/* * AppArmor security module * * This file contains AppArmor label definitions * * Copyright 2017 Canonical Ltd. * * This program is free software; you can redistribute it and/or * modify it under the terms of the GNU General Public License as * published by the Free Software Foundation, version 2 of the * License. */ #include #include #include #include "include/apparmor.h" #include "include/cred.h" #include "include/label.h" #include "include/policy.h" #include "include/secid.h" /* * the aa_label represents the set of profiles confining an object * * Labels maintain a reference count to the set of pointers they reference * Labels are ref counted by * tasks and object via the security field/security context off the field * code - will take a ref count on a label if it needs the label * beyond what is possible with an rcu_read_lock. * profiles - each profile is a label * secids - a pinned secid will keep a refcount of the label it is * referencing * objects - inode, files, sockets, ... * * Labels are not ref counted by the label set, so they maybe removed and * freed when no longer in use. * */ #define PROXY_POISON 97 #define LABEL_POISON 100 static void free_proxy(struct aa_proxy *proxy) { if (proxy) { /* p->label will not updated any more as p is dead */ aa_put_label(rcu_dereference_protected(proxy->label, true)); memset(proxy, 0, sizeof(*proxy)); RCU_INIT_POINTER(proxy->label, (struct aa_label *)PROXY_POISON); kfree(proxy); } } void aa_proxy_kref(struct kref *kref) { struct aa_proxy *proxy = container_of(kref, struct aa_proxy, count); free_proxy(proxy); } struct aa_proxy *aa_alloc_proxy(struct aa_label *label, gfp_t gfp) { struct aa_proxy *new; new = kzalloc(sizeof(struct aa_proxy), gfp); if (new) { kref_init(&new->count); rcu_assign_pointer(new->label, aa_get_label(label)); } return new; } /* requires profile list write lock held */ void __aa_proxy_redirect(struct aa_label *orig, struct aa_label *new) { struct aa_label *tmp; AA_BUG(!orig); AA_BUG(!new); lockdep_assert_held_exclusive(&labels_set(orig)->lock); tmp = rcu_dereference_protected(orig->proxy->label, &labels_ns(orig)->lock); rcu_assign_pointer(orig->proxy->label, aa_get_label(new)); orig->flags |= FLAG_STALE; aa_put_label(tmp); } static void __proxy_share(struct aa_label *old, struct aa_label *new) { struct aa_proxy *proxy = new->proxy; new->proxy = aa_get_proxy(old->proxy); __aa_proxy_redirect(old, new); aa_put_proxy(proxy); } /** * ns_cmp - compare ns for label set ordering * @a: ns to compare (NOT NULL) * @b: ns to compare (NOT NULL) * * Returns: <0 if a < b * ==0 if a == b * >0 if a > b */ static int ns_cmp(struct aa_ns *a, struct aa_ns *b) { int res; AA_BUG(!a); AA_BUG(!b); AA_BUG(!a->base.hname); AA_BUG(!b->base.hname); if (a == b) return 0; res = a->level - b->level; if (res) return res; return strcmp(a->base.hname, b->base.hname); } /** * profile_cmp - profile comparison for set ordering * @a: profile to compare (NOT NULL) * @b: profile to compare (NOT NULL) * * Returns: <0 if a < b * ==0 if a == b * >0 if a > b */ static int profile_cmp(struct aa_profile *a, struct aa_profile *b) { int res; AA_BUG(!a); AA_BUG(!b); AA_BUG(!a->ns); AA_BUG(!b->ns); AA_BUG(!a->base.hname); AA_BUG(!b->base.hname); if (a == b || a->base.hname == b->base.hname) return 0; res = ns_cmp(a->ns, b->ns); if (res) return res; return strcmp(a->base.hname, b->base.hname); } /** * vec_cmp - label comparison for set ordering * @a: label to compare (NOT NULL) * @vec: vector of profiles to compare (NOT NULL) * @n: length of @vec * * Returns: <0 if a < vec * ==0 if a == vec * >0 if a > vec */ static int vec_cmp(struct aa_profile **a, int an, struct aa_profile **b, int bn) { int i; AA_BUG(!a); AA_BUG(!*a); AA_BUG(!b); AA_BUG(!*b); AA_BUG(an <= 0); AA_BUG(bn <= 0); for (i = 0; i < an && i < bn; i++) { int res = profile_cmp(a[i], b[i]); if (res != 0) return res; } return an - bn; } static bool vec_is_stale(struct aa_profile **vec, int n) { int i; AA_BUG(!vec); for (i = 0; i < n; i++) { if (profile_is_stale(vec[i])) return true; } return false; } static bool vec_unconfined(struct aa_profile **vec, int n) { int i; AA_BUG(!vec); for (i = 0; i < n; i++) { if (!profile_unconfined(vec[i])) return false; } return true; } static int sort_cmp(const void *a, const void *b) { return profile_cmp(*(struct aa_profile **)a, *(struct aa_profile **)b); } /* * assumes vec is sorted * Assumes @vec has null terminator at vec[n], and will null terminate * vec[n - dups] */ static inline int unique(struct aa_profile **vec, int n) { int i, pos, dups = 0; AA_BUG(n < 1); AA_BUG(!vec); pos = 0; for (i = 1; i < n; i++) { int res = profile_cmp(vec[pos], vec[i]); AA_BUG(res > 0, "vec not sorted"); if (res == 0) { /* drop duplicate */ aa_put_profile(vec[i]); dups++; continue; } pos++; if (dups) vec[pos] = vec[i]; } AA_BUG(dups < 0); return dups; } /** * aa_vec_unique - canonical sort and unique a list of profiles * @n: number of refcounted profiles in the list (@n > 0) * @vec: list of profiles to sort and merge * * Returns: the number of duplicates eliminated == references put * * If @flags & VEC_FLAG_TERMINATE @vec has null terminator at vec[n], and will * null terminate vec[n - dups] */ int aa_vec_unique(struct aa_profile **vec, int n, int flags) { int i, dups = 0; AA_BUG(n < 1); AA_BUG(!vec); /* vecs are usually small and inorder, have a fallback for larger */ if (n > 8) { sort(vec, n, sizeof(struct aa_profile *), sort_cmp, NULL); dups = unique(vec, n); goto out; } /* insertion sort + unique in one */ for (i = 1; i < n; i++) { struct aa_profile *tmp = vec[i]; int pos, j; for (pos = i - 1 - dups; pos >= 0; pos--) { int res = profile_cmp(vec[pos], tmp); if (res == 0) { /* drop duplicate entry */ aa_put_profile(tmp); dups++; goto continue_outer; } else if (res < 0) break; } /* pos is at entry < tmp, or index -1. Set to insert pos */ pos++; for (j = i - dups; j > pos; j--) vec[j] = vec[j - 1]; vec[pos] = tmp; continue_outer: ; } AA_BUG(dups < 0); out: if (flags & VEC_FLAG_TERMINATE) vec[n - dups] = NULL; return dups; } static void