Al Viro | 74c3cbe | 2007-07-22 08:04:18 -0400 | [diff] [blame] | 1 | #include "audit.h" |
Eric Paris | 28a3a7e | 2009-12-17 20:12:05 -0500 | [diff] [blame] | 2 | #include <linux/fsnotify_backend.h> |
Al Viro | 74c3cbe | 2007-07-22 08:04:18 -0400 | [diff] [blame] | 3 | #include <linux/namei.h> |
| 4 | #include <linux/mount.h> |
Al Viro | 916d757 | 2009-06-24 00:02:38 -0400 | [diff] [blame] | 5 | #include <linux/kthread.h> |
Tejun Heo | 5a0e3ad | 2010-03-24 17:04:11 +0900 | [diff] [blame] | 6 | #include <linux/slab.h> |
Al Viro | 74c3cbe | 2007-07-22 08:04:18 -0400 | [diff] [blame] | 7 | |
| 8 | struct audit_tree; |
| 9 | struct audit_chunk; |
| 10 | |
| 11 | struct audit_tree { |
| 12 | atomic_t count; |
| 13 | int goner; |
| 14 | struct audit_chunk *root; |
| 15 | struct list_head chunks; |
| 16 | struct list_head rules; |
| 17 | struct list_head list; |
| 18 | struct list_head same_root; |
| 19 | struct rcu_head head; |
| 20 | char pathname[]; |
| 21 | }; |
| 22 | |
| 23 | struct audit_chunk { |
| 24 | struct list_head hash; |
Eric Paris | e61ce86 | 2009-12-17 21:24:24 -0500 | [diff] [blame] | 25 | struct fsnotify_mark mark; |
Al Viro | 74c3cbe | 2007-07-22 08:04:18 -0400 | [diff] [blame] | 26 | struct list_head trees; /* with root here */ |
| 27 | int dead; |
| 28 | int count; |
Al Viro | 8f7b0ba | 2008-11-15 01:15:43 +0000 | [diff] [blame] | 29 | atomic_long_t refs; |
Al Viro | 74c3cbe | 2007-07-22 08:04:18 -0400 | [diff] [blame] | 30 | struct rcu_head head; |
| 31 | struct node { |
| 32 | struct list_head list; |
| 33 | struct audit_tree *owner; |
| 34 | unsigned index; /* index; upper bit indicates 'will prune' */ |
| 35 | } owners[]; |
| 36 | }; |
| 37 | |
| 38 | static LIST_HEAD(tree_list); |
| 39 | static LIST_HEAD(prune_list); |
| 40 | |
| 41 | /* |
| 42 | * One struct chunk is attached to each inode of interest. |
| 43 | * We replace struct chunk on tagging/untagging. |
| 44 | * Rules have pointer to struct audit_tree. |
| 45 | * Rules have struct list_head rlist forming a list of rules over |
| 46 | * the same tree. |
| 47 | * References to struct chunk are collected at audit_inode{,_child}() |
| 48 | * time and used in AUDIT_TREE rule matching. |
| 49 | * These references are dropped at the same time we are calling |
| 50 | * audit_free_names(), etc. |
| 51 | * |
| 52 | * Cyclic lists galore: |
| 53 | * tree.chunks anchors chunk.owners[].list hash_lock |
| 54 | * tree.rules anchors rule.rlist audit_filter_mutex |
| 55 | * chunk.trees anchors tree.same_root hash_lock |
| 56 | * chunk.hash is a hash with middle bits of watch.inode as |
| 57 | * a hash function. RCU, hash_lock |
| 58 | * |
| 59 | * tree is refcounted; one reference for "some rules on rules_list refer to |
| 60 | * it", one for each chunk with pointer to it. |
| 61 | * |
Eric Paris | 28a3a7e | 2009-12-17 20:12:05 -0500 | [diff] [blame] | 62 | * chunk is refcounted by embedded fsnotify_mark + .refs (non-zero refcount |
Al Viro | 8f7b0ba | 2008-11-15 01:15:43 +0000 | [diff] [blame] | 63 | * of watch contributes 1 to .refs). |
Al Viro | 74c3cbe | 2007-07-22 08:04:18 -0400 | [diff] [blame] | 64 | * |
| 65 | * node.index allows to get from node.list to containing chunk. |
| 66 | * MSB of that sucker is stolen to mark taggings that we might have to |
| 67 | * revert - several operations have very unpleasant cleanup logics and |
| 68 | * that makes a difference. Some. |
| 69 | */ |
| 70 | |
Eric Paris | 28a3a7e | 2009-12-17 20:12:05 -0500 | [diff] [blame] | 71 | static struct fsnotify_group *audit_tree_group; |
Al Viro | 74c3cbe | 2007-07-22 08:04:18 -0400 | [diff] [blame] | 72 | |
| 73 | static struct audit_tree *alloc_tree(const char *s) |
| 74 | { |
| 75 | struct audit_tree *tree; |
| 76 | |
| 77 | tree = kmalloc(sizeof(struct audit_tree) + strlen(s) + 1, GFP_KERNEL); |
| 78 | if (tree) { |
| 79 | atomic_set(&tree->count, 1); |
| 80 | tree->goner = 0; |
| 81 | INIT_LIST_HEAD(&tree->chunks); |
| 82 | INIT_LIST_HEAD(&tree->rules); |
| 83 | INIT_LIST_HEAD(&tree->list); |
| 84 | INIT_LIST_HEAD(&tree->same_root); |
| 85 | tree->root = NULL; |
| 86 | strcpy(tree->pathname, s); |
| 87 | } |
| 88 | return tree; |
| 89 | } |
| 90 | |
| 91 | static inline void get_tree(struct audit_tree *tree) |
| 92 | { |
| 93 | atomic_inc(&tree->count); |
| 94 | } |
| 95 | |
Al Viro | 74c3cbe | 2007-07-22 08:04:18 -0400 | [diff] [blame] | 96 | static inline void put_tree(struct audit_tree *tree) |
| 97 | { |
| 98 | if (atomic_dec_and_test(&tree->count)) |
Lai Jiangshan | 3b097c4 | 2011-03-15 18:03:53 +0800 | [diff] [blame] | 99 | kfree_rcu(tree, head); |
Al Viro | 74c3cbe | 2007-07-22 08:04:18 -0400 | [diff] [blame] | 100 | } |
| 101 | |
| 102 | /* to avoid bringing the entire thing in audit.h */ |
| 103 | const char *audit_tree_path(struct audit_tree *tree) |
| 104 | { |
| 105 | return tree->pathname; |
| 106 | } |
| 107 | |
