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1/*
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"
90
91
92/* root profile namespace */
93struct aa_namespace *root_ns;
94
95const char *const aa_profile_mode_names[] = {
96 "enforce",
97 "complain",
98 "kill",
99 "unconfined",
100};
101
102/**
103 * hname_tail - find the last component of an hname
104 * @name: hname to find the base profile name component of (NOT NULL)
105 *
106 * Returns: the tail (base profile name) name component of an hname
107 */
108static const char *hname_tail(const char *hname)
109{
110 char *split;
111 hname = strim((char *)hname);
112 for (split = strstr(hname, "//"); split; split = strstr(hname, "//"))
113 hname = split + 2;
114
115 return hname;
116}
117
118/**
119 * policy_init - initialize a policy structure
120 * @policy: policy to initialize (NOT NULL)
121 * @prefix: prefix name if any is required. (MAYBE NULL)
122 * @name: name of the policy, init will make a copy of it (NOT NULL)
123 *
124 * Note: this fn creates a copy of strings passed in
125 *
126 * Returns: true if policy init successful
127 */
128static bool policy_init(struct aa_policy *policy, const char *prefix,
129 const char *name)
130{
131 /* freed by policy_free */
132 if (prefix) {
133 policy->hname = kmalloc(strlen(prefix) + strlen(name) + 3,
134 GFP_KERNEL);
135 if (policy->hname)
136 sprintf(policy->hname, "%s//%s", prefix, name);
137 } else
138 policy->hname = kstrdup(name, GFP_KERNEL);
139 if (!policy->hname)
140 return 0;
141 /* base.name is a substring of fqname */
142 policy->name = (char *)hname_tail(policy->hname);
143 INIT_LIST_HEAD(&policy->list);
144 INIT_LIST_HEAD(&policy->profiles);
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 (on_list_rcu(&policy->profiles)) {
157 AA_ERROR("%s: internal error, "
158 "policy '%s' still contains profiles\n",
159 __func__, policy->name);
160 BUG();
161 }
162 if (on_list_rcu(&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: rcu_read_lock 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_rcu(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: rcu_read_lock 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_rcu(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 mutex_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
294 ns->unconfined->flags = PFLAG_IX_ON_NAME_ERROR |
295 PFLAG_IMMUTABLE | PFLAG_NS_COUNT;
296 ns->unconfined->mode = APPARMOR_UNCONFINED;
297
298 /* ns and ns->unconfined share ns->unconfined refcount */
299 ns->unconfined->ns = ns;
300
301 atomic_set(&ns->uniq_null, 0);
302
303 return ns;
304
305fail_unconfined:
306 kzfree(ns->base.hname);
307fail_ns:
308 kzfree(ns);
309 return NULL;
310}
311
312/**
313 * free_namespace - free a profile namespace
314 * @ns: the namespace to free (MAYBE NULL)
315 *
316 * Requires: All references to the namespace must have been put, if the
317 * namespace was referenced by a profile confining a task,
318 */
319static void free_namespace(struct aa_namespace *ns)
320{
321 if (!ns)
322 return;
323
324 policy_destroy(&ns->base);
325 aa_put_namespace(ns->parent);
326
327 ns->unconfined->ns = NULL;
328 aa_free_profile(ns->unconfined);
329 kzfree(ns);
330}
331
332/**
333 * __aa_find_namespace - find a namespace on a list by @name
334 * @head: list to search for namespace on (NOT NULL)
335 * @name: name of namespace to look for (NOT NULL)
336 *
337 * Returns: unrefcounted namespace
338 *
339 * Requires: rcu_read_lock be held
340 */
341static struct aa_namespace *__aa_find_namespace(struct list_head *head,
342 const char *name)
343{
344 return (struct aa_namespace *)__policy_find(head, name);
345}
346
347/**
348 * aa_find_namespace - look up a profile namespace on the namespace list
349 * @root: namespace to search in (NOT NULL)
350 * @name: name of namespace to find (NOT NULL)
351 *
352 * Returns: a refcounted namespace on the list, or NULL if no namespace
353 * called @name exists.
354 *
355 * refcount released by caller
356 */
357struct aa_namespace *aa_find_namespace(struct aa_namespace *root,
358 const char *name)
359{
360 struct aa_namespace *ns = NULL;
361
362 rcu_read_lock();
363 ns = aa_get_namespace(__aa_find_namespace(&root->sub_ns, name));
364 rcu_read_unlock();
365
366 return ns;
367}
368
369/**
370 * aa_prepare_namespace - find an existing or create a new namespace of @name
371 * @name: the namespace to find or add (MAYBE NULL)
372 *
373 * Returns: refcounted namespace or NULL if failed to create one
374 */
375static struct aa_namespace *aa_prepare_namespace(const char *name)
376{
377 struct aa_namespace *ns, *root;
378
379 root = aa_current_profile()->ns;
380
381 mutex_lock(&root->lock);
382
383 /* if name isn't specified the profile is loaded to the current ns */
384 if (!name) {
385 /* released by caller */
386 ns = aa_get_namespace(root);
387 goto out;
388 }
389
390 /* try and find the specified ns and if it doesn't exist create it */
391 /* released by caller */
392 ns = aa_get_namespace(__aa_find_namespace(&root->sub_ns, name));
393 if (!ns) {
394 ns = alloc_namespace(root->base.hname, name);
395 if (!ns)
396 goto out;
397 if (__aa_fs_namespace_mkdir(ns, ns_subns_dir(root), name)) {
398 AA_ERROR("Failed to create interface for ns %s\n",
399 ns->base.name);
400 free_namespace(ns);
401 ns = NULL;
402 goto out;
403 }
404 ns->parent = aa_get_namespace(root);
405 list_add_rcu(&ns->base.list, &root->sub_ns);
406 /* add list ref */
407 aa_get_namespace(ns);
408 }
409out:
410 mutex_unlock(&root->lock);
411
412 /* return ref */
413 return ns;
414}
415
416/**
417 * __list_add_profile - add a profile to a list
418 * @list: list to add it to (NOT NULL)
419 * @profile: the profile to add (NOT NULL)
420 *
421 * refcount @profile, should be put by __list_remove_profile
422 *
423 * Requires: namespace lock be held, or list not be shared
424 */
425static void __list_add_profile(struct list_head *list,
426 struct aa_profile *profile)
427{
428 list_add_rcu(&profile->base.list, list);
429 /* get list reference */
430 aa_get_profile(profile);
431}
432
433/**
434 * __list_remove_profile - remove a profile from the list it is on
435 * @profile: the profile to remove (NOT NULL)
436 *
437 * remove a profile from the list, warning generally removal should
438 * be done with __replace_profile as most profile removals are
439 * replacements to the unconfined profile.
440 *
441 * put @profile list refcount
442 *
443 * Requires: namespace lock be held, or list not have been live
444 */
445static void __list_remove_profile(struct aa_profile *profile)
446{
447 list_del_rcu(&profile->base.list);
448 aa_put_profile(profile);
449}
450
451static void __profile_list_release(struct list_head *head);
452
453/**
454 * __remove_profile - remove old profile, and children
455 * @profile: profile to be replaced (NOT NULL)
456 *
457 * Requires: namespace list lock be held, or list not be shared
458 */
459static void __remove_profile(struct aa_profile *profile)
460{
461 /* release any children lists first */
462 __profile_list_release(&profile->base.profiles);
463 /* released by free_profile */
464 __aa_update_replacedby(profile, profile->ns->unconfined);
465 __aa_fs_profile_rmdir(profile);
466 __list_remove_profile(profile);
467}
468
469/**
470 * __profile_list_release - remove all profiles on the list and put refs
471 * @head: list of profiles (NOT NULL)
472 *
473 * Requires: namespace lock be held
474 */
475static void __profile_list_release(struct list_head *head)
476{
477 struct aa_profile *profile, *tmp;
478 list_for_each_entry_safe(profile, tmp, head, base.list)
479 __remove_profile(profile);
480}
481
482static void __ns_list_release(struct list_head *head);
483
484/**
485 * destroy_namespace - remove everything contained by @ns
486 * @ns: namespace to have it contents removed (NOT NULL)
487 */
488static void destroy_namespace(struct aa_namespace *ns)
489{
490 if (!ns)
491 return;
492
493 mutex_lock(&ns->lock);
494 /* release all profiles in this namespace */
495 __profile_list_release(&ns->base.profiles);
496
497 /* release all sub namespaces */
498 __ns_list_release(&ns->sub_ns);
499
500 if (ns->parent)
501 __aa_update_replacedby(ns->unconfined, ns->parent->unconfined);
502 __aa_fs_namespace_rmdir(ns);
503 mutex_unlock(&ns->lock);
504}
505
506/**
507 * __remove_namespace - remove a namespace and all its children
508 * @ns: namespace to be removed (NOT NULL)
509 *
510 * Requires: ns->parent->lock be held and ns removed from parent.
511 */
512static void __remove_namespace(struct aa_namespace *ns)
513{
514 /* remove ns from namespace list */
515 list_del_rcu(&ns->base.list);
516 destroy_namespace(ns);
517 aa_put_namespace(ns);
518}
519
520/**
521 * __ns_list_release - remove all profile namespaces on the list put refs
522 * @head: list of profile namespaces (NOT NULL)
523 *
524 * Requires: namespace lock be held
525 */
526static void __ns_list_release(struct list_head *head)
527{
528 struct aa_namespace *ns, *tmp;
529 list_for_each_entry_safe(ns, tmp, head, base.list)
530 __remove_namespace(ns);
531
532}
533
534/**
535 * aa_alloc_root_ns - allocate the root profile namespace
536 *
537 * Returns: %0 on success else error
538 *
539 */
540int __init aa_alloc_root_ns(void)
541{
542 /* released by aa_free_root_ns - used as list ref*/
543 root_ns = alloc_namespace(NULL, "root");
544 if (!root_ns)
545 return -ENOMEM;
546
547 return 0;
548}
549
550 /**
551 * aa_free_root_ns - free the root profile namespace
552 */
553void __init aa_free_root_ns(void)
554 {
555 struct aa_namespace *ns = root_ns;
556 root_ns = NULL;
557
558 destroy_namespace(ns);
559 aa_put_namespace(ns);
560}
561
562
563static void free_replacedby(struct aa_replacedby *r)
564{
565 if (r) {
566 /* r->profile will not be updated any more as r is dead */
567 aa_put_profile(rcu_dereference_protected(r->profile, true));
568 kzfree(r);
569 }
570}
571
572
573void aa_free_replacedby_kref(struct kref *kref)
574{
575 struct aa_replacedby *r = container_of(kref, struct aa_replacedby,
576 count);
577 free_replacedby(r);
578}
579
580/**
581 * aa_free_profile - free a profile
582 * @profile: the profile to free (MAYBE NULL)
583 *
584 * Free a profile, its hats and null_profile. All references to the profile,
585 * its hats and null_profile must have been put.
