2 * AppArmor security module
4 * This file contains AppArmor label definitions
6 * Copyright 2017 Canonical Ltd.
8 * This program is free software; you can redistribute it and/or
9 * modify it under the terms of the GNU General Public License as
10 * published by the Free Software Foundation, version 2 of the
14 #include <linux/audit.h>
15 #include <linux/seq_file.h>
16 #include <linux/sort.h>
18 #include "include/apparmor.h"
19 #include "include/cred.h"
20 #include "include/label.h"
21 #include "include/policy.h"
22 #include "include/secid.h"
26 * the aa_label represents the set of profiles confining an object
28 * Labels maintain a reference count to the set of pointers they reference
29 * Labels are ref counted by
30 * tasks and object via the security field/security context off the field
31 * code - will take a ref count on a label if it needs the label
32 * beyond what is possible with an rcu_read_lock.
33 * profiles - each profile is a label
34 * secids - a pinned secid will keep a refcount of the label it is
36 * objects - inode, files, sockets, ...
38 * Labels are not ref counted by the label set, so they maybe removed and
39 * freed when no longer in use.
43 #define PROXY_POISON 97
44 #define LABEL_POISON 100
46 static void free_proxy(struct aa_proxy *proxy)
49 /* p->label will not updated any more as p is dead */
50 aa_put_label(rcu_dereference_protected(proxy->label, true));
51 memset(proxy, 0, sizeof(*proxy));
52 RCU_INIT_POINTER(proxy->label, (struct aa_label *)PROXY_POISON);
57 void aa_proxy_kref(struct kref *kref)
59 struct aa_proxy *proxy = container_of(kref, struct aa_proxy, count);
64 struct aa_proxy *aa_alloc_proxy(struct aa_label *label, gfp_t gfp)
68 new = kzalloc(sizeof(struct aa_proxy), gfp);
70 kref_init(&new->count);
71 rcu_assign_pointer(new->label, aa_get_label(label));
76 /* requires profile list write lock held */
77 void __aa_proxy_redirect(struct aa_label *orig, struct aa_label *new)
83 lockdep_assert_held_exclusive(&labels_set(orig)->lock);
85 tmp = rcu_dereference_protected(orig->proxy->label,
86 &labels_ns(orig)->lock);
87 rcu_assign_pointer(orig->proxy->label, aa_get_label(new));
88 orig->flags |= FLAG_STALE;
92 static void __proxy_share(struct aa_label *old, struct aa_label *new)
94 struct aa_proxy *proxy = new->proxy;
96 new->proxy = aa_get_proxy(old->proxy);
97 __aa_proxy_redirect(old, new);
103 * ns_cmp - compare ns for label set ordering
104 * @a: ns to compare (NOT NULL)
105 * @b: ns to compare (NOT NULL)
107 * Returns: <0 if a < b
111 static int ns_cmp(struct aa_ns *a, struct aa_ns *b)
117 AA_BUG(!a->base.hname);
118 AA_BUG(!b->base.hname);
123 res = a->level - b->level;
127 return strcmp(a->base.hname, b->base.hname);
131 * profile_cmp - profile comparison for set ordering
132 * @a: profile to compare (NOT NULL)
133 * @b: profile to compare (NOT NULL)
135 * Returns: <0 if a < b
139 static int profile_cmp(struct aa_profile *a, struct aa_profile *b)
147 AA_BUG(!a->base.hname);
148 AA_BUG(!b->base.hname);
150 if (a == b || a->base.hname == b->base.hname)
152 res = ns_cmp(a->ns, b->ns);
156 return strcmp(a->base.hname, b->base.hname);
160 * vec_cmp - label comparison for set ordering
161 * @a: label to compare (NOT NULL)
162 * @vec: vector of profiles to compare (NOT NULL)
165 * Returns: <0 if a < vec
169 static int vec_cmp(struct aa_profile **a, int an, struct aa_profile **b, int bn)
180 for (i = 0; i < an && i < bn; i++) {
181 int res = profile_cmp(a[i], b[i]);
190 static bool vec_is_stale(struct aa_profile **vec, int n)
196 for (i = 0; i < n; i++) {
197 if (profile_is_stale(vec[i]))
204 static bool vec_unconfined(struct aa_profile **vec, int n)
210 for (i = 0; i < n; i++) {
211 if (!profile_unconfined(vec[i]))
218 static int sort_cmp(const void *a, const void *b)
220 return profile_cmp(*(struct aa_profile **)a, *(struct aa_profile **)b);
224 * assumes vec is sorted
225 * Assumes @vec has null terminator at vec[n], and will null terminate
228 static inline int unique(struct aa_profile **vec, int n)
230 int i, pos, dups = 0;
236 for (i = 1; i < n; i++) {
237 int res = profile_cmp(vec[pos], vec[i]);
239 AA_BUG(res > 0, "vec not sorted");
242 aa_put_profile(vec[i]);
257 * aa_vec_unique - canonical sort and unique a list of profiles
258 * @n: number of refcounted profiles in the list (@n > 0)
259 * @vec: list of profiles to sort and merge
261 * Returns: the number of duplicates eliminated == references put
263 * If @flags & VEC_FLAG_TERMINATE @vec has null terminator at vec[n], and will
264 * null terminate vec[n - dups]
266 int aa_vec_unique(struct aa_profile **vec, int n, int flags)
273 /* vecs are usually small and inorder, have a fallback for larger */
275 sort(vec, n, sizeof(struct aa_profile *), sort_cmp, NULL);
276 dups = unique(vec, n);
280 /* insertion sort + unique in one */
281 for (i = 1; i < n; i++) {
282 struct aa_profile *tmp = vec[i];
285 for (pos = i - 1 - dups; pos >= 0; pos--) {
286 int res = profile_cmp(vec[pos], tmp);
289 /* drop duplicate entry */
296 /* pos is at entry < tmp, or index -1. Set to insert pos */
299 for (j = i - dups; j > pos; j--)
309 if (flags & VEC_FLAG_TERMINATE)
310 vec[n - dups] = NULL;
316 static void label_destroy(struct aa_label *label)
318 struct aa_label *tmp;
322 if (!label_isprofile(label)) {
323 struct aa_profile *profile;
326 aa_put_str(label->hname);
328 label_for_each(i, label, profile) {
329 aa_put_profile(profile);
330 label->vec[i.i] = (struct aa_profile *)
331 (LABEL_POISON + (long) i.i);
335 if (rcu_dereference_protected(label->proxy->label, true) == label)
336 rcu_assign_pointer(label->proxy->label, NULL);
338 aa_free_secid(label->secid);