label_destroy(struct aa_label *label) { struct aa_label *tmp; AA_BUG(!label); if (!label_isprofile(label)) { struct aa_profile *profile; struct label_it i; aa_put_str(label->hname); label_for_each(i, label, profile) { aa_put_profile(profile); label->vec[i.i] = (struct aa_profile *) (LABEL_POISON + (long) i.i); } } if (rcu_dereference_protected(label->proxy->label, true) == label) rcu_assign_pointer(label->proxy->label, NULL); aa_free_secid(label->secid); tmp = rcu_dereference_protected(label->proxy->label, true); if (tmp == label) rcu_assign_pointer(label->proxy->label, NULL); aa_put_proxy(label->proxy); label->proxy = (struct aa_proxy *) PROXY_POISON + 1; } void aa_label_free(struct aa_label *label) { if (!label) return; label_destroy(label); kfree(label); } static void label_free_switch(struct aa_label *label) { if (label->flags & FLAG_NS_COUNT) aa_free_ns(labels_ns(label)); else if (label_isprofile(label)) aa_free_profile(labels_profile(label)); else aa_label_free(label); } static void label_free_rcu(struct rcu_head *head) { struct aa_label *label = container_of(head, struct aa_label, rcu); if (label->flags & FLAG_IN_TREE) (void) aa_label_remove(label); label_free_switch(label); } void aa_label_kref(struct kref *kref) { struct aa_label *label = container_of(kref, struct aa_label, count); struct aa_ns *ns = labels_ns(label); if (!ns) { /* never live, no rcu callback needed, just using the fn */ label_free_switch(label); return; } /* TODO: update labels_profile macro so it works here */ AA_BUG(label_isprofile(label) && on_list_rcu(&label->vec[0]->base.profiles)); AA_BUG(label_isprofile(label) && on_list_rcu(&label->vec[0]->base.list)); /* TODO: if compound label and not stale add to reclaim cache */ call_rcu(&label->rcu, label_free_rcu); } static void label_free_or_put_new(struct aa_label *label, struct aa_label *new) { if (label != new) /* need to free directly to break circular ref with proxy */ aa_label_free(new); else aa_put_label(new); } bool aa_label_init(struct aa_label *label, int size, gfp_t gfp) { AA_BUG(!label); AA_BUG(size < 1); if (aa_alloc_secid(label, gfp) < 0) return false; label->size = size; /* doesn't include null */ label->vec[size] = NULL; /* null terminate */ kref_init(&label->count); RB_CLEAR_NODE(&label->node); return true; } /** * aa_label_alloc - allocate a label with a profile vector of @size length * @size: size of profile vector in the label * @proxy: proxy to use OR null if to allocate a new one * @gfp: memory allocation type * * Returns: new label * else NULL if failed */ struct aa_label *aa_label_alloc(int size, struct aa_proxy *proxy, gfp_t gfp) { struct aa_label *new; AA_BUG(size < 1); /* + 1 for null terminator entry on vec */ new = kzalloc(sizeof(*new) + sizeof(struct aa_profile *) * (size + 1), gfp); AA_DEBUG("%s (%p)\n", __func__, new); if (!new) goto fail; if (!aa_label_init(new, size, gfp)) goto fail; if (!proxy) { proxy = aa_alloc_proxy(new, gfp); if (!proxy) goto fail; } else aa_get_proxy(proxy); /* just set new's proxy, don't redirect proxy here if it was passed in*/ new->proxy = proxy; return new; fail: kfree(new); return NULL; } /** * label_cmp - label comparison for set ordering * @a: label to compare (NOT NULL) * @b: label to compare (NOT NULL) * * Returns: <0 if a < b * ==0 if a == b * >0 if a > b */ static int label_cmp(struct aa_label *a, struct aa_label *b) { AA_BUG(!b); if (a == b) return 0; return vec_cmp(a->vec, a->size, b->vec, b->size); } /* helper fn for label_for_each_confined */ int aa_label_next_confined(struct aa_label *label, int i) { AA_BUG(!label); AA_BUG(i < 0); for (; i < label->size; i++) { if (!profile_unconfined(label->vec[i])) return i; } return i; } /** * aa_label_next_not_in_set - return the next profile of @sub not in @set * @I: label iterator * @set: label to test against * @sub: label to if is subset of @set * * Returns: profile in @sub that is not in @set, with iterator set pos after * else NULL if @sub is a subset of @set */ struct aa_profile *__aa_label_next_not_in_set(struct label_it *I, struct aa_label *set, struct aa_label *sub) { AA_BUG(!set); AA_BUG(!I); AA_BUG(I->i < 0); AA_BUG(I->i > set->size); AA_BUG(!sub); AA_BUG(I->j < 0); AA_BUG(I->j > sub->size); while (I->j < sub->size && I->i < set->size) { int res = profile_cmp(sub->vec[I->j], set->vec[I->i]); if (res == 0) { (I->j)++; (I->i)++; } else if (res > 0) (I->i)++; else return sub->vec[(I->j)++]; } if (I->j < sub->size) return sub->vec[(I->j)++]; return NULL; } /** * aa_label_is_subset - test if @sub is a subset of @set * @set: label to test against * @sub: label to test if is subset of @set * * Returns: true if @sub is subset of @set * else false */ bool aa_label_is_subset(struct aa_label *set, struct aa_label *sub) { struct label_it i = { }; AA_BUG(!set); AA_BUG(!sub); if (sub == set) return true; return __aa_label_next_not_in_set(&i, set, sub) == NULL; } /** * __label_remove - remove @label from the label set * @l: label to remove * @new: label to redirect to * * Requires: labels_set(@label)->lock write_lock * Returns: true if the label was in the tree and removed */ static bool __label_remove(struct aa_label *label, struct aa_label *new) { struct aa_labelset *ls = labels_set(label); AA_BUG(!ls); AA_BUG(!label); lockdep_assert_held_exclusive(&ls->lock); if (new) __aa_proxy_redirect(label, new); if (!label_is_stale(label)) __label_make_stale(label); if (label->flags & FLAG_IN_TREE) { rb_erase(&label->node, &ls->root); label->flags &= ~FLAG_IN_TREE; return true; } return false; } /** * __label_replace - replace @old with @new in label set * @old: label to remove from label set * @new: label to replace @old with * * Requires: labels_set(@old)->lock write_lock * valid ref count be held on @new * Returns: true if @old was in set and replaced by @new * * Note: current implementation requires label set be order in such a way * that @new directly replaces @old position in the set (ie. * using pointer comparison of the label address would not work) */ static bool __label_replace(struct aa_label *old, struct