586 *
587 * If the profile was referenced from a task context, free_profile() will
588 * be called from an rcu callback routine, so we must not sleep here.
589 */
590void aa_free_profile(struct aa_profile *profile)
591{
592 AA_DEBUG("%s(%p)\n", __func__, profile);
593
594 if (!profile)
595 return;
596
597 /* free children profiles */
598 policy_destroy(&profile->base);
599 aa_put_profile(rcu_access_pointer(profile->parent));
600
601 aa_put_namespace(profile->ns);
602 kzfree(profile->rename);
603
604 aa_free_file_rules(&profile->file);
605 aa_free_cap_rules(&profile->caps);
606 aa_free_rlimit_rules(&profile->rlimits);
607
608 kzfree(profile->dirname);
609 aa_put_dfa(profile->xmatch);
610 aa_put_dfa(profile->policy.dfa);
611 aa_put_replacedby(profile->replacedby);
612
613 kzfree(profile->hash);
614 kzfree(profile);
615}
616
617/**
618 * aa_free_profile_rcu - free aa_profile by rcu (called by aa_free_profile_kref)
619 * @head: rcu_head callback for freeing of a profile (NOT NULL)
620 */
621static void aa_free_profile_rcu(struct rcu_head *head)
622{
623 struct aa_profile *p = container_of(head, struct aa_profile, rcu);
624 if (p->flags & PFLAG_NS_COUNT)
625 free_namespace(p->ns);
626 else
627 aa_free_profile(p);
628}
629
630/**
631 * aa_free_profile_kref - free aa_profile by kref (called by aa_put_profile)
632 * @kr: kref callback for freeing of a profile (NOT NULL)
633 */
634void aa_free_profile_kref(struct kref *kref)
635{
636 struct aa_profile *p = container_of(kref, struct aa_profile, count);
637 call_rcu(&p->rcu, aa_free_profile_rcu);
638}
639
640/**
641 * aa_alloc_profile - allocate, initialize and return a new profile
642 * @hname: name of the profile (NOT NULL)
643 *
644 * Returns: refcount profile or NULL on failure
645 */
646struct aa_profile *aa_alloc_profile(const char *hname)
647{
648 struct aa_profile *profile;
649
650 /* freed by free_profile - usually through aa_put_profile */
651 profile = kzalloc(sizeof(*profile), GFP_KERNEL);
652 if (!profile)
653 return NULL;
654
655 profile->replacedby = kzalloc(sizeof(struct aa_replacedby), GFP_KERNEL);
656 if (!profile->replacedby)
657 goto fail;
658 kref_init(&profile->replacedby->count);
659
660 if (!policy_init(&profile->base, NULL, hname))
661 goto fail;
662 kref_init(&profile->count);
663
664 /* refcount released by caller */
665 return profile;
666
667fail:
668 kzfree(profile->replacedby);
669 kzfree(profile);
670
671 return NULL;
672}
673
674/**
675 * aa_new_null_profile - create a new null-X learning profile
676 * @parent: profile that caused this profile to be created (NOT NULL)
677 * @hat: true if the null- learning profile is a hat
678 *
679 * Create a null- complain mode profile used in learning mode. The name of
680 * the profile is unique and follows the format of parent//null-<uniq>.
681 *
682 * null profiles are added to the profile list but the list does not
683 * hold a count on them so that they are automatically released when
684 * not in use.
685 *
686 * Returns: new refcounted profile else NULL on failure
687 */
688struct aa_profile *aa_new_null_profile(struct aa_profile *parent, int hat)
689{
690 struct aa_profile *profile = NULL;
691 char *name;
692 int uniq = atomic_inc_return(&parent->ns->uniq_null);
693
694 /* freed below */
695 name = kmalloc(strlen(parent->base.hname) + 2 + 7 + 8, GFP_KERNEL);
696 if (!name)
697 goto fail;
698 sprintf(name, "%s//null-%x", parent->base.hname, uniq);
699
700 profile = aa_alloc_profile(name);
701 kfree(name);
702 if (!profile)
703 goto fail;
704
705 profile->mode = APPARMOR_COMPLAIN;
706 profile->flags = PFLAG_NULL;
707 if (hat)
708 profile->flags |= PFLAG_HAT;
709
710 /* released on free_profile */
711 rcu_assign_pointer(profile->parent, aa_get_profile(parent));
712 profile->ns = aa_get_namespace(parent->ns);
713
714 mutex_lock(&profile->ns->lock);
715 __list_add_profile(&parent->base.profiles, profile);
716 mutex_unlock(&profile->ns->lock);
717
718 /* refcount released by caller */
719 return profile;
720
721fail:
722 return NULL;
723}
724
725/* TODO: profile accounting - setup in remove */
726
727/**
728 * __find_child - find a profile on @head list with a name matching @name
729 * @head: list to search (NOT NULL)
730 * @name: name of profile (NOT NULL)
731 *
732 * Requires: rcu_read_lock be held
733 *
734 * Returns: unrefcounted profile ptr, or NULL if not found
735 */
736static struct aa_profile *__find_child(struct list_head *head, const char *name)
737{
738 return (struct aa_profile *)__policy_find(head, name);
739}
740
741/**
742 * __strn_find_child - find a profile on @head list using substring of @name
743 * @head: list to search (NOT NULL)
744 * @name: name of profile (NOT NULL)
745 * @len: length of @name substring to match
746 *
747 * Requires: rcu_read_lock be held
748 *
749 * Returns: unrefcounted profile ptr, or NULL if not found
750 */
751static struct aa_profile *__strn_find_child(struct list_head *head,
752 const char *name, int len)
753{
754 return (struct aa_profile *)__policy_strn_find(head, name, len);
755}
756
757/**
758 * aa_find_child - find a profile by @name in @parent
759 * @parent: profile to search (NOT NULL)
760 * @name: profile name to search for (NOT NULL)
761 *
762 * Returns: a refcounted profile or NULL if not found
763 */
764struct aa_profile *aa_find_child(struct aa_profile *parent, const char *name)
765{
766 struct aa_profile *profile;
767
768 rcu_read_lock();
769 profile = aa_get_profile(__find_child(&parent->base.profiles, name));
770 rcu_read_unlock();
771
772 /* refcount released by caller */
773 return profile;
774}
775
776/**
777 * __lookup_parent - lookup the parent of a profile of name @hname
778 * @ns: namespace to lookup profile in (NOT NULL)
779 * @hname: hierarchical profile name to find parent of (NOT NULL)
780 *
781 * Lookups up the parent of a fully qualified profile name, the profile
782 * that matches hname does not need to exist, in general this
783 * is used to load a new profile.
784 *
785 * Requires: rcu_read_lock be held
786 *
787 * Returns: unrefcounted policy or NULL if not found
788 */
789static struct aa_policy *__lookup_parent(struct aa_namespace *ns,
790 const char *hname)
791{
792 struct aa_policy *policy;
793 struct aa_profile *profile = NULL;
794 char *split;
795
796 policy = &ns->base;
797
798 for (split = strstr(hname, "//"); split;) {
799 profile = __strn_find_child(&policy->profiles, hname,
800 split - hname);
801 if (!profile)
802 return NULL;
803 policy = &profile->base;
804 hname = split + 2;
805 split = strstr(hname, "//");
806 }
807 if (!profile)
808 return &ns->base;
809 return &profile->base;
810}
811
812/**
813 * __lookup_profile - lookup the profile matching @hname
814 * @base: base list to start looking up profile name from (NOT NULL)
815 * @hname: hierarchical profile name (NOT NULL)
816 *
817 * Requires: rcu_read_lock be held
818 *
819 * Returns: unrefcounted profile pointer or NULL if not found
820 *
821 * Do a relative name lookup, recursing through profile tree.