340 tmp = rcu_dereference_protected(label->proxy->label, true);
342 rcu_assign_pointer(label->proxy->label, NULL);
344 aa_put_proxy(label->proxy);
345 label->proxy = (struct aa_proxy *) PROXY_POISON + 1;
348 void aa_label_free(struct aa_label *label)
353 label_destroy(label);
357 static void label_free_switch(struct aa_label *label)
359 if (label->flags & FLAG_NS_COUNT)
360 aa_free_ns(labels_ns(label));
361 else if (label_isprofile(label))
362 aa_free_profile(labels_profile(label));
364 aa_label_free(label);
367 static void label_free_rcu(struct rcu_head *head)
369 struct aa_label *label = container_of(head, struct aa_label, rcu);
371 if (label->flags & FLAG_IN_TREE)
372 (void) aa_label_remove(label);
373 label_free_switch(label);
376 void aa_label_kref(struct kref *kref)
378 struct aa_label *label = container_of(kref, struct aa_label, count);
379 struct aa_ns *ns = labels_ns(label);
382 /* never live, no rcu callback needed, just using the fn */
383 label_free_switch(label);
386 /* TODO: update labels_profile macro so it works here */
387 AA_BUG(label_isprofile(label) &&
388 on_list_rcu(&label->vec[0]->base.profiles));
389 AA_BUG(label_isprofile(label) &&
390 on_list_rcu(&label->vec[0]->base.list));
392 /* TODO: if compound label and not stale add to reclaim cache */
393 call_rcu(&label->rcu, label_free_rcu);
396 static void label_free_or_put_new(struct aa_label *label, struct aa_label *new)
399 /* need to free directly to break circular ref with proxy */
405 bool aa_label_init(struct aa_label *label, int size, gfp_t gfp)
410 if (aa_alloc_secid(label, gfp) < 0)
413 label->size = size; /* doesn't include null */
414 label->vec[size] = NULL; /* null terminate */
415 kref_init(&label->count);
416 RB_CLEAR_NODE(&label->node);
422 * aa_label_alloc - allocate a label with a profile vector of @size length
423 * @size: size of profile vector in the label
424 * @proxy: proxy to use OR null if to allocate a new one
425 * @gfp: memory allocation type
428 * else NULL if failed
430 struct aa_label *aa_label_alloc(int size, struct aa_proxy *proxy, gfp_t gfp)
432 struct aa_label *new;
436 /* + 1 for null terminator entry on vec */
437 new = kzalloc(sizeof(*new) + sizeof(struct aa_profile *) * (size + 1),
439 AA_DEBUG("%s (%p)\n", __func__, new);
443 if (!aa_label_init(new, size, gfp))
447 proxy = aa_alloc_proxy(new, gfp);
452 /* just set new's proxy, don't redirect proxy here if it was passed in*/
465 * label_cmp - label comparison for set ordering
466 * @a: label to compare (NOT NULL)
467 * @b: label to compare (NOT NULL)
469 * Returns: <0 if a < b
473 static int label_cmp(struct aa_label *a, struct aa_label *b)
480 return vec_cmp(a->vec, a->size, b->vec, b->size);
483 /* helper fn for label_for_each_confined */
484 int aa_label_next_confined(struct aa_label *label, int i)
489 for (; i < label->size; i++) {
490 if (!profile_unconfined(label->vec[i]))
498 * aa_label_next_not_in_set - return the next profile of @sub not in @set
500 * @set: label to test against
501 * @sub: label to if is subset of @set
503 * Returns: profile in @sub that is not in @set, with iterator set pos after
504 * else NULL if @sub is a subset of @set
506 struct aa_profile *__aa_label_next_not_in_set(struct label_it *I,
507 struct aa_label *set,
508 struct aa_label *sub)
513 AA_BUG(I->i > set->size);
516 AA_BUG(I->j > sub->size);
518 while (I->j < sub->size && I->i < set->size) {
519 int res = profile_cmp(sub->vec[I->j], set->vec[I->i]);
527 return sub->vec[(I->j)++];
530 if (I->j < sub->size)
531 return sub->vec[(I->j)++];
537 * aa_label_is_subset - test if @sub is a subset of @set
538 * @set: label to test against
539 * @sub: label to test if is subset of @set
541 * Returns: true if @sub is subset of @set
544 bool aa_label_is_subset(struct aa_label *set, struct aa_label *sub)
546 struct label_it i = { };
554 return __aa_label_next_not_in_set(&i, set, sub) == NULL;
558 * aa_label_is_unconfined_subset - test if @sub is a subset of @set
559 * @set: label to test against
560 * @sub: label to test if is subset of @set
562 * This checks for subset but taking into account unconfined. IF
563 * @sub contains an unconfined profile that does not have a matching
564 * unconfined in @set then this will not cause the test to fail.
565 * Conversely we don't care about an unconfined in @set that is not in
568 * Returns: true if @sub is special_subset of @set
571 bool aa_label_is_unconfined_subset(struct aa_label *set, struct aa_label *sub)
573 struct label_it i = { };
574 struct aa_profile *p;
583 p = __aa_label_next_not_in_set(&i, set, sub);
584 if (p && !profile_unconfined(p))
593 * __label_remove - remove @label from the label set
594 * @l: label to remove
595 * @new: label to redirect to
597 * Requires: labels_set(@label)->lock write_lock
598 * Returns: true if the label was in the tree and removed
600 static bool __label_remove(struct aa_label *label, struct aa_label *new)
602 struct aa_labelset *ls = labels_set(label);
606 lockdep_assert_held_exclusive(&ls->lock);
609 __aa_proxy_redirect(label, new);
611 if (!label_is_stale(label))
612 __label_make_stale(label);
614 if (label->flags & FLAG_IN_TREE) {
615 rb_erase(&label->node, &ls->root);
616 label->flags &= ~FLAG_IN_TREE;
624 * __label_replace - replace @old with @new in label set
625 * @old: label to remove from label set
626 * @new: label to replace @old with
628 * Requires: labels_set(@old)->lock write_lock
629 * valid ref count be held on @new
630 * Returns: true if @old was in set and replaced by @new
632 * Note: current implementation requires label set be order in such a way
633 * that @new directly replaces @old position in the set (ie.
