| #include "audit.h" |
| #include <linux/inotify.h> |
| #include <linux/namei.h> |
| #include <linux/mount.h> |
| #include <linux/kthread.h> |
| #include <linux/slab.h> |
| |
| struct audit_tree; |
| struct audit_chunk; |
| |
| struct audit_tree { |
| atomic_t count; |
| int goner; |
| struct audit_chunk *root; |
| struct list_head chunks; |
| struct list_head rules; |
| struct list_head list; |
| struct list_head same_root; |
| struct rcu_head head; |
| char pathname[]; |
| }; |
| |
| struct audit_chunk { |
| struct list_head hash; |
| struct inotify_watch watch; |
| struct list_head trees; /* with root here */ |
| int dead; |
| int count; |
| atomic_long_t refs; |
| struct rcu_head head; |
| struct node { |
| struct list_head list; |
| struct audit_tree *owner; |
| unsigned index; /* index; upper bit indicates 'will prune' */ |
| } owners[]; |
| }; |
| |
| static LIST_HEAD(tree_list); |
| static LIST_HEAD(prune_list); |
| |
| /* |
| * One struct chunk is attached to each inode of interest. |
| * We replace struct chunk on tagging/untagging. |
| * Rules have pointer to struct audit_tree. |
| * Rules have struct list_head rlist forming a list of rules over |
| * the same tree. |
| * References to struct chunk are collected at audit_inode{,_child}() |
| * time and used in AUDIT_TREE rule matching. |
| * These references are dropped at the same time we are calling |
| * audit_free_names(), etc. |
| * |
| * Cyclic lists galore: |
| * tree.chunks anchors chunk.owners[].list hash_lock |
| * tree.rules anchors rule.rlist audit_filter_mutex |
| * chunk.trees anchors tree.same_root hash_lock |
| * chunk.hash is a hash with middle bits of watch.inode as |
| * a hash function. RCU, hash_lock |
| * |
| * tree is refcounted; one reference for "some rules on rules_list refer to |
| * it", one for each chunk with pointer to it. |
| * |
| * chunk is refcounted by embedded inotify_watch + .refs (non-zero refcount |
| * of watch contributes 1 to .refs). |
| * |
| * node.index allows to get from node.list to containing chunk. |
| * MSB of that sucker is stolen to mark taggings that we might have to |
| * revert - several operations have very unpleasant cleanup logics and |
| * that makes a difference. Some. |
| */ |
| |
| static struct inotify_handle *rtree_ih; |
| |
| static struct audit_tree *alloc_tree(const char *s) |
| { |
| struct audit_tree *tree; |
| |
| tree = kmalloc(sizeof(struct audit_tree) + strlen(s) + 1, GFP_KERNEL); |
| if (tree) { |
| atomic_set(&tree->count, 1); |
| tree->goner = 0; |
| INIT_LIST_HEAD(&tree->chunks); |
| INIT_LIST_HEAD(&tree->rules); |
| INIT_LIST_HEAD(&tree->list); |
| INIT_LIST_HEAD(&tree->same_root); |
| tree->root = NULL; |
| strcpy(tree->pathname, s); |
| } |
| return tree; |
| } |
| |
| static inline void get_tree(struct audit_tree *tree) |
| { |
| atomic_inc(&tree->count); |
| } |
| |
| static void __put_tree(struct rcu_head *rcu) |
| { |
| struct audit_tree *tree = container_of(rcu, struct audit_tree, head); |
| kfree(tree); |
| } |
| |
| static inline void put_tree(struct audit_tree *tree) |
| { |
| if (atomic_dec_and_test(&tree->count)) |
| call_rcu(&tree->head, __put_tree); |
| } |
| |
| /* to avoid bringing the entire thing in audit.h */ |
| const char *audit_tree_path(struct audit_tree *tree) |
| { |
| return tree->pathname; |
| } |
| |
| static struct audit_chunk *alloc_chunk(int count) |
| { |
| struct audit_chunk *chunk; |