822 */
823static struct aa_profile *__lookup_profile(struct aa_policy *base,
824 const char *hname)
825{
826 struct aa_profile *profile = NULL;
827 char *split;
828
829 for (split = strstr(hname, "//"); split;) {
830 profile = __strn_find_child(&base->profiles, hname,
831 split - hname);
832 if (!profile)
833 return NULL;
834
835 base = &profile->base;
836 hname = split + 2;
837 split = strstr(hname, "//");
838 }
839
840 profile = __find_child(&base->profiles, hname);
841
842 return profile;
843}
844
845/**
846 * aa_lookup_profile - find a profile by its full or partial name
847 * @ns: the namespace to start from (NOT NULL)
848 * @hname: name to do lookup on. Does not contain namespace prefix (NOT NULL)
849 *
850 * Returns: refcounted profile or NULL if not found
851 */
852struct aa_profile *aa_lookup_profile(struct aa_namespace *ns, const char *hname)
853{
854 struct aa_profile *profile;
855
856 rcu_read_lock();
857 do {
858 profile = __lookup_profile(&ns->base, hname);
859 } while (profile && !aa_get_profile_not0(profile));
860 rcu_read_unlock();
861
862 /* the unconfined profile is not in the regular profile list */
863 if (!profile && strcmp(hname, "unconfined") == 0)
864 profile = aa_get_newest_profile(ns->unconfined);
865
866 /* refcount released by caller */
867 return profile;
868}
869
870/**
871 * replacement_allowed - test to see if replacement is allowed
872 * @profile: profile to test if it can be replaced (MAYBE NULL)
873 * @noreplace: true if replacement shouldn't be allowed but addition is okay
874 * @info: Returns - info about why replacement failed (NOT NULL)
875 *
876 * Returns: %0 if replacement allowed else error code
877 */
878static int replacement_allowed(struct aa_profile *profile, int noreplace,
879 const char **info)
880{
881 if (profile) {
882 if (profile->flags & PFLAG_IMMUTABLE) {
883 *info = "cannot replace immutible profile";
884 return -EPERM;
885 } else if (noreplace) {
886 *info = "profile already exists";
887 return -EEXIST;
888 }
889 }
890 return 0;
891}
892
893/**
894 * aa_audit_policy - Do auditing of policy changes
895 * @op: policy operation being performed
896 * @gfp: memory allocation flags
897 * @name: name of profile being manipulated (NOT NULL)
898 * @info: any extra information to be audited (MAYBE NULL)
899 * @error: error code
900 *
901 * Returns: the error to be returned after audit is done
902 */
903static int audit_policy(int op, gfp_t gfp, const char *name, const char *info,
904 int error)
905{
906 struct common_audit_data sa;
907 struct apparmor_audit_data aad = {0,};
908 sa.type = LSM_AUDIT_DATA_NONE;
909 sa.aad = &aad;
910 aad.op = op;
911 aad.name = name;
912 aad.info = info;
913 aad.error = error;
914
915 return aa_audit(AUDIT_APPARMOR_STATUS, __aa_current_profile(), gfp,
916 &sa, NULL);
917}
918
919/**
920 * aa_may_manage_policy - can the current task manage policy
921 * @op: the policy manipulation operation being done
922 *
923 * Returns: true if the task is allowed to manipulate policy
924 */
925bool aa_may_manage_policy(int op)
926{
927 /* check if loading policy is locked out */
928 if (aa_g_lock_policy) {
929 audit_policy(op, GFP_KERNEL, NULL, "policy_locked", -EACCES);
930 return 0;
931 }
932
933 if (!capable(CAP_MAC_ADMIN)) {
934 audit_policy(op, GFP_KERNEL, NULL, "not policy admin", -EACCES);
935 return 0;
936 }
937
938 return 1;
939}
940
941static struct aa_profile *__list_lookup_parent(struct list_head *lh,
942 struct aa_profile *profile)
943{
944 const char *base = hname_tail(profile->base.hname);
945 long len = base - profile->base.hname;
946 struct aa_load_ent *ent;
947
948 /* parent won't have trailing // so remove from len */
949 if (len <= 2)
950 return NULL;
951 len -= 2;
952
953 list_for_each_entry(ent, lh, list) {
954 if (ent->new == profile)
955 continue;
956 if (strncmp(ent->new->base.hname, profile->base.hname, len) ==
957 0 && ent->new->base.hname[len] == 0)
958 return ent->new;
959 }
960
961 return NULL;
962}
963
964/**
965 * __replace_profile - replace @old with @new on a list
966 * @old: profile to be replaced (NOT NULL)
967 * @new: profile to replace @old with (NOT NULL)
968 * @share_replacedby: transfer @old->replacedby to @new
969 *
970 * Will duplicate and refcount elements that @new inherits from @old
971 * and will inherit @old children.
972 *
973 * refcount @new for list, put @old list refcount
974 *
975 * Requires: namespace list lock be held, or list not be shared
976 */
977static void __replace_profile(struct aa_profile *old, struct aa_profile *new,
978 bool share_replacedby)
979{
980 struct aa_profile *child, *tmp;
981
982 if (!list_empty(&old->base.profiles)) {
983 LIST_HEAD(lh);
984 list_splice_init_rcu(&old->base.profiles, &lh, synchronize_rcu);
985
986 list_for_each_entry_safe(child, tmp, &lh, base.list) {
987 struct aa_profile *p;
988
989 list_del_init(&child->base.list);
990 p = __find_child(&new->base.profiles, child->base.name);
991 if (p) {
992 /* @p replaces @child */
993 __replace_profile(child, p, share_replacedby);
994 continue;
995 }
996
997 /* inherit @child and its children */
998 /* TODO: update hname of inherited children */
999 /* list refcount transferred to @new */
1000 p = aa_deref_parent(child);
1001 rcu_assign_pointer(child->parent, aa_get_profile(new));
1002 list_add_rcu(&child->base.list, &new->base.profiles);
1003 aa_put_profile(p);
1004 }
1005 }
1006
1007 if (!rcu_access_pointer(new->parent)) {
1008 struct aa_profile *parent = aa_deref_parent(old);
1009 rcu_assign_pointer(new->parent, aa_get_profile(parent));
1010 }
1011 __aa_update_replacedby(old, new);
1012 if (share_replacedby) {
1013 aa_put_replacedby(new->replacedby);
1014 new->replacedby = aa_get_replacedby(old->replacedby);
1015 } else if (!rcu_access_pointer(new->replacedby->profile))
1016 /* aafs interface uses replacedby */
1017 rcu_assign_pointer(new->replacedby->profile,
1018 aa_get_profile(new));
1019 __aa_fs_profile_migrate_dents(old, new);
1020
1021 if (list_empty(&new->base.list)) {
1022 /* new is not on a list already */
1023 list_replace_rcu(&old->base.list, &new->base.list);
1024 aa_get_profile(new);
1025 aa_put_profile(old);
1026 } else
1027 __list_remove_profile(old);
1028}
1029
1030/**
1031 * __lookup_replace - lookup replacement information for a profile
1032 * @ns - namespace the lookup occurs in
1033 * @hname - name of profile to lookup
1034 * @noreplace - true if not replacing an existing profile
1035 * @p - Returns: profile to be replaced
1036 * @info - Returns: info string on why lookup failed
1037 *
1038 * Returns: profile to replace (no ref) on success else ptr error
1039 */
1040static int __lookup_replace(struct aa_namespace *ns, const char *hname,
1041 bool noreplace, struct aa_profile **p,
1042 const char **info)
1043{
1044 *p = aa_get_profile(__lookup_profile(&ns->base, hname));
1045 if (*p) {
1046 int error = replacement_allowed(*p, noreplace, info);
1047 if (error) {
1048 *info = "profile can not be replaced";
1049 return error;
1050 }
1051 }
1052
1053 return 0;
1054}
1055
1056/**
1057 * aa_replace_profiles - replace profile(s) on the profile list
1058 * @udata: serialized data stream (NOT NULL)
1059 * @size: size of the serialized data stream
1060 * @noreplace: true if only doing addition, no replacement allowed
1061 *
1062 * unpack and replace a profile on the profile list and uses of that profile
1063 * by any aa_task_cxt. If the profile does not exist on the profile list
1064 * it is added.
1065 *
1066 * Returns: size of data consumed else error code on failure.
1067 */
1068ssize_t aa_replace_profiles(void *udata, size_t size, bool noreplace)
1069{
1070 const char *ns_name, *name = NULL, *info = NULL;
1071 struct aa_namespace *ns = NULL;
1072 struct aa_load_ent *ent, *tmp;
1073 int op = OP_PROF_REPL;
1074 ssize_t error;
1075 LIST_HEAD(lh);
1076
1077 /* released below */
1078 error = aa_unpack(udata, size, &lh, &ns_name);
1079 if (error)
1080 goto out;
1081
1082 /* released below */
1083 ns = aa_prepare_namespace(ns_name);
1084 if (!ns) {
1085 info = "failed to prepare namespace";
1086 error = -ENOMEM;
1087 name = ns_name;
1088 goto fail;
1089 }
1090
1091 mutex_lock(&ns->lock);
1092 /* setup parent and ns info */
1093 list_for_each_entry(ent, &lh, list) {
1094 struct aa_policy *policy;
1095
1096 name = ent->new->base.hname;
1097 error = __lookup_replace(ns, ent->new->base.hname, noreplace,
1098 &ent->old, &info);
1099 if (error)
1100 goto fail_lock;
1101
1102 if (ent->new->rename) {
1103 error = __lookup_replace(ns, ent->new->rename,
1104 noreplace, &ent->rename,
1105 &info);
1106 if (error)
1107 goto fail_lock;
1108 }
1109
1110 /* released when @new is freed */
1111 ent->new->ns = aa_get_namespace(ns);
1112
1113 if (ent->old || ent->rename)
1114 continue;
1115
1116 /* no ref on policy only use inside lock */
1117 policy = __lookup_parent(ns, ent->new->base.hname);
1118 if (!policy) {
1119 struct aa_profile *p;
1120 p = __list_lookup_parent(&lh, ent->new);
1121 if (!p) {
1122 error = -ENOENT;
1123 info = "parent does not exist";
1124 name = ent->new->base.hname;
1125 goto fail_lock;
1126 }
1127 rcu_assign_pointer(ent->new->parent, aa_get_profile(p));
1128 } else if (policy != &ns->base) {
1129 /* released on profile replacement or free_profile */
1130 struct aa_profile *p = (struct aa_profile *) policy;
1131 rcu_assign_pointer(ent->new->parent, aa_get_profile(p));
1132 }
1133 }
1134
1135 /* create new fs entries for introspection if needed */
1136 list_for_each_entry(ent, &lh, list) {
1137 if (ent->old) {
1138 /* inherit old interface files */
1139
1140 /* if (ent->rename)
1141 TODO: support rename */
1142 /* } else if (ent->rename) {
1143 TODO: support rename */
