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John Johansenc88d4c72010-07-29 14:48:00 -07001/*
2 * AppArmor security module
3 *
4 * This file contains AppArmor policy manipulation functions
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 * AppArmor policy is based around profiles, which contain the rules a
16 * task is confined by. Every task in the system has a profile attached
17 * to it determined either by matching "unconfined" tasks against the
18 * visible set of profiles or by following a profiles attachment rules.
19 *
20 * Each profile exists in a profile namespace which is a container of
21 * visible profiles. Each namespace contains a special "unconfined" profile,
22 * which doesn't enforce any confinement on a task beyond DAC.
23 *
24 * Namespace and profile names can be written together in either
25 * of two syntaxes.
26 * :namespace:profile - used by kernel interfaces for easy detection
27 * namespace://profile - used by policy
28 *
29 * Profile names can not start with : or @ or ^ and may not contain \0
30 *
31 * Reserved profile names
32 * unconfined - special automatically generated unconfined profile
33 * inherit - special name to indicate profile inheritance
34 * null-XXXX-YYYY - special automatically generated learning profiles
35 *
36 * Namespace names may not start with / or @ and may not contain \0 or :
37 * Reserved namespace names
38 * user-XXXX - user defined profiles
39 *
40 * a // in a profile or namespace name indicates a hierarchical name with the
41 * name before the // being the parent and the name after the child.
42 *
43 * Profile and namespace hierarchies serve two different but similar purposes.
44 * The namespace contains the set of visible profiles that are considered
45 * for attachment. The hierarchy of namespaces allows for virtualizing
46 * the namespace so that for example a chroot can have its own set of profiles
47 * which may define some local user namespaces.
48 * The profile hierarchy severs two distinct purposes,
49 * - it allows for sub profiles or hats, which allows an application to run
50 * subprograms under its own profile with different restriction than it
51 * self, and not have it use the system profile.
52 * eg. if a mail program starts an editor, the policy might make the
53 * restrictions tighter on the editor tighter than the mail program,
54 * and definitely different than general editor restrictions
55 * - it allows for binary hierarchy of profiles, so that execution history
56 * is preserved. This feature isn't exploited by AppArmor reference policy
57 * but is allowed. NOTE: this is currently suboptimal because profile
58 * aliasing is not currently implemented so that a profile for each
59 * level must be defined.
60 * eg. /bin/bash///bin/ls as a name would indicate /bin/ls was started
61 * from /bin/bash
62 *
63 * A profile or namespace name that can contain one or more // separators
64 * is referred to as an hname (hierarchical).
65 * eg. /bin/bash//bin/ls
66 *
67 * An fqname is a name that may contain both namespace and profile hnames.
68 * eg. :ns:/bin/bash//bin/ls
69 *
70 * NOTES:
71 * - locking of profile lists is currently fairly coarse. All profile
72 * lists within a namespace use the namespace lock.
73 * FIXME: move profile lists to using rcu_lists
74 */
75
76#include <linux/slab.h>
77#include <linux/spinlock.h>
78#include <linux/string.h>
79
80#include "include/apparmor.h"
81#include "include/capability.h"
82#include "include/context.h"
83#include "include/file.h"
84#include "include/ipc.h"
85#include "include/match.h"
86#include "include/path.h"
87#include "include/policy.h"
88#include "include/policy_unpack.h"
89#include "include/resource.h"
John Johansenc88d4c72010-07-29 14:48:00 -070090
91
92/* root profile namespace */
93struct aa_namespace *root_ns;
94
Jan Engelhardt2d4cee72012-03-14 13:30:36 +010095const char *const profile_mode_names[] = {
John Johansenc88d4c72010-07-29 14:48:00 -070096 "enforce",
97 "complain",
98 "kill",
99};
100
101/**
102 * hname_tail - find the last component of an hname
103 * @name: hname to find the base profile name component of (NOT NULL)
104 *
105 * Returns: the tail (base profile name) name component of an hname
106 */
107static const char *hname_tail(const char *hname)
108{
109 char *split;
110 hname = strim((char *)hname);
111 for (split = strstr(hname, "//"); split; split = strstr(hname, "//"))
112 hname = split + 2;
113
114 return hname;
115}
116
117/**
118 * policy_init - initialize a policy structure
119 * @policy: policy to initialize (NOT NULL)