| size_t size; |
| int i; |
| |
| size = offsetof(struct audit_chunk, owners) + count * sizeof(struct node); |
| chunk = kzalloc(size, GFP_KERNEL); |
| if (!chunk) |
| return NULL; |
| |
| INIT_LIST_HEAD(&chunk->hash); |
| INIT_LIST_HEAD(&chunk->trees); |
| chunk->count = count; |
| atomic_long_set(&chunk->refs, 1); |
| for (i = 0; i < count; i++) { |
| INIT_LIST_HEAD(&chunk->owners[i].list); |
| chunk->owners[i].index = i; |
| } |
| inotify_init_watch(&chunk->watch); |
| return chunk; |
| } |
| |
| static void free_chunk(struct audit_chunk *chunk) |
| { |
| int i; |
| |
| for (i = 0; i < chunk->count; i++) { |
| if (chunk->owners[i].owner) |
| put_tree(chunk->owners[i].owner); |
| } |
| kfree(chunk); |
| } |
| |
| void audit_put_chunk(struct audit_chunk *chunk) |
| { |
| if (atomic_long_dec_and_test(&chunk->refs)) |
| free_chunk(chunk); |
| } |
| |
| static void __put_chunk(struct rcu_head *rcu) |
| { |
| struct audit_chunk *chunk = container_of(rcu, struct audit_chunk, head); |
| audit_put_chunk(chunk); |
| } |
| |
| enum {HASH_SIZE = 128}; |
| static struct list_head chunk_hash_heads[HASH_SIZE]; |
| static __cacheline_aligned_in_smp DEFINE_SPINLOCK(hash_lock); |
| |
| static inline struct list_head *chunk_hash(const struct inode *inode) |
| { |
| unsigned long n = (unsigned long)inode / L1_CACHE_BYTES; |
| return chunk_hash_heads + n % HASH_SIZE; |
| } |
| |
| /* hash_lock is held by caller */ |
| static void insert_hash(struct audit_chunk *chunk) |
| { |
| struct list_head *list = chunk_hash(chunk->watch.inode); |
| list_add_rcu(&chunk->hash, list); |
| } |
| |
| /* called under rcu_read_lock */ |
| struct audit_chunk *audit_tree_lookup(const struct inode *inode) |
| { |
| struct list_head *list = chunk_hash(inode); |
| struct audit_chunk *p; |
| |
| list_for_each_entry_rcu(p, list, hash) { |
| if (p->watch.inode == inode) { |
| atomic_long_inc(&p->refs); |
| return p; |
| } |
| } |
| return NULL; |
| } |
| |
| int audit_tree_match(struct audit_chunk *chunk, struct audit_tree *tree) |
| { |
| int n; |
| for (n = 0; n < chunk->count; n++) |
| if (chunk->owners[n].owner == tree) |
| return 1; |
| return 0; |
| } |
| |
| /* tagging and untagging inodes with trees */ |
| |
| static struct audit_chunk *find_chunk(struct node *p) |
| { |
| int index = p->index & ~(1U<<31); |
| p -= index; |
| return container_of(p, struct audit_chunk, owners[0]); |
| } |
| |
| static void untag_chunk(struct node *p) |
| { |
| struct audit_chunk *chunk = find_chunk(p); |
| struct audit_chunk *new; |
| struct audit_tree *owner; |
| int size = chunk->count - 1; |
| int i, j; |
| |
| if (!pin_inotify_watch(&chunk->watch)) { |
| /* |
| * Filesystem is shutting down; all watches are getting |
| * evicted, just take it off the node list for this |
| * tree and let the eviction logics take care of the |
| * rest. |
| */ |
| owner = p->owner; |
| if (owner->root == chunk) { |
| list_del_init(&owner->same_root); |
| owner->root = NULL; |
| } |
| list_del_init(&p->list); |
| p->owner = NULL; |
| put_tree(owner); |
| return; |
| } |
| |
| spin_unlock(&hash_lock); |
| |
| /* |
| * pin_inotify_watch() succeeded, so the watch won't go away |
| * from under us. |
| */ |
| mutex_lock(&chunk->watch.inode->inotify_mutex); |
| if (chunk->dead) { |
| mutex_unlock(&chunk->watch.inode->inotify_mutex); |
| goto out; |
| } |
| |
| owner = p->owner; |
| |
| if (!size) { |
| chunk->dead = 1; |
| spin_lock(&hash_lock); |
