the "current" and "exec" process attributes */
603 		return -EINVAL;
604 	}
605 	if (!error)
606 		error = size;
607 	return error;
608 }
609 
610 static int apparmor_task_setrlimit(struct task_struct *task,
611 		unsigned int resource, struct rlimit *new_rlim)
612 {
613 	struct aa_profile *profile = aa_current_profile();
614 	int error = 0;
615 
616 	if (!unconfined(profile))
617 		error = aa_task_setrlimit(profile, task, resource, new_rlim);
618 
619 	return error;
620 }
621 
622 static struct security_operations apparmor_ops = {
623 	.name =				"apparmor",
624 
625 	.ptrace_access_check =		apparmor_ptrace_access_check,
626 	.ptrace_traceme =		apparmor_ptrace_traceme,
627 	.capget =			apparmor_capget,
628 	.capable =			apparmor_capable,
629 
630 	.path_link =			apparmor_path_link,
631 	.path_unlink =			apparmor_path_unlink,
632 	.path_symlink =			apparmor_path_symlink,
633 	.path_mkdir =			apparmor_path_mkdir,
634 	.path_rmdir =			apparmor_path_rmdir,
635 	.path_mknod =			apparmor_path_mknod,
636 	.path_rename =			apparmor_path_rename,
637 	.path_chmod =			apparmor_path_chmod,
638 	.path_chown =			apparmor_path_chown,
639 	.path_truncate =		apparmor_path_truncate,
640 	.dentry_open =			apparmor_dentry_open,
641 	.inode_getattr =                apparmor_inode_getattr,
642 
643 	.file_permission =		apparmor_file_permission,
644 	.file_alloc_security =		apparmor_file_alloc_security,
645 	.file_free_security =		apparmor_file_free_security,
646 	.file_mmap =			apparmor_file_mmap,
647 	.file_mprotect =		apparmor_file_mprotect,
648 	.file_lock =			apparmor_file_lock,
649 
650 	.getprocattr =			apparmor_getprocattr,
651 	.setprocattr =			apparmor_setprocattr,
652 
653 	.cred_alloc_blank =		apparmor_cred_alloc_blank,
654 	.cred_free =			apparmor_cred_free,
655 	.cred_prepare =			apparmor_cred_prepare,
656 	.cred_transfer =		apparmor_cred_transfer,
657 
658 	.bprm_set_creds =		apparmor_bprm_set_creds,
659 	.bprm_committing_creds =	apparmor_bprm_committing_creds,
660 	.bprm_committed_creds =		apparmor_bprm_committed_creds,
661 	.bprm_secureexec =		apparmor_bprm_secureexec,
662 
663 	.task_setrlimit =		apparmor_task_setrlimit,
664 };
665 
666 /*
667  * AppArmor sysfs module parameters
668  */
669 
670 static int param_set_aabool(const char *val, const struct kernel_param *kp);
671 static int param_get_aabool(char *buffer, const struct kernel_param *kp);
672 #define param_check_aabool(name, p) __param_check(name, p, int)
673 static struct kernel_param_ops param_ops_aabool = {
674 	.set = param_set_aabool,
675 	.get = param_get_aabool
676 };
677 
678 static int param_set_aauint(const char *val, const struct kernel_param *kp);
679 static int param_get_aauint(char *buffer, const struct kernel_param *kp);
680 #define param_check_aauint(name, p) __param_check(name, p, int)
681 static struct kernel_param_ops param_ops_aauint = {
682 	.set = param_set_aauint,
683 	.get = param_get_aauint
684 };
685 
686 static int param_set_aalockpolicy(const char *val, const struct kernel_param *kp);
687 static int param_get_aalockpolicy(char *buffer, const struct kernel_param *kp);
688 #define param_check_aalockpolicy(name, p) __param_check(name, p, int)
689 static struct kernel_param_ops param_ops_aalockpolicy = {
690 	.set = param_set_aalockpolicy,
691 	.get = param_get_aalockpolicy
692 };
693 
694 static int param_set_audit(const char *val, struct kernel_param *kp);
695 static int param_get_audit(char *buffer, struct kernel_param *kp);
696 
697 static int param_set_mode(const char *val, struct kernel_param *kp);
698 static int param_get_mode(char *buffer, struct kernel_param *kp);
699 
700 /* Flag values, also controllable via /sys/module/apparmor/parameters
701  * We define special types as we want to do additional mediation.