120 * @prefix: prefix name if any is required. (MAYBE NULL)
121 * @name: name of the policy, init will make a copy of it (NOT NULL)
122 *
123 * Note: this fn creates a copy of strings passed in
124 *
125 * Returns: true if policy init successful
126 */
127static bool policy_init(struct aa_policy *policy, const char *prefix,
128 const char *name)
129{
130 /* freed by policy_free */
131 if (prefix) {
132 policy->hname = kmalloc(strlen(prefix) + strlen(name) + 3,
133 GFP_KERNEL);
134 if (policy->hname)
135 sprintf(policy->hname, "%s//%s", prefix, name);
136 } else
137 policy->hname = kstrdup(name, GFP_KERNEL);
138 if (!policy->hname)
139 return 0;
140 /* base.name is a substring of fqname */
141 policy->name = (char *)hname_tail(policy->hname);
142 INIT_LIST_HEAD(&policy->list);
143 INIT_LIST_HEAD(&policy->profiles);
144 kref_init(&policy->count);
145
146 return 1;
147}
148
149/**
150 * policy_destroy - free the elements referenced by @policy
151 * @policy: policy that is to have its elements freed (NOT NULL)
152 */
153static void policy_destroy(struct aa_policy *policy)
154{
155 /* still contains profiles -- invalid */
156 if (!list_empty(&policy->profiles)) {
157 AA_ERROR("%s: internal error, "
158 "policy '%s' still contains profiles\n",
159 __func__, policy->name);
160 BUG();
161 }
162 if (!list_empty(&policy->list)) {
163 AA_ERROR("%s: internal error, policy '%s' still on list\n",
164 __func__, policy->name);
165 BUG();
166 }
167
168 /* don't free name as its a subset of hname */
169 kzfree(policy->hname);
170}
171
172/**
173 * __policy_find - find a policy by @name on a policy list
174 * @head: list to search (NOT NULL)
175 * @name: name to search for (NOT NULL)
176 *
177 * Requires: correct locks for the @head list be held
178 *
179 * Returns: unrefcounted policy that match @name or NULL if not found
180 */
181static struct aa_policy *__policy_find(struct list_head *head, const char *name)
182{
183 struct aa_policy *policy;
184
185 list_for_each_entry(policy, head, list) {
186 if (!strcmp(policy->name, name))
187 return policy;
188 }
189 return NULL;
190}
191
192/**
193 * __policy_strn_find - find a policy that's name matches @len chars of @str
194 * @head: list to search (NOT NULL)
195 * @str: string to search for (NOT NULL)
196 * @len: length of match required
197 *
198 * Requires: correct locks for the @head list be held
199 *
200 * Returns: unrefcounted policy that match @str or NULL if not found
201 *
202 * if @len == strlen(@strlen) then this is equiv to __policy_find
203 * other wise it allows searching for policy by a partial match of name
204 */
205static struct aa_policy *__policy_strn_find(struct list_head *head,
206 const char *str, int len)
207{
208 struct aa_policy *policy;
209
210 list_for_each_entry(policy, head, list) {
211 if (aa_strneq(policy->name, str, len))
212 return policy;
213 }
214
215 return NULL;
216}
217
218/*
219 * Routines for AppArmor namespaces
220 */
221
222static const char *hidden_ns_name = "---";
223/**
224 * aa_ns_visible - test if @view is visible from @curr
225 * @curr: namespace to treat as the parent (NOT NULL)
226 * @view: namespace to test if visible from @curr (NOT NULL)
227 *
228 * Returns: true if @view is visible from @curr else false
229 */
230bool aa_ns_visible(struct aa_namespace *curr, struct aa_namespace *view)
231{
232 if (curr == view)
233 return true;
234
235 for ( ; view; view = view->parent) {
236 if (view->parent == curr)
237 return true;
238 }
239 return false;
240}
241
242/**
243 * aa_na_name - Find the ns name to display for @view from @curr
244 * @curr - current namespace (NOT NULL)
245 * @view - namespace attempting to view (NOT NULL)
246 *
247 * Returns: name of @view visible from @curr
248 */
249const char *aa_ns_name(struct aa_namespace *curr, struct aa_namespace *view)
250{
251 /* if view == curr then the namespace name isn't displayed */
252 if (curr == view)
253 return "";
254
255 if (aa_ns_visible(curr, view)) {
256 /* at this point if a ns is visible it is in a view ns
257 * thus the curr ns.hname is a prefix of its name.
258 * Only output the virtualized portion of the name
259 * Add + 2 to skip over // separating curr hname prefix
260 * from the visible tail of the views hname
261 */
262 return view->base.hname + strlen(curr->base.hname) + 2;
263 } else
264 return hidden_ns_name;
265}
266
267/**
268 * alloc_namespace - allocate, initialize and return a new namespace
269 * @prefix: parent namespace name (MAYBE NULL)
270 * @name: a preallocated name (NOT NULL)
271 *
272 * Returns: refcounted namespace or NULL on failure.