Al Viro | 8f7b0ba | 2008-11-15 01:15:43 +0000 | [diff] [blame] | 108 | static void free_chunk(struct audit_chunk *chunk) |
Al Viro | 74c3cbe | 2007-07-22 08:04:18 -0400 | [diff] [blame] | 109 | { |
Al Viro | 74c3cbe | 2007-07-22 08:04:18 -0400 | [diff] [blame] | 110 | int i; |
| 111 | |
| 112 | for (i = 0; i < chunk->count; i++) { |
| 113 | if (chunk->owners[i].owner) |
| 114 | put_tree(chunk->owners[i].owner); |
| 115 | } |
| 116 | kfree(chunk); |
| 117 | } |
| 118 | |
Al Viro | 74c3cbe | 2007-07-22 08:04:18 -0400 | [diff] [blame] | 119 | void audit_put_chunk(struct audit_chunk *chunk) |
| 120 | { |
Al Viro | 8f7b0ba | 2008-11-15 01:15:43 +0000 | [diff] [blame] | 121 | if (atomic_long_dec_and_test(&chunk->refs)) |
| 122 | free_chunk(chunk); |
| 123 | } |
| 124 | |
| 125 | static void __put_chunk(struct rcu_head *rcu) |
| 126 | { |
| 127 | struct audit_chunk *chunk = container_of(rcu, struct audit_chunk, head); |
| 128 | audit_put_chunk(chunk); |
Al Viro | 74c3cbe | 2007-07-22 08:04:18 -0400 | [diff] [blame] | 129 | } |
| 130 | |
Eric Paris | e61ce86 | 2009-12-17 21:24:24 -0500 | [diff] [blame] | 131 | static void audit_tree_destroy_watch(struct fsnotify_mark *entry) |
Eric Paris | 28a3a7e | 2009-12-17 20:12:05 -0500 | [diff] [blame] | 132 | { |
| 133 | struct audit_chunk *chunk = container_of(entry, struct audit_chunk, mark); |
| 134 | call_rcu(&chunk->head, __put_chunk); |
| 135 | } |
| 136 | |
| 137 | static struct audit_chunk *alloc_chunk(int count) |
| 138 | { |
| 139 | struct audit_chunk *chunk; |
| 140 | size_t size; |
| 141 | int i; |
| 142 | |
| 143 | size = offsetof(struct audit_chunk, owners) + count * sizeof(struct node); |
| 144 | chunk = kzalloc(size, GFP_KERNEL); |
| 145 | if (!chunk) |
| 146 | return NULL; |
| 147 | |
| 148 | INIT_LIST_HEAD(&chunk->hash); |
| 149 | INIT_LIST_HEAD(&chunk->trees); |
| 150 | chunk->count = count; |
| 151 | atomic_long_set(&chunk->refs, 1); |
| 152 | for (i = 0; i < count; i++) { |
| 153 | INIT_LIST_HEAD(&chunk->owners[i].list); |
| 154 | chunk->owners[i].index = i; |
| 155 | } |
| 156 | fsnotify_init_mark(&chunk->mark, audit_tree_destroy_watch); |
| 157 | return chunk; |
| 158 | } |
| 159 | |
Al Viro | 74c3cbe | 2007-07-22 08:04:18 -0400 | [diff] [blame] | 160 | enum {HASH_SIZE = 128}; |
| 161 | static struct list_head chunk_hash_heads[HASH_SIZE]; |
| 162 | static __cacheline_aligned_in_smp DEFINE_SPINLOCK(hash_lock); |
| 163 | |
| 164 | static inline struct list_head *chunk_hash(const struct inode *inode) |
| 165 | { |
| 166 | unsigned long n = (unsigned long)inode / L1_CACHE_BYTES; |
| 167 | return chunk_hash_heads + n % HASH_SIZE; |
| 168 | } |
| 169 | |
Eric Paris | 28a3a7e | 2009-12-17 20:12:05 -0500 | [diff] [blame] | 170 | /* hash_lock & entry->lock is held by caller */ |
Al Viro | 74c3cbe | 2007-07-22 08:04:18 -0400 | [diff] [blame] | 171 | static void insert_hash(struct audit_chunk *chunk) |
| 172 | { |
Eric Paris | e61ce86 | 2009-12-17 21:24:24 -0500 | [diff] [blame] | 173 | struct fsnotify_mark *entry = &chunk->mark; |
Eric Paris | 28a3a7e | 2009-12-17 20:12:05 -0500 | [diff] [blame] | 174 | struct list_head *list; |
| 175 | |
Eric Paris | 2823e04 | 2009-12-17 21:24:23 -0500 | [diff] [blame] | 176 | if (!entry->i.inode) |
Eric Paris | 28a3a7e | 2009-12-17 20:12:05 -0500 | [diff] [blame] | 177 | return; |
Eric Paris | 2823e04 | 2009-12-17 21:24:23 -0500 | [diff] [blame] | 178 | list = chunk_hash(entry->i.inode); |
Al Viro | 74c3cbe | 2007-07-22 08:04:18 -0400 | [diff] [blame] | 179 | list_add_rcu(&chunk->hash, list); |
| 180 | } |
| 181 | |
| 182 | /* called under rcu_read_lock */ |
| 183 | struct audit_chunk *audit_tree_lookup(const struct inode *inode) |
| 184 | { |
| 185 | struct list_head *list = chunk_hash(inode); |
Paul E. McKenney | 6793a05 | 2008-05-14 17:10:12 -0700 | [diff] [blame] | 186 | struct audit_chunk *p; |
Al Viro | 74c3cbe | 2007-07-22 08:04:18 -0400 | [diff] [blame] | 187 | |
Paul E. McKenney | 6793a05 | 2008-05-14 17:10:12 -0700 | [diff] [blame] | 188 | list_for_each_entry_rcu(p, list, hash) { |
Eric Paris | 28a3a7e | 2009-12-17 20:12:05 -0500 | [diff] [blame] | 189 | /* mark.inode may have gone NULL, but who cares? */ |
Eric Paris | 2823e04 | 2009-12-17 21:24:23 -0500 | [diff] [blame] | 190 | if (p->mark.i.inode == inode) { |
Al Viro | 8f7b0ba | 2008-11-15 01:15:43 +0000 | [diff] [blame] | 191 | atomic_long_inc(&p->refs); |
Al Viro | 74c3cbe | 2007-07-22 08:04:18 -0400 | [diff] [blame] | 192 | return p; |
| 193 | } |
| 194 | } |
| 195 | return NULL; |
| 196 | } |
| 197 | |
| 198 | int audit_tree_match(struct audit_chunk *chunk, struct audit_tree *tree) |
| 199 | { |
| 200 | int n; |
| 201 | for (n = 0; n < chunk->count; n++) |
| 202 | if (chunk->owners[n].owner == tree) |
| 203 | return 1; |
| 204 | return 0; |
| 205 | } |
| 206 | |
| 207 | /* tagging and untagging inodes with trees */ |
| 208 | |
Al Viro | 8f7b0ba | 2008-11-15 01:15:43 +0000 | [diff] [blame] | 209 | static struct audit_chunk *find_chunk(struct node *p) |