634 * using pointer comparison of the label address would not work)
636 static bool __label_replace(struct aa_label *old, struct aa_label *new)
638 struct aa_labelset *ls = labels_set(old);
643 lockdep_assert_held_exclusive(&ls->lock);
644 AA_BUG(new->flags & FLAG_IN_TREE);
646 if (!label_is_stale(old))
647 __label_make_stale(old);
649 if (old->flags & FLAG_IN_TREE) {
650 rb_replace_node(&old->node, &new->node, &ls->root);
651 old->flags &= ~FLAG_IN_TREE;
652 new->flags |= FLAG_IN_TREE;
660 * __label_insert - attempt to insert @l into a label set
661 * @ls: set of labels to insert @l into (NOT NULL)
662 * @label: new label to insert (NOT NULL)
663 * @replace: whether insertion should replace existing entry that is not stale
665 * Requires: @ls->lock
666 * caller to hold a valid ref on l
667 * if @replace is true l has a preallocated proxy associated
668 * Returns: @l if successful in inserting @l - with additional refcount
669 * else ref counted equivalent label that is already in the set,
670 * the else condition only happens if @replace is false
672 static struct aa_label *__label_insert(struct aa_labelset *ls,
673 struct aa_label *label, bool replace)
675 struct rb_node **new, *parent = NULL;
679 AA_BUG(labels_set(label) != ls);
680 lockdep_assert_held_exclusive(&ls->lock);
681 AA_BUG(label->flags & FLAG_IN_TREE);
683 /* Figure out where to put new node */
684 new = &ls->root.rb_node;
686 struct aa_label *this = rb_entry(*new, struct aa_label, node);
687 int result = label_cmp(label, this);
691 /* !__aa_get_label means queued for destruction,
692 * so replace in place, however the label has
693 * died before the replacement so do not share
696 if (!replace && !label_is_stale(this)) {
697 if (__aa_get_label(this))
700 __proxy_share(this, label);
701 AA_BUG(!__label_replace(this, label));
702 return aa_get_label(label);
703 } else if (result < 0)
704 new = &((*new)->rb_left);
705 else /* (result > 0) */
706 new = &((*new)->rb_right);
709 /* Add new node and rebalance tree. */
710 rb_link_node(&label->node, parent, new);
711 rb_insert_color(&label->node, &ls->root);
712 label->flags |= FLAG_IN_TREE;
714 return aa_get_label(label);
718 * __vec_find - find label that matches @vec in label set
719 * @vec: vec of profiles to find matching label for (NOT NULL)
722 * Requires: @vec_labelset(vec) lock held
723 * caller to hold a valid ref on l
725 * Returns: ref counted @label if matching label is in tree
726 * ref counted label that is equiv to @l in tree
727 * else NULL if @vec equiv is not in tree
729 static struct aa_label *__vec_find(struct aa_profile **vec, int n)
731 struct rb_node *node;
737 node = vec_labelset(vec, n)->root.rb_node;
739 struct aa_label *this = rb_entry(node, struct aa_label, node);
740 int result = vec_cmp(this->vec, this->size, vec, n);
743 node = node->rb_left;
745 node = node->rb_right;
747 return __aa_get_label(this);
754 * __label_find - find label @label in label set
755 * @label: label to find (NOT NULL)
757 * Requires: labels_set(@label)->lock held
758 * caller to hold a valid ref on l
760 * Returns: ref counted @label if @label is in tree OR
761 * ref counted label that is equiv to @label in tree
762 * else NULL if @label or equiv is not in tree
764 static struct aa_label *__label_find(struct aa_label *label)
768 return __vec_find(label->vec, label->size);
773 * aa_label_remove - remove a label from the labelset
774 * @label: label to remove
776 * Returns: true if @label was removed from the tree
777 * else @label was not in tree so it could not be removed
779 bool aa_label_remove(struct aa_label *label)
781 struct aa_labelset *ls = labels_set(label);
787 write_lock_irqsave(&ls->lock, flags);
788 res = __label_remove(label, ns_unconfined(labels_ns(label)));
789 write_unlock_irqrestore(&ls->lock, flags);
795 * aa_label_replace - replace a label @old with a new version @new
796 * @old: label to replace
797 * @new: label replacing @old
799 * Returns: true if @old was in tree and replaced
800 * else @old was not in tree, and @new was not inserted
802 bool aa_label_replace(struct aa_label *old, struct aa_label *new)
807 if (name_is_shared(old, new) && labels_ns(old) == labels_ns(new)) {
808 write_lock_irqsave(&labels_set(old)->lock, flags);
809 if (old->proxy != new->proxy)
810 __proxy_share(old, new);
812 __aa_proxy_redirect(old, new);
813 res = __label_replace(old, new);
814 write_unlock_irqrestore(&labels_set(old)->lock, flags);
817 struct aa_labelset *ls = labels_set(old);
819 write_lock_irqsave(&ls->lock, flags);
820 res = __label_remove(old, new);
821 if (labels_ns(old) != labels_ns(new)) {
822 write_unlock_irqrestore(&ls->lock, flags);
823 ls = labels_set(new);
824 write_lock_irqsave(&ls->lock, flags);
826 l = __label_insert(ls, new, true);
828 write_unlock_irqrestore(&ls->lock, flags);
836 * vec_find - find label @l in label set
837 * @vec: array of profiles to find equiv label for (NOT NULL)
840 * Returns: refcounted label if @vec equiv is in tree
841 * else NULL if @vec equiv is not in tree
843 static struct aa_label *vec_find(struct aa_profile **vec, int n)
845 struct aa_labelset *ls;
846 struct aa_label *label;
853 ls = vec_labelset(vec, n);
854 read_lock_irqsave(&ls->lock, flags);
855 label = __vec_find(vec, n);
856 read_unlock_irqrestore(&ls->lock, flags);
861 /* requires sort and merge done first */
862 static struct aa_label *vec_create_and_insert_label(struct aa_profile **vec,
865 struct aa_label *label = NULL;
866 struct aa_labelset *ls;
868 struct aa_label *new;
874 return aa_get_label(&vec[0]->label);
876 ls = labels_set(&vec[len - 1]->label);
878 /* TODO: enable when read side is lockless
879 * check if label exists before taking locks
881 new = aa_label_alloc(len, NULL, gfp);
885 for (i = 0; i < len; i++)
886 new->vec[i] = aa_get_profile(vec[i]);
888 write_lock_irqsave(&ls->lock, flags);
889 label = __label_insert(ls, new, false);
890 write_unlock_irqrestore(&ls->lock, flags);
891 label_free_or_put_new(label, new);
896 struct aa_label *aa_vec_find_or_create_label(struct aa_profile **vec, int len,
899 struct aa_label *label = vec_find(vec, len);
904 return vec_create_and_insert_label(vec, len, gfp);
908 * aa_label_find - find label @label in label set
909 * @label: label to find (NOT NULL)
911 * Requires: caller to hold a valid ref on l
913 * Returns: refcounted @label if @label is in tree
914 * refcounted label that is equiv to @label in tree