273 */
274static struct aa_namespace *alloc_namespace(const char *prefix,
275 const char *name)
276{
277 struct aa_namespace *ns;
278
279 ns = kzalloc(sizeof(*ns), GFP_KERNEL);
280 AA_DEBUG("%s(%p)\n", __func__, ns);
281 if (!ns)
282 return NULL;
283 if (!policy_init(&ns->base, prefix, name))
284 goto fail_ns;
285
286 INIT_LIST_HEAD(&ns->sub_ns);
287 rwlock_init(&ns->lock);
288
289 /* released by free_namespace */
290 ns->unconfined = aa_alloc_profile("unconfined");
291 if (!ns->unconfined)
292 goto fail_unconfined;
293
John Johansenc88d4c72010-07-29 14:48:00 -0700294 ns->unconfined->flags = PFLAG_UNCONFINED | PFLAG_IX_ON_NAME_ERROR |
295 PFLAG_IMMUTABLE;
296
297 /*
298 * released by free_namespace, however __remove_namespace breaks
299 * the cyclic references (ns->unconfined, and unconfined->ns) and
300 * replaces with refs to parent namespace unconfined
301 */
302 ns->unconfined->ns = aa_get_namespace(ns);
303
John Johansena4987852013-02-18 16:10:34 -0800304 atomic_set(&ns->uniq_null, 0);
305
John Johansenc88d4c72010-07-29 14:48:00 -0700306 return ns;
307
308fail_unconfined:
wzt.wzt@gmail.com246c3fb2010-11-10 11:31:55 +0800309 kzfree(ns->base.hname);
John Johansenc88d4c72010-07-29 14:48:00 -0700310fail_ns:
311 kzfree(ns);
312 return NULL;
313}
314
315/**
316 * free_namespace - free a profile namespace
317 * @ns: the namespace to free (MAYBE NULL)
318 *
319 * Requires: All references to the namespace must have been put, if the
320 * namespace was referenced by a profile confining a task,
321 */
322static void free_namespace(struct aa_namespace *ns)
323{
324 if (!ns)
325 return;
326
327 policy_destroy(&ns->base);
328 aa_put_namespace(ns->parent);
329
330 if (ns->unconfined && ns->unconfined->ns == ns)
331 ns->unconfined->ns = NULL;
332
333 aa_put_profile(ns->unconfined);
334 kzfree(ns);
335}
336
337/**
338 * aa_free_namespace_kref - free aa_namespace by kref (see aa_put_namespace)
339 * @kr: kref callback for freeing of a namespace (NOT NULL)
340 */
341void aa_free_namespace_kref(struct kref *kref)
342{
343 free_namespace(container_of(kref, struct aa_namespace, base.count));
344}
345
346/**
347 * __aa_find_namespace - find a namespace on a list by @name
348 * @head: list to search for namespace on (NOT NULL)
349 * @name: name of namespace to look for (NOT NULL)
350 *
351 * Returns: unrefcounted namespace
352 *
353 * Requires: ns lock be held
354 */
355static struct aa_namespace *__aa_find_namespace(struct list_head *head,
356 const char *name)
357{
358 return (struct aa_namespace *)__policy_find(head, name);
359}
360
361/**
362 * aa_find_namespace - look up a profile namespace on the namespace list
363 * @root: namespace to search in (NOT NULL)
364 * @name: name of namespace to find (NOT NULL)
365 *
366 * Returns: a refcounted namespace on the list, or NULL if no namespace
367 * called @name exists.
368 *
369 * refcount released by caller
370 */
371struct aa_namespace *aa_find_namespace(struct aa_namespace *root,
372 const char *name)
373{
374 struct aa_namespace *ns = NULL;
375
376 read_lock(&root->lock);
377 ns = aa_get_namespace(__aa_find_namespace(&root->sub_ns, name));
378 read_unlock(&root->lock);
379
380 return ns;
381}
382
383/**
384 * aa_prepare_namespace - find an existing or create a new namespace of @name
385 * @name: the namespace to find or add (MAYBE NULL)
386 *
387 * Returns: refcounted namespace or NULL if failed to create one
388 */
389static struct aa_namespace *aa_prepare_namespace(const char *name)
390{
391 struct aa_namespace *ns, *root;
392
393 root = aa_current_profile()->ns;
394
395 write_lock(&root->lock);
396
397 /* if name isn't specified the profile is loaded to the current ns */
398 if (!name) {
399 /* released by caller */
400 ns = aa_get_namespace(root);
401 goto out;
402 }
403
404 /* try and find the specified ns and if it doesn't exist create it */
405 /* released by caller */
406 ns = aa_get_namespace(__aa_find_namespace(&root->sub_ns, name));
407 if (!ns) {
408 /* namespace not found */
409 struct aa_namespace *new_ns;
410 write_unlock(&root->lock);
411 new_ns = alloc_namespace(root->base.hname, name);
412 if (!new_ns)
413 return NULL;
414 write_lock(&root->lock);
415 /* test for race when new_ns was allocated */
416 ns = __aa_find_namespace(&root->sub_ns, name);
417 if (!ns) {
418 /* add parent ref */
419 new_ns->parent = aa_get_namespace(root);
420
421 list_add(&new_ns->base.list, &root->sub_ns);
422 /* add list ref */
423 ns = aa_get_namespace(new_ns);
424 } else {
425 /* raced so free the new one */
426 free_namespace(new_ns);
427 /* get reference on namespace */
428 aa_get_namespace(ns);
429 }
430 }
431out:
432 write_unlock(&root->lock);
433
434 /* return ref */
435 return ns;
436}
437
438/**
439 * __list_add_profile - add a profile to a list
440 * @list: list to add it to (NOT NULL)
441 * @profile: the profile to add (NOT NULL)
442 *
443 * refcount @profile, should be put by __list_remove_profile
444 *
445 * Requires: namespace lock be held, or list not be shared
446 */
447static void __list_add_profile(struct list_head *list,
448 struct aa_profile *profile)
449{
450 list_add(&profile->base.list, list);
451 /* get list reference */
452 aa_get_profile(profile);
453}
454
455/**
456 * __list_remove_profile - remove a profile from the list it is on
457 * @profile: the profile to remove (NOT NULL)
458 *
459 * remove a profile from the list, warning generally removal should
460 * be done with __replace_profile as most profile removals are
461 * replacements to the unconfined profile.