Al Viro | 74c3cbe | 2007-07-22 08:04:18 -0400 | [diff] [blame] | 210 | { |
Al Viro | 8f7b0ba | 2008-11-15 01:15:43 +0000 | [diff] [blame] | 211 | int index = p->index & ~(1U<<31); |
| 212 | p -= index; |
| 213 | return container_of(p, struct audit_chunk, owners[0]); |
| 214 | } |
| 215 | |
| 216 | static void untag_chunk(struct node *p) |
| 217 | { |
| 218 | struct audit_chunk *chunk = find_chunk(p); |
Eric Paris | e61ce86 | 2009-12-17 21:24:24 -0500 | [diff] [blame] | 219 | struct fsnotify_mark *entry = &chunk->mark; |
Al Viro | f7a998a | 2010-10-30 02:18:32 -0400 | [diff] [blame] | 220 | struct audit_chunk *new = NULL; |
Al Viro | 74c3cbe | 2007-07-22 08:04:18 -0400 | [diff] [blame] | 221 | struct audit_tree *owner; |
| 222 | int size = chunk->count - 1; |
| 223 | int i, j; |
| 224 | |
Eric Paris | 28a3a7e | 2009-12-17 20:12:05 -0500 | [diff] [blame] | 225 | fsnotify_get_mark(entry); |
Al Viro | 8f7b0ba | 2008-11-15 01:15:43 +0000 | [diff] [blame] | 226 | |
| 227 | spin_unlock(&hash_lock); |
| 228 | |
Al Viro | f7a998a | 2010-10-30 02:18:32 -0400 | [diff] [blame] | 229 | if (size) |
| 230 | new = alloc_chunk(size); |
| 231 | |
Eric Paris | 28a3a7e | 2009-12-17 20:12:05 -0500 | [diff] [blame] | 232 | spin_lock(&entry->lock); |
Eric Paris | 2823e04 | 2009-12-17 21:24:23 -0500 | [diff] [blame] | 233 | if (chunk->dead || !entry->i.inode) { |
Eric Paris | 28a3a7e | 2009-12-17 20:12:05 -0500 | [diff] [blame] | 234 | spin_unlock(&entry->lock); |
Al Viro | f7a998a | 2010-10-30 02:18:32 -0400 | [diff] [blame] | 235 | if (new) |
| 236 | free_chunk(new); |
Al Viro | 8f7b0ba | 2008-11-15 01:15:43 +0000 | [diff] [blame] | 237 | goto out; |
Al Viro | 74c3cbe | 2007-07-22 08:04:18 -0400 | [diff] [blame] | 238 | } |
| 239 | |
| 240 | owner = p->owner; |
| 241 | |
| 242 | if (!size) { |
| 243 | chunk->dead = 1; |
| 244 | spin_lock(&hash_lock); |
| 245 | list_del_init(&chunk->trees); |
| 246 | if (owner->root == chunk) |
| 247 | owner->root = NULL; |
| 248 | list_del_init(&p->list); |
| 249 | list_del_rcu(&chunk->hash); |
| 250 | spin_unlock(&hash_lock); |
Eric Paris | 28a3a7e | 2009-12-17 20:12:05 -0500 | [diff] [blame] | 251 | spin_unlock(&entry->lock); |
Lino Sanfilippo | e2a2994 | 2011-06-14 17:29:51 +0200 | [diff] [blame] | 252 | fsnotify_destroy_mark(entry, audit_tree_group); |
Al Viro | 8f7b0ba | 2008-11-15 01:15:43 +0000 | [diff] [blame] | 253 | goto out; |
Al Viro | 74c3cbe | 2007-07-22 08:04:18 -0400 | [diff] [blame] | 254 | } |
| 255 | |
Al Viro | 74c3cbe | 2007-07-22 08:04:18 -0400 | [diff] [blame] | 256 | if (!new) |
| 257 | goto Fallback; |
Al Viro | f7a998a | 2010-10-30 02:18:32 -0400 | [diff] [blame] | 258 | |
Eric Paris | 28a3a7e | 2009-12-17 20:12:05 -0500 | [diff] [blame] | 259 | fsnotify_duplicate_mark(&new->mark, entry); |
Eric Paris | 5444e29 | 2009-12-17 21:24:27 -0500 | [diff] [blame] | 260 | if (fsnotify_add_mark(&new->mark, new->mark.group, new->mark.i.inode, NULL, 1)) { |
Miklos Szeredi | 0fe33aa | 2012-08-15 12:55:22 +0200 | [diff] [blame] | 261 | fsnotify_put_mark(&new->mark); |
Al Viro | 74c3cbe | 2007-07-22 08:04:18 -0400 | [diff] [blame] | 262 | goto Fallback; |
| 263 | } |
| 264 | |
| 265 | chunk->dead = 1; |
| 266 | spin_lock(&hash_lock); |
| 267 | list_replace_init(&chunk->trees, &new->trees); |
| 268 | if (owner->root == chunk) { |
| 269 | list_del_init(&owner->same_root); |
| 270 | owner->root = NULL; |
| 271 | } |
| 272 | |
Al Viro | 6f5d511 | 2009-12-19 15:59:45 +0000 | [diff] [blame] | 273 | for (i = j = 0; j <= size; i++, j++) { |
Al Viro | 74c3cbe | 2007-07-22 08:04:18 -0400 | [diff] [blame] | 274 | struct audit_tree *s; |
| 275 | if (&chunk->owners[j] == p) { |
| 276 | list_del_init(&p->list); |
| 277 | i--; |
| 278 | continue; |
| 279 | } |
| 280 | s = chunk->owners[j].owner; |
| 281 | new->owners[i].owner = s; |
| 282 | new->owners[i].index = chunk->owners[j].index - j + i; |
| 283 | if (!s) /* result of earlier fallback */ |
| 284 | continue; |
| 285 | get_tree(s); |
Al Viro | 6f5d511 | 2009-12-19 15:59:45 +0000 | [diff] [blame] | 286 | list_replace_init(&chunk->owners[j].list, &new->owners[i].list); |
Al Viro | 74c3cbe | 2007-07-22 08:04:18 -0400 | [diff] [blame] | 287 | } |
| 288 | |
| 289 | list_replace_rcu(&chunk->hash, &new->hash); |
| 290 | list_for_each_entry(owner, &new->trees, same_root) |
| 291 | owner->root = new; |
| 292 | spin_unlock(&hash_lock); |
Eric Paris | 28a3a7e | 2009-12-17 20:12:05 -0500 | [diff] [blame] | 293 | spin_unlock(&entry->lock); |
Lino Sanfilippo | e2a2994 | 2011-06-14 17:29:51 +0200 | [diff] [blame] | 294 | fsnotify_destroy_mark(entry, audit_tree_group); |
Miklos Szeredi | b3e8692 | 2012-08-15 12:55:22 +0200 | [diff] [blame] | 295 | fsnotify_put_mark(&new->mark); /* drop initial reference */ |
Al Viro | 8f7b0ba | 2008-11-15 01:15:43 +0000 | [diff] [blame] | 296 | goto out; |
Al Viro | 74c3cbe | 2007-07-22 08:04:18 -0400 | [diff] [blame] | 297 | |