aa_label *new) { struct aa_labelset *ls = labels_set(old); AA_BUG(!ls); AA_BUG(!old); AA_BUG(!new); lockdep_assert_held_exclusive(&ls->lock); AA_BUG(new->flags & FLAG_IN_TREE); if (!label_is_stale(old)) __label_make_stale(old); if (old->flags & FLAG_IN_TREE) { rb_replace_node(&old->node, &new->node, &ls->root); old->flags &= ~FLAG_IN_TREE; new->flags |= FLAG_IN_TREE; return true; } return false; } /** * __label_insert - attempt to insert @l into a label set * @ls: set of labels to insert @l into (NOT NULL) * @label: new label to insert (NOT NULL) * @replace: whether insertion should replace existing entry that is not stale * * Requires: @ls->lock * caller to hold a valid ref on l * if @replace is true l has a preallocated proxy associated * Returns: @l if successful in inserting @l - with additional refcount * else ref counted equivalent label that is already in the set, * the else condition only happens if @replace is false */ static struct aa_label *__label_insert(struct aa_labelset *ls, struct aa_label *label, bool replace) { struct rb_node **new, *parent = NULL; AA_BUG(!ls); AA_BUG(!label); AA_BUG(labels_set(label) != ls); lockdep_assert_held_exclusive(&ls->lock); AA_BUG(label->flags & FLAG_IN_TREE); /* Figure out where to put new node */ new = &ls->root.rb_node; while (*new) { struct aa_label *this = rb_entry(*new, struct aa_label, node); int result = label_cmp(label, this); parent = *new; if (result == 0) { /* !__aa_get_label means queued for destruction, * so replace in place, however the label has * died before the replacement so do not share * the proxy */ if (!replace && !label_is_stale(this)) { if (__aa_get_label(this)) return this; } else __proxy_share(this, label); AA_BUG(!__label_replace(this, label)); return aa_get_label(label); } else if (result < 0) new = &((*new)->rb_left); else /* (result > 0) */ new = &((*new)->rb_right); } /* Add new node and rebalance tree. */ rb_link_node(&label->node, parent, new); rb_insert_color(&label->node, &ls->root); label->flags |= FLAG_IN_TREE; return aa_get_label(label); } /** * __vec_find - find label that matches @vec in label set * @vec: vec of profiles to find matching label for (NOT NULL) * @n: length of @vec * * Requires: @vec_labelset(vec) lock held * caller to hold a valid ref on l * * Returns: ref counted @label if matching label is in tree * ref counted label that is equiv to @l in tree * else NULL if @vec equiv is not in tree */ static struct aa_label *__vec_find(struct aa_profile **vec, int n) { struct rb_node *node; AA_BUG(!vec); AA_BUG(!*vec); AA_BUG(n <= 0); node = vec_labelset(vec, n)->root.rb_node; while (node) { struct aa_label *this = rb_entry(node, struct aa_label, node); int result = vec_cmp(this->vec, this->size, vec, n); if (result > 0) node = node->rb_left; else if (result < 0) node = node->rb_right; else return __aa_get_label(this); } return NULL; } /** * __label_find - find label @label in label set * @label: label to find (NOT NULL) * * Requires: labels_set(@label)->lock held * caller to hold a valid ref on l * * Returns: ref counted @label if @label is in tree OR * ref counted label that is equiv to @label in tree * else NULL if @label or equiv is not in tree */ static struct aa_label *__label_find(struct aa_label *label) { AA_BUG(!label); return __vec_find(label->vec, label->size); } /** * aa_label_remove - remove a label from the labelset * @label: label to remove * * Returns: true if @label was removed from the tree * else @label was not in tree so it could not be removed */ bool aa_label_remove(struct aa_label *label) { struct aa_labelset *ls = labels_set(label); unsigned long flags; bool res; AA_BUG(!ls); write_lock_irqsave(&ls->lock, flags); res = __label_remove(label, ns_unconfined(labels_ns(label))); write_unlock_irqrestore(&ls->lock, flags); return res; } /** * aa_label_replace - replace a label @old with a new version @new * @old: label to replace * @new: label replacing @old * * Returns: true if @old was in tree and replaced * else @old was not in tree, and @new was not inserted */ bool aa_label_replace(struct aa_label *old, struct aa_label *new) { unsigned long flags; bool res; if (name_is_shared(old, new) && labels_ns(old) == labels_ns(new)) { write_lock_irqsave(&labels_set(old)->lock, flags); if (old->proxy != new->proxy) __proxy_share(old, new); else __aa_proxy_redirect(old, new); res = __label_replace(old, new); write_unlock_irqrestore(&labels_set(old)->lock, flags); } else { struct aa_label *l; struct aa_labelset *ls = labels_set(old); write_lock_irqsave(&ls->lock, flags); res = __label_remove(old, new); if (labels_ns(old) != labels_ns(new)) { write_unlock_irqrestore(&ls->lock, flags); ls = labels_set(new); write_lock_irqsave(&ls->lock, flags); } l = __label_insert(ls, new, true); res = (l == new); write_unlock_irqrestore(&ls->lock, flags); aa_put_label(l); } return res; } /** * vec_find - find label @l in label set * @vec: array of profiles to find equiv label for (NOT NULL) * @n: length of @vec * * Returns: refcounted label if @vec equiv is in tree * else NULL if @vec equiv is not in tree */ static struct aa_label *vec_find(struct aa_profile **vec, int n) { struct aa_labelset *ls; struct aa_label *label; unsigned long flags; AA_BUG(!vec); AA_BUG(!