915 * else NULL if @label or equiv is not in tree
917 struct aa_label *aa_label_find(struct aa_label *label)
921 return vec_find(label->vec, label->size);
926 * aa_label_insert - insert label @label into @ls or return existing label
927 * @ls - labelset to insert @label into
928 * @label - label to insert
930 * Requires: caller to hold a valid ref on @label
932 * Returns: ref counted @label if successful in inserting @label
933 * else ref counted equivalent label that is already in the set
935 struct aa_label *aa_label_insert(struct aa_labelset *ls, struct aa_label *label)
943 /* check if label exists before taking lock */
944 if (!label_is_stale(label)) {
945 read_lock_irqsave(&ls->lock, flags);
946 l = __label_find(label);
947 read_unlock_irqrestore(&ls->lock, flags);
952 write_lock_irqsave(&ls->lock, flags);
953 l = __label_insert(ls, label, false);
954 write_unlock_irqrestore(&ls->lock, flags);
961 * aa_label_next_in_merge - find the next profile when merging @a and @b
966 * Returns: next profile
967 * else null if no more profiles
969 struct aa_profile *aa_label_next_in_merge(struct label_it *I,
977 AA_BUG(I->i > a->size);
979 AA_BUG(I->j > b->size);
981 if (I->i < a->size) {
982 if (I->j < b->size) {
983 int res = profile_cmp(a->vec[I->i], b->vec[I->j]);
986 return b->vec[(I->j)++];
991 return a->vec[(I->i)++];
995 return b->vec[(I->j)++];
1001 * label_merge_cmp - cmp of @a merging with @b against @z for set ordering
1002 * @a: label to merge then compare (NOT NULL)
1003 * @b: label to merge then compare (NOT NULL)
1004 * @z: label to compare merge against (NOT NULL)
1006 * Assumes: using the most recent versions of @a, @b, and @z
1008 * Returns: <0 if a < b
1012 static int label_merge_cmp(struct aa_label *a, struct aa_label *b,
1015 struct aa_profile *p = NULL;
1016 struct label_it i = { };
1024 k < z->size && (p = aa_label_next_in_merge(&i, a, b));
1026 int res = profile_cmp(p, z->vec[k]);
1034 else if (k < z->size)
1040 * label_merge_insert - create a new label by merging @a and @b
1041 * @new: preallocated label to merge into (NOT NULL)
1042 * @a: label to merge with @b (NOT NULL)
1043 * @b: label to merge with @a (NOT NULL)
1045 * Requires: preallocated proxy
1047 * Returns: ref counted label either @new if merge is unique
1048 * @a if @b is a subset of @a
1049 * @b if @a is a subset of @b
1051 * NOTE: will not use @new if the merge results in @new == @a or @b
1053 * Must be used within labelset write lock to avoid racing with
1054 * setting labels stale.
1056 static struct aa_label *label_merge_insert(struct aa_label *new,
1060 struct aa_label *label;
1061 struct aa_labelset *ls;
1062 struct aa_profile *next;
1064 unsigned long flags;
1065 int k = 0, invcount = 0;
1069 AA_BUG(a->size < 0);
1071 AA_BUG(b->size < 0);
1073 AA_BUG(new->size < a->size + b->size);
1075 label_for_each_in_merge(i, a, b, next) {
1077 if (profile_is_stale(next)) {
1078 new->vec[k] = aa_get_newest_profile(next);
1079 AA_BUG(!new->vec[k]->label.proxy);
1080 AA_BUG(!new->vec[k]->label.proxy->label);
1081 if (next->label.proxy != new->vec[k]->label.proxy)
1086 new->vec[k++] = aa_get_profile(next);
1088 /* set to actual size which is <= allocated len */
1093 new->size -= aa_vec_unique(&new->vec[0], new->size,
1094 VEC_FLAG_TERMINATE);
1095 /* TODO: deal with reference labels */
1096 if (new->size == 1) {
1097 label = aa_get_label(&new->vec[0]->label);
1100 } else if (!stale) {
1102 * merge could be same as a || b, note: it is not possible
1103 * for new->size == a->size == b->size unless a == b
1106 return aa_get_label(a);
1107 else if (k == b->size)
1108 return aa_get_label(b);
1110 if (vec_unconfined(new->vec, new->size))
1111 new->flags |= FLAG_UNCONFINED;
1112 ls = labels_set(new);
1113 write_lock_irqsave(&ls->lock, flags);
1114 label = __label_insert(labels_set(new), new, false);
1115 write_unlock_irqrestore(&ls->lock, flags);
1121 * labelset_of_merge - find which labelset a merged label should be inserted
1122 * @a: label to merge and insert
1123 * @b: label to merge and insert
1125 * Returns: labelset that the merged label should be inserted into
1127 static struct aa_labelset *labelset_of_merge(struct aa_label *a,
1130 struct aa_ns *nsa = labels_ns(a);
1131 struct aa_ns *nsb = labels_ns(b);
1133 if (ns_cmp(nsa, nsb) <= 0)
1134 return &nsa->labels;
1135 return &nsb->labels;
1139 * __label_find_merge - find label that is equiv to merge of @a and @b
1140 * @ls: set of labels to search (NOT NULL)
1141 * @a: label to merge with @b (NOT NULL)
1142 * @b: label to merge with @a (NOT NULL)
1144 * Requires: ls->lock read_lock held
1146 * Returns: ref counted label that is equiv to merge of @a and @b
1147 * else NULL if merge of @a and @b is not in set
1149 static struct aa_label *__label_find_merge(struct aa_labelset *ls,
1153 struct rb_node *node;
1160 return __label_find(a);
1162 node = ls->root.rb_node;
1164 struct aa_label *this = container_of(node, struct aa_label,
1166 int result = label_merge_cmp(a, b, this);
1169 node = node->rb_left;
1170 else if (result > 0)
1171 node = node->rb_right;
1173 return __aa_get_label(this);
1181 * aa_label_find_merge - find label that is equiv to merge of @a and @b
1182 * @a: label to merge with @b (NOT NULL)
1183 * @b: label to merge with @a (NOT NULL)
1185 * Requires: labels be fully constructed with a valid ns
1187 * Returns: ref counted label that is equiv to merge of @a and @b
1188 * else NULL if merge of @a and @b is not in set
1190 struct aa_label *aa_label_find_merge(struct aa_label *a, struct aa_label *b)
1192 struct aa_labelset *ls;
1193 struct aa_label *label, *ar = NULL, *br = NULL;
1194 unsigned long flags;
1199 if (label_is_stale(a))
1200 a = ar = aa_get_newest_label(a);
1201 if (label_is_stale(b))
1202 b = br = aa_get_newest_label(b);
1203 ls = labelset_of_merge(a, b);
1204 read_lock_irqsave(&ls->lock, flags);
1205 label = __label_find_merge(ls, a, b);
1206 read_unlock_irqrestore(&ls->lock, flags);
1214 * aa_label_merge - attempt to insert new merged label of @a and @b
1215 * @ls: set of labels to insert label into (NOT NULL)
1216 * @a: label to merge with @b (NOT NULL)
1217 * @b: label to merge with @a (NOT NULL)
1218 * @gfp: memory allocation type
1220 * Requires: caller to hold valid refs on @a and @b
1221 * labels be fully constructed with a valid ns
1223 * Returns: ref counted new label if successful in inserting merge of a & b
1224 * else ref counted equivalent label that is already in the set.