462 *
463 * put @profile list refcount
464 *
465 * Requires: namespace lock be held, or list not have been live
466 */
467static void __list_remove_profile(struct aa_profile *profile)
468{
469 list_del_init(&profile->base.list);
470 if (!(profile->flags & PFLAG_NO_LIST_REF))
471 /* release list reference */
472 aa_put_profile(profile);
473}
474
475/**
476 * __replace_profile - replace @old with @new on a list
477 * @old: profile to be replaced (NOT NULL)
478 * @new: profile to replace @old with (NOT NULL)
479 *
480 * Will duplicate and refcount elements that @new inherits from @old
481 * and will inherit @old children.
482 *
483 * refcount @new for list, put @old list refcount
484 *
485 * Requires: namespace list lock be held, or list not be shared
486 */
487static void __replace_profile(struct aa_profile *old, struct aa_profile *new)
488{
489 struct aa_policy *policy;
490 struct aa_profile *child, *tmp;
491
492 if (old->parent)
493 policy = &old->parent->base;
494 else
495 policy = &old->ns->base;
496
497 /* released when @new is freed */
498 new->parent = aa_get_profile(old->parent);
499 new->ns = aa_get_namespace(old->ns);
John Johansenc88d4c72010-07-29 14:48:00 -0700500 __list_add_profile(&policy->profiles, new);
501 /* inherit children */
502 list_for_each_entry_safe(child, tmp, &old->base.profiles, base.list) {
503 aa_put_profile(child->parent);
504 child->parent = aa_get_profile(new);
505 /* list refcount transferred to @new*/
506 list_move(&child->base.list, &new->base.profiles);
507 }
508
509 /* released by free_profile */
510 old->replacedby = aa_get_profile(new);
511 __list_remove_profile(old);
512}
513
514static void __profile_list_release(struct list_head *head);
515
516/**
517 * __remove_profile - remove old profile, and children
518 * @profile: profile to be replaced (NOT NULL)
519 *
520 * Requires: namespace list lock be held, or list not be shared
521 */
522static void __remove_profile(struct aa_profile *profile)
523{
524 /* release any children lists first */
525 __profile_list_release(&profile->base.profiles);
526 /* released by free_profile */
527 profile->replacedby = aa_get_profile(profile->ns->unconfined);
528 __list_remove_profile(profile);
529}
530
531/**
532 * __profile_list_release - remove all profiles on the list and put refs
533 * @head: list of profiles (NOT NULL)
534 *
535 * Requires: namespace lock be held
536 */
537static void __profile_list_release(struct list_head *head)
538{
539 struct aa_profile *profile, *tmp;
540 list_for_each_entry_safe(profile, tmp, head, base.list)
541 __remove_profile(profile);
542}
543
544static void __ns_list_release(struct list_head *head);
545
546/**
547 * destroy_namespace - remove everything contained by @ns
548 * @ns: namespace to have it contents removed (NOT NULL)
549 */
550static void destroy_namespace(struct aa_namespace *ns)
551{
552 if (!ns)
553 return;
554
555 write_lock(&ns->lock);
556 /* release all profiles in this namespace */
557 __profile_list_release(&ns->base.profiles);
558
559 /* release all sub namespaces */
560 __ns_list_release(&ns->sub_ns);
561
562 write_unlock(&ns->lock);
563}
564
565/**
566 * __remove_namespace - remove a namespace and all its children
567 * @ns: namespace to be removed (NOT NULL)
568 *
569 * Requires: ns->parent->lock be held and ns removed from parent.
570 */
571static void __remove_namespace(struct aa_namespace *ns)
572{
573 struct aa_profile *unconfined = ns->unconfined;
574
575 /* remove ns from namespace list */
576 list_del_init(&ns->base.list);
577
578 /*
579 * break the ns, unconfined profile cyclic reference and forward
580 * all new unconfined profiles requests to the parent namespace
581 * This will result in all confined tasks that have a profile
582 * being removed, inheriting the parent->unconfined profile.
583 */
584 if (ns->parent)
585 ns->unconfined = aa_get_profile(ns->parent->unconfined);
586
587 destroy_namespace(ns);
588
589 /* release original ns->unconfined ref */
590 aa_put_profile(unconfined);
591 /* release ns->base.list ref, from removal above */
592 aa_put_namespace(ns);
593}
594
595/**
596 * __ns_list_release - remove all profile namespaces on the list put refs
597 * @head: list of profile namespaces (NOT NULL)
598 *
599 * Requires: namespace lock be held
600 */
601static void __ns_list_release(struct list_head *head)
602{
603 struct aa_namespace *ns, *tmp;
604 list_for_each_entry_safe(ns, tmp, head, base.list)
605 __remove_namespace(ns);
606
607}
608
609/**
610 * aa_alloc_root_ns - allocate the root profile namespace
611 *
612 * Returns: %0 on success else error
613 *
614 */
615int __init aa_alloc_root_ns(void)
616{
617 /* released by aa_free_root_ns - used as list ref*/
618 root_ns = alloc_namespace(NULL, "root");
619 if (!root_ns)
620 return -ENOMEM;
621
622 return 0;
623}
624
625 /**
626 * aa_free_root_ns - free the root profile namespace
627 */
628void __init aa_free_root_ns(void)
629 {
630 struct aa_namespace *ns = root_ns;
631 root_ns = NULL;
632
633 destroy_namespace(ns);
634 aa_put_namespace(ns);
635}
636
637/**
John Johansenc88d4c72010-07-29 14:48:00 -0700638 * free_profile - free a profile
639 * @profile: the profile to free (MAYBE NULL)
640 *
641 * Free a profile, its hats and null_profile. All references to the profile,
642 * its hats and null_profile must have been put.