| 298 | Fallback: |
| 299 | // do the best we can |
| 300 | spin_lock(&hash_lock); |
| 301 | if (owner->root == chunk) { |
| 302 | list_del_init(&owner->same_root); |
| 303 | owner->root = NULL; |
| 304 | } |
| 305 | list_del_init(&p->list); |
| 306 | p->owner = NULL; |
| 307 | put_tree(owner); |
| 308 | spin_unlock(&hash_lock); |
Eric Paris | 28a3a7e | 2009-12-17 20:12:05 -0500 | [diff] [blame] | 309 | spin_unlock(&entry->lock); |
Al Viro | 8f7b0ba | 2008-11-15 01:15:43 +0000 | [diff] [blame] | 310 | out: |
Eric Paris | 28a3a7e | 2009-12-17 20:12:05 -0500 | [diff] [blame] | 311 | fsnotify_put_mark(entry); |
Al Viro | 8f7b0ba | 2008-11-15 01:15:43 +0000 | [diff] [blame] | 312 | spin_lock(&hash_lock); |
Al Viro | 74c3cbe | 2007-07-22 08:04:18 -0400 | [diff] [blame] | 313 | } |
| 314 | |
| 315 | static int create_chunk(struct inode *inode, struct audit_tree *tree) |
| 316 | { |
Eric Paris | e61ce86 | 2009-12-17 21:24:24 -0500 | [diff] [blame] | 317 | struct fsnotify_mark *entry; |
Al Viro | 74c3cbe | 2007-07-22 08:04:18 -0400 | [diff] [blame] | 318 | struct audit_chunk *chunk = alloc_chunk(1); |
| 319 | if (!chunk) |
| 320 | return -ENOMEM; |
| 321 | |
Eric Paris | 28a3a7e | 2009-12-17 20:12:05 -0500 | [diff] [blame] | 322 | entry = &chunk->mark; |
Eric Paris | 5444e29 | 2009-12-17 21:24:27 -0500 | [diff] [blame] | 323 | if (fsnotify_add_mark(entry, audit_tree_group, inode, NULL, 0)) { |
Miklos Szeredi | 0fe33aa | 2012-08-15 12:55:22 +0200 | [diff] [blame] | 324 | fsnotify_put_mark(entry); |
Al Viro | 74c3cbe | 2007-07-22 08:04:18 -0400 | [diff] [blame] | 325 | return -ENOSPC; |
| 326 | } |
| 327 | |
Eric Paris | 28a3a7e | 2009-12-17 20:12:05 -0500 | [diff] [blame] | 328 | spin_lock(&entry->lock); |
Al Viro | 74c3cbe | 2007-07-22 08:04:18 -0400 | [diff] [blame] | 329 | spin_lock(&hash_lock); |
| 330 | if (tree->goner) { |
| 331 | spin_unlock(&hash_lock); |
| 332 | chunk->dead = 1; |
Eric Paris | 28a3a7e | 2009-12-17 20:12:05 -0500 | [diff] [blame] | 333 | spin_unlock(&entry->lock); |
Lino Sanfilippo | e2a2994 | 2011-06-14 17:29:51 +0200 | [diff] [blame] | 334 | fsnotify_destroy_mark(entry, audit_tree_group); |
Eric Paris | 28a3a7e | 2009-12-17 20:12:05 -0500 | [diff] [blame] | 335 | fsnotify_put_mark(entry); |
Al Viro | 74c3cbe | 2007-07-22 08:04:18 -0400 | [diff] [blame] | 336 | return 0; |
| 337 | } |
| 338 | chunk->owners[0].index = (1U << 31); |
| 339 | chunk->owners[0].owner = tree; |
| 340 | get_tree(tree); |
| 341 | list_add(&chunk->owners[0].list, &tree->chunks); |
| 342 | if (!tree->root) { |
| 343 | tree->root = chunk; |
| 344 | list_add(&tree->same_root, &chunk->trees); |
| 345 | } |
| 346 | insert_hash(chunk); |
| 347 | spin_unlock(&hash_lock); |
Eric Paris | 28a3a7e | 2009-12-17 20:12:05 -0500 | [diff] [blame] | 348 | spin_unlock(&entry->lock); |
Miklos Szeredi | b3e8692 | 2012-08-15 12:55:22 +0200 | [diff] [blame] | 349 | fsnotify_put_mark(entry); /* drop initial reference */ |
Al Viro | 74c3cbe | 2007-07-22 08:04:18 -0400 | [diff] [blame] | 350 | return 0; |
| 351 | } |
| 352 | |
| 353 | /* the first tagged inode becomes root of tree */ |
| 354 | static int tag_chunk(struct inode *inode, struct audit_tree *tree) |
| 355 | { |
Eric Paris | e61ce86 | 2009-12-17 21:24:24 -0500 | [diff] [blame] | 356 | struct fsnotify_mark *old_entry, *chunk_entry; |
Al Viro | 74c3cbe | 2007-07-22 08:04:18 -0400 | [diff] [blame] | 357 | struct audit_tree *owner; |
| 358 | struct audit_chunk *chunk, *old; |
| 359 | struct node *p; |
| 360 | int n; |
| 361 | |
Eric Paris | 5444e29 | 2009-12-17 21:24:27 -0500 | [diff] [blame] | 362 | old_entry = fsnotify_find_inode_mark(audit_tree_group, inode); |
Eric Paris | 28a3a7e | 2009-12-17 20:12:05 -0500 | [diff] [blame] | 363 | if (!old_entry) |
Al Viro | 74c3cbe | 2007-07-22 08:04:18 -0400 | [diff] [blame] | 364 | return create_chunk(inode, tree); |
| 365 | |
Eric Paris | 28a3a7e | 2009-12-17 20:12:05 -0500 | [diff] [blame] | 366 | old = container_of(old_entry, struct audit_chunk, mark); |
Al Viro | 74c3cbe | 2007-07-22 08:04:18 -0400 | [diff] [blame] | 367 | |
| 368 | /* are we already there? */ |
| 369 | spin_lock(&hash_lock); |
| 370 | for (n = 0; n < old->count; n++) { |
| 371 | if (old->owners[n].owner == tree) { |
| 372 | spin_unlock(&hash_lock); |
Eric Paris | 28a3a7e | 2009-12-17 20:12:05 -0500 | [diff] [blame] | 373 | fsnotify_put_mark(old_entry); |
Al Viro | 74c3cbe | 2007-07-22 08:04:18 -0400 | [diff] [blame] | 374 | return 0; |
| 375 | } |
| 376 | } |
| 377 | spin_unlock(&hash_lock); |
| 378 | |
| 379 | chunk = alloc_chunk(old->count + 1); |
Al Viro | b4c30aa | 2009-12-19 16:03:30 +0000 | [diff] [blame] | 380 | if (!chunk) { |
Eric Paris | 28a3a7e | 2009-12-17 20:12:05 -0500 | [diff] [blame] | 381 | fsnotify_put_mark(old_entry); |
Al Viro | 74c3cbe | 2007-07-22 08:04:18 -0400 | [diff] [blame] | 382 | return -ENOMEM; |