1144 } else {
1145 struct dentry *parent;
1146 if (rcu_access_pointer(ent->new->parent)) {
1147 struct aa_profile *p;
1148 p = aa_deref_parent(ent->new);
1149 parent = prof_child_dir(p);
1150 } else
1151 parent = ns_subprofs_dir(ent->new->ns);
1152 error = __aa_fs_profile_mkdir(ent->new, parent);
1153 }
1154
1155 if (error) {
1156 info = "failed to create ";
1157 goto fail_lock;
1158 }
1159 }
1160
1161 /* Done with checks that may fail - do actual replacement */
1162 list_for_each_entry_safe(ent, tmp, &lh, list) {
1163 list_del_init(&ent->list);
1164 op = (!ent->old && !ent->rename) ? OP_PROF_LOAD : OP_PROF_REPL;
1165
1166 audit_policy(op, GFP_ATOMIC, ent->new->base.name, NULL, error);
1167
1168 if (ent->old) {
1169 __replace_profile(ent->old, ent->new, 1);
1170 if (ent->rename) {
1171 /* aafs interface uses replacedby */
1172 struct aa_replacedby *r = ent->new->replacedby;
1173 rcu_assign_pointer(r->profile,
1174 aa_get_profile(ent->new));
1175 __replace_profile(ent->rename, ent->new, 0);
1176 }
1177 } else if (ent->rename) {
1178 /* aafs interface uses replacedby */
1179 rcu_assign_pointer(ent->new->replacedby->profile,
1180 aa_get_profile(ent->new));
1181 __replace_profile(ent->rename, ent->new, 0);
1182 } else if (ent->new->parent) {
1183 struct aa_profile *parent, *newest;
1184 parent = aa_deref_parent(ent->new);
1185 newest = aa_get_newest_profile(parent);
1186
1187 /* parent replaced in this atomic set? */
1188 if (newest != parent) {
1189 aa_get_profile(newest);
1190 aa_put_profile(parent);
1191 rcu_assign_pointer(ent->new->parent, newest);
1192 } else
1193 aa_put_profile(newest);
1194 /* aafs interface uses replacedby */
1195 rcu_assign_pointer(ent->new->replacedby->profile,
1196 aa_get_profile(ent->new));
1197 __list_add_profile(&parent->base.profiles, ent->new);
1198 } else {
1199 /* aafs interface uses replacedby */
1200 rcu_assign_pointer(ent->new->replacedby->profile,
1201 aa_get_profile(ent->new));
1202 __list_add_profile(&ns->base.profiles, ent->new);
1203 }
1204 aa_load_ent_free(ent);
1205 }
1206 mutex_unlock(&ns->lock);
1207
1208out:
1209 aa_put_namespace(ns);
1210
1211 if (error)
1212 return error;
1213 return size;
1214
1215fail_lock:
1216 mutex_unlock(&ns->lock);
1217fail:
1218 error = audit_policy(op, GFP_KERNEL, name, info, error);
1219
1220 list_for_each_entry_safe(ent, tmp, &lh, list) {
1221 list_del_init(&ent->list);
1222 aa_load_ent_free(ent);
1223 }
1224
1225 goto out;
1226}
1227
1228/**
1229 * aa_remove_profiles - remove profile(s) from the system
1230 * @fqname: name of the profile or namespace to remove (NOT NULL)
1231 * @size: size of the name
1232 *
1233 * Remove a profile or sub namespace from the current namespace, so that
1234 * they can not be found anymore and mark them as replaced by unconfined
1235 *
1236 * NOTE: removing confinement does not restore rlimits to preconfinemnet values
1237 *
1238 * Returns: size of data consume else error code if fails
1239 */
1240ssize_t aa_remove_profiles(char *fqname, size_t size)
1241{
1242 struct aa_namespace *root, *ns = NULL;
1243 struct aa_profile *profile = NULL;
1244 const char *name = fqname, *info = NULL;
1245 ssize_t error = 0;
1246
1247 if (*fqname == 0) {
1248 info = "no profile specified";
1249 error = -ENOENT;
1250 goto fail;
1251 }
1252
1253 root = aa_current_profile()->ns;
1254
1255 if (fqname[0] == ':') {
1256 char *ns_name;
1257 name = aa_split_fqname(fqname, &ns_name);
1258 /* released below */
1259 ns = aa_find_namespace(root, ns_name);
1260 if (!ns) {
1261 info = "namespace does not exist";
1262 error = -ENOENT;
1263 goto fail;
1264 }
1265 } else
1266 /* released below */
1267 ns = aa_get_namespace(root);
1268
1269 if (!name) {
1270 /* remove namespace - can only happen if fqname[0] == ':' */
1271 mutex_lock(&ns->parent->lock);
1272 __remove_namespace(ns);
1273 mutex_unlock(&ns->parent->lock);
1274 } else {
1275 /* remove profile */
1276 mutex_lock(&ns->lock);
1277 profile = aa_get_profile(__lookup_profile(&ns->base, name));
1278 if (!profile) {
1279 error = -ENOENT;
1280 info = "profile does not exist";
1281 goto fail_ns_lock;
1282 }
1283 name = profile->base.hname;
1284 __remove_profile(profile);
1285 mutex_unlock(&ns->lock);
1286 }
1287
1288 /* don't fail removal if audit fails */
1289 (void) audit_policy(OP_PROF_RM, GFP_KERNEL, name, info, error);
1290 aa_put_namespace(ns);
1291 aa_put_profile(profile);
1292 return size;
1293
1294fail_ns_lock:
1295 mutex_unlock(&ns->lock);
1296 aa_put_namespace(ns);
1297
1298fail:
1299 (void) audit_policy(OP_PROF_RM, GFP_KERNEL, name, info, error);
1300 return error;
1301}
1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * AppArmor security module
4 *
5 * This file contains AppArmor policy manipulation functions
6 *
7 * Copyright (C) 1998-2008 Novell/SUSE
8 * Copyright 2009-2010 Canonical Ltd.
9 *
10 * AppArmor policy is based around profiles, which contain the rules a
11 * task is confined by. Every task in the system has a profile attached
12 * to it determined either by matching "unconfined" tasks against the
13 * visible set of profiles or by following a profiles attachment rules.
14 *
15 * Each profile exists in a profile namespace which is a container of
16 * visible profiles. Each namespace contains a special "unconfined" profile,
17 * which doesn't enforce any confinement on a task beyond DAC.
18 *
19 * Namespace and profile names can be written together in either
20 * of two syntaxes.
21 * :namespace:profile - used by kernel interfaces for easy detection
22 * namespace://profile - used by policy
23 *
24 * Profile names can not start with : or @ or ^ and may not contain \0
25 *
26 * Reserved profile names
27 * unconfined - special automatically generated unconfined profile
28 * inherit - special name to indicate profile inheritance
29 * null-XXXX-YYYY - special automatically generated learning profiles
30 *
31 * Namespace names may not start with / or @ and may not contain \0 or :
32 * Reserved namespace names
33 * user-XXXX - user defined profiles
34 *
35 * a // in a profile or namespace name indicates a hierarchical name with the
36 * name before the // being the parent and the name after the child.
37 *
38 * Profile and namespace hierarchies serve two different but similar purposes.
39 * The namespace contains the set of visible profiles that are considered
40 * for attachment. The hierarchy of namespaces allows for virtualizing
41 * the namespace so that for example a chroot can have its own set of profiles
42 * which may define some local user namespaces.
43 * The profile hierarchy severs two distinct purposes,
44 * - it allows for sub profiles or hats, which allows an application to run
45 * subprograms under its own profile with different restriction than it
46 * self, and not have it use the system profile.
47 * eg. if a mail program starts an editor, the policy might make the
48 * restrictions tighter on the editor tighter than the mail program,
49 * and definitely different than general editor restrictions
50 * - it allows for binary hierarchy of profiles, so that execution history
51 * is preserved. This feature isn't exploited by AppArmor reference policy
52 * but is allowed. NOTE: this is currently suboptimal because profile
53 * aliasing is not currently implemented so that a profile for each
54 * level must be defined.
55 * eg. /bin/bash///bin/ls as a name would indicate /bin/ls was started
56 * from /bin/bash
57 *
58 * A profile or namespace name that can contain one or more // separators
59 * is referred to as an hname (hierarchical).
60 * eg. /bin/bash//bin/ls
61 *
62 * An fqname is a name that may contain both namespace and profile hnames.
63 * eg. :ns:/bin/bash//bin/ls
64 *
65 * NOTES:
66 * - locking of profile lists is currently fairly coarse. All profile
67 * lists within a namespace use the namespace lock.
68 * FIXME: move profile lists to using rcu_lists
69 */
70
71#include <linux/slab.h>
72#include <linux/spinlock.h>
73#include <linux/string.h>
74#include <linux/cred.h>
75#include <linux/rculist.h>
76#include <linux/user_namespace.h>
77
78#include "include/apparmor.h"
79#include "include/capability.h"
80#include "include/cred.h"
81#include "include/file.h"
82#include "include/ipc.h"
83#include "include/match.h"
84#include "include/path.h"
85#include "include/policy.h"
86#include "include/policy_ns.h"
87#include "include/policy_unpack.h"
88#include "include/resource.h"
89
90int unprivileged_userns_apparmor_policy = 1;
91
92const char *const aa_profile_mode_names[] = {
93 "enforce",
94 "complain",
95 "kill",
96 "unconfined",
97 "user",
98};
99
100
101/**
102 * __add_profile - add a profiles to list and label tree
103 * @list: list to add it to (NOT NULL)
104 * @profile: the profile to add (NOT NULL)
105 *
106 * refcount @profile, should be put by __list_remove_profile
107 *
108 * Requires: namespace lock be held, or list not be shared
109 */
110static void __add_profile(struct list_head *list, struct aa_profile *profile)
111{
112 struct aa_label *l;
113
114 AA_BUG(!list);
115 AA_BUG(!profile);
116 AA_BUG(!profile->ns);
117 AA_BUG(!mutex_is_locked(&profile->ns->lock));
118
119 list_add_rcu(&profile->base.list, list);
120 /* get list reference */
121 aa_get_profile(profile);
122 l = aa_label_insert(&profile->ns->labels, &profile->label);
123 AA_BUG(l != &profile->label);
124 aa_put_label(l);
125}
126
127/**
128 * __list_remove_profile - remove a profile from the list it is on
129 * @profile: the profile to remove (NOT NULL)
130 *
131 * remove a profile from the list, warning generally removal should
132 * be done with __replace_profile as most profile removals are
133 * replacements to the unconfined profile.