643 *
644 * If the profile was referenced from a task context, free_profile() will
645 * be called from an rcu callback routine, so we must not sleep here.
646 */
647static void free_profile(struct aa_profile *profile)
648{
John Johansen2e680dd2012-10-24 06:27:32 -0700649 struct aa_profile *p;
650
John Johansenc88d4c72010-07-29 14:48:00 -0700651 AA_DEBUG("%s(%p)\n", __func__, profile);
652
653 if (!profile)
654 return;
655
656 if (!list_empty(&profile->base.list)) {
657 AA_ERROR("%s: internal error, "
658 "profile '%s' still on ns list\n",
659 __func__, profile->base.name);
660 BUG();
661 }
662
663 /* free children profiles */
664 policy_destroy(&profile->base);
665 aa_put_profile(profile->parent);
666
667 aa_put_namespace(profile->ns);
668 kzfree(profile->rename);
669
670 aa_free_file_rules(&profile->file);
671 aa_free_cap_rules(&profile->caps);
672 aa_free_rlimit_rules(&profile->rlimits);
673
John Johansenc88d4c72010-07-29 14:48:00 -0700674 aa_put_dfa(profile->xmatch);
John Johansenad5ff3d2012-02-16 07:07:53 -0800675 aa_put_dfa(profile->policy.dfa);
John Johansenc88d4c72010-07-29 14:48:00 -0700676
John Johansen2e680dd2012-10-24 06:27:32 -0700677 /* put the profile reference for replacedby, but not via
678 * put_profile(kref_put).
679 * replacedby can form a long chain that can result in cascading
680 * frees that blows the stack because kref_put makes a nested fn
681 * call (it looks like recursion, with free_profile calling
682 * free_profile) for each profile in the chain lp#1056078.
683 */
684 for (p = profile->replacedby; p; ) {
685 if (atomic_dec_and_test(&p->base.count.refcount)) {
686 /* no more refs on p, grab its replacedby */
687 struct aa_profile *next = p->replacedby;
688 /* break the chain */
689 p->replacedby = NULL;
690 /* now free p, chain is broken */
691 free_profile(p);
692
693 /* follow up with next profile in the chain */
694 p = next;
695 } else
696 break;
697 }
John Johansenc88d4c72010-07-29 14:48:00 -0700698
699 kzfree(profile);
700}
701
702/**
703 * aa_free_profile_kref - free aa_profile by kref (called by aa_put_profile)
704 * @kr: kref callback for freeing of a profile (NOT NULL)
705 */
706void aa_free_profile_kref(struct kref *kref)
707{
708 struct aa_profile *p = container_of(kref, struct aa_profile,
709 base.count);
710
711 free_profile(p);
712}
713
John Johansen4da05cc2013-02-18 16:11:34 -0800714/**
715 * aa_alloc_profile - allocate, initialize and return a new profile
716 * @hname: name of the profile (NOT NULL)
717 *
718 * Returns: refcount profile or NULL on failure
719 */
720struct aa_profile *aa_alloc_profile(const char *hname)
721{
722 struct aa_profile *profile;
723
724 /* freed by free_profile - usually through aa_put_profile */
725 profile = kzalloc(sizeof(*profile), GFP_KERNEL);
726 if (!profile)
727 return NULL;
728
729 if (!policy_init(&profile->base, NULL, hname)) {
730 kzfree(profile);
731 return NULL;
732 }
733
734 /* refcount released by caller */
735 return profile;
736}
737
738/**
739 * aa_new_null_profile - create a new null-X learning profile
740 * @parent: profile that caused this profile to be created (NOT NULL)
741 * @hat: true if the null- learning profile is a hat
742 *
743 * Create a null- complain mode profile used in learning mode. The name of
744 * the profile is unique and follows the format of parent//null-<uniq>.
745 *
746 * null profiles are added to the profile list but the list does not
747 * hold a count on them so that they are automatically released when
748 * not in use.