702  */
703 
704 /* AppArmor global enforcement switch - complain, enforce, kill */
705 enum profile_mode aa_g_profile_mode = APPARMOR_ENFORCE;
706 module_param_call(mode, param_set_mode, param_get_mode,
707 		  &aa_g_profile_mode, S_IRUSR | S_IWUSR);
708 
709 /* Debug mode */
710 int aa_g_debug;
711 module_param_named(debug, aa_g_debug, aabool, S_IRUSR | S_IWUSR);
712 
713 /* Audit mode */
714 enum audit_mode aa_g_audit;
715 module_param_call(audit, param_set_audit, param_get_audit,
716 		  &aa_g_audit, S_IRUSR | S_IWUSR);
717 
718 /* Determines if audit header is included in audited messages.  This
719  * provides more context if the audit daemon is not running
720  */
721 int aa_g_audit_header = 1;
722 module_param_named(audit_header, aa_g_audit_header, aabool,
723 		   S_IRUSR | S_IWUSR);
724 
725 /* lock out loading/removal of policy
726  * TODO: add in at boot loading of policy, which is the only way to
727  *       load policy, if lock_policy is set
728  */
729 int aa_g_lock_policy;
730 module_param_named(lock_policy, aa_g_lock_policy, aalockpolicy,
731 		   S_IRUSR | S_IWUSR);
732 
733 /* Syscall logging mode */
734 int aa_g_logsyscall;
735 module_param_named(logsyscall, aa_g_logsyscall, aabool, S_IRUSR | S_IWUSR);
736 
737 /* Maximum pathname length before accesses will start getting rejected */
738 unsigned int aa_g_path_max = 2 * PATH_MAX;
739 module_param_named(path_max, aa_g_path_max, aauint, S_IRUSR | S_IWUSR);
740 
741 /* Determines how paranoid loading of policy is and how much verification
742  * on the loaded policy is done.
743  */
744 int aa_g_paranoid_load = 1;
745 module_param_named(paranoid_load, aa_g_paranoid_load, aabool,
746 		   S_IRUSR | S_IWUSR);
747 
748 /* Boot time disable flag */
749 static unsigned int apparmor_enabled = CONFIG_SECURITY_APPARMOR_BOOTPARAM_VALUE;
750 module_param_named(enabled, apparmor_enabled, aabool, S_IRUSR);
751 
752 static int __init apparmor_enabled_setup(char *str)
753 {
754 	unsigned long enabled;
755 	int error = strict_strtoul(str, 0, &enabled);
756 	if (!error)
757 		apparmor_enabled = enabled ? 1 : 0;
758 	return 1;
759 }
760 
761 __setup("apparmor=", apparmor_enabled_setup);
762 
763 /* set global flag turning off the ability to load policy */
764 static int param_set_aalockpolicy(const char *val, const struct kernel_param *kp)
765 {
766 	if (!capable(CAP_MAC_ADMIN))
767 		return -EPERM;
768 	if (aa_g_lock_policy)
769 		return -EACCES;
770 	return param_set_bool(val, kp);
771 }
772 
773 static int param_get_aalockpolicy(char *buffer, const struct kernel_param *kp)
774 {
775 	if (!capable(CAP_MAC_ADMIN))
776 		return -EPERM;
777 	return param_get_bool(buffer, kp);
778 }
779 
780 static int param_set_aabool(const char *val, const struct kernel_param *kp)
781 {
782 	if (!capable(CAP_MAC_ADMIN))
783 		return -EPERM;
784 	return param_set_bool(val, kp);
785 }
786 
787 static int param_get_aabool(char *buffer, const struct kernel_param *kp)
788 {
789 	if (!capable(CAP_MAC_ADMIN))
790 		return -EPERM;
791 	return param_get_bool(buffer, kp);
792 }
793 
794 static int param_set_aauint(const char *val, const struct kernel_param *kp)
795 {
796 	if (!capable(CAP_MAC_ADMIN))
797 		return -EPERM;
798 	return param_set_uint(val, kp);
799 }
800 
801 static int param_get_aauint(char *buffer, const struct kernel_param *kp)
802 {
803 	if (!capable(CAP_MAC_ADMIN))
804 		return -EPERM;
805 	return param_get_uint(buffer, kp);