134 *
135 * put @profile list refcount
136 *
137 * Requires: namespace lock be held, or list not have been live
138 */
139static void __list_remove_profile(struct aa_profile *profile)
140{
141 AA_BUG(!profile);
142 AA_BUG(!profile->ns);
143 AA_BUG(!mutex_is_locked(&profile->ns->lock));
144
145 list_del_rcu(&profile->base.list);
146 aa_put_profile(profile);
147}
148
149/**
150 * __remove_profile - remove old profile, and children
151 * @profile: profile to be replaced (NOT NULL)
152 *
153 * Requires: namespace list lock be held, or list not be shared
154 */
155static void __remove_profile(struct aa_profile *profile)
156{
157 AA_BUG(!profile);
158 AA_BUG(!profile->ns);
159 AA_BUG(!mutex_is_locked(&profile->ns->lock));
160
161 /* release any children lists first */
162 __aa_profile_list_release(&profile->base.profiles);
163 /* released by free_profile */
164 aa_label_remove(&profile->label);
165 __aafs_profile_rmdir(profile);
166 __list_remove_profile(profile);
167}
168
169/**
170 * __aa_profile_list_release - remove all profiles on the list and put refs
171 * @head: list of profiles (NOT NULL)
172 *
173 * Requires: namespace lock be held
174 */
175void __aa_profile_list_release(struct list_head *head)
176{
177 struct aa_profile *profile, *tmp;
178 list_for_each_entry_safe(profile, tmp, head, base.list)
179 __remove_profile(profile);
180}
181
182/**
183 * aa_free_data - free a data blob
184 * @ptr: data to free
185 * @arg: unused
186 */
187static void aa_free_data(void *ptr, void *arg)
188{
189 struct aa_data *data = ptr;
190
191 kfree_sensitive(data->data);
192 kfree_sensitive(data->key);
193 kfree_sensitive(data);
194}
195
196static void free_attachment(struct aa_attachment *attach)
197{
198 int i;
199
200 for (i = 0; i < attach->xattr_count; i++)
201 kfree_sensitive(attach->xattrs[i]);
202 kfree_sensitive(attach->xattrs);
203 aa_destroy_policydb(&attach->xmatch);
204}
205
206static void free_ruleset(struct aa_ruleset *rules)
207{
208 int i;
209
210 aa_destroy_policydb(&rules->file);
211 aa_destroy_policydb(&rules->policy);
212 aa_free_cap_rules(&rules->caps);
213 aa_free_rlimit_rules(&rules->rlimits);
214
215 for (i = 0; i < rules->secmark_count; i++)
216 kfree_sensitive(rules->secmark[i].label);
217 kfree_sensitive(rules->secmark);
218 kfree_sensitive(rules);
219}
220
221struct aa_ruleset *aa_alloc_ruleset(gfp_t gfp)
222{
223 struct aa_ruleset *rules;
224
225 rules = kzalloc(sizeof(*rules), gfp);
226 if (rules)
227 INIT_LIST_HEAD(&rules->list);
228
229 return rules;
230}
231
232/**
233 * aa_free_profile - free a profile
234 * @profile: the profile to free (MAYBE NULL)
235 *
236 * Free a profile, its hats and null_profile. All references to the profile,
237 * its hats and null_profile must have been put.
238 *
239 * If the profile was referenced from a task context, free_profile() will
240 * be called from an rcu callback routine, so we must not sleep here.
241 */
242void aa_free_profile(struct aa_profile *profile)
243{
244 struct aa_ruleset *rule, *tmp;
245 struct rhashtable *rht;
246
247 AA_DEBUG("%s(%p)\n", __func__, profile);
248
249 if (!profile)
250 return;
251
252 /* free children profiles */
253 aa_policy_destroy(&profile->base);
254 aa_put_profile(rcu_access_pointer(profile->parent));
255
256 aa_put_ns(profile->ns);
257 kfree_sensitive(profile->rename);
258
259 free_attachment(&profile->attach);
260
261 /*
262 * at this point there are no tasks that can have a reference
263 * to rules
264 */
265 list_for_each_entry_safe(rule, tmp, &profile->rules, list) {
266 list_del_init(&rule->list);
267 free_ruleset(rule);
268 }
269 kfree_sensitive(profile->dirname);
270
271 if (profile->data) {
272 rht = profile->data;
273 profile->data = NULL;
274 rhashtable_free_and_destroy(rht, aa_free_data, NULL);
275 kfree_sensitive(rht);
276 }
277
278 kfree_sensitive(profile->hash);
279 aa_put_loaddata(profile->rawdata);
280 aa_label_destroy(&profile->label);
281
282 kfree_sensitive(profile);
283}
284
285/**
286 * aa_alloc_profile - allocate, initialize and return a new profile
287 * @hname: name of the profile (NOT NULL)
288 * @gfp: allocation type
289 *
290 * Returns: refcount profile or NULL on failure
291 */
292struct aa_profile *aa_alloc_profile(const char *hname, struct aa_proxy *proxy,
293 gfp_t gfp)
294{
295 struct aa_profile *profile;
296 struct aa_ruleset *rules;
297
298 /* freed by free_profile - usually through aa_put_profile */
299 profile = kzalloc(struct_size(profile, label.vec, 2), gfp);
300 if (!profile)
301 return NULL;
302
303 if (!aa_policy_init(&profile->base, NULL, hname, gfp))
304 goto fail;
305 if (!aa_label_init(&profile->label, 1, gfp))
306 goto fail;
307
308 INIT_LIST_HEAD(&profile->rules);
309
310 /* allocate the first ruleset, but leave it empty */
311 rules = aa_alloc_ruleset(gfp);
312 if (!rules)
313 goto fail;
314 list_add(&rules->list, &profile->rules);
315
316 /* update being set needed by fs interface */
317 if (!proxy) {
318 proxy = aa_alloc_proxy(&profile->label, gfp);
319 if (!proxy)
320 goto fail;
321 } else
322 aa_get_proxy(proxy);
323 profile->label.proxy = proxy;
324
325 profile->label.hname = profile->base.hname;
326 profile->label.flags |= FLAG_PROFILE;
327 profile->label.vec[0] = profile;
328
329 /* refcount released by caller */
330 return profile;
331
332fail:
333 aa_free_profile(profile);
334
335 return NULL;
336}
337
338/* TODO: profile accounting - setup in remove */
339
340/**
341 * __strn_find_child - find a profile on @head list using substring of @name
342 * @head: list to search (NOT NULL)
343 * @name: name of profile (NOT NULL)
344 * @len: length of @name substring to match
345 *
346 * Requires: rcu_read_lock be held
347 *
348 * Returns: unrefcounted profile ptr, or NULL if not found
349 */
350static struct aa_profile *__strn_find_child(struct list_head *head,
351 const char *name, int len)
352{
353 return (struct aa_profile *)__policy_strn_find(head, name, len);
354}
355
356/**
357 * __find_child - find a profile on @head list with a name matching @name
358 * @head: list to search (NOT NULL)
359 * @name: name of profile (NOT NULL)
360 *
361 * Requires: rcu_read_lock be held
362 *
363 * Returns: unrefcounted profile ptr, or NULL if not found
364 */
365static struct aa_profile *__find_child(struct list_head *head, const char *name)
366{
367 return __strn_find_child(head, name, strlen(name));
368}
369
370/**
371 * aa_find_child - find a profile by @name in @parent
372 * @parent: profile to search (NOT NULL)
373 * @name: profile name to search for (NOT NULL)
374 *
375 * Returns: a refcounted profile or NULL if not found
376 */
377struct aa_profile *aa_find_child(struct aa_profile *parent, const char *name)
378{
379 struct aa_profile *profile;
380
381 rcu_read_lock();
382 do {
383 profile = __find_child(&parent->base.profiles, name);
384 } while (profile && !aa_get_profile_not0(profile));
385 rcu_read_unlock();
386
387 /* refcount released by caller */
388 return profile;
389}
390
391/**
392 * __lookup_parent - lookup the parent of a profile of name @hname
393 * @ns: namespace to lookup profile in (NOT NULL)
394 * @hname: hierarchical profile name to find parent of (NOT NULL)
395 *
396 * Lookups up the parent of a fully qualified profile name, the profile
397 * that matches hname does not need to exist, in general this
398 * is used to load a new profile.
399 *
400 * Requires: rcu_read_lock be held
401 *
402 * Returns: unrefcounted policy or NULL if not found
403 */
404static struct aa_policy *__lookup_parent(struct aa_ns *ns,
405 const char *hname)
406{
407 struct aa_policy *policy;
408 struct aa_profile *profile = NULL;
409 char *split;
410
411 policy = &ns->base;
412
413 for (split = strstr(hname, "//"); split;) {
414 profile = __strn_find_child(&policy->profiles, hname,
415 split - hname);
416 if (!profile)
417 return NULL;
418 policy = &profile->base;
419 hname = split + 2;
420 split = strstr(hname, "//");
421 }
422 if (!profile)
423 return &ns->base;
424 return &profile->base;
425}
426
427/**
428 * __create_missing_ancestors - create place holders for missing ancestores
429 * @ns: namespace to lookup profile in (NOT NULL)
430 * @hname: hierarchical profile name to find parent of (NOT NULL)
431 * @gfp: type of allocation.
432 *
433 * Returns: NULL on error, parent profile on success
434 *
435 * Requires: ns mutex lock held
436 *
437 * Returns: unrefcounted parent policy or NULL if error creating
438 * place holder profiles.