*vec); AA_BUG(n <= 0); ls = vec_labelset(vec, n); read_lock_irqsave(&ls->lock, flags); label = __vec_find(vec, n); read_unlock_irqrestore(&ls->lock, flags); return label; } /* requires sort and merge done first */ static struct aa_label *vec_create_and_insert_label(struct aa_profile **vec, int len, gfp_t gfp) { struct aa_label *label = NULL; struct aa_labelset *ls; unsigned long flags; struct aa_label *new; int i; AA_BUG(!vec); if (len == 1) return aa_get_label(&vec[0]->label); ls = labels_set(&vec[len - 1]->label); /* TODO: enable when read side is lockless * check if label exists before taking locks */ new = aa_label_alloc(len, NULL, gfp); if (!new) return NULL; for (i = 0; i < len; i++) new->vec[i] = aa_get_profile(vec[i]); write_lock_irqsave(&ls->lock, flags); label = __label_insert(ls, new, false); write_unlock_irqrestore(&ls->lock, flags); label_free_or_put_new(label, new); return label; } struct aa_label *aa_vec_find_or_create_label(struct aa_profile **vec, int len, gfp_t gfp) { struct aa_label *label = vec_find(vec, len); if (label) return label; return vec_create_and_insert_label(vec, len, gfp); } /** * aa_label_find - find label @label in label set * @label: label to find (NOT NULL) * * Requires: caller to hold a valid ref on l * * Returns: refcounted @label if @label is in tree * refcounted label that is equiv to @label in tree * else NULL if @label or equiv is not in tree */ struct aa_label *aa_label_find(struct aa_label *label) { AA_BUG(!label); return vec_find(label->vec, label->size); } /** * aa_label_insert - insert label @label into @ls or return existing label * @ls - labelset to insert @label into * @label - label to insert * * Requires: caller to hold a valid ref on @label * * Returns: ref counted @label if successful in inserting @label * else ref counted equivalent label that is already in the set */ struct aa_label *aa_label_insert(struct aa_labelset *ls, struct aa_label *label) { struct aa_label *l; unsigned long flags; AA_BUG(!ls); AA_BUG(!label); /* check if label exists before taking lock */ if (!label_is_stale(label)) { read_lock_irqsave(&ls->lock, flags); l = __label_find(label); read_unlock_irqrestore(&ls->lock, flags); if (l) return l; } write_lock_irqsave(&ls->lock, flags); l = __label_insert(ls, label, false); write_unlock_irqrestore(&ls->lock, flags); return l; } /** * aa_label_next_in_merge - find the next profile when merging @a and @b * @I: label iterator * @a: label to merge * @b: label to merge * * Returns: next profile * else null if no more profiles */ struct aa_profile *aa_label_next_in_merge(struct label_it *I, struct aa_label *a, struct aa_label *b) { AA_BUG(!a); AA_BUG(!b); AA_BUG(!I); AA_BUG(I->i < 0); AA_BUG(I->i > a->size); AA_BUG(I->j < 0); AA_BUG(I->j > b->size); if (I->i < a->size) { if (I->j < b->size) { int res = profile_cmp(a->vec[I->i], b->vec[I->j]); if (res > 0) return b->vec[(I->j)++]; if (res == 0) (I->j)++; } return a->vec[(I->i)++]; } if (I->j < b->size) return b->vec[(I->j)++]; return NULL; } /** * label_merge_cmp - cmp of @a merging with @b against @z for set ordering * @a: label to merge then compare (NOT NULL) * @b: label to merge then compare (NOT NULL) * @z: label to compare merge against (NOT NULL) * * Assumes: using the most recent versions of @a, @b, and @z * * Returns: <0 if a < b * ==0 if a == b * >0 if a > b */ static int label_merge_cmp(struct aa_label *a, struct aa_label *b, struct aa_label *z) { struct aa_profile *p = NULL; struct label_it i = { }; int k; AA_BUG(!a); AA_BUG(!b); AA_BUG(!z); for (k = 0; k < z->size && (p = aa_label_next_in_merge(&i, a, b)); k++) { int res = profile_cmp(p, z->vec[k]); if (res != 0) return res; } if (p) return 1; else if (k < z->size) return -1; return 0; } /** * label_merge_insert - create a new label by merging @a and @b * @new: preallocated label to merge into (NOT NULL) * @a: label to merge with @b (NOT NULL) * @b: label to merge with @a (NOT NULL) * * Requires: preallocated proxy * * Returns: ref counted label either @new if merge is unique * @a if @b is a subset of @a * @b if @a is a subset of @b * * NOTE: will not use @new if the merge results in @new == @a or @b * * Must be used within labelset write lock to avoid racing with * setting labels stale. */ static struct aa_label *label_merge_insert(struct aa_label *new, struct aa_label *a, struct aa_label *b) { struct aa_label *label; struct aa_labelset *ls; struct aa_profile *next; struct label_it i; unsigned long flags; int k = 0, invcount = 0; bool stale = false; AA_BUG(!a); AA_BUG(a->size < 0); AA_BUG(!b); AA_BUG(b->size < 0); AA_BUG(!new); AA_BUG(new->size < a->size + b->size); label_for_each_in_merge(i, a, b, next) { AA_BUG(!next); if (profile_is_stale(next)) { new->vec[k] = aa_get_newest_profile(next); AA_BUG(!new->vec[k]->label.proxy); AA_BUG(!new->vec[k]->label.proxy->label); if (next->label.proxy != new->vec[k]->label.proxy) invcount++; k++; stale = true; } else new->vec[k++] = aa_get_profile(next); } /* set to actual size which is <= allocated len */ new->size = k; new->vec[k] = NULL; if (invcount) { new->size -= aa_vec_unique(&new->vec[0], new->size, VEC_FLAG_TERMINATE); /* TODO: deal with reference labels */ if (new->size == 1) { label = aa_get_label(&new->vec[0]->label); return label; } } else if (!stale) { /* * merge could be same as a || b, note: it is not possible * for new->size == a->size == b->size unless a == b */ if (k == a->size) return aa_get_label(a); else if (k == b->size) return aa_get_label(b); } if (vec_unconfined(new->vec, new->size)) new->flags |= FLAG_UNCONFINED; ls = labels_set(new); write_lock_irqsave(&ls->lock, flags); label = __label_insert(labels_set(new), new, false); write_unlock_irqrestore(&ls->lock, flags); return label; } /** * labelset_of_merge - find which labelset a merged label should be inserted * @a: label to merge and insert * @b: label to merge and insert * * Returns: labelset that the merged label should be inserted into */ static struct aa_labelset *labelset_of_merge(struct aa_label *a, struct aa_label *b) { struct aa_ns *nsa = labels_ns(a); struct aa_ns *nsb = labels_ns(b); if (ns_cmp(nsa, nsb) <= 0) return &nsa->labels; return &nsb->labels; } /** * __label_find_merge - find label that is equiv to merge of @a and @b * @ls: set of labels to search (NOT NULL) * @a: label to merge with @b (NOT NULL) * @b: label to merge with @a (NOT NULL) * * Requires: ls->lock read_lock held * * Returns: ref counted label that is equiv to merge of @a and @b * else NULL if merge of @a and @b is not in set */ static struct aa_label *__label_find_merge(struct aa_labelset *ls, struct aa_label *a, struct aa_label *b) { struct rb_node *node; AA_BUG(!ls); AA_BUG(!a); AA_BUG(!b); if (a == b) return __label_find(a); node = ls->root.rb_node; while (node) { struct aa_label *this = container_of(node, struct aa_label, node); int result = label_merge_cmp(a, b, this); if (result < 0) node = node->rb_left; else if (result > 0) node = node->rb_right; else return __aa_get_label(this); } return NULL; } /** * aa_label_find_merge - find label that is equiv to merge of @a and @b * @a: label to merge with @b (NOT NULL) * @b: label to merge with @a (NOT NULL) * * Requires: labels be fully constructed with a valid ns * * Returns: ref counted label that is equiv to merge of @a and @b * else NULL if merge of @a and @b is not in set */ struct aa_label *aa_label_find_merge(struct aa_label *a, struct aa_label *b) { struct aa_labelset *ls; struct aa_label *label, *ar = NULL, *br = NULL; unsigned long flags; AA_BUG(!a); AA_BUG(!b); if (label_is_stale(a)) a = ar = aa_get_newest_label(a); if (label_is_stale(b)) b = br = aa_get_newest_label(b); ls = labelset_of_merge(a, b); read_lock_irqsave(&ls->lock, flags); label = __label_find_merge(ls, a, b); read_unlock_irqrestore(&ls->lock, flags); aa_put_label(ar); aa_put_label(br); return label; } /** * aa_label_merge - attempt to insert new merged label of @a and @b * @ls: set of labels to insert label into (NOT NULL) * @a: label to merge with @b (NOT NULL) * @b: label to merge with @a (NOT NULL) * @gfp: memory allocation type * * Requires: caller to hold valid refs on @a and @b * labels be fully constructed with a valid ns * * Returns: ref counted new label if successful in inserting merge of a & b * else ref counted equivalent label that is already in the set. * else NULL if could not create label (-ENOMEM) */ struct aa_label *aa_label_merge(struct aa_label *a, struct aa_label *b, gfp_t gfp) { struct aa_label *label = NULL; AA_BUG(!a); AA_BUG(!b); if (a == b) return aa_get_newest_label(a); /* TODO: enable when read side is lockless * check if label exists before taking locks if (!label_is_stale(a) && !label_is_stale(b)) label = aa_label_find_merge(a, b); */ if (!label) { struct aa_label *new; a = aa_get_newest_label(a); b = aa_get_newest_label(b); /* could use label_merge_len(a, b), but requires double * comparison for small savings */ new = aa_label_alloc(a->size + b->size, NULL, gfp); if (!new) goto out; label = label_merge_insert(new, a, b); label_free_or_put_new(label, new); out: aa_put_label(a); aa_put_label(b); } return label; } static inline bool label_is_visible(struct aa_profile *profile, struct aa_label *label) { return aa_ns_visible(profile->ns, labels_ns(label), true); } /* match a profile and its associated ns component if needed * Assumes visibility test has already been done. * If a subns profile is not to be matched should be prescreened with * visibility test. */ static inline unsigned int match_component(struct aa_profile *profile, struct aa_profile *tp, unsigned int state) { const char *ns_name; if (profile->ns == tp->ns) return aa_dfa_match(profile->policy.dfa, state, tp->base.hname); /* try matching with namespace name and then profile */ ns_name = aa_ns_name(profile->ns, tp->ns, true); state = aa_dfa_match_len(profile->policy.dfa, state, ":", 1); state = aa_dfa_match(profile->policy.dfa, state, ns_name); state = aa_dfa_match_len(profile->policy.dfa, state, ":", 1); return aa_dfa_match(profile->policy.dfa, state, tp->base.hname); } /** * label_compound_match - find perms for full compound label * @profile: profile to find perms for * @label: label to check access permissions for * @start: state to start match in * @subns: whether to do permission checks on components in a subns * @request: permissions to request * @perms: perms struct to set * * Returns: 0 on success else ERROR * * For the label A//&B//&C this does the perm match for A//&B//&C * @perms should be preinitialized with allperms OR a previous permission * check to be stacked. */ static int label_compound_match(struct aa_profile *profile, struct aa_label *label, unsigned int state, bool subns, u32 request, struct aa_perms *perms) { struct aa_profile *tp; struct label_it i; /* find first subcomponent that is visible */ label_for_each(i, label, tp) { if (!aa_ns_visible(profile->ns, tp->ns, subns)) continue; state = match_component(profile, tp, state); if (!state) goto fail; goto next; } /* no component visible */ *perms = allperms; return 0; next: label_for_each_cont(i, label, tp) { if (!aa_ns_visible(profile->ns, tp->ns, subns)) continue; state = aa_dfa_match(profile->policy.dfa, state, "//&"); state = match_component(profile, tp, state); if (!state) goto fail; } aa_compute_perms(profile->policy.dfa, state, perms); aa_apply_modes_to_perms(profile, perms); if ((perms->allow & request) != request) return -EACCES; return 0; fail: *perms = nullperms; return state; } /** * label_components_match - find perms for all subcomponents of a label * @profile: profile to find perms for * @label: label to check access permissions for * @start: state to start match in * @subns: whether to do permission checks on components in a subns * @request: permissions to request * @perms: an initialized perms struct to add accumulation to * * Returns: 0 on success else ERROR * * For the label A//&B//&C this does the perm match for each of A and B and C * @perms should be preinitialized with allperms OR a previous permission * check to be stacked. */ static int label_components_match(struct aa_profile *profile, struct aa_label *label, unsigned int start, bool subns, u32 request, struct aa_perms *perms) { struct aa_profile *tp; struct label_it i; struct aa_perms tmp; unsigned int state = 0; /* find first subcomponent to test */ label_for_each(i, label, tp) { if (!aa_ns_visible(profile->ns, tp->ns, subns)) continue; state = match_component(profile, tp, start); if (!state) goto fail; goto next; } /* no subcomponents visible - no change in perms */ return 0; next: aa_compute_perms(profile->policy.dfa, state, &tmp); aa_apply_modes_to_perms(profile, &tmp); aa_perms_accum(perms, &tmp); label_for_each_cont(i, label, tp) { if (!aa_ns_visible(profile->ns, tp->ns, subns)) continue; state = match_component(profile, tp, start); if (!state) goto