| list_del_init(&chunk->trees); |
| if (owner->root == chunk) |
| owner->root = NULL; |
| list_del_init(&p->list); |
| list_del_rcu(&chunk->hash); |
| spin_unlock(&hash_lock); |
| inotify_evict_watch(&chunk->watch); |
| mutex_unlock(&chunk->watch.inode->inotify_mutex); |
| put_inotify_watch(&chunk->watch); |
| goto out; |
| } |
| |
| new = alloc_chunk(size); |
| if (!new) |
| goto Fallback; |
| if (inotify_clone_watch(&chunk->watch, &new->watch) < 0) { |
| free_chunk(new); |
| goto Fallback; |
| } |
| |
| chunk->dead = 1; |
| spin_lock(&hash_lock); |
| list_replace_init(&chunk->trees, &new->trees); |
| if (owner->root == chunk) { |
| list_del_init(&owner->same_root); |
| owner->root = NULL; |
| } |
| |
| for (i = j = 0; j <= size; i++, j++) { |
| struct audit_tree *s; |
| if (&chunk->owners[j] == p) { |
| list_del_init(&p->list); |
| i--; |
| continue; |
| } |
| s = chunk->owners[j].owner; |
| new->owners[i].owner = s; |
| new->owners[i].index = chunk->owners[j].index - j + i; |
| if (!s) /* result of earlier fallback */ |
| continue; |
| get_tree(s); |
| list_replace_init(&chunk->owners[j].list, &new->owners[i].list); |
| } |
| |
| list_replace_rcu(&chunk->hash, &new->hash); |
| list_for_each_entry(owner, &new->trees, same_root) |
| owner->root = new; |
| spin_unlock(&hash_lock); |
| inotify_evict_watch(&chunk->watch); |
| mutex_unlock(&chunk->watch.inode->inotify_mutex); |
| put_inotify_watch(&chunk->watch); |
| goto out; |
| |
| Fallback: |
| // do the best we can |
| spin_lock(&hash_lock); |
| if (owner->root == chunk) { |
| list_del_init(&owner->same_root); |
| owner->root = NULL; |
| } |
| list_del_init(&p->list); |
| p->owner = NULL; |
| put_tree(owner); |
| spin_unlock(&hash_lock); |
| mutex_unlock(&chunk->watch.inode->inotify_mutex); |
| out: |
| unpin_inotify_watch(&chunk->watch); |
| spin_lock(&hash_lock); |
| } |
| |
| static int create_chunk(struct inode *inode, struct audit_tree *tree) |
| { |
| struct audit_chunk *chunk = alloc_chunk(1); |
| if (!chunk) |
| return -ENOMEM; |
| |
| if (inotify_add_watch(rtree_ih, &chunk->watch, inode, IN_IGNORED | IN_DELETE_SELF) < 0) { |
| free_chunk(chunk); |
| return -ENOSPC; |
| } |
| |
| mutex_lock(&inode->inotify_mutex); |
| spin_lock(&hash_lock); |
| if (tree->goner) { |
| spin_unlock(&hash_lock); |
| chunk->dead = 1; |
| inotify_evict_watch(&chunk->watch); |
| mutex_unlock(&inode->inotify_mutex); |
| put_inotify_watch(&chunk->watch); |
| return 0; |
| } |
| chunk->owners[0].index = (1U << 31); |
| chunk->owners[0].owner = tree; |
| get_tree(tree); |
| list_add(&chunk->owners[0].list, &tree->chunks); |
| if (!tree->root) { |
| tree->root = chunk; |
| list_add(&tree->same_root, &chunk->trees); |
| } |
| insert_hash(chunk); |
| spin_unlock(&hash_lock); |
| mutex_unlock(&inode->inotify_mutex); |
| return 0; |
| } |
| |
| /* the first tagged inode becomes root of tree */ |
| static int tag_chunk(struct inode *inode, struct audit_tree *tree) |
| { |
| struct inotify_watch *watch; |
| struct audit_tree *owner; |
| struct audit_chunk *chunk, *old; |
| struct node *p; |
| int n; |
| |
| if (inotify_find_watch(rtree_ih, inode, &watch) < 0) |
| return create_chunk(inode, tree); |
| |
| old = container_of(watch, struct audit_chunk, watch); |
| |
| /* are we already there? */ |
| spin_lock(&hash_lock); |
| for (n = 0; n < old->count; n++) { |
| if (old->owners[n].owner == tree) { |
| spin_unlock(&hash_lock); |