439 */
440static struct aa_policy *__create_missing_ancestors(struct aa_ns *ns,
441 const char *hname,
442 gfp_t gfp)
443{
444 struct aa_policy *policy;
445 struct aa_profile *parent, *profile = NULL;
446 char *split;
447
448 AA_BUG(!ns);
449 AA_BUG(!hname);
450
451 policy = &ns->base;
452
453 for (split = strstr(hname, "//"); split;) {
454 parent = profile;
455 profile = __strn_find_child(&policy->profiles, hname,
456 split - hname);
457 if (!profile) {
458 const char *name = kstrndup(hname, split - hname,
459 gfp);
460 if (!name)
461 return NULL;
462 profile = aa_alloc_null(parent, name, gfp);
463 kfree(name);
464 if (!profile)
465 return NULL;
466 if (!parent)
467 profile->ns = aa_get_ns(ns);
468 }
469 policy = &profile->base;
470 hname = split + 2;
471 split = strstr(hname, "//");
472 }
473 if (!profile)
474 return &ns->base;
475 return &profile->base;
476}
477
478/**
479 * __lookupn_profile - lookup the profile matching @hname
480 * @base: base list to start looking up profile name from (NOT NULL)
481 * @hname: hierarchical profile name (NOT NULL)
482 * @n: length of @hname
483 *
484 * Requires: rcu_read_lock be held
485 *
486 * Returns: unrefcounted profile pointer or NULL if not found
487 *
488 * Do a relative name lookup, recursing through profile tree.
489 */
490static struct aa_profile *__lookupn_profile(struct aa_policy *base,
491 const char *hname, size_t n)
492{
493 struct aa_profile *profile = NULL;
494 const char *split;
495
496 for (split = strnstr(hname, "//", n); split;
497 split = strnstr(hname, "//", n)) {
498 profile = __strn_find_child(&base->profiles, hname,
499 split - hname);
500 if (!profile)
501 return NULL;
502
503 base = &profile->base;
504 n -= split + 2 - hname;
505 hname = split + 2;
506 }
507
508 if (n)
509 return __strn_find_child(&base->profiles, hname, n);
510 return NULL;
511}
512
513static struct aa_profile *__lookup_profile(struct aa_policy *base,
514 const char *hname)
515{
516 return __lookupn_profile(base, hname, strlen(hname));
517}
518
519/**
520 * aa_lookupn_profile - find a profile by its full or partial name
521 * @ns: the namespace to start from (NOT NULL)
522 * @hname: name to do lookup on. Does not contain namespace prefix (NOT NULL)
523 * @n: size of @hname
524 *
525 * Returns: refcounted profile or NULL if not found
526 */
527struct aa_profile *aa_lookupn_profile(struct aa_ns *ns, const char *hname,
528 size_t n)
529{
530 struct aa_profile *profile;
531
532 rcu_read_lock();
533 do {
534 profile = __lookupn_profile(&ns->base, hname, n);
535 } while (profile && !aa_get_profile_not0(profile));
536 rcu_read_unlock();
537
538 /* the unconfined profile is not in the regular profile list */
539 if (!profile && strncmp(hname, "unconfined", n) == 0)
540 profile = aa_get_newest_profile(ns->unconfined);
541
542 /* refcount released by caller */
543 return profile;
544}
545
546struct aa_profile *aa_lookup_profile(struct aa_ns *ns, const char *hname)
547{
548 return aa_lookupn_profile(ns, hname, strlen(hname));
549}
550
551struct aa_profile *aa_fqlookupn_profile(struct aa_label *base,
552 const char *fqname, size_t n)
553{
554 struct aa_profile *profile;
555 struct aa_ns *ns;
556 const char *name, *ns_name;
557 size_t ns_len;
558
559 name = aa_splitn_fqname(fqname, n, &ns_name, &ns_len);
560 if (ns_name) {
561 ns = aa_lookupn_ns(labels_ns(base), ns_name, ns_len);
562 if (!ns)
563 return NULL;
564 } else
565 ns = aa_get_ns(labels_ns(base));
566
567 if (name)
568 profile = aa_lookupn_profile(ns, name, n - (name - fqname));
569 else if (ns)
570 /* default profile for ns, currently unconfined */
571 profile = aa_get_newest_profile(ns->unconfined);
572 else
573 profile = NULL;
574 aa_put_ns(ns);
575
576 return profile;
577}
578
579
580struct aa_profile *aa_alloc_null(struct aa_profile *parent, const char *name,
581 gfp_t gfp)
582{
583 struct aa_profile *profile;
584 struct aa_ruleset *rules;
585
586 profile = aa_alloc_profile(name, NULL, gfp);
587 if (!profile)
588 return NULL;
589
590 /* TODO: ideally we should inherit abi from parent */
591 profile->label.flags |= FLAG_NULL;
592 rules = list_first_entry(&profile->rules, typeof(*rules), list);
593 rules->file.dfa = aa_get_dfa(nulldfa);
594 rules->policy.dfa = aa_get_dfa(nulldfa);
595
596 if (parent) {
597 profile->path_flags = parent->path_flags;
598
599 /* released on free_profile */
600 rcu_assign_pointer(profile->parent, aa_get_profile(parent));
601 profile->ns = aa_get_ns(parent->ns);
602 }
603
604 return profile;
605}
606
607/**
608 * aa_new_learning_profile - create or find a null-X learning profile
609 * @parent: profile that caused this profile to be created (NOT NULL)
610 * @hat: true if the null- learning profile is a hat
611 * @base: name to base the null profile off of
612 * @gfp: type of allocation
613 *
614 * Find/Create a null- complain mode profile used in learning mode. The
615 * name of the profile is unique and follows the format of parent//null-XXX.
616 * where XXX is based on the @name or if that fails or is not supplied
617 * a unique number
618 *
619 * null profiles are added to the profile list but the list does not
620 * hold a count on them so that they are automatically released when
621 * not in use.
622 *
623 * Returns: new refcounted profile else NULL on failure
624 */
625struct aa_profile *aa_new_learning_profile(struct aa_profile *parent, bool hat,
626 const char *base, gfp_t gfp)
627{
628 struct aa_profile *p, *profile;
629 const char *bname;
630 char *name = NULL;
631
632 AA_BUG(!parent);
633
634 if (base) {
635 name = kmalloc(strlen(parent->base.hname) + 8 + strlen(base),
636 gfp);
637 if (name) {
638 sprintf(name, "%s//null-%s", parent->base.hname, base);
639 goto name;
640 }
641 /* fall through to try shorter uniq */
642 }
643
644 name = kmalloc(strlen(parent->base.hname) + 2 + 7 + 8, gfp);
645 if (!name)
646 return NULL;
647 sprintf(name, "%s//null-%x", parent->base.hname,
648 atomic_inc_return(&parent->ns->uniq_null));
649
650name:
651 /* lookup to see if this is a dup creation */
652 bname = basename(name);
653 profile = aa_find_child(parent, bname);
654 if (profile)
655 goto out;
656
657 profile = aa_alloc_null(parent, name, gfp);
658 if (!profile)
659 goto fail;
660 profile->mode = APPARMOR_COMPLAIN;
661 if (hat)
662 profile->label.flags |= FLAG_HAT;
663
664 mutex_lock_nested(&profile->ns->lock, profile->ns->level);
665 p = __find_child(&parent->base.profiles, bname);
666 if (p) {
667 aa_free_profile(profile);
668 profile = aa_get_profile(p);
669 } else {
670 __add_profile(&parent->base.profiles, profile);
671 }
672 mutex_unlock(&profile->ns->lock);
673
674 /* refcount released by caller */
675out:
676 kfree(name);
677
678 return profile;
679
680fail:
681 kfree(name);
682 aa_free_profile(profile);
683 return NULL;
684}
685
686/**
687 * replacement_allowed - test to see if replacement is allowed
688 * @profile: profile to test if it can be replaced (MAYBE NULL)
689 * @noreplace: true if replacement shouldn't be allowed but addition is okay
690 * @info: Returns - info about why replacement failed (NOT NULL)
691 *
692 * Returns: %0 if replacement allowed else error code
693 */
694static int replacement_allowed(struct aa_profile *profile, int noreplace,
695 const char **info)
696{
697 if (profile) {
698 if (profile->label.flags & FLAG_IMMUTIBLE) {
699 *info = "cannot replace immutable profile";
700 return -EPERM;
701 } else if (noreplace) {
702 *info = "profile already exists";
703 return -EEXIST;
704 }
705 }
706 return 0;
707}
708
709/* audit callback for net specific fields */
710static void audit_cb(struct audit_buffer *ab, void *va)
711{
712 struct common_audit_data *sa = va;
713
714 if (aad(sa)->iface.ns) {
715 audit_log_format(ab, " ns=");
716 audit_log_untrustedstring(ab, aad(sa)->iface.ns);
717 }
718}
719
720/**
721 * audit_policy - Do auditing of policy changes
722 * @label: label to check if it can manage policy
723 * @op: policy operation being performed
724 * @ns_name: name of namespace being manipulated
725 * @name: name of profile being manipulated (NOT NULL)
726 * @info: any extra information to be audited (MAYBE NULL)
727 * @error: error code
728 *
729 * Returns: the error to be returned after audit is done
730 */
731static int audit_policy(struct aa_label *label, const char *op,
732 const char *ns_name, const char *name,
733 const char *info, int error)
734{
735 DEFINE_AUDIT_DATA(sa, LSM_AUDIT_DATA_NONE, AA_CLASS_NONE, op);
736
737 aad(&sa)->iface.ns = ns_name;
738 aad(&sa)->name = name;
739 aad(&sa)->info = info;
740 aad(&sa)->error = error;
741 aad(&sa)->label = label;
742
743 aa_audit_msg(AUDIT_APPARMOR_STATUS, &sa, audit_cb);
744
745 return error;
746}
747
748/* don't call out to other LSMs in the stack for apparmor policy admin
749 * permissions
750 */
751static int policy_ns_capable(struct aa_label *label,
752 struct user_namespace *userns, int cap)
753{
754 int err;
755
756 /* check for MAC_ADMIN cap in cred */
757 err = cap_capable(current_cred(), userns, cap, CAP_OPT_NONE);
758 if (!err)
759 err = aa_capable(label, cap, CAP_OPT_NONE);
760
761 return err;
762}
763
764/**
765 * aa_policy_view_capable - check if viewing policy in at @ns is allowed
766 * label: label that is trying to view policy in ns
767 * ns: namespace being viewed by @label (may be NULL if @label's ns)
768 * Returns: true if viewing policy is allowed
769 *
770 * If @ns is NULL then the namespace being viewed is assumed to be the
771 * tasks current namespace.