Al Viro | b4c30aa | 2009-12-19 16:03:30 +0000 | [diff] [blame] | 383 | } |
Al Viro | 74c3cbe | 2007-07-22 08:04:18 -0400 | [diff] [blame] | 384 | |
Eric Paris | 28a3a7e | 2009-12-17 20:12:05 -0500 | [diff] [blame] | 385 | chunk_entry = &chunk->mark; |
| 386 | |
| 387 | spin_lock(&old_entry->lock); |
Eric Paris | 2823e04 | 2009-12-17 21:24:23 -0500 | [diff] [blame] | 388 | if (!old_entry->i.inode) { |
Eric Paris | 28a3a7e | 2009-12-17 20:12:05 -0500 | [diff] [blame] | 389 | /* old_entry is being shot, lets just lie */ |
| 390 | spin_unlock(&old_entry->lock); |
| 391 | fsnotify_put_mark(old_entry); |
Al Viro | 74c3cbe | 2007-07-22 08:04:18 -0400 | [diff] [blame] | 392 | free_chunk(chunk); |
Eric Paris | 28a3a7e | 2009-12-17 20:12:05 -0500 | [diff] [blame] | 393 | return -ENOENT; |
| 394 | } |
| 395 | |
| 396 | fsnotify_duplicate_mark(chunk_entry, old_entry); |
Eric Paris | 5444e29 | 2009-12-17 21:24:27 -0500 | [diff] [blame] | 397 | if (fsnotify_add_mark(chunk_entry, chunk_entry->group, chunk_entry->i.inode, NULL, 1)) { |
Eric Paris | 28a3a7e | 2009-12-17 20:12:05 -0500 | [diff] [blame] | 398 | spin_unlock(&old_entry->lock); |
Miklos Szeredi | 0fe33aa | 2012-08-15 12:55:22 +0200 | [diff] [blame] | 399 | fsnotify_put_mark(chunk_entry); |
Eric Paris | 28a3a7e | 2009-12-17 20:12:05 -0500 | [diff] [blame] | 400 | fsnotify_put_mark(old_entry); |
Al Viro | 74c3cbe | 2007-07-22 08:04:18 -0400 | [diff] [blame] | 401 | return -ENOSPC; |
| 402 | } |
Eric Paris | 28a3a7e | 2009-12-17 20:12:05 -0500 | [diff] [blame] | 403 | |
| 404 | /* even though we hold old_entry->lock, this is safe since chunk_entry->lock could NEVER have been grabbed before */ |
| 405 | spin_lock(&chunk_entry->lock); |
Al Viro | 74c3cbe | 2007-07-22 08:04:18 -0400 | [diff] [blame] | 406 | spin_lock(&hash_lock); |
Eric Paris | 28a3a7e | 2009-12-17 20:12:05 -0500 | [diff] [blame] | 407 | |
| 408 | /* we now hold old_entry->lock, chunk_entry->lock, and hash_lock */ |
Al Viro | 74c3cbe | 2007-07-22 08:04:18 -0400 | [diff] [blame] | 409 | if (tree->goner) { |
| 410 | spin_unlock(&hash_lock); |
| 411 | chunk->dead = 1; |
Eric Paris | 28a3a7e | 2009-12-17 20:12:05 -0500 | [diff] [blame] | 412 | spin_unlock(&chunk_entry->lock); |
| 413 | spin_unlock(&old_entry->lock); |
| 414 | |
Lino Sanfilippo | e2a2994 | 2011-06-14 17:29:51 +0200 | [diff] [blame] | 415 | fsnotify_destroy_mark(chunk_entry, audit_tree_group); |
Eric Paris | 28a3a7e | 2009-12-17 20:12:05 -0500 | [diff] [blame] | 416 | |
| 417 | fsnotify_put_mark(chunk_entry); |
| 418 | fsnotify_put_mark(old_entry); |
Al Viro | 74c3cbe | 2007-07-22 08:04:18 -0400 | [diff] [blame] | 419 | return 0; |
| 420 | } |
| 421 | list_replace_init(&old->trees, &chunk->trees); |
| 422 | for (n = 0, p = chunk->owners; n < old->count; n++, p++) { |
| 423 | struct audit_tree *s = old->owners[n].owner; |
| 424 | p->owner = s; |
| 425 | p->index = old->owners[n].index; |
| 426 | if (!s) /* result of fallback in untag */ |
| 427 | continue; |
| 428 | get_tree(s); |
| 429 | list_replace_init(&old->owners[n].list, &p->list); |
| 430 | } |
| 431 | p->index = (chunk->count - 1) | (1U<<31); |
| 432 | p->owner = tree; |
| 433 | get_tree(tree); |
| 434 | list_add(&p->list, &tree->chunks); |
| 435 | list_replace_rcu(&old->hash, &chunk->hash); |
| 436 | list_for_each_entry(owner, &chunk->trees, same_root) |
| 437 | owner->root = chunk; |
| 438 | old->dead = 1; |
| 439 | if (!tree->root) { |
| 440 | tree->root = chunk; |
| 441 | list_add(&tree->same_root, &chunk->trees); |
| 442 | } |
| 443 | spin_unlock(&hash_lock); |
Eric Paris | 28a3a7e | 2009-12-17 20:12:05 -0500 | [diff] [blame] | 444 | spin_unlock(&chunk_entry->lock); |
| 445 | spin_unlock(&old_entry->lock); |
Lino Sanfilippo | e2a2994 | 2011-06-14 17:29:51 +0200 | [diff] [blame] | 446 | fsnotify_destroy_mark(old_entry, audit_tree_group); |
Miklos Szeredi | b3e8692 | 2012-08-15 12:55:22 +0200 | [diff] [blame] | 447 | fsnotify_put_mark(chunk_entry); /* drop initial reference */ |
Eric Paris | 28a3a7e | 2009-12-17 20:12:05 -0500 | [diff] [blame] | 448 | fsnotify_put_mark(old_entry); /* pair to fsnotify_find mark_entry */ |
Al Viro | 74c3cbe | 2007-07-22 08:04:18 -0400 | [diff] [blame] | 449 | return 0; |
| 450 | } |
| 451 | |
Kees Cook | 0644ec0 | 2013-01-11 14:32:07 -0800 | [diff] [blame] | 452 | static void audit_log_remove_rule(struct audit_krule *rule) |
| 453 | { |
| 454 | struct audit_buffer *ab; |
| 455 | |
| 456 | ab = audit_log_start(NULL, GFP_KERNEL, AUDIT_CONFIG_CHANGE); |
| 457 | if (unlikely(!ab)) |
| 458 | return; |
| 459 | audit_log_format(ab, "op="); |
| 460 | audit_log_string(ab, "remove rule"); |
| 461 | audit_log_format(ab, " dir="); |
| 462 | audit_log_untrustedstring(ab, rule->tree->pathname); |
| 463 | audit_log_key(ab, rule->filterkey); |
| 464 | audit_log_format(ab, " list=%d res=1", rule->listnr); |
| 465 | audit_log_end(ab); |
| 466 | } |
| 467 | |