749 *
750 * Returns: new refcounted profile else NULL on failure
751 */
752struct aa_profile *aa_new_null_profile(struct aa_profile *parent, int hat)
753{
754 struct aa_profile *profile = NULL;
755 char *name;
756 int uniq = atomic_inc_return(&parent->ns->uniq_null);
757
758 /* freed below */
759 name = kmalloc(strlen(parent->base.hname) + 2 + 7 + 8, GFP_KERNEL);
760 if (!name)
761 goto fail;
762 sprintf(name, "%s//null-%x", parent->base.hname, uniq);
763
764 profile = aa_alloc_profile(name);
765 kfree(name);
766 if (!profile)
767 goto fail;
768
769 profile->mode = APPARMOR_COMPLAIN;
770 profile->flags = PFLAG_NULL;
771 if (hat)
772 profile->flags |= PFLAG_HAT;
773
774 /* released on free_profile */
775 profile->parent = aa_get_profile(parent);
776 profile->ns = aa_get_namespace(parent->ns);
777
778 write_lock(&profile->ns->lock);
779 __list_add_profile(&parent->base.profiles, profile);
780 write_unlock(&profile->ns->lock);
781
782 /* refcount released by caller */
783 return profile;
784
785fail:
786 return NULL;
787}
788
John Johansenc88d4c72010-07-29 14:48:00 -0700789/* TODO: profile accounting - setup in remove */
790
791/**
792 * __find_child - find a profile on @head list with a name matching @name
793 * @head: list to search (NOT NULL)
794 * @name: name of profile (NOT NULL)
795 *
796 * Requires: ns lock protecting list be held
797 *
798 * Returns: unrefcounted profile ptr, or NULL if not found
799 */
800static struct aa_profile *__find_child(struct list_head *head, const char *name)
801{
802 return (struct aa_profile *)__policy_find(head, name);
803}
804
805/**
806 * __strn_find_child - find a profile on @head list using substring of @name
807 * @head: list to search (NOT NULL)
808 * @name: name of profile (NOT NULL)
809 * @len: length of @name substring to match
810 *
811 * Requires: ns lock protecting list be held
812 *
813 * Returns: unrefcounted profile ptr, or NULL if not found
814 */
815static struct aa_profile *__strn_find_child(struct list_head *head,
816 const char *name, int len)
817{
818 return (struct aa_profile *)__policy_strn_find(head, name, len);
819}
820
821/**
822 * aa_find_child - find a profile by @name in @parent
823 * @parent: profile to search (NOT NULL)
824 * @name: profile name to search for (NOT NULL)
825 *
826 * Returns: a refcounted profile or NULL if not found
827 */
828struct aa_profile *aa_find_child(struct aa_profile *parent, const char *name)
829{
830 struct aa_profile *profile;
831
832 read_lock(&parent->ns->lock);
833 profile = aa_get_profile(__find_child(&parent->base.profiles, name));
834 read_unlock(&parent->ns->lock);
835
836 /* refcount released by caller */
837 return profile;
838}
839
840/**
841 * __lookup_parent - lookup the parent of a profile of name @hname
842 * @ns: namespace to lookup profile in (NOT NULL)
843 * @hname: hierarchical profile name to find parent of (NOT NULL)
844 *
845 * Lookups up the parent of a fully qualified profile name, the profile
846 * that matches hname does not need to exist, in general this
847 * is used to load a new profile.
848 *
849 * Requires: ns->lock be held
850 *
851 * Returns: unrefcounted policy or NULL if not found
852 */
853static struct aa_policy *__lookup_parent(struct aa_namespace *ns,
854 const char *hname)
855{
856 struct aa_policy *policy;
857 struct aa_profile *profile = NULL;
858 char *split;
859
860 policy = &ns->base;
861
862 for (split = strstr(hname, "//"); split;) {
863 profile = __strn_find_child(&policy->profiles, hname,
864 split - hname);
865 if (!profile)
866 return NULL;
867 policy = &profile->base;
868 hname = split + 2;
869 split = strstr(hname, "//");
870 }
871 if (!profile)
872 return &ns->base;
873 return &profile->base;
874}
875
876/**
877 * __lookup_profile - lookup the profile matching @hname
878 * @base: base list to start looking up profile name from (NOT NULL)
879 * @hname: hierarchical profile name (NOT NULL)
880 *
881 * Requires: ns->lock be held
882 *
883 * Returns: unrefcounted profile pointer or NULL if not found
884 *
885 * Do a relative name lookup, recursing through profile tree.
886 */
887static struct aa_profile *__lookup_profile(struct aa_policy *base,
888 const char *hname)
889{
890 struct aa_profile *profile = NULL;
891 char *split;
892
893 for (split = strstr(hname, "//"); split;) {
894 profile = __strn_find_child(&base->profiles, hname,
895 split - hname);
896 if (!profile)
897 return NULL;
898
899 base = &profile->base;
900 hname = split + 2;
901 split = strstr(hname, "//");