772 */
773bool aa_policy_view_capable(struct aa_label *label, struct aa_ns *ns)
774{
775 struct user_namespace *user_ns = current_user_ns();
776 struct aa_ns *view_ns = labels_view(label);
777 bool root_in_user_ns = uid_eq(current_euid(), make_kuid(user_ns, 0)) ||
778 in_egroup_p(make_kgid(user_ns, 0));
779 bool response = false;
780 if (!ns)
781 ns = view_ns;
782
783 if (root_in_user_ns && aa_ns_visible(view_ns, ns, true) &&
784 (user_ns == &init_user_ns ||
785 (unprivileged_userns_apparmor_policy != 0 &&
786 user_ns->level == view_ns->level)))
787 response = true;
788
789 return response;
790}
791
792bool aa_policy_admin_capable(struct aa_label *label, struct aa_ns *ns)
793{
794 struct user_namespace *user_ns = current_user_ns();
795 bool capable = policy_ns_capable(label, user_ns, CAP_MAC_ADMIN) == 0;
796
797 AA_DEBUG("cap_mac_admin? %d\n", capable);
798 AA_DEBUG("policy locked? %d\n", aa_g_lock_policy);
799
800 return aa_policy_view_capable(label, ns) && capable &&
801 !aa_g_lock_policy;
802}
803
804bool aa_current_policy_view_capable(struct aa_ns *ns)
805{
806 struct aa_label *label;
807 bool res;
808
809 label = __begin_current_label_crit_section();
810 res = aa_policy_view_capable(label, ns);
811 __end_current_label_crit_section(label);
812
813 return res;
814}
815
816bool aa_current_policy_admin_capable(struct aa_ns *ns)
817{
818 struct aa_label *label;
819 bool res;
820
821 label = __begin_current_label_crit_section();
822 res = aa_policy_admin_capable(label, ns);
823 __end_current_label_crit_section(label);
824
825 return res;
826}
827
828/**
829 * aa_may_manage_policy - can the current task manage policy
830 * @label: label to check if it can manage policy
831 * @op: the policy manipulation operation being done
832 *
833 * Returns: 0 if the task is allowed to manipulate policy else error
834 */
835int aa_may_manage_policy(struct aa_label *label, struct aa_ns *ns, u32 mask)
836{
837 const char *op;
838
839 if (mask & AA_MAY_REMOVE_POLICY)
840 op = OP_PROF_RM;
841 else if (mask & AA_MAY_REPLACE_POLICY)
842 op = OP_PROF_REPL;
843 else
844 op = OP_PROF_LOAD;
845
846 /* check if loading policy is locked out */
847 if (aa_g_lock_policy)
848 return audit_policy(label, op, NULL, NULL, "policy_locked",
849 -EACCES);
850
851 if (!aa_policy_admin_capable(label, ns))
852 return audit_policy(label, op, NULL, NULL, "not policy admin",
853 -EACCES);
854
855 /* TODO: add fine grained mediation of policy loads */
856 return 0;
857}
858
859static struct aa_profile *__list_lookup_parent(struct list_head *lh,
860 struct aa_profile *profile)
861{
862 const char *base = basename(profile->base.hname);
863 long len = base - profile->base.hname;
864 struct aa_load_ent *ent;
865
866 /* parent won't have trailing // so remove from len */
867 if (len <= 2)
868 return NULL;
869 len -= 2;
870
871 list_for_each_entry(ent, lh, list) {
872 if (ent->new == profile)
873 continue;
874 if (strncmp(ent->new->base.hname, profile->base.hname, len) ==
875 0 && ent->new->base.hname[len] == 0)
876 return ent->new;
877 }
878
879 return NULL;
880}
881
882/**
883 * __replace_profile - replace @old with @new on a list
884 * @old: profile to be replaced (NOT NULL)
885 * @new: profile to replace @old with (NOT NULL)
886 * @share_proxy: transfer @old->proxy to @new
887 *
888 * Will duplicate and refcount elements that @new inherits from @old
889 * and will inherit @old children.
890 *
891 * refcount @new for list, put @old list refcount
892 *
893 * Requires: namespace list lock be held, or list not be shared
894 */
895static void __replace_profile(struct aa_profile *old, struct aa_profile *new)
896{
897 struct aa_profile *child, *tmp;
898
899 if (!list_empty(&old->base.profiles)) {
900 LIST_HEAD(lh);
901 list_splice_init_rcu(&old->base.profiles, &lh, synchronize_rcu);
902
903 list_for_each_entry_safe(child, tmp, &lh, base.list) {
904 struct aa_profile *p;
905
906 list_del_init(&child->base.list);
907 p = __find_child(&new->base.profiles, child->base.name);
908 if (p) {
909 /* @p replaces @child */
910 __replace_profile(child, p);
911 continue;
912 }
913
914 /* inherit @child and its children */
915 /* TODO: update hname of inherited children */
916 /* list refcount transferred to @new */
917 p = aa_deref_parent(child);
918 rcu_assign_pointer(child->parent, aa_get_profile(new));
919 list_add_rcu(&child->base.list, &new->base.profiles);
920 aa_put_profile(p);
921 }
922 }
923
924 if (!rcu_access_pointer(new->parent)) {
925 struct aa_profile *parent = aa_deref_parent(old);
926 rcu_assign_pointer(new->parent, aa_get_profile(parent));
927 }
928 aa_label_replace(&old->label, &new->label);
929 /* migrate dents must come after label replacement b/c update */
930 __aafs_profile_migrate_dents(old, new);
931
932 if (list_empty(&new->base.list)) {
933 /* new is not on a list already */
934 list_replace_rcu(&old->base.list, &new->base.list);
935 aa_get_profile(new);
936 aa_put_profile(old);
937 } else
938 __list_remove_profile(old);
939}
940
941/**
942 * __lookup_replace - lookup replacement information for a profile
943 * @ns - namespace the lookup occurs in
944 * @hname - name of profile to lookup
945 * @noreplace - true if not replacing an existing profile
946 * @p - Returns: profile to be replaced
947 * @info - Returns: info string on why lookup failed
948 *
949 * Returns: profile to replace (no ref) on success else ptr error
950 */
951static int __lookup_replace(struct aa_ns *ns, const char *hname,
952 bool noreplace, struct aa_profile **p,
953 const char **info)
954{
955 *p = aa_get_profile(__lookup_profile(&ns->base, hname));
956 if (*p) {
957 int error = replacement_allowed(*p, noreplace, info);
958 if (error) {
959 *info = "profile can not be replaced";
960 return error;
961 }
962 }
963
964 return 0;
965}
966
967static void share_name(struct aa_profile *old, struct aa_profile *new)
968{
969 aa_put_str(new->base.hname);
970 aa_get_str(old->base.hname);
971 new->base.hname = old->base.hname;
972 new->base.name = old->base.name;
973 new->label.hname = old->label.hname;
974}
975
976/* Update to newest version of parent after previous replacements
977 * Returns: unrefcount newest version of parent
978 */
979static struct aa_profile *update_to_newest_parent(struct aa_profile *new)
980{
981 struct aa_profile *parent, *newest;
982
983 parent = rcu_dereference_protected(new->parent,
984 mutex_is_locked(&new->ns->lock));
985 newest = aa_get_newest_profile(parent);
986
987 /* parent replaced in this atomic set? */
988 if (newest != parent) {
989 aa_put_profile(parent);
990 rcu_assign_pointer(new->parent, newest);
991 } else
992 aa_put_profile(newest);
993
994 return newest;
995}
996
997/**
998 * aa_replace_profiles - replace profile(s) on the profile list
999 * @policy_ns: namespace load is occurring on
1000 * @label: label that is attempting to load/replace policy
1001 * @mask: permission mask
1002 * @udata: serialized data stream (NOT NULL)
1003 *
1004 * unpack and replace a profile on the profile list and uses of that profile
1005 * by any task creds via invalidating the old version of the profile, which
1006 * tasks will notice to update their own cred. If the profile does not exist
1007 * on the profile list it is added.
1008 *
1009 * Returns: size of data consumed else error code on failure.