Al Viro | 74c3cbe | 2007-07-22 08:04:18 -0400 | [diff] [blame] | 468 | static void kill_rules(struct audit_tree *tree) |
| 469 | { |
| 470 | struct audit_krule *rule, *next; |
| 471 | struct audit_entry *entry; |
Al Viro | 74c3cbe | 2007-07-22 08:04:18 -0400 | [diff] [blame] | 472 | |
| 473 | list_for_each_entry_safe(rule, next, &tree->rules, rlist) { |
| 474 | entry = container_of(rule, struct audit_entry, rule); |
| 475 | |
| 476 | list_del_init(&rule->rlist); |
| 477 | if (rule->tree) { |
| 478 | /* not a half-baked one */ |
Kees Cook | 0644ec0 | 2013-01-11 14:32:07 -0800 | [diff] [blame] | 479 | audit_log_remove_rule(rule); |
Al Viro | 74c3cbe | 2007-07-22 08:04:18 -0400 | [diff] [blame] | 480 | rule->tree = NULL; |
| 481 | list_del_rcu(&entry->list); |
Al Viro | e45aa21 | 2008-12-15 01:17:50 -0500 | [diff] [blame] | 482 | list_del(&entry->rule.list); |
Al Viro | 74c3cbe | 2007-07-22 08:04:18 -0400 | [diff] [blame] | 483 | call_rcu(&entry->rcu, audit_free_rule_rcu); |
| 484 | } |
| 485 | } |
| 486 | } |
| 487 | |
| 488 | /* |
| 489 | * finish killing struct audit_tree |
| 490 | */ |
| 491 | static void prune_one(struct audit_tree *victim) |
| 492 | { |
| 493 | spin_lock(&hash_lock); |
| 494 | while (!list_empty(&victim->chunks)) { |
| 495 | struct node *p; |
Al Viro | 74c3cbe | 2007-07-22 08:04:18 -0400 | [diff] [blame] | 496 | |
| 497 | p = list_entry(victim->chunks.next, struct node, list); |
Al Viro | 74c3cbe | 2007-07-22 08:04:18 -0400 | [diff] [blame] | 498 | |
Al Viro | 8f7b0ba | 2008-11-15 01:15:43 +0000 | [diff] [blame] | 499 | untag_chunk(p); |
Al Viro | 74c3cbe | 2007-07-22 08:04:18 -0400 | [diff] [blame] | 500 | } |
| 501 | spin_unlock(&hash_lock); |
| 502 | put_tree(victim); |
| 503 | } |
| 504 | |
| 505 | /* trim the uncommitted chunks from tree */ |
| 506 | |
| 507 | static void trim_marked(struct audit_tree *tree) |
| 508 | { |
| 509 | struct list_head *p, *q; |
| 510 | spin_lock(&hash_lock); |
| 511 | if (tree->goner) { |
| 512 | spin_unlock(&hash_lock); |
| 513 | return; |
| 514 | } |
| 515 | /* reorder */ |
| 516 | for (p = tree->chunks.next; p != &tree->chunks; p = q) { |
| 517 | struct node *node = list_entry(p, struct node, list); |
| 518 | q = p->next; |
| 519 | if (node->index & (1U<<31)) { |
| 520 | list_del_init(p); |
| 521 | list_add(p, &tree->chunks); |
| 522 | } |
| 523 | } |
| 524 | |
| 525 | while (!list_empty(&tree->chunks)) { |
| 526 | struct node *node; |
Al Viro | 74c3cbe | 2007-07-22 08:04:18 -0400 | [diff] [blame] | 527 | |
| 528 | node = list_entry(tree->chunks.next, struct node, list); |
| 529 | |
| 530 | /* have we run out of marked? */ |
| 531 | if (!(node->index & (1U<<31))) |
| 532 | break; |
| 533 | |
Al Viro | 8f7b0ba | 2008-11-15 01:15:43 +0000 | [diff] [blame] | 534 | untag_chunk(node); |
Al Viro | 74c3cbe | 2007-07-22 08:04:18 -0400 | [diff] [blame] | 535 | } |
| 536 | if (!tree->root && !tree->goner) { |
| 537 | tree->goner = 1; |
| 538 | spin_unlock(&hash_lock); |
| 539 | mutex_lock(&audit_filter_mutex); |
| 540 | kill_rules(tree); |
| 541 | list_del_init(&tree->list); |
| 542 | mutex_unlock(&audit_filter_mutex); |
| 543 | prune_one(tree); |
| 544 | } else { |
| 545 | spin_unlock(&hash_lock); |
| 546 | } |
| 547 | } |
| 548 | |
Al Viro | 916d757 | 2009-06-24 00:02:38 -0400 | [diff] [blame] | 549 | static void audit_schedule_prune(void); |
| 550 | |
Al Viro | 74c3cbe | 2007-07-22 08:04:18 -0400 | [diff] [blame] | 551 | /* called with audit_filter_mutex */ |
| 552 | int audit_remove_tree_rule(struct audit_krule *rule) |
| 553 | { |
| 554 | struct audit_tree *tree; |
| 555 | tree = rule->tree; |
| 556 | if (tree) { |
| 557 | spin_lock(&hash_lock); |
| 558 | list_del_init(&rule->rlist); |
| 559 | if (list_empty(&tree->rules) && !tree->goner) { |
| 560 | tree->root = NULL; |
| 561 | list_del_init(&tree->same_root); |
| 562 | tree->goner = 1; |
| 563 | list_move(&tree->list, &prune_list); |
| 564 | rule->tree = NULL; |
| 565 | spin_unlock(&hash_lock); |
| 566 | audit_schedule_prune(); |
| 567 | return 1; |
| 568 | } |
| 569 | rule->tree = NULL; |
| 570 | spin_unlock(&hash_lock); |
| 571 | return 1; |
| 572 | } |
| 573 | return 0; |
| 574 | } |
| 575 | |
Al Viro | 1f70713 | 2010-01-30 22:51:25 -0500 | [diff] [blame] | 576 | static int compare_root(struct vfsmount *mnt, void *arg) |
| 577 | { |
| 578 | return mnt->mnt_root->d_inode == arg; |
| 579 | } |
| 580 | |
Al Viro | 74c3cbe | 2007-07-22 08:04:18 -0400 | [diff] [blame] | 581 | void audit_trim_trees(void) |
| 582 | { |
| 583 | struct list_head cursor; |
| 584 | |
| 585 | mutex_lock(&audit_filter_mutex); |
| 586 | list_add(&cursor, &tree_list); |
| 587 | while (cursor.next != &tree_list) { |
| 588 | struct audit_tree *tree; |
Al Viro | 98bc993 | 2008-08-02 01:06:21 -0400 | [diff] [blame] | 589 | struct path path; |
Al Viro | 74c3cbe | 2007-07-22 08:04:18 -0400 | [diff] [blame] | 590 | struct vfsmount *root_mnt; |
| 591 | struct node *node; |