902 }
903
904 profile = __find_child(&base->profiles, hname);
905
906 return profile;
907}
908
909/**
910 * aa_lookup_profile - find a profile by its full or partial name
911 * @ns: the namespace to start from (NOT NULL)
912 * @hname: name to do lookup on. Does not contain namespace prefix (NOT NULL)
913 *
914 * Returns: refcounted profile or NULL if not found
915 */
916struct aa_profile *aa_lookup_profile(struct aa_namespace *ns, const char *hname)
917{
918 struct aa_profile *profile;
919
920 read_lock(&ns->lock);
921 profile = aa_get_profile(__lookup_profile(&ns->base, hname));
922 read_unlock(&ns->lock);
923
John Johansenbf832082012-05-16 11:00:05 -0700924 /* the unconfined profile is not in the regular profile list */
925 if (!profile && strcmp(hname, "unconfined") == 0)
926 profile = aa_get_profile(ns->unconfined);
927
John Johansenc88d4c72010-07-29 14:48:00 -0700928 /* refcount released by caller */
929 return profile;
930}
931
932/**
933 * replacement_allowed - test to see if replacement is allowed
934 * @profile: profile to test if it can be replaced (MAYBE NULL)
935 * @noreplace: true if replacement shouldn't be allowed but addition is okay
936 * @info: Returns - info about why replacement failed (NOT NULL)
937 *
938 * Returns: %0 if replacement allowed else error code
939 */
940static int replacement_allowed(struct aa_profile *profile, int noreplace,
941 const char **info)
942{
943 if (profile) {
944 if (profile->flags & PFLAG_IMMUTABLE) {
945 *info = "cannot replace immutible profile";
946 return -EPERM;
947 } else if (noreplace) {
948 *info = "profile already exists";
949 return -EEXIST;
950 }
951 }
952 return 0;
953}
954
955/**
956 * __add_new_profile - simple wrapper around __list_add_profile
957 * @ns: namespace that profile is being added to (NOT NULL)
958 * @policy: the policy container to add the profile to (NOT NULL)
959 * @profile: profile to add (NOT NULL)
960 *
961 * add a profile to a list and do other required basic allocations
962 */
963static void __add_new_profile(struct aa_namespace *ns, struct aa_policy *policy,
964 struct aa_profile *profile)
965{
966 if (policy != &ns->base)
967 /* released on profile replacement or free_profile */
968 profile->parent = aa_get_profile((struct aa_profile *) policy);
969 __list_add_profile(&policy->profiles, profile);
970 /* released on free_profile */
John Johansenc88d4c72010-07-29 14:48:00 -0700971 profile->ns = aa_get_namespace(ns);
972}
973
974/**
975 * aa_audit_policy - Do auditing of policy changes
976 * @op: policy operation being performed
977 * @gfp: memory allocation flags
978 * @name: name of profile being manipulated (NOT NULL)
979 * @info: any extra information to be audited (MAYBE NULL)
980 * @error: error code
981 *
982 * Returns: the error to be returned after audit is done
983 */
984static int audit_policy(int op, gfp_t gfp, const char *name, const char *info,
985 int error)
986{
987 struct common_audit_data sa;
Eric Paris3b3b0e42012-04-03 09:37:02 -0700988 struct apparmor_audit_data aad = {0,};
Eric Paris50c205f2012-04-04 15:01:43 -0400989 sa.type = LSM_AUDIT_DATA_NONE;
Eric Paris3b3b0e42012-04-03 09:37:02 -0700990 sa.aad = &aad;
991 aad.op = op;
992 aad.name = name;
993 aad.info = info;
994 aad.error = error;
John Johansenc88d4c72010-07-29 14:48:00 -0700995
996 return aa_audit(AUDIT_APPARMOR_STATUS, __aa_current_profile(), gfp,
997 &sa, NULL);
998}
999
1000/**
1001 * aa_may_manage_policy - can the current task manage policy
1002 * @op: the policy manipulation operation being done
1003 *
1004 * Returns: true if the task is allowed to manipulate policy
1005 */
1006bool aa_may_manage_policy(int op)
1007{
1008 /* check if loading policy is locked out */
1009 if (aa_g_lock_policy) {
1010 audit_policy(op, GFP_KERNEL, NULL, "policy_locked", -EACCES);
1011 return 0;
1012 }
1013
1014 if (!capable(CAP_MAC_ADMIN)) {
1015 audit_policy(op, GFP_KERNEL, NULL, "not policy admin", -EACCES);
1016 return 0;
1017 }
1018
1019 return 1;
1020}
1021
1022/**
1023 * aa_replace_profiles - replace profile(s) on the profile list
1024 * @udata: serialized data stream (NOT NULL)
1025 * @size: size of the serialized data stream
1026 * @noreplace: true if only doing addition, no replacement allowed
1027 *
1028 * unpack and replace a profile on the profile list and uses of that profile
1029 * by any aa_task_cxt. If the profile does not exist on the profile list
1030 * it is added.
1031 *
1032 * Returns: size of data consumed else error code on failure.