1225 * else NULL if could not create label (-ENOMEM)
1227 struct aa_label *aa_label_merge(struct aa_label *a, struct aa_label *b,
1230 struct aa_label *label = NULL;
1236 return aa_get_newest_label(a);
1238 /* TODO: enable when read side is lockless
1239 * check if label exists before taking locks
1240 if (!label_is_stale(a) && !label_is_stale(b))
1241 label = aa_label_find_merge(a, b);
1245 struct aa_label *new;
1247 a = aa_get_newest_label(a);
1248 b = aa_get_newest_label(b);
1250 /* could use label_merge_len(a, b), but requires double
1251 * comparison for small savings
1253 new = aa_label_alloc(a->size + b->size, NULL, gfp);
1257 label = label_merge_insert(new, a, b);
1258 label_free_or_put_new(label, new);
1267 static inline bool label_is_visible(struct aa_profile *profile,
1268 struct aa_label *label)
1270 return aa_ns_visible(profile->ns, labels_ns(label), true);
1273 /* match a profile and its associated ns component if needed
1274 * Assumes visibility test has already been done.
1275 * If a subns profile is not to be matched should be prescreened with
1278 static inline unsigned int match_component(struct aa_profile *profile,
1279 struct aa_profile *tp,
1282 const char *ns_name;
1284 if (profile->ns == tp->ns)
1285 return aa_dfa_match(profile->policy.dfa, state, tp->base.hname);
1287 /* try matching with namespace name and then profile */
1288 ns_name = aa_ns_name(profile->ns, tp->ns, true);
1289 state = aa_dfa_match_len(profile->policy.dfa, state, ":", 1);
1290 state = aa_dfa_match(profile->policy.dfa, state, ns_name);
1291 state = aa_dfa_match_len(profile->policy.dfa, state, ":", 1);
1292 return aa_dfa_match(profile->policy.dfa, state, tp->base.hname);
1296 * label_compound_match - find perms for full compound label
1297 * @profile: profile to find perms for
1298 * @label: label to check access permissions for
1299 * @start: state to start match in
1300 * @subns: whether to do permission checks on components in a subns
1301 * @request: permissions to request
1302 * @perms: perms struct to set
1304 * Returns: 0 on success else ERROR
1306 * For the label A//&B//&C this does the perm match for A//&B//&C
1307 * @perms should be preinitialized with allperms OR a previous permission
1308 * check to be stacked.
1310 static int label_compound_match(struct aa_profile *profile,
1311 struct aa_label *label,
1312 unsigned int state, bool subns, u32 request,
1313 struct aa_perms *perms)
1315 struct aa_profile *tp;
1318 /* find first subcomponent that is visible */
1319 label_for_each(i, label, tp) {
1320 if (!aa_ns_visible(profile->ns, tp->ns, subns))
1322 state = match_component(profile, tp, state);
1328 /* no component visible */
1333 label_for_each_cont(i, label, tp) {
1334 if (!aa_ns_visible(profile->ns, tp->ns, subns))
1336 state = aa_dfa_match(profile->policy.dfa, state, "//&");
1337 state = match_component(profile, tp, state);
1341 aa_compute_perms(profile->policy.dfa, state, perms);
1342 aa_apply_modes_to_perms(profile, perms);
1343 if ((perms->allow & request) != request)
1354 * label_components_match - find perms for all subcomponents of a label
1355 * @profile: profile to find perms for
1356 * @label: label to check access permissions for
1357 * @start: state to start match in
1358 * @subns: whether to do permission checks on components in a subns
1359 * @request: permissions to request
1360 * @perms: an initialized perms struct to add accumulation to
1362 * Returns: 0 on success else ERROR
1364 * For the label A//&B//&C this does the perm match for each of A and B and C
1365 * @perms should be preinitialized with allperms OR a previous permission
1366 * check to be stacked.