| put_inotify_watch(&old->watch); |
| return 0; |
| } |
| } |
| spin_unlock(&hash_lock); |
| |
| chunk = alloc_chunk(old->count + 1); |
| if (!chunk) { |
| put_inotify_watch(&old->watch); |
| return -ENOMEM; |
| } |
| |
| mutex_lock(&inode->inotify_mutex); |
| if (inotify_clone_watch(&old->watch, &chunk->watch) < 0) { |
| mutex_unlock(&inode->inotify_mutex); |
| put_inotify_watch(&old->watch); |
| free_chunk(chunk); |
| return -ENOSPC; |
| } |
| spin_lock(&hash_lock); |
| if (tree->goner) { |
| spin_unlock(&hash_lock); |
| chunk->dead = 1; |
| inotify_evict_watch(&chunk->watch); |
| mutex_unlock(&inode->inotify_mutex); |
| put_inotify_watch(&old->watch); |
| put_inotify_watch(&chunk->watch); |
| return 0; |
| } |
| list_replace_init(&old->trees, &chunk->trees); |
| for (n = 0, p = chunk->owners; n < old->count; n++, p++) { |
| struct audit_tree *s = old->owners[n].owner; |
| p->owner = s; |
| p->index = old->owners[n].index; |
| if (!s) /* result of fallback in untag */ |
| continue; |
| get_tree(s); |
| list_replace_init(&old->owners[n].list, &p->list); |
| } |
| p->index = (chunk->count - 1) | (1U<<31); |
| p->owner = tree; |
| get_tree(tree); |
| list_add(&p->list, &tree->chunks); |
| list_replace_rcu(&old->hash, &chunk->hash); |
| list_for_each_entry(owner, &chunk->trees, same_root) |
| owner->root = chunk; |
| old->dead = 1; |
| if (!tree->root) { |
| tree->root = chunk; |
| list_add(&tree->same_root, &chunk->trees); |
| } |
| spin_unlock(&hash_lock); |
| inotify_evict_watch(&old->watch); |
| mutex_unlock(&inode->inotify_mutex); |
| put_inotify_watch(&old->watch); /* pair to inotify_find_watch */ |
| put_inotify_watch(&old->watch); /* and kill it */ |
| return 0; |
| } |
| |
| static void kill_rules(struct audit_tree *tree) |
| { |
| struct audit_krule *rule, *next; |
| struct audit_entry *entry; |
| struct audit_buffer *ab; |
| |
| list_for_each_entry_safe(rule, next, &tree->rules, rlist) { |
| entry = container_of(rule, struct audit_entry, rule); |
| |
| list_del_init(&rule->rlist); |
| if (rule->tree) { |
| /* not a half-baked one */ |
| ab = audit_log_start(NULL, GFP_KERNEL, AUDIT_CONFIG_CHANGE); |
| audit_log_format(ab, "op="); |
| audit_log_string(ab, "remove rule"); |
| audit_log_format(ab, " dir="); |
| audit_log_untrustedstring(ab, rule->tree->pathname); |
| audit_log_key(ab, rule->filterkey); |
| audit_log_format(ab, " list=%d res=1", rule->listnr); |
| audit_log_end(ab); |
| rule->tree = NULL; |
| list_del_rcu(&entry->list); |
| list_del(&entry->rule.list); |
| call_rcu(&entry->rcu, audit_free_rule_rcu); |
| } |
| } |
| } |
| |
| /* |
| * finish killing struct audit_tree |
| */ |
| static void prune_one(struct audit_tree *victim) |
| { |
| spin_lock(&hash_lock); |
| while (!list_empty(&victim->chunks)) { |
| struct node *p; |
| |
| p = list_entry(victim->chunks.next, struct node, list); |
| |
| untag_chunk(p); |
| } |
| spin_unlock(&hash_lock); |
| put_tree(victim); |
| } |
| |
| /* trim the uncommitted chunks from tree */ |
| |
| static void trim_marked(struct audit_tree *tree) |
| { |
| struct list_head *p, *q; |
| spin_lock(&hash_lock); |
| if (tree->goner) { |
| spin_unlock(&hash_lock); |
| return; |
| } |
| /* reorder */ |
| for (p = tree->chunks.next; p != &tree->chunks; p = q) { |
| struct node *node = list_entry(p, struct node, list); |
| q = p->next; |
| if (node->index & (1U<<31)) { |
| list_del_init(p); |
| list_add(p, &tree->chunks); |