1033 */
1034ssize_t aa_replace_profiles(void *udata, size_t size, bool noreplace)
1035{
1036 struct aa_policy *policy;
1037 struct aa_profile *old_profile = NULL, *new_profile = NULL;
1038 struct aa_profile *rename_profile = NULL;
1039 struct aa_namespace *ns = NULL;
1040 const char *ns_name, *name = NULL, *info = NULL;
1041 int op = OP_PROF_REPL;
1042 ssize_t error;
1043
1044 /* released below */
1045 new_profile = aa_unpack(udata, size, &ns_name);
1046 if (IS_ERR(new_profile)) {
1047 error = PTR_ERR(new_profile);
1048 new_profile = NULL;
1049 goto fail;
1050 }
1051
1052 /* released below */
1053 ns = aa_prepare_namespace(ns_name);
1054 if (!ns) {
1055 info = "failed to prepare namespace";
1056 error = -ENOMEM;
1057 name = ns_name;
1058 goto fail;
1059 }
1060
1061 name = new_profile->base.hname;
1062
1063 write_lock(&ns->lock);
1064 /* no ref on policy only use inside lock */
1065 policy = __lookup_parent(ns, new_profile->base.hname);
1066
1067 if (!policy) {
1068 info = "parent does not exist";
1069 error = -ENOENT;
1070 goto audit;
1071 }
1072
1073 old_profile = __find_child(&policy->profiles, new_profile->base.name);
1074 /* released below */
1075 aa_get_profile(old_profile);
1076
1077 if (new_profile->rename) {
1078 rename_profile = __lookup_profile(&ns->base,
1079 new_profile->rename);
1080 /* released below */
1081 aa_get_profile(rename_profile);
1082
1083 if (!rename_profile) {
1084 info = "profile to rename does not exist";
1085 name = new_profile->rename;
1086 error = -ENOENT;
1087 goto audit;
1088 }
1089 }
1090
1091 error = replacement_allowed(old_profile, noreplace, &info);
1092 if (error)
1093 goto audit;
1094
1095 error = replacement_allowed(rename_profile, noreplace, &info);
1096 if (error)
1097 goto audit;
1098
1099audit:
1100 if (!old_profile && !rename_profile)
1101 op = OP_PROF_LOAD;
1102
1103 error = audit_policy(op, GFP_ATOMIC, name, info, error);
1104
1105 if (!error) {
1106 if (rename_profile)
1107 __replace_profile(rename_profile, new_profile);
John Johansena4987852013-02-18 16:10:34 -08001108 if (old_profile)
John Johansenc88d4c72010-07-29 14:48:00 -07001109 __replace_profile(old_profile, new_profile);
John Johansenc88d4c72010-07-29 14:48:00 -07001110 if (!(old_profile || rename_profile))
1111 __add_new_profile(ns, policy, new_profile);
1112 }
1113 write_unlock(&ns->lock);
1114
1115out:
1116 aa_put_namespace(ns);
1117 aa_put_profile(rename_profile);
1118 aa_put_profile(old_profile);
1119 aa_put_profile(new_profile);
1120 if (error)
1121 return error;
1122 return size;
1123
1124fail:
1125 error = audit_policy(op, GFP_KERNEL, name, info, error);
1126 goto out;
1127}
1128
1129/**
1130 * aa_remove_profiles - remove profile(s) from the system
1131 * @fqname: name of the profile or namespace to remove (NOT NULL)
1132 * @size: size of the name
1133 *
1134 * Remove a profile or sub namespace from the current namespace, so that
1135 * they can not be found anymore and mark them as replaced by unconfined
1136 *
1137 * NOTE: removing confinement does not restore rlimits to preconfinemnet values
1138 *
1139 * Returns: size of data consume else error code if fails
1140 */
1141ssize_t aa_remove_profiles(char *fqname, size_t size)
1142{
1143 struct aa_namespace *root, *ns = NULL;
1144 struct aa_profile *profile = NULL;
1145 const char *name = fqname, *info = NULL;
1146 ssize_t error = 0;
1147
1148 if (*fqname == 0) {
1149 info = "no profile specified";
1150 error = -ENOENT;
1151 goto fail;
1152 }
1153
1154 root = aa_current_profile()->ns;
1155
1156 if (fqname[0] == ':') {
1157 char *ns_name;
1158 name = aa_split_fqname(fqname, &ns_name);
John Johansen41d1b3e2013-02-21 01:14:17 -08001159 /* released below */
1160 ns = aa_find_namespace(root, ns_name);
1161 if (!ns) {
1162 info = "namespace does not exist";
1163 error = -ENOENT;
1164 goto fail;
John Johansenc88d4c72010-07-29 14:48:00 -07001165 }
1166 } else
1167 /* released below */
1168 ns = aa_get_namespace(root);
1169
John Johansenc88d4c72010-07-29 14:48:00 -07001170 if (!name) {
1171 /* remove namespace - can only happen if fqname[0] == ':' */
John Johansen999b4f02010-08-27 18:33:29 -07001172 write_lock(&ns->parent->lock);
John Johansenc88d4c72010-07-29 14:48:00 -07001173 __remove_namespace(ns);
John Johansen999b4f02010-08-27 18:33:29 -07001174 write_unlock(&ns->parent->lock);
John Johansenc88d4c72010-07-29 14:48:00 -07001175 } else {
1176 /* remove profile */
John Johansen999b4f02010-08-27 18:33:29 -07001177 write_lock(&ns->lock);
John Johansenc88d4c72010-07-29 14:48:00 -07001178 profile = aa_get_profile(__lookup_profile(&ns->base, name));
1179 if (!profile) {
1180 error = -ENOENT;
1181 info = "profile does not exist";
1182 goto fail_ns_lock;
1183 }
1184 name = profile->base.hname;
1185 __remove_profile(profile);
John Johansen999b4f02010-08-27 18:33:29 -07001186 write_unlock(&ns->lock);
John Johansenc88d4c72010-07-29 14:48:00 -07001187 }
John Johansenc88d4c72010-07-29 14:48:00 -07001188
1189 /* don't fail removal if audit fails */
1190 (void) audit_policy(OP_PROF_RM, GFP_KERNEL, name, info, error);
1191 aa_put_namespace(ns);
1192 aa_put_profile(profile);
1193 return size;
1194
1195fail_ns_lock:
1196 write_unlock(&ns->lock);
1197 aa_put_namespace(ns);
1198
1199fail:
1200 (void) audit_policy(OP_PROF_RM, GFP_KERNEL, name, info, error);
1201 return error;
1202}