1368 static int label_components_match(struct aa_profile *profile,
1369 struct aa_label *label, unsigned int start,
1370 bool subns, u32 request,
1371 struct aa_perms *perms)
1373 struct aa_profile *tp;
1375 struct aa_perms tmp;
1376 unsigned int state = 0;
1378 /* find first subcomponent to test */
1379 label_for_each(i, label, tp) {
1380 if (!aa_ns_visible(profile->ns, tp->ns, subns))
1382 state = match_component(profile, tp, start);
1388 /* no subcomponents visible - no change in perms */
1392 aa_compute_perms(profile->policy.dfa, state, &tmp);
1393 aa_apply_modes_to_perms(profile, &tmp);
1394 aa_perms_accum(perms, &tmp);
1395 label_for_each_cont(i, label, tp) {
1396 if (!aa_ns_visible(profile->ns, tp->ns, subns))
1398 state = match_component(profile, tp, start);
1401 aa_compute_perms(profile->policy.dfa, state, &tmp);
1402 aa_apply_modes_to_perms(profile, &tmp);
1403 aa_perms_accum(perms, &tmp);
1406 if ((perms->allow & request) != request)
1417 * aa_label_match - do a multi-component label match
1418 * @profile: profile to match against (NOT NULL)
1419 * @label: label to match (NOT NULL)
1420 * @state: state to start in
1421 * @subns: whether to match subns components
1422 * @request: permission request
1423 * @perms: Returns computed perms (NOT NULL)
1425 * Returns: the state the match finished in, may be the none matching state
1427 int aa_label_match(struct aa_profile *profile, struct aa_label *label,
1428 unsigned int state, bool subns, u32 request,
1429 struct aa_perms *perms)
1431 int error = label_compound_match(profile, label, state, subns, request,
1437 return label_components_match(profile, label, state, subns, request,
1443 * aa_update_label_name - update a label to have a stored name
1444 * @ns: ns being viewed from (NOT NULL)
1445 * @label: label to update (NOT NULL)
1446 * @gfp: type of memory allocation
1448 * Requires: labels_set(label) not locked in caller
1450 * note: only updates the label name if it does not have a name already
1451 * and if it is in the labelset
1453 bool aa_update_label_name(struct aa_ns *ns, struct aa_label *label, gfp_t gfp)
1455 struct aa_labelset *ls;
1456 unsigned long flags;
1457 char __counted *name;
1463 if (label->hname || labels_ns(label) != ns)
1466 if (aa_label_acntsxprint(&name, ns, label, FLAGS_NONE, gfp) < 0)
1469 ls = labels_set(label);
1470 write_lock_irqsave(&ls->lock, flags);
1471 if (!label->hname && label->flags & FLAG_IN_TREE) {
1472 label->hname = name;
1476 write_unlock_irqrestore(&ls->lock, flags);
1482 * cached label name is present and visible
1483 * @label->hname only exists if label is namespace hierachical
1485 static inline bool use_label_hname(struct aa_ns *ns, struct aa_label *label,
1488 if (label->hname && (!ns || labels_ns(label) == ns) &&
1489 !(flags & ~FLAG_SHOW_MODE))
1495 /* helper macro for snprint routines */
1496 #define update_for_len(total, len, size, str) \
1498 size_t ulen = len; \
1502 ulen = min(ulen, size); \
1508 * aa_profile_snxprint - print a profile name to a buffer
1509 * @str: buffer to write to. (MAY BE NULL if @size == 0)
1510 * @size: size of buffer
1511 * @view: namespace profile is being viewed from
1512 * @profile: profile to view (NOT NULL)
1513 * @flags: whether to include the mode string
1514 * @prev_ns: last ns printed when used in compound print
1516 * Returns: size of name written or would be written if larger than
1519 * Note: will not print anything if the profile is not visible
1521 static int aa_profile_snxprint(char *str, size_t size, struct aa_ns *view,
1522 struct aa_profile *profile, int flags,
1523 struct aa_ns **prev_ns)
1525 const char *ns_name = NULL;
1527 AA_BUG(!str && size != 0);
1531 view = profiles_ns(profile);
1533 if (view != profile->ns &&
1534 (!prev_ns || (*prev_ns != profile->ns))) {
1536 *prev_ns = profile->ns;
1537 ns_name = aa_ns_name(view, profile->ns,
1538 flags & FLAG_VIEW_SUBNS);
1539 if (ns_name == aa_hidden_ns_name) {
1540 if (flags & FLAG_HIDDEN_UNCONFINED)
1541 return snprintf(str, size, "%s", "unconfined");
1542 return snprintf(str, size, "%s", ns_name);
1546 if ((flags & FLAG_SHOW_MODE) && profile != profile->ns->unconfined) {
1547 const char *modestr = aa_profile_mode_names[profile->mode];
1550 return snprintf(str, size, ":%s:%s (%s)", ns_name,
1551 profile->base.hname, modestr);
1552 return snprintf(str, size, "%s (%s)", profile->base.hname,
1557 return snprintf(str, size, ":%s:%s", ns_name,
1558 profile->base.hname);
1559 return snprintf(str, size, "%s", profile->base.hname);
1562 static const char *label_modename(struct aa_ns *ns, struct aa_label *label,
1565 struct aa_profile *profile;
1567 int mode = -1, count = 0;
1569 label_for_each(i, label, profile) {
1570 if (aa_ns_visible(ns, profile->ns, flags & FLAG_VIEW_SUBNS)) {
1572 if (profile == profile->ns->unconfined)
1573 /* special case unconfined so stacks with
1574 * unconfined don't report as mixed. ie.
1575 * profile_foo//&:ns1:unconfined (mixed)
1579 mode = profile->mode;
1580 else if (mode != profile->mode)
1588 /* everything was unconfined */
1589 mode = APPARMOR_UNCONFINED;
1591 return aa_profile_mode_names[mode];
1594 /* if any visible label is not unconfined the display_mode returns true */
1595 static inline bool display_mode(struct aa_ns *ns, struct aa_label *label,
1598 if ((flags & FLAG_SHOW_MODE)) {
1599 struct aa_profile *profile;
1602 label_for_each(i, label, profile) {
1603 if (aa_ns_visible(ns, profile->ns,
1604 flags & FLAG_VIEW_SUBNS) &&
1605 profile != profile->ns->unconfined)
1608 /* only ns->unconfined in set of profiles in ns */
1616 * aa_label_snxprint - print a label name to a string buffer
1617 * @str: buffer to write to. (MAY BE NULL if @size == 0)
1618 * @size: size of buffer
1619 * @ns: namespace profile is being viewed from
1620 * @label: label to view (NOT NULL)
1621 * @flags: whether to include the mode string
1623 * Returns: size of name written or would be written if larger than
1626 * Note: labels do not have to be strictly hierarchical to the ns as
1627 * objects may be shared across different namespaces and thus
1628 * pickup labeling from each ns. If a particular part of the
1629 * label is not visible it will just be excluded. And if none
1630 * of the label is visible "---" will be used.