| } |
| } |
| |
| while (!list_empty(&tree->chunks)) { |
| struct node *node; |
| |
| node = list_entry(tree->chunks.next, struct node, list); |
| |
| /* have we run out of marked? */ |
| if (!(node->index & (1U<<31))) |
| break; |
| |
| untag_chunk(node); |
| } |
| if (!tree->root && !tree->goner) { |
| tree->goner = 1; |
| spin_unlock(&hash_lock); |
| mutex_lock(&audit_filter_mutex); |
| kill_rules(tree); |
| list_del_init(&tree->list); |
| mutex_unlock(&audit_filter_mutex); |
| prune_one(tree); |
| } else { |
| spin_unlock(&hash_lock); |
| } |
| } |
| |
| static void audit_schedule_prune(void); |
| |
| /* called with audit_filter_mutex */ |
| int audit_remove_tree_rule(struct audit_krule *rule) |
| { |
| struct audit_tree *tree; |
| tree = rule->tree; |
| if (tree) { |
| spin_lock(&hash_lock); |
| list_del_init(&rule->rlist); |
| if (list_empty(&tree->rules) && !tree->goner) { |
| tree->root = NULL; |
| list_del_init(&tree->same_root); |
| tree->goner = 1; |
| list_move(&tree->list, &prune_list); |
| rule->tree = NULL; |
| spin_unlock(&hash_lock); |
| audit_schedule_prune(); |
| return 1; |
| } |
| rule->tree = NULL; |
| spin_unlock(&hash_lock); |
| return 1; |
| } |
| return 0; |
| } |
| |
| static int compare_root(struct vfsmount *mnt, void *arg) |
| { |
| return mnt->mnt_root->d_inode == arg; |
| } |
| |
| void audit_trim_trees(void) |
| { |
| struct list_head cursor; |
| |
| mutex_lock(&audit_filter_mutex); |
| list_add(&cursor, &tree_list); |
| while (cursor.next != &tree_list) { |
| struct audit_tree *tree; |
| struct path path; |
| struct vfsmount *root_mnt; |
| struct node *node; |
| int err; |
| |
| tree = container_of(cursor.next, struct audit_tree, list); |
| get_tree(tree); |
| list_del(&cursor); |
| list_add(&cursor, &tree->list); |
| mutex_unlock(&audit_filter_mutex); |
| |
| err = kern_path(tree->pathname, 0, &path); |
| if (err) |
| goto skip_it; |
| |
| root_mnt = collect_mounts(&path); |
| path_put(&path); |
| if (!root_mnt) |
| goto skip_it; |
| |
| spin_lock(&hash_lock); |
| list_for_each_entry(node, &tree->chunks, list) { |
| struct inode *inode = find_chunk(node)->watch.inode; |
| node->index |= 1U<<31; |
| if (iterate_mounts(compare_root, inode, root_mnt)) |
| node->index &= ~(1U<<31); |
| } |
| spin_unlock(&hash_lock); |
| trim_marked(tree); |
| put_tree(tree); |
| drop_collected_mounts(root_mnt); |
| skip_it: |
| mutex_lock(&audit_filter_mutex); |
| } |
| list_del(&cursor); |
| mutex_unlock(&audit_filter_mutex); |
| } |
| |
| int audit_make_tree(struct audit_krule *rule, char *pathname, u32 op) |
| { |
| |
| if (pathname[0] != '/' || |
| rule->listnr != AUDIT_FILTER_EXIT || |
| op != Audit_equal || |
| rule->inode_f || rule->watch || rule->tree) |
| return -EINVAL; |
| rule->tree = alloc_tree(pathname); |
| if (!rule->tree) |
| return -ENOMEM; |
| return 0; |
| } |
| |
| void audit_put_tree(struct audit_tree *tree) |
| { |
| put_tree(tree); |
| } |
| |
| static int tag_mount(struct vfsmount *mnt, void *arg) |
| { |
| return tag_chunk(mnt->mnt_root->d_inode, arg); |
| } |
| |
| /* called with audit_filter_mutex */ |
| int audit_add_tree_rule(struct audit_krule *rule) |
| { |
| struct audit_tree *seed = rule->tree, *tree; |
| struct path path; |
| struct vfsmount *mnt; |
| int err; |
| |
| list_for_each_entry(tree, &tree_list, list) { |
| if (!strcmp(seed->pathname, tree->pathname)) { |
| put_tree(seed); |
| rule->tree = tree; |