fail; aa_compute_perms(profile->policy.dfa, state, &tmp); aa_apply_modes_to_perms(profile, &tmp); aa_perms_accum(perms, &tmp); } if ((perms->allow & request) != request) return -EACCES; return 0; fail: *perms = nullperms; return -EACCES; } /** * aa_label_match - do a multi-component label match * @profile: profile to match against (NOT NULL) * @label: label to match (NOT NULL) * @state: state to start in * @subns: whether to match subns components * @request: permission request * @perms: Returns computed perms (NOT NULL) * * Returns: the state the match finished in, may be the none matching state */ int aa_label_match(struct aa_profile *profile, struct aa_label *label, unsigned int state, bool subns, u32 request, struct aa_perms *perms) { int error = label_compound_match(profile, label, state, subns, request, perms); if (!error) return error; *perms = allperms; return label_components_match(profile, label, state, subns, request, perms); } /** * aa_update_label_name - update a label to have a stored name * @ns: ns being viewed from (NOT NULL) * @label: label to update (NOT NULL) * @gfp: type of memory allocation * * Requires: labels_set(label) not locked in caller * * note: only updates the label name if it does not have a name already * and if it is in the labelset */ bool aa_update_label_name(struct aa_ns *ns, struct aa_label *label, gfp_t gfp) { struct aa_labelset *ls; unsigned long flags; char __counted *name; bool res = false; AA_BUG(!ns); AA_BUG(!label); if (label->hname || labels_ns(label) != ns) return res; if (aa_label_acntsxprint(&name, ns, label, FLAGS_NONE, gfp) == -1) return res; ls = labels_set(label); write_lock_irqsave(&ls->lock, flags); if (!label->hname && label->flags & FLAG_IN_TREE) { label->hname = name; res = true; } else aa_put_str(name); write_unlock_irqrestore(&ls->lock, flags); return res; } /* * cached label name is present and visible * @label->hname only exists if label is namespace hierachical */ static inline bool use_label_hname(struct aa_ns *ns, struct aa_label *label, int flags) { if (label->hname && (!ns || labels_ns(label) == ns) && !(flags & ~FLAG_SHOW_MODE)) return true; return false; } /* helper macro for snprint routines */ #define update_for_len(total, len, size, str) \ do { \ AA_BUG(len < 0); \ total += len; \ len = min(len, size); \ size -= len; \ str += len; \ } while (0) /** * aa_profile_snxprint - print a profile name to a buffer * @str: buffer to write to. (MAY BE NULL if @size == 0) * @size: size of buffer * @view: namespace profile is being viewed from * @profile: profile to view (NOT NULL) * @flags: whether to include the mode string * @prev_ns: last ns printed when used in compound print * * Returns: size of name written or would be written if larger than * available buffer * * Note: will not print anything if the profile is not visible */ static int aa_profile_snxprint(char *str, size_t size, struct aa_ns *view, struct aa_profile *profile, int flags, struct aa_ns **prev_ns) { const char *ns_name = NULL; AA_BUG(!str && size != 0); AA_BUG(!profile); if (!view) view = profiles_ns(profile); if (view != profile->ns && (!prev_ns || (*prev_ns != profile->ns))) { if (prev_ns) *prev_ns = profile->ns; ns_name = aa_ns_name(view, profile->ns, flags & FLAG_VIEW_SUBNS); if (ns_name == aa_hidden_ns_name) { if (flags & FLAG_HIDDEN_UNCONFINED) return snprintf(str, size, "%s", "unconfined"); return snprintf(str, size, "%s", ns_name); } } if ((flags & FLAG_SHOW_MODE) && profile != profile->ns->unconfined) { const char *modestr = aa_profile_mode_names[profile->mode]; if (ns_name) return snprintf(str, size, ":%s:%s (%s)", ns_name, profile->base.hname, modestr); return snprintf(str, size, "%s (%s)", profile->base.hname, modestr); } if (ns_name) return snprintf(str, size, ":%s:%s", ns_name, profile->base.hname); return snprintf(str, size, "%s", profile->base.hname); } static const char *label_modename(struct aa_ns *ns, struct aa_label *label, int flags) { struct aa_profile *profile; struct label_it i; int mode = -1, count = 0; label_for_each(i, label, profile) { if (aa_ns_visible(ns, profile->ns, flags & FLAG_VIEW_SUBNS)) { if (profile->mode == APPARMOR_UNCONFINED) /* special case unconfined so stacks with * unconfined don't report as mixed. ie. * profile_foo//&:ns1:unconfined (mixed) */ continue; count++; if (mode == -1) mode = profile->mode; else if (mode != profile->mode) return "mixed"; } } if (count == 0) return "-"; if (mode == -1) /* everything was unconfined */ mode = APPARMOR_UNCONFINED; return aa_profile_mode_names[mode]; } /* if any visible label is not unconfined the display_mode returns true */ static inline bool display_mode(struct aa_ns *ns, struct aa_label *label, int flags) { if ((flags & FLAG_SHOW_MODE)) { struct aa_profile *profile; struct label_it i; label_for_each(i, label, profile) { if (aa_ns_visible(ns, profile->ns, flags & FLAG_VIEW_SUBNS) && profile != profile->ns->unconfined) return true; } /* only ns->unconfined in set of profiles in ns */ return false; } return false; } /** * aa_label_snxprint - print a label name to a string buffer * @str: buffer to write to. (MAY BE NULL if @size == 0) * @size: size of buffer * @ns: namespace profile is being viewed from * @label: label to view (NOT NULL) * @flags: whether to include the mode string * * Returns: size of name written or would be written if larger than * available buffer * * Note: labels do not have to be strictly hierarchical to the ns as * objects may be shared across different namespaces and thus * pickup labeling from each ns. If a particular part of the * label is not visible it will just be excluded. And if none * of the label is visible "---" will be used. */ int aa_label_snxprint(char *str, size_t size, struct aa_ns *ns, struct aa_label *label, int flags) { struct aa_profile *profile; struct aa_ns *prev_ns = NULL; struct label_it i; int count = 0, total = 0; size_t len; AA_BUG(!str && size != 0); AA_BUG(!label); if (flags & FLAG_ABS_ROOT) { ns = root_ns; len = snprintf(str, size, "="); update_for_len(total, len, size, str); } else if (!ns) { ns = labels_ns(label); } label_for_each(i, label, profile) { if (aa_ns_visible(ns, profile->ns, flags & FLAG_VIEW_SUBNS)) { if (count > 0) { len = snprintf(str, size, "//&"); update_for_len(total, len, size, str); } len = aa_profile_snxprint(str, size, ns, profile, flags & FLAG_VIEW_SUBNS, &prev_ns); update_for_len(total, len, size, str); count++; } } if (count == 0) { if (flags & FLAG_HIDDEN_UNCONFINED) return snprintf(str, size, "%s", "unconfined"); return snprintf(str, size, "%s", aa_hidden_ns_name); } /* count == 1 && ... is for backwards compat where the mode * is not displayed for 'unconfined' in the current ns */ if (display_mode(ns, label, flags)) { len = snprintf(str, size, " (%s)", label_modename(ns, label, flags)); update_for_len(total, len, size, str); } return total; } #undef update_for_len /** * aa_label_asxprint - allocate a string buffer and print label into it * @strp: Returns - the allocated buffer with the label name. (NOT NULL) * @ns: namespace profile is being viewed from * @label: label to view (NOT NULL) * @flags: flags controlling what label info is printed * @gfp: kernel memory allocation type * * Returns: size of name written or would be written if larger than * available buffer */ int aa_label_asxprint(char **strp, struct aa_ns *ns, struct aa_label *label, int flags, gfp_t gfp) { int size; AA_BUG(!strp); AA_BUG(!label); size = aa_label_snxprint(NULL, 0, ns, label, flags); if (size < 0) return size; *strp = kmalloc(size + 1, gfp); if (!*strp) return -ENOMEM; return aa_label_snxprint(*strp, size + 1, ns, label, flags); } /** * aa_label_acntsxprint - allocate a __counted string buffer and print label * @strp: buffer to write to. (MAY BE NULL if @size == 0) * @ns: namespace profile is being viewed from * @label: label to view (NOT NULL) * @flags: flags controlling what label info is printed * @gfp: kernel memory allocation type * * Returns: size of name written or would be written if larger than * available buffer */ int aa_label_acntsxprint(char __counted **strp, struct aa_ns *ns, struct aa_label *label, int flags, gfp_t gfp) { int size; AA_BUG(!strp); AA_BUG(!label); size = aa_label_snxprint(NULL, 0, ns, label, flags); if (size < 0) return size; *strp = aa_str_alloc(size + 1, gfp); if (!*strp) return -ENOMEM; return aa_label_snxprint(*strp, size + 1, ns, label, flags); } void aa_label_xaudit(struct audit_buffer *ab, struct aa_ns *ns, struct aa_label *label, int flags, gfp_t gfp) { const char *str; char *name = NULL; int len; AA_BUG(!ab); AA_BUG(!label); if (!use_label_hname(ns, label, flags) || display_mode(ns, label, flags)) { len = aa_label_asxprint(&name, ns, label, flags, gfp); if (len == -1) { AA_DEBUG("label print error"); return; } str = name; } else { str = (char *) label->hname; len = strlen(str); } if (audit_string_contains_control(str, len)) audit_log_n_hex(ab, str, len); else audit_log_n_string(ab, str, len); kfree(name); } void aa_label_seq_xprint(struct seq_file *f, struct aa_ns *ns, struct aa_label *label, int flags, gfp_t gfp) { AA_BUG(!f); AA_BUG(!label); if (!use_label_hname(ns, label, flags)) { char *str; int len; len = aa_label_asxprint(&str, ns, label, flags, gfp); if (len == -1) { AA_DEBUG("label print error"); return; } seq_printf(f, "%s", str); kfree(str); } else if (display_mode(ns, label, flags)) seq_printf(f, "%s (%s)", label->hname, label_modename(ns, label, flags)); else seq_printf(f, "%s", label->hname); } void aa_label_xprintk(struct aa_ns *ns, struct aa_label *label, int flags, gfp_t gfp) { AA_BUG(!label); if (!use_label_hname(ns, label, flags)) { char *str; int len; len = aa_label_asxprint(&str, ns, label, flags, gfp); if (len == -1) { AA_DEBUG("label print error"); return; } pr_info("%s", str); kfree(str); } else if (display_mode(ns, label, flags)) pr_info("%s (%s)", label->hname, label_modename(ns, label, flags)); else pr_info("%s", label->hname); } void aa_label_audit(struct audit_buffer *ab, struct aa_label *label, gfp_t gfp) { struct aa_ns *ns = aa_get_current_ns(); aa_label_xaudit(ab, ns, label, FLAG_VIEW_SUBNS, gfp); aa_put_ns(ns); } void aa_label_seq_print(struct seq_file *f, struct aa_label *label, gfp_t gfp) { struct aa_ns *ns = aa_get_current_ns(); aa_label_seq_xprint(f, ns, label, FLAG_VIEW_SUBNS, gfp); aa_put_ns(ns); } void aa_label_printk(struct aa_label *label, gfp_t gfp) { struct aa_ns *ns = aa_get_current_ns(); aa_label_xprintk(ns, label, FLAG_VIEW_SUBNS, gfp); aa_put_ns(ns); } static int label_count_strn_entries(const char *str, size_t n) { const char *end = str + n; const char *split; int count = 1; AA_BUG(!str); for (split = aa_label_strn_split(str, end - str); split; split = aa_label_strn_split(str, end - str)) { count++; str = split + 3; } return count; } /* * ensure stacks with components like * :ns:A//&B * have :ns: applied to both 'A' and 'B' by making the lookup relative * to the base if the lookup specifies an ns, else making the stacked lookup * relative to the last embedded ns in the string. */ static struct aa_profile *fqlookupn_profile(struct aa_label *base, struct aa_label *currentbase, const char *str, size_t n) { const char *first = skipn_spaces(str, n); if (first && *first == ':') return aa_fqlookupn_profile(base, str, n); return aa_fqlookupn_profile(currentbase, str, n); } /** * aa_label_strn_parse - parse, validate and convert a text string to a label * @base: base label to use for lookups (NOT NULL) * @str: null terminated text string (NOT NULL) * @n: length of str to parse, will stop at \0 if encountered before n * @gfp: allocation type * @create: true if should create compound labels if they don't exist * @force_stack: true if should stack even if no leading & * * Returns: the matching refcounted label if present * else ERRPTR */ struct aa_label *aa_label_strn_parse(struct aa_label *base, const char *str, size_t n, gfp_t gfp, bool create, bool force_stack) { DEFINE_VEC(profile, vec); struct aa_label *label, *currbase = base; int i, len, stack = 0, error; const char *end = str + n; const char *split; AA_BUG(!base); AA_BUG(!str); str = skipn_spaces(str, n); if (str == NULL || (*str == '=' && base != &root_ns->unconfined->label)) return ERR_PTR(-EINVAL); len = label_count_strn_entries(str, end - str); if (*str == '&' || force_stack) { /* stack on top of base */ stack = base->size; len += stack; if (*str == '&') str++; } error = vec_setup(profile, vec, len, gfp); if (error) return ERR_PTR(error); for (i = 0; i < stack; i++) vec[i] = aa_get_profile(base->vec[i]); for (split = aa_label_strn_split(str, end - str), i = stack; split && i < len; i++) { vec[i] = fqlookupn_profile(base, currbase, str, split - str); if (!vec[i]) goto fail; /* * if component specified a new ns it becomes the new base * so that subsequent lookups are relative to it */ if (vec[i]->ns != labels_ns(currbase)) currbase = &vec[i]->label; str = split + 3; split = aa_label_strn_split(str, end - str); } /* last element doesn't have a split */ if (i < len) { vec[i] = fqlookupn_profile(base, currbase, str, end - str); if (!vec[i]) goto fail; } if (len == 1) /* no need to free vec as len < LOCAL_VEC_ENTRIES */ return &vec[0]->label; len -= aa_vec_unique(vec, len, VEC_FLAG_TERMINATE); /* TODO: deal with reference labels */ if (len == 1) { label = aa_get_label(&vec[0]->label); goto out; } if (create) label = aa_vec_find_or_create_label(vec, len, gfp); else label = vec_find(vec, len); if (!label) goto fail; out: /* use adjusted len from after vec_unique, not original */ vec_cleanup(profile, vec, len); return label; fail: label = ERR_PTR(-ENOENT); goto out; } struct aa_label *aa_label_parse(struct aa_label *base, const char *str, gfp_t gfp, bool create, bool force_stack) { return aa_label_strn_parse(base, str, strlen(str), gfp, create, force_stack); } /** * aa_labelset_destroy - remove all labels from the label set * @ls: label set to cleanup (NOT NULL) * * Labels that are removed from the set may still exist beyond the set * being destroyed depending on their reference counting */ void aa_labelset_destroy(struct aa_labelset *ls) { struct rb_node *node; unsigned long flags; AA_BUG(!ls); write_lock_irqsave(&ls->lock, flags); for (node = rb_first(&ls->root); node; node = rb_first(&ls->root)) { struct aa_label *this = rb_entry(node, struct aa_label, node); if (labels_ns(this) != root_ns) __label_remove(this, ns_unconfined(labels_ns(this)->parent)); else __label_remove(this, NULL); } write_unlock_irqrestore(&ls->lock, flags); } /* * @ls: labelset to init (NOT NULL) */ void aa_labelset_init(struct aa_labelset *ls) { AA_BUG(!ls); rwlock_init(&ls->lock); ls->root = RB_ROOT; } static struct aa_label *labelset_next_stale(struct aa_labelset *ls) { struct aa_label *label; struct rb_node *node; unsigned long flags; AA_BUG(!ls); read_lock_irqsave(&ls->lock, flags); __labelset_for_each(ls, node) { label = rb_entry(node, struct aa_label, node); if ((label_is_stale(label) || vec_is_stale(label->vec, label->size)) && __aa_get_label(label)) goto out; } label = NULL; out: read_unlock_irqrestore(&ls->lock, flags); return label; } /** * __label_update - insert updated version of @label into labelset * @label - the label to update/replace * * Returns: new label that is up to date * else NULL on failure * * Requires: @ns lock be held * * Note: worst case is the stale @label does not get updated and has * to be updated at a later time. */ static struct aa_label *__label_update(struct aa_label *label) { struct aa_label *new, *tmp; struct aa_labelset *ls; unsigned long flags; int i, invcount = 0; AA_BUG(!label); AA_BUG(!mutex_is_locked(&labels_ns(label)->lock)); new = aa_label_alloc(label->size, label->proxy, GFP_KERNEL); if (!new) return NULL; /* * while holding the ns_lock will stop profile replacement, removal, * and label updates, label merging and removal can be occurring */ ls = labels_set(label); write_lock_irqsave(&ls->lock, flags); for (i = 0; i < label->size; i++) { AA_BUG(!label->vec[i]); new->vec[i] = aa_get_newest_profile(label->vec[i]); AA_BUG(!new->vec[i]); AA_BUG(!new->vec[i]->label.proxy); AA_BUG(!new->vec[i]->label.proxy->label); if (new->vec[i]->label.proxy != label->vec[i]->label.proxy) invcount++; } /* updated stale label by being removed/renamed from labelset */ if (invcount) { new->size -= aa_vec_unique(&new->vec[0], new->size, VEC_FLAG_TERMINATE); /* TODO: deal with reference labels */ if (new->size == 1) { tmp = aa_get_label(&new->vec[0]->label); AA_BUG(tmp == label); goto remove; } if (labels_set(label) != labels_set(new)) { write_unlock_irqrestore(&ls->lock, flags); tmp = aa_label_insert(labels_set(new), new); write_lock_irqsave(&ls->lock, flags); goto remove; } } else AA_BUG(labels_ns(label) != labels_ns(new)); tmp = __label_insert(labels_set(label), new, true); remove: /* ensure label is removed, and redirected correctly */ __label_remove(label, tmp); write_unlock_irqrestore(&ls->lock, flags); label_free_or_put_new(tmp, new); return tmp; } /** * __labelset_update - update labels in @ns * @ns: namespace to update labels in (NOT NULL) * * Requires: @ns lock be held * * Walk the labelset ensuring that all labels are up to date and valid * Any label that has a stale component is marked stale and replaced and * by an updated version. * * If failures happen due to memory pressures then stale labels will * be left in place until the next pass. */ static void __labelset_update(struct aa_ns *ns) { struct aa_label *label; AA_BUG(!ns); AA_BUG(!mutex_is_locked(&ns->lock)); do { label = labelset_next_stale(&ns->labels); if (label) { struct aa_label *l = __label_update(label); aa_put_label(l); aa_put_label(label); } } while (label); } /** * __aa_labelset_udate_subtree - update all labels with a stale component * @ns: ns to start update at (NOT NULL) * * Requires: @ns lock be held * * Invalidates labels based on @p in @ns and any children namespaces. */ void __aa_labelset_update_subtree(struct aa_ns *ns) { struct aa_ns *child; AA_BUG(!ns); AA_BUG(!mutex_is_locked(&ns->lock)); __labelset_update(ns); list_for_each_entry(child, &ns->sub_ns, base.list) { mutex_lock_nested(&child->lock, child->level); __aa_labelset_update_subtree(child); mutex_unlock(&child->lock); } }