1632 int aa_label_snxprint(char *str, size_t size, struct aa_ns *ns,
1633 struct aa_label *label, int flags)
1635 struct aa_profile *profile;
1636 struct aa_ns *prev_ns = NULL;
1638 int count = 0, total = 0;
1641 AA_BUG(!str && size != 0);
1644 if (flags & FLAG_ABS_ROOT) {
1646 len = snprintf(str, size, "=");
1647 update_for_len(total, len, size, str);
1649 ns = labels_ns(label);
1652 label_for_each(i, label, profile) {
1653 if (aa_ns_visible(ns, profile->ns, flags & FLAG_VIEW_SUBNS)) {
1655 len = snprintf(str, size, "//&");
1656 update_for_len(total, len, size, str);
1658 len = aa_profile_snxprint(str, size, ns, profile,
1659 flags & FLAG_VIEW_SUBNS,
1661 update_for_len(total, len, size, str);
1667 if (flags & FLAG_HIDDEN_UNCONFINED)
1668 return snprintf(str, size, "%s", "unconfined");
1669 return snprintf(str, size, "%s", aa_hidden_ns_name);
1672 /* count == 1 && ... is for backwards compat where the mode
1673 * is not displayed for 'unconfined' in the current ns
1675 if (display_mode(ns, label, flags)) {
1676 len = snprintf(str, size, " (%s)",
1677 label_modename(ns, label, flags));
1678 update_for_len(total, len, size, str);
1683 #undef update_for_len
1686 * aa_label_asxprint - allocate a string buffer and print label into it
1687 * @strp: Returns - the allocated buffer with the label name. (NOT NULL)
1688 * @ns: namespace profile is being viewed from
1689 * @label: label to view (NOT NULL)
1690 * @flags: flags controlling what label info is printed
1691 * @gfp: kernel memory allocation type
1693 * Returns: size of name written or would be written if larger than
1696 int aa_label_asxprint(char **strp, struct aa_ns *ns, struct aa_label *label,
1697 int flags, gfp_t gfp)
1704 size = aa_label_snxprint(NULL, 0, ns, label, flags);
1708 *strp = kmalloc(size + 1, gfp);
1711 return aa_label_snxprint(*strp, size + 1, ns, label, flags);
1715 * aa_label_acntsxprint - allocate a __counted string buffer and print label
1716 * @strp: buffer to write to.
1717 * @ns: namespace profile is being viewed from
1718 * @label: label to view (NOT NULL)
1719 * @flags: flags controlling what label info is printed
1720 * @gfp: kernel memory allocation type
1722 * Returns: size of name written or would be written if larger than
1725 int aa_label_acntsxprint(char __counted **strp, struct aa_ns *ns,
1726 struct aa_label *label, int flags, gfp_t gfp)
1733 size = aa_label_snxprint(NULL, 0, ns, label, flags);
1737 *strp = aa_str_alloc(size + 1, gfp);
1740 return aa_label_snxprint(*strp, size + 1, ns, label, flags);
1744 void aa_label_xaudit(struct audit_buffer *ab, struct aa_ns *ns,
1745 struct aa_label *label, int flags, gfp_t gfp)
1754 if (!use_label_hname(ns, label, flags) ||
1755 display_mode(ns, label, flags)) {
1756 len = aa_label_asxprint(&name, ns, label, flags, gfp);
1758 AA_DEBUG("label print error");
1763 str = (char *) label->hname;
1766 if (audit_string_contains_control(str, len))
1767 audit_log_n_hex(ab, str, len);
1769 audit_log_n_string(ab, str, len);
1774 void aa_label_seq_xprint(struct seq_file *f, struct aa_ns *ns,
1775 struct aa_label *label, int flags, gfp_t gfp)
1780 if (!use_label_hname(ns, label, flags)) {
1784 len = aa_label_asxprint(&str, ns, label, flags, gfp);
1786 AA_DEBUG("label print error");
1789 seq_printf(f, "%s", str);
1791 } else if (display_mode(ns, label, flags))
1792 seq_printf(f, "%s (%s)", label->hname,
1793 label_modename(ns, label, flags));
1795 seq_printf(f, "%s", label->hname);
1798 void aa_label_xprintk(struct aa_ns *ns, struct aa_label *label, int flags,
1803 if (!use_label_hname(ns, label, flags)) {
1807 len = aa_label_asxprint(&str, ns, label, flags, gfp);
1809 AA_DEBUG("label print error");
1814 } else if (display_mode(ns, label, flags))
1815 pr_info("%s (%s)", label->hname,
1816 label_modename(ns, label, flags));
1818 pr_info("%s", label->hname);
1821 void aa_label_audit(struct audit_buffer *ab, struct aa_label *label, gfp_t gfp)
1823 struct aa_ns *ns = aa_get_current_ns();
1825 aa_label_xaudit(ab, ns, label, FLAG_VIEW_SUBNS, gfp);
1829 void aa_label_seq_print(struct seq_file *f, struct aa_label *label, gfp_t gfp)
1831 struct aa_ns *ns = aa_get_current_ns();
1833 aa_label_seq_xprint(f, ns, label, FLAG_VIEW_SUBNS, gfp);
1837 void aa_label_printk(struct aa_label *label, gfp_t gfp)
1839 struct aa_ns *ns = aa_get_current_ns();
1841 aa_label_xprintk(ns, label, FLAG_VIEW_SUBNS, gfp);
1845 static int label_count_strn_entries(const char *str, size_t n)
1847 const char *end = str + n;
1853 for (split = aa_label_strn_split(str, end - str);
1855 split = aa_label_strn_split(str, end - str)) {
1864 * ensure stacks with components like
1866 * have :ns: applied to both 'A' and 'B' by making the lookup relative
1867 * to the base if the lookup specifies an ns, else making the stacked lookup
1868 * relative to the last embedded ns in the string.