Al Viro | 74c3cbe | 2007-07-22 08:04:18 -0400 | [diff] [blame] | 592 | int err; |
| 593 | |
| 594 | tree = container_of(cursor.next, struct audit_tree, list); |
| 595 | get_tree(tree); |
| 596 | list_del(&cursor); |
| 597 | list_add(&cursor, &tree->list); |
| 598 | mutex_unlock(&audit_filter_mutex); |
| 599 | |
Al Viro | 98bc993 | 2008-08-02 01:06:21 -0400 | [diff] [blame] | 600 | err = kern_path(tree->pathname, 0, &path); |
Al Viro | 74c3cbe | 2007-07-22 08:04:18 -0400 | [diff] [blame] | 601 | if (err) |
| 602 | goto skip_it; |
| 603 | |
Al Viro | 589ff87 | 2009-04-18 03:28:19 -0400 | [diff] [blame] | 604 | root_mnt = collect_mounts(&path); |
Al Viro | 98bc993 | 2008-08-02 01:06:21 -0400 | [diff] [blame] | 605 | path_put(&path); |
David Howells | be34d1a | 2012-06-25 12:55:18 +0100 | [diff] [blame] | 606 | if (IS_ERR(root_mnt)) |
Al Viro | 74c3cbe | 2007-07-22 08:04:18 -0400 | [diff] [blame] | 607 | goto skip_it; |
| 608 | |
Al Viro | 74c3cbe | 2007-07-22 08:04:18 -0400 | [diff] [blame] | 609 | spin_lock(&hash_lock); |
| 610 | list_for_each_entry(node, &tree->chunks, list) { |
Eric Paris | 28a3a7e | 2009-12-17 20:12:05 -0500 | [diff] [blame] | 611 | struct audit_chunk *chunk = find_chunk(node); |
Lucas De Marchi | 25985ed | 2011-03-30 22:57:33 -0300 | [diff] [blame] | 612 | /* this could be NULL if the watch is dying else where... */ |
Eric Paris | 2823e04 | 2009-12-17 21:24:23 -0500 | [diff] [blame] | 613 | struct inode *inode = chunk->mark.i.inode; |
Al Viro | 74c3cbe | 2007-07-22 08:04:18 -0400 | [diff] [blame] | 614 | node->index |= 1U<<31; |
Al Viro | 1f70713 | 2010-01-30 22:51:25 -0500 | [diff] [blame] | 615 | if (iterate_mounts(compare_root, inode, root_mnt)) |
| 616 | node->index &= ~(1U<<31); |
Al Viro | 74c3cbe | 2007-07-22 08:04:18 -0400 | [diff] [blame] | 617 | } |
| 618 | spin_unlock(&hash_lock); |
| 619 | trim_marked(tree); |
Al Viro | 74c3cbe | 2007-07-22 08:04:18 -0400 | [diff] [blame] | 620 | drop_collected_mounts(root_mnt); |
| 621 | skip_it: |
Chen Gang | 12b2f11 | 2013-04-29 15:05:19 -0700 | [diff] [blame] | 622 | put_tree(tree); |
Al Viro | 74c3cbe | 2007-07-22 08:04:18 -0400 | [diff] [blame] | 623 | mutex_lock(&audit_filter_mutex); |
| 624 | } |
| 625 | list_del(&cursor); |
| 626 | mutex_unlock(&audit_filter_mutex); |
| 627 | } |
| 628 | |
Al Viro | 74c3cbe | 2007-07-22 08:04:18 -0400 | [diff] [blame] | 629 | int audit_make_tree(struct audit_krule *rule, char *pathname, u32 op) |
| 630 | { |
| 631 | |
| 632 | if (pathname[0] != '/' || |
| 633 | rule->listnr != AUDIT_FILTER_EXIT || |
Al Viro | 5af75d8 | 2008-12-16 05:59:26 -0500 | [diff] [blame] | 634 | op != Audit_equal || |
Al Viro | 74c3cbe | 2007-07-22 08:04:18 -0400 | [diff] [blame] | 635 | rule->inode_f || rule->watch || rule->tree) |
| 636 | return -EINVAL; |
| 637 | rule->tree = alloc_tree(pathname); |
| 638 | if (!rule->tree) |
| 639 | return -ENOMEM; |
| 640 | return 0; |
| 641 | } |
| 642 | |
| 643 | void audit_put_tree(struct audit_tree *tree) |
| 644 | { |
| 645 | put_tree(tree); |
| 646 | } |
| 647 | |
Al Viro | 1f70713 | 2010-01-30 22:51:25 -0500 | [diff] [blame] | 648 | static int tag_mount(struct vfsmount *mnt, void *arg) |
| 649 | { |
| 650 | return tag_chunk(mnt->mnt_root->d_inode, arg); |
| 651 | } |
| 652 | |
Al Viro | 74c3cbe | 2007-07-22 08:04:18 -0400 | [diff] [blame] | 653 | /* called with audit_filter_mutex */ |
| 654 | int audit_add_tree_rule(struct audit_krule *rule) |
| 655 | { |
| 656 | struct audit_tree *seed = rule->tree, *tree; |
Al Viro | 98bc993 | 2008-08-02 01:06:21 -0400 | [diff] [blame] | 657 | struct path path; |
Al Viro | 1f70713 | 2010-01-30 22:51:25 -0500 | [diff] [blame] | 658 | struct vfsmount *mnt; |
Al Viro | 74c3cbe | 2007-07-22 08:04:18 -0400 | [diff] [blame] | 659 | int err; |
| 660 | |
Chen Gang | 736f320 | 2013-06-12 14:05:07 -0700 | [diff] [blame] | 661 | rule->tree = NULL; |
Al Viro | 74c3cbe | 2007-07-22 08:04:18 -0400 | [diff] [blame] | 662 | list_for_each_entry(tree, &tree_list, list) { |
| 663 | if (!strcmp(seed->pathname, tree->pathname)) { |
| 664 | put_tree(seed); |
| 665 | rule->tree = tree; |
| 666 | list_add(&rule->rlist, &tree->rules); |
| 667 | return 0; |
| 668 | } |
| 669 | } |
| 670 | tree = seed; |
| 671 | list_add(&tree->list, &tree_list); |
| 672 | list_add(&rule->rlist, &tree->rules); |
| 673 | /* do not set rule->tree yet */ |
| 674 | mutex_unlock(&audit_filter_mutex); |
| 675 | |
Al Viro | 98bc993 | 2008-08-02 01:06:21 -0400 | [diff] [blame] | 676 | err = kern_path(tree->pathname, 0, &path); |
Al Viro | 74c3cbe | 2007-07-22 08:04:18 -0400 | [diff] [blame] | 677 | if (err) |
| 678 | goto Err; |
Al Viro | 589ff87 | 2009-04-18 03:28:19 -0400 | [diff] [blame] | 679 | mnt = collect_mounts(&path); |
Al Viro | 98bc993 | 2008-08-02 01:06:21 -0400 | [diff] [blame] | 680 | path_put(&path); |
David Howells | be34d1a | 2012-06-25 12:55:18 +0100 | [diff] [blame] | 681 | if (IS_ERR(mnt)) { |
| 682 | err = PTR_ERR(mnt); |