| list_add(&rule->rlist, &tree->rules); |
| return 0; |
| } |
| } |
| tree = seed; |
| list_add(&tree->list, &tree_list); |
| list_add(&rule->rlist, &tree->rules); |
| /* do not set rule->tree yet */ |
| mutex_unlock(&audit_filter_mutex); |
| |
| err = kern_path(tree->pathname, 0, &path); |
| if (err) |
| goto Err; |
| mnt = collect_mounts(&path); |
| path_put(&path); |
| if (!mnt) { |
| err = -ENOMEM; |
| goto Err; |
| } |
| |
| get_tree(tree); |
| err = iterate_mounts(tag_mount, tree, mnt); |
| drop_collected_mounts(mnt); |
| |
| if (!err) { |
| struct node *node; |
| spin_lock(&hash_lock); |
| list_for_each_entry(node, &tree->chunks, list) |
| node->index &= ~(1U<<31); |
| spin_unlock(&hash_lock); |
| } else { |
| trim_marked(tree); |
| goto Err; |
| } |
| |
| mutex_lock(&audit_filter_mutex); |
| if (list_empty(&rule->rlist)) { |
| put_tree(tree); |
| return -ENOENT; |
| } |
| rule->tree = tree; |
| put_tree(tree); |
| |
| return 0; |
| Err: |
| mutex_lock(&audit_filter_mutex); |
| list_del_init(&tree->list); |
| list_del_init(&tree->rules); |
| put_tree(tree); |
| return err; |
| } |
| |
| int audit_tag_tree(char *old, char *new) |
| { |
| struct list_head cursor, barrier; |
| int failed = 0; |
| struct path path1, path2; |
| struct vfsmount *tagged; |
| int err; |
| |
| err = kern_path(new, 0, &path2); |
| if (err) |
| return err; |
| tagged = collect_mounts(&path2); |
| path_put(&path2); |
| if (!tagged) |
| return -ENOMEM; |
| |
| err = kern_path(old, 0, &path1); |
| if (err) { |
| drop_collected_mounts(tagged); |
| return err; |
| } |
| |
| mutex_lock(&audit_filter_mutex); |
| list_add(&barrier, &tree_list); |
| list_add(&cursor, &barrier); |
| |
| while (cursor.next != &tree_list) { |
| struct audit_tree *tree; |
| int good_one = 0; |
| |
| tree = container_of(cursor.next, struct audit_tree, list); |
| get_tree(tree); |
| list_del(&cursor); |
| list_add(&cursor, &tree->list); |
| mutex_unlock(&audit_filter_mutex); |
| |
| err = kern_path(tree->pathname, 0, &path2); |
| if (!err) { |
| good_one = path_is_under(&path1, &path2); |
| path_put(&path2); |
| } |
| |
| if (!good_one) { |
| put_tree(tree); |
| mutex_lock(&audit_filter_mutex); |
| continue; |
| } |
| |
| failed = iterate_mounts(tag_mount, tree, tagged); |
| if (failed) { |
| put_tree(tree); |
| mutex_lock(&audit_filter_mutex); |
| break; |
| } |
| |
| mutex_lock(&audit_filter_mutex); |
| spin_lock(&hash_lock); |
| if (!tree->goner) { |
| list_del(&tree->list); |
| list_add(&tree->list, &tree_list); |
| } |
| spin_unlock(&hash_lock); |
| put_tree(tree); |
| } |
| |
| while (barrier.prev != &tree_list) { |
| struct audit_tree *tree; |
| |
| tree = container_of(barrier.prev, struct audit_tree, list); |
| get_tree(tree); |
| list_del(&tree->list); |
| list_add(&tree->list, &barrier); |
| mutex_unlock(&audit_filter_mutex); |
| |
| if (!failed) { |
| struct node *node; |
| spin_lock(&hash_lock); |
| list_for_each_entry(node, &tree->chunks, list) |
| node->index &= ~(1U<<31); |
| spin_unlock(&hash_lock); |
| } else { |
| trim_marked(tree); |
| } |
| |
| put_tree(tree); |
| mutex_lock(&audit_filter_mutex); |
| } |
| list_del(&barrier); |
| list_del(&cursor); |
| mutex_unlock(&audit_filter_mutex); |
| path_put(&path1); |
| drop_collected_mounts(tagged); |
| return failed; |
| } |
| |
| /* |
| * That gets run when evict_chunk() ends up needing to kill audit_tree. |
| * Runs from a separate thread. |