1870 static struct aa_profile *fqlookupn_profile(struct aa_label *base,
1871 struct aa_label *currentbase,
1872 const char *str, size_t n)
1874 const char *first = skipn_spaces(str, n);
1876 if (first && *first == ':')
1877 return aa_fqlookupn_profile(base, str, n);
1879 return aa_fqlookupn_profile(currentbase, str, n);
1883 * aa_label_strn_parse - parse, validate and convert a text string to a label
1884 * @base: base label to use for lookups (NOT NULL)
1885 * @str: null terminated text string (NOT NULL)
1886 * @n: length of str to parse, will stop at \0 if encountered before n
1887 * @gfp: allocation type
1888 * @create: true if should create compound labels if they don't exist
1889 * @force_stack: true if should stack even if no leading &
1891 * Returns: the matching refcounted label if present
1894 struct aa_label *aa_label_strn_parse(struct aa_label *base, const char *str,
1895 size_t n, gfp_t gfp, bool create,
1898 DEFINE_VEC(profile, vec);
1899 struct aa_label *label, *currbase = base;
1900 int i, len, stack = 0, error;
1901 const char *end = str + n;
1907 str = skipn_spaces(str, n);
1908 if (str == NULL || (*str == '=' && base != &root_ns->unconfined->label))
1909 return ERR_PTR(-EINVAL);
1911 len = label_count_strn_entries(str, end - str);
1912 if (*str == '&' || force_stack) {
1913 /* stack on top of base */
1920 error = vec_setup(profile, vec, len, gfp);
1922 return ERR_PTR(error);
1924 for (i = 0; i < stack; i++)
1925 vec[i] = aa_get_profile(base->vec[i]);
1927 for (split = aa_label_strn_split(str, end - str), i = stack;
1928 split && i < len; i++) {
1929 vec[i] = fqlookupn_profile(base, currbase, str, split - str);
1933 * if component specified a new ns it becomes the new base
1934 * so that subsequent lookups are relative to it
1936 if (vec[i]->ns != labels_ns(currbase))
1937 currbase = &vec[i]->label;
1939 split = aa_label_strn_split(str, end - str);
1941 /* last element doesn't have a split */
1943 vec[i] = fqlookupn_profile(base, currbase, str, end - str);
1948 /* no need to free vec as len < LOCAL_VEC_ENTRIES */
1949 return &vec[0]->label;
1951 len -= aa_vec_unique(vec, len, VEC_FLAG_TERMINATE);
1952 /* TODO: deal with reference labels */
1954 label = aa_get_label(&vec[0]->label);
1959 label = aa_vec_find_or_create_label(vec, len, gfp);
1961 label = vec_find(vec, len);
1966 /* use adjusted len from after vec_unique, not original */
1967 vec_cleanup(profile, vec, len);
1971 label = ERR_PTR(-ENOENT);
1975 struct aa_label *aa_label_parse(struct aa_label *base, const char *str,
1976 gfp_t gfp, bool create, bool force_stack)
1978 return aa_label_strn_parse(base, str, strlen(str), gfp, create,
1983 * aa_labelset_destroy - remove all labels from the label set
1984 * @ls: label set to cleanup (NOT NULL)
1986 * Labels that are removed from the set may still exist beyond the set
1987 * being destroyed depending on their reference counting
1989 void aa_labelset_destroy(struct aa_labelset *ls)
1991 struct rb_node *node;
1992 unsigned long flags;
1996 write_lock_irqsave(&ls->lock, flags);
1997 for (node = rb_first(&ls->root); node; node = rb_first(&ls->root)) {
1998 struct aa_label *this = rb_entry(node, struct aa_label, node);
2000 if (labels_ns(this) != root_ns)
2001 __label_remove(this,
2002 ns_unconfined(labels_ns(this)->parent));
2004 __label_remove(this, NULL);
2006 write_unlock_irqrestore(&ls->lock, flags);
2010 * @ls: labelset to init (NOT NULL)
2012 void aa_labelset_init(struct aa_labelset *ls)
2016 rwlock_init(&ls->lock);
2020 static struct aa_label *labelset_next_stale(struct aa_labelset *ls)
2022 struct aa_label *label;
2023 struct rb_node *node;
2024 unsigned long flags;
2028 read_lock_irqsave(&ls->lock, flags);
2030 __labelset_for_each(ls, node) {
2031 label = rb_entry(node, struct aa_label, node);
2032 if ((label_is_stale(label) ||
2033 vec_is_stale(label->vec, label->size)) &&
2034 __aa_get_label(label))
2041 read_unlock_irqrestore(&ls->lock, flags);
2047 * __label_update - insert updated version of @label into labelset
2048 * @label - the label to update/replace
2050 * Returns: new label that is up to date
2051 * else NULL on failure
2053 * Requires: @ns lock be held
2055 * Note: worst case is the stale @label does not get updated and has
2056 * to be updated at a later time.
2058 static struct aa_label *__label_update(struct aa_label *label)
2060 struct aa_label *new, *tmp;
2061 struct aa_labelset *ls;
2062 unsigned long flags;
2063 int i, invcount = 0;
2066 AA_BUG(!mutex_is_locked(&labels_ns(label)->lock));
2068 new = aa_label_alloc(label->size, label->proxy, GFP_KERNEL);
2073 * while holding the ns_lock will stop profile replacement, removal,
2074 * and label updates, label merging and removal can be occurring
2076 ls = labels_set(label);
2077 write_lock_irqsave(&ls->lock, flags);
2078 for (i = 0; i < label->size; i++) {
2079 AA_BUG(!label->vec[i]);
2080 new->vec[i] = aa_get_newest_profile(label->vec[i]);
2081 AA_BUG(!new->vec[i]);
2082 AA_BUG(!new->vec[i]->label.proxy);
2083 AA_BUG(!new->vec[i]->label.proxy->label);
2084 if (new->vec[i]->label.proxy != label->vec[i]->label.proxy)
2088 /* updated stale label by being removed/renamed from labelset */
2090 new->size -= aa_vec_unique(&new->vec[0], new->size,
2091 VEC_FLAG_TERMINATE);
2092 /* TODO: deal with reference labels */
2093 if (new->size == 1) {
2094 tmp = aa_get_label(&new->vec[0]->label);
2095 AA_BUG(tmp == label);
2098 if (labels_set(label) != labels_set(new)) {
2099 write_unlock_irqrestore(&ls->lock, flags);
2100 tmp = aa_label_insert(labels_set(new), new);
2101 write_lock_irqsave(&ls->lock, flags);
2105 AA_BUG(labels_ns(label) != labels_ns(new));
2107 tmp = __label_insert(labels_set(label), new, true);
2109 /* ensure label is removed, and redirected correctly */
2110 __label_remove(label, tmp);
2111 write_unlock_irqrestore(&ls->lock, flags);
2112 label_free_or_put_new(tmp, new);
2118 * __labelset_update - update labels in @ns
2119 * @ns: namespace to update labels in (NOT NULL)
2121 * Requires: @ns lock be held
2123 * Walk the labelset ensuring that all labels are up to date and valid
2124 * Any label that has a stale component is marked stale and replaced and
2125 * by an updated version.
2127 * If failures happen due to memory pressures then stale labels will
2128 * be left in place until the next pass.
2130 static void __labelset_update(struct aa_ns *ns)
2132 struct aa_label *label;
2135 AA_BUG(!mutex_is_locked(&ns->lock));
2138 label = labelset_next_stale(&ns->labels);
2140 struct aa_label *l = __label_update(label);
2143 aa_put_label(label);
2149 * __aa_labelset_udate_subtree - update all labels with a stale component
2150 * @ns: ns to start update at (NOT NULL)
2152 * Requires: @ns lock be held
2154 * Invalidates labels based on @p in @ns and any children namespaces.
2156 void __aa_labelset_update_subtree(struct aa_ns *ns)
2158 struct aa_ns *child;
2161 AA_BUG(!mutex_is_locked(&ns->lock));
2163 __labelset_update(ns);
2165 list_for_each_entry(child, &ns->sub_ns, base.list) {
2166 mutex_lock_nested(&child->lock, child->level);
2167 __aa_labelset_update_subtree(child);
2168 mutex_unlock(&child->lock);