Al Viro | 74c3cbe | 2007-07-22 08:04:18 -0400 | [diff] [blame] | 683 | goto Err; |
| 684 | } |
Al Viro | 74c3cbe | 2007-07-22 08:04:18 -0400 | [diff] [blame] | 685 | |
| 686 | get_tree(tree); |
Al Viro | 1f70713 | 2010-01-30 22:51:25 -0500 | [diff] [blame] | 687 | err = iterate_mounts(tag_mount, tree, mnt); |
Al Viro | 74c3cbe | 2007-07-22 08:04:18 -0400 | [diff] [blame] | 688 | drop_collected_mounts(mnt); |
| 689 | |
| 690 | if (!err) { |
| 691 | struct node *node; |
| 692 | spin_lock(&hash_lock); |
| 693 | list_for_each_entry(node, &tree->chunks, list) |
| 694 | node->index &= ~(1U<<31); |
| 695 | spin_unlock(&hash_lock); |
| 696 | } else { |
| 697 | trim_marked(tree); |
| 698 | goto Err; |
| 699 | } |
| 700 | |
| 701 | mutex_lock(&audit_filter_mutex); |
| 702 | if (list_empty(&rule->rlist)) { |
| 703 | put_tree(tree); |
| 704 | return -ENOENT; |
| 705 | } |
| 706 | rule->tree = tree; |
| 707 | put_tree(tree); |
| 708 | |
| 709 | return 0; |
| 710 | Err: |
| 711 | mutex_lock(&audit_filter_mutex); |
| 712 | list_del_init(&tree->list); |
| 713 | list_del_init(&tree->rules); |
| 714 | put_tree(tree); |
| 715 | return err; |
| 716 | } |
| 717 | |
| 718 | int audit_tag_tree(char *old, char *new) |
| 719 | { |
| 720 | struct list_head cursor, barrier; |
| 721 | int failed = 0; |
Al Viro | 2096f75 | 2010-01-30 13:16:21 -0500 | [diff] [blame] | 722 | struct path path1, path2; |
Al Viro | 74c3cbe | 2007-07-22 08:04:18 -0400 | [diff] [blame] | 723 | struct vfsmount *tagged; |
Al Viro | 74c3cbe | 2007-07-22 08:04:18 -0400 | [diff] [blame] | 724 | int err; |
| 725 | |
Al Viro | 2096f75 | 2010-01-30 13:16:21 -0500 | [diff] [blame] | 726 | err = kern_path(new, 0, &path2); |
Al Viro | 74c3cbe | 2007-07-22 08:04:18 -0400 | [diff] [blame] | 727 | if (err) |
| 728 | return err; |
Al Viro | 2096f75 | 2010-01-30 13:16:21 -0500 | [diff] [blame] | 729 | tagged = collect_mounts(&path2); |
| 730 | path_put(&path2); |
David Howells | be34d1a | 2012-06-25 12:55:18 +0100 | [diff] [blame] | 731 | if (IS_ERR(tagged)) |
| 732 | return PTR_ERR(tagged); |
Al Viro | 74c3cbe | 2007-07-22 08:04:18 -0400 | [diff] [blame] | 733 | |
Al Viro | 2096f75 | 2010-01-30 13:16:21 -0500 | [diff] [blame] | 734 | err = kern_path(old, 0, &path1); |
Al Viro | 74c3cbe | 2007-07-22 08:04:18 -0400 | [diff] [blame] | 735 | if (err) { |
| 736 | drop_collected_mounts(tagged); |
| 737 | return err; |
| 738 | } |
Al Viro | 74c3cbe | 2007-07-22 08:04:18 -0400 | [diff] [blame] | 739 | |
Al Viro | 74c3cbe | 2007-07-22 08:04:18 -0400 | [diff] [blame] | 740 | mutex_lock(&audit_filter_mutex); |
| 741 | list_add(&barrier, &tree_list); |
| 742 | list_add(&cursor, &barrier); |
| 743 | |
| 744 | while (cursor.next != &tree_list) { |
| 745 | struct audit_tree *tree; |
Al Viro | 2096f75 | 2010-01-30 13:16:21 -0500 | [diff] [blame] | 746 | int good_one = 0; |
Al Viro | 74c3cbe | 2007-07-22 08:04:18 -0400 | [diff] [blame] | 747 | |
| 748 | tree = container_of(cursor.next, struct audit_tree, list); |
| 749 | get_tree(tree); |
| 750 | list_del(&cursor); |
| 751 | list_add(&cursor, &tree->list); |
| 752 | mutex_unlock(&audit_filter_mutex); |
| 753 | |
Al Viro | 2096f75 | 2010-01-30 13:16:21 -0500 | [diff] [blame] | 754 | err = kern_path(tree->pathname, 0, &path2); |
| 755 | if (!err) { |
| 756 | good_one = path_is_under(&path1, &path2); |
| 757 | path_put(&path2); |
Al Viro | 74c3cbe | 2007-07-22 08:04:18 -0400 | [diff] [blame] | 758 | } |
| 759 | |
Al Viro | 2096f75 | 2010-01-30 13:16:21 -0500 | [diff] [blame] | 760 | if (!good_one) { |
Al Viro | 74c3cbe | 2007-07-22 08:04:18 -0400 | [diff] [blame] | 761 | put_tree(tree); |
| 762 | mutex_lock(&audit_filter_mutex); |
| 763 | continue; |
| 764 | } |
Al Viro | 74c3cbe | 2007-07-22 08:04:18 -0400 | [diff] [blame] | 765 | |
Al Viro | 1f70713 | 2010-01-30 22:51:25 -0500 | [diff] [blame] | 766 | failed = iterate_mounts(tag_mount, tree, tagged); |
Al Viro | 74c3cbe | 2007-07-22 08:04:18 -0400 | [diff] [blame] | 767 | if (failed) { |
| 768 | put_tree(tree); |
| 769 | mutex_lock(&audit_filter_mutex); |
| 770 | break; |
| 771 | } |
| 772 | |
| 773 | mutex_lock(&audit_filter_mutex); |
| 774 | spin_lock(&hash_lock); |
| 775 | if (!tree->goner) { |
| 776 | list_del(&tree->list); |
| 777 | list_add(&tree->list, &tree_list); |
| 778 | } |
| 779 | spin_unlock(&hash_lock); |
| 780 | put_tree(tree); |
| 781 | } |
| 782 | |
| 783 | while (barrier.prev != &tree_list) { |
| 784 | struct audit_tree *tree; |
| 785 | |
| 786 | tree = container_of(barrier.prev, struct audit_tree, list); |
| 787 | get_tree(tree); |
| 788 | list_del(&tree->list); |
| 789 | list_add(&tree->list, &barrier); |
| 790 | mutex_unlock(&audit_filter_mutex); |
| 791 | |
| 792 | if (!failed) { |
| 793 | struct node *node; |
| 794 | spin_lock(&hash_lock); |
| 795 | list_for_each_entry(node, &tree->chunks, list) |
| 796 | node->index &= ~(1U<<31); |
| 797 | spin_unlock(&hash_lock); |
| 798 | } else