| */ |
| static int prune_tree_thread(void *unused) |
| { |
| mutex_lock(&audit_cmd_mutex); |
| mutex_lock(&audit_filter_mutex); |
| |
| while (!list_empty(&prune_list)) { |
| struct audit_tree *victim; |
| |
| victim = list_entry(prune_list.next, struct audit_tree, list); |
| list_del_init(&victim->list); |
| |
| mutex_unlock(&audit_filter_mutex); |
| |
| prune_one(victim); |
| |
| mutex_lock(&audit_filter_mutex); |
| } |
| |
| mutex_unlock(&audit_filter_mutex); |
| mutex_unlock(&audit_cmd_mutex); |
| return 0; |
| } |
| |
| static void audit_schedule_prune(void) |
| { |
| kthread_run(prune_tree_thread, NULL, "audit_prune_tree"); |
| } |
| |
| /* |
| * ... and that one is done if evict_chunk() decides to delay until the end |
| * of syscall. Runs synchronously. |
| */ |
| void audit_kill_trees(struct list_head *list) |
| { |
| mutex_lock(&audit_cmd_mutex); |
| mutex_lock(&audit_filter_mutex); |
| |
| while (!list_empty(list)) { |
| struct audit_tree *victim; |
| |
| victim = list_entry(list->next, struct audit_tree, list); |
| kill_rules(victim); |
| list_del_init(&victim->list); |
| |
| mutex_unlock(&audit_filter_mutex); |
| |
| prune_one(victim); |
| |
| mutex_lock(&audit_filter_mutex); |
| } |
| |
| mutex_unlock(&audit_filter_mutex); |
| mutex_unlock(&audit_cmd_mutex); |
| } |
| |
| /* |
| * Here comes the stuff asynchronous to auditctl operations |
| */ |
| |
| /* inode->inotify_mutex is locked */ |
| static void evict_chunk(struct audit_chunk *chunk) |
| { |
| struct audit_tree *owner; |
| struct list_head *postponed = audit_killed_trees(); |
| int need_prune = 0; |
| int n; |
| |
| if (chunk->dead) |
| return; |
| |
| chunk->dead = 1; |
| mutex_lock(&audit_filter_mutex); |
| spin_lock(&hash_lock); |
| while (!list_empty(&chunk->trees)) { |
| owner = list_entry(chunk->trees.next, |
| struct audit_tree, same_root); |
| owner->goner = 1; |
| owner->root = NULL; |
| list_del_init(&owner->same_root); |
| spin_unlock(&hash_lock); |
| if (!postponed) { |
| kill_rules(owner); |
| list_move(&owner->list, &prune_list); |
| need_prune = 1; |
| } else { |
| list_move(&owner->list, postponed); |
| } |
| spin_lock(&hash_lock); |
| } |
| list_del_rcu(&chunk->hash); |
| for (n = 0; n < chunk->count; n++) |
| list_del_init(&chunk->owners[n].list); |
| spin_unlock(&hash_lock); |
| if (need_prune) |
| audit_schedule_prune(); |
| mutex_unlock(&audit_filter_mutex); |
| } |
| |
| static void handle_event(struct inotify_watch *watch, u32 wd, u32 mask, |
| u32 cookie, const char *dname, struct inode *inode) |
| { |
| struct audit_chunk *chunk = container_of(watch, struct audit_chunk, watch); |
| |
| if (mask & IN_IGNORED) { |
| evict_chunk(chunk); |
| put_inotify_watch(watch); |
| } |
| } |
| |
| static void destroy_watch(struct inotify_watch *watch) |
| { |
| struct audit_chunk *chunk = container_of(watch, struct audit_chunk, watch); |
| call_rcu(&chunk->head, __put_chunk); |
| } |
| |
| static const struct inotify_operations rtree_inotify_ops = { |
| .handle_event = handle_event, |
| .destroy_watch = destroy_watch, |
| }; |
| |
| static int __init audit_tree_init(void) |
| { |
| int i; |
| |
| rtree_ih = inotify_init(&rtree_inotify_ops); |
| if (IS_ERR(rtree_ih)) |
| audit_panic("cannot initialize inotify handle for rectree watches"); |
| |
| for (i = 0; i < HASH_SIZE; i++) |
| INIT_LIST_HEAD(&chunk_hash_heads[i]); |
| |
| return 0; |
| } |
| __initcall(audit_tree_init); |