806 }
807 
808 static int param_get_audit(char *buffer, struct kernel_param *kp)
809 {
810 	if (!capable(CAP_MAC_ADMIN))
811 		return -EPERM;
812 
813 	if (!apparmor_enabled)
814 		return -EINVAL;
815 
816 	return sprintf(buffer, "%s", audit_mode_names[aa_g_audit]);
817 }
818 
819 static int param_set_audit(const char *val, struct kernel_param *kp)
820 {
821 	int i;
822 	if (!capable(CAP_MAC_ADMIN))
823 		return -EPERM;
824 
825 	if (!apparmor_enabled)
826 		return -EINVAL;
827 
828 	if (!val)
829 		return -EINVAL;
830 
831 	for (i = 0; i < AUDIT_MAX_INDEX; i++) {
832 		if (strcmp(val, audit_mode_names[i]) == 0) {
833 			aa_g_audit = i;
834 			return 0;
835 		}
836 	}
837 
838 	return -EINVAL;
839 }
840 
841 static int param_get_mode(char *buffer, struct kernel_param *kp)
842 {
843 	if (!capable(CAP_MAC_ADMIN))
844 		return -EPERM;
845 
846 	if (!apparmor_enabled)
847 		return -EINVAL;
848 
849 	return sprintf(buffer, "%s", profile_mode_names[aa_g_profile_mode]);
850 }
851 
852 static int param_set_mode(const char *val, struct kernel_param *kp)
853 {
854 	int i;
855 	if (!capable(CAP_MAC_ADMIN))
856 		return -EPERM;
857 
858 	if (!apparmor_enabled)
859 		return -EINVAL;
860 
861 	if (!val)
862 		return -EINVAL;
863 
864 	for (i = 0; i < APPARMOR_NAMES_MAX_INDEX; i++) {
865 		if (strcmp(val, profile_mode_names[i]) == 0) {
866 			aa_g_profile_mode = i;
867 			return 0;
868 		}
869 	}
870 
871 	return -EINVAL;
872 }
873 
874 /*
875  * AppArmor init functions
876  */
877 
878 /**
879  * set_init_cxt - set a task context and profile on the first task.
880  *
881  * TODO: allow setting an alternate profile than unconfined
882  */
883 static int __init set_init_cxt(void)
884 {
885 	struct cred *cred = (struct cred *)current->real_cred;
886 	struct aa_task_cxt *cxt;
887 
888 	cxt = aa_alloc_task_context(GFP_KERNEL);
889 	if (!cxt)
890 		return -ENOMEM;
891 
892 	cxt->profile = aa_get_profile(root_ns->unconfined);
893 	cred->security = cxt;
894 
895 	return 0;
896 }
897 
898 static int __init apparmor_init(void)
899 {
900 	int error;
901 
902 	if (!apparmor_enabled || !security_module_enable(&apparmor_ops)) {
903 		aa_info_message("AppArmor disabled by boot time parameter");
904 		apparmor_enabled = 0;
905 		return 0;
906 	}
907 
908 	error = aa_alloc_root_ns();
909 	if (error) {
910 		AA_ERROR("Unable to allocate default profile namespace\n");
911 		goto alloc_out;
912 	}
913 
914 	error = set_init_cxt();
915 	if (error) {
916 		AA_ERROR("Failed to set context on init task\n");
917 		goto register_security_out;
918 	}
919 
920 	error = register_security(&apparmor_ops);
921 	if (error) {
922 		AA_ERROR("Unable to register AppArmor\n");
923 		goto set_init_cxt_out;
924 	}
925 
926 	/* Report that AppArmor successfully initialized */
927 	apparmor_initialized = 1;
928 	if (aa_g_profile_mode == APPARMOR_COMPLAIN)
929 		aa_info_message("AppArmor initialized: complain mode enabled");
930 	else if (aa_g_profile_mode == APPARMOR_KILL)
931 		aa_info_message("AppArmor initialized: kill mode enabled");
932 	else
933 		aa_info_message("AppArmor initialized");
934 
935 	return error;
936 
937 set_init_cxt_out:
938 	aa_free_task_context(current->real_cred->security);
939 
940 register_security_out:
941 	aa_free_root_ns();
942 
943 alloc_out:
944 	aa_destroy_aafs();
945 
946 	apparmor_enabled = 0;
947 	return error;
948 }
949 
950 security_initcall(apparmor_init);
951