1010 */
1011ssize_t aa_replace_profiles(struct aa_ns *policy_ns, struct aa_label *label,
1012 u32 mask, struct aa_loaddata *udata)
1013{
1014 const char *ns_name = NULL, *info = NULL;
1015 struct aa_ns *ns = NULL;
1016 struct aa_load_ent *ent, *tmp;
1017 struct aa_loaddata *rawdata_ent;
1018 const char *op;
1019 ssize_t count, error;
1020 LIST_HEAD(lh);
1021
1022 op = mask & AA_MAY_REPLACE_POLICY ? OP_PROF_REPL : OP_PROF_LOAD;
1023 aa_get_loaddata(udata);
1024 /* released below */
1025 error = aa_unpack(udata, &lh, &ns_name);
1026 if (error)
1027 goto out;
1028
1029 /* ensure that profiles are all for the same ns
1030 * TODO: update locking to remove this constaint. All profiles in
1031 * the load set must succeed as a set or the load will
1032 * fail. Sort ent list and take ns locks in hierarchy order
1033 */
1034 count = 0;
1035 list_for_each_entry(ent, &lh, list) {
1036 if (ns_name) {
1037 if (ent->ns_name &&
1038 strcmp(ent->ns_name, ns_name) != 0) {
1039 info = "policy load has mixed namespaces";
1040 error = -EACCES;
1041 goto fail;
1042 }
1043 } else if (ent->ns_name) {
1044 if (count) {
1045 info = "policy load has mixed namespaces";
1046 error = -EACCES;
1047 goto fail;
1048 }
1049 ns_name = ent->ns_name;
1050 } else
1051 count++;
1052 }
1053 if (ns_name) {
1054 ns = aa_prepare_ns(policy_ns ? policy_ns : labels_ns(label),
1055 ns_name);
1056 if (IS_ERR(ns)) {
1057 op = OP_PROF_LOAD;
1058 info = "failed to prepare namespace";
1059 error = PTR_ERR(ns);
1060 ns = NULL;
1061 ent = NULL;
1062 goto fail;
1063 }
1064 } else
1065 ns = aa_get_ns(policy_ns ? policy_ns : labels_ns(label));
1066
1067 mutex_lock_nested(&ns->lock, ns->level);
1068 /* check for duplicate rawdata blobs: space and file dedup */
1069 if (!list_empty(&ns->rawdata_list)) {
1070 list_for_each_entry(rawdata_ent, &ns->rawdata_list, list) {
1071 if (aa_rawdata_eq(rawdata_ent, udata)) {
1072 struct aa_loaddata *tmp;
1073
1074 tmp = __aa_get_loaddata(rawdata_ent);
1075 /* check we didn't fail the race */
1076 if (tmp) {
1077 aa_put_loaddata(udata);
1078 udata = tmp;
1079 break;
1080 }
1081 }
1082 }
1083 }
1084 /* setup parent and ns info */
1085 list_for_each_entry(ent, &lh, list) {
1086 struct aa_policy *policy;
1087 struct aa_profile *p;
1088
1089 if (aa_g_export_binary)
1090 ent->new->rawdata = aa_get_loaddata(udata);
1091 error = __lookup_replace(ns, ent->new->base.hname,
1092 !(mask & AA_MAY_REPLACE_POLICY),
1093 &ent->old, &info);
1094 if (error)
1095 goto fail_lock;
1096
1097 if (ent->new->rename) {
1098 error = __lookup_replace(ns, ent->new->rename,
1099 !(mask & AA_MAY_REPLACE_POLICY),
1100 &ent->rename, &info);
1101 if (error)
1102 goto fail_lock;
1103 }
1104
1105 /* released when @new is freed */
1106 ent->new->ns = aa_get_ns(ns);
1107
1108 if (ent->old || ent->rename)
1109 continue;
1110
1111 /* no ref on policy only use inside lock */
1112 p = NULL;
1113 policy = __lookup_parent(ns, ent->new->base.hname);
1114 if (!policy) {
1115 /* first check for parent in the load set */
1116 p = __list_lookup_parent(&lh, ent->new);
1117 if (!p) {
1118 /*
1119 * fill in missing parent with null
1120 * profile that doesn't have
1121 * permissions. This allows for
1122 * individual profile loading where
1123 * the child is loaded before the
1124 * parent, and outside of the current
1125 * atomic set. This unfortunately can
1126 * happen with some userspaces. The
1127 * null profile will be replaced once
1128 * the parent is loaded.
1129 */
1130 policy = __create_missing_ancestors(ns,
1131 ent->new->base.hname,
1132 GFP_KERNEL);
1133 if (!policy) {
1134 error = -ENOENT;
1135 info = "parent does not exist";
1136 goto fail_lock;
1137 }
1138 }
1139 }
1140 if (!p && policy != &ns->base)
1141 /* released on profile replacement or free_profile */
1142 p = (struct aa_profile *) policy;
1143 rcu_assign_pointer(ent->new->parent, aa_get_profile(p));
1144 }
1145
1146 /* create new fs entries for introspection if needed */
1147 if (!udata->dents[AAFS_LOADDATA_DIR] && aa_g_export_binary) {
1148 error = __aa_fs_create_rawdata(ns, udata);
1149 if (error) {
1150 info = "failed to create raw_data dir and files";
1151 ent = NULL;
1152 goto fail_lock;
1153 }
1154 }
1155 list_for_each_entry(ent, &lh, list) {
1156 if (!ent->old) {
1157 struct dentry *parent;
1158 if (rcu_access_pointer(ent->new->parent)) {
1159 struct aa_profile *p;
1160 p = aa_deref_parent(ent->new);
1161 parent = prof_child_dir(p);
1162 } else
1163 parent = ns_subprofs_dir(ent->new->ns);
1164 error = __aafs_profile_mkdir(ent->new, parent);
1165 }
1166
1167 if (error) {
1168 info = "failed to create";
1169 goto fail_lock;
1170 }
1171 }
1172
1173 /* Done with checks that may fail - do actual replacement */
1174 __aa_bump_ns_revision(ns);
1175 if (aa_g_export_binary)
1176 __aa_loaddata_update(udata, ns->revision);
1177 list_for_each_entry_safe(ent, tmp, &lh, list) {
1178 list_del_init(&ent->list);
1179 op = (!ent->old && !ent->rename) ? OP_PROF_LOAD : OP_PROF_REPL;
1180
1181 if (ent->old && ent->old->rawdata == ent->new->rawdata &&
1182 ent->new->rawdata) {
1183 /* dedup actual profile replacement */
1184 audit_policy(label, op, ns_name, ent->new->base.hname,
1185 "same as current profile, skipping",
1186 error);
1187 /* break refcount cycle with proxy. */
1188 aa_put_proxy(ent->new->label.proxy);
1189 ent->new->label.proxy = NULL;
1190 goto skip;
1191 }
1192
1193 /*
1194 * TODO: finer dedup based on profile range in data. Load set
1195 * can differ but profile may remain unchanged
1196 */
1197 audit_policy(label, op, ns_name, ent->new->base.hname, NULL,
1198 error);
1199
1200 if (ent->old) {
1201 share_name(ent->old, ent->new);
1202 __replace_profile(ent->old, ent->new);
1203 } else {
1204 struct list_head *lh;
1205
1206 if (rcu_access_pointer(ent->new->parent)) {
1207 struct aa_profile *parent;
1208
1209 parent = update_to_newest_parent(ent->new);
1210 lh = &parent->base.profiles;
1211 } else
1212 lh = &ns->base.profiles;
1213 __add_profile(lh, ent->new);
1214 }
1215 skip:
1216 aa_load_ent_free(ent);
1217 }
1218 __aa_labelset_update_subtree(ns);
1219 mutex_unlock(&ns->lock);
1220
1221out:
1222 aa_put_ns(ns);
1223 aa_put_loaddata(udata);
1224 kfree(ns_name);
1225
1226 if (error)
1227 return error;
1228 return udata->size;
1229
1230fail_lock:
1231 mutex_unlock(&ns->lock);
1232
1233 /* audit cause of failure */
1234 op = (ent && !ent->old) ? OP_PROF_LOAD : OP_PROF_REPL;
1235fail:
1236 audit_policy(label, op, ns_name, ent ? ent->new->base.hname : NULL,
1237 info, error);
1238 /* audit status that rest of profiles in the atomic set failed too */
1239 info = "valid profile in failed atomic policy load";
1240 list_for_each_entry(tmp, &lh, list) {
1241 if (tmp == ent) {
1242 info = "unchecked profile in failed atomic policy load";
1243 /* skip entry that caused failure */
1244 continue;
1245 }
1246 op = (!tmp->old) ? OP_PROF_LOAD : OP_PROF_REPL;
1247 audit_policy(label, op, ns_name, tmp->new->base.hname, info,
1248 error);
1249 }
1250 list_for_each_entry_safe(ent, tmp, &lh, list) {
1251 list_del_init(&ent->list);
1252 aa_load_ent_free(ent);
1253 }
1254
1255 goto out;
1256}
1257
1258/**
1259 * aa_remove_profiles - remove profile(s) from the system
1260 * @policy_ns: namespace the remove is being done from
1261 * @subj: label attempting to remove policy
1262 * @fqname: name of the profile or namespace to remove (NOT NULL)
1263 * @size: size of the name
1264 *
1265 * Remove a profile or sub namespace from the current namespace, so that
1266 * they can not be found anymore and mark them as replaced by unconfined
1267 *
1268 * NOTE: removing confinement does not restore rlimits to preconfinement values
1269 *
1270 * Returns: size of data consume else error code if fails
1271 */
1272ssize_t aa_remove_profiles(struct aa_ns *policy_ns, struct aa_label *subj,
1273 char *fqname, size_t size)
1274{
1275 struct aa_ns *ns = NULL;
1276 struct aa_profile *profile = NULL;
1277 const char *name = fqname, *info = NULL;
1278 const char *ns_name = NULL;
1279 ssize_t error = 0;
1280
1281 if (*fqname == 0) {
1282 info = "no profile specified";
1283 error = -ENOENT;
1284 goto fail;
1285 }
1286
1287 if (fqname[0] == ':') {
1288 size_t ns_len;
1289
1290 name = aa_splitn_fqname(fqname, size, &ns_name, &ns_len);
1291 /* released below */
1292 ns = aa_lookupn_ns(policy_ns ? policy_ns : labels_ns(subj),
1293 ns_name, ns_len);
1294 if (!ns) {
1295 info = "namespace does not exist";
1296 error = -ENOENT;
1297 goto fail;
1298 }
1299 } else
1300 /* released below */
1301 ns = aa_get_ns(policy_ns ? policy_ns : labels_ns(subj));
1302
1303 if (!name) {
1304 /* remove namespace - can only happen if fqname[0] == ':' */
1305 mutex_lock_nested(&ns->parent->lock, ns->parent->level);
1306 __aa_bump_ns_revision(ns);
1307 __aa_remove_ns(ns);
1308 mutex_unlock(&ns->parent->lock);
1309 } else {
1310 /* remove profile */
1311 mutex_lock_nested(&ns->lock, ns->level);
1312 profile = aa_get_profile(__lookup_profile(&ns->base, name));
1313 if (!profile) {
1314 error = -ENOENT;
1315 info = "profile does not exist";
1316 goto fail_ns_lock;
1317 }
1318 name = profile->base.hname;
1319 __aa_bump_ns_revision(ns);
1320 __remove_profile(profile);
1321 __aa_labelset_update_subtree(ns);
1322 mutex_unlock(&ns->lock);
1323 }
1324
1325 /* don't fail removal if audit fails */
1326 (void) audit_policy(subj, OP_PROF_RM, ns_name, name, info,
1327 error);
1328 aa_put_ns(ns);
1329 aa_put_profile(profile);
1330 return size;
1331
1332fail_ns_lock:
1333 mutex_unlock(&ns->lock);
1334 aa_put_ns(ns);
1335
1336fail:
1337 (void) audit_policy(subj, OP_PROF_RM, ns_name, name, info,
1338 error);
1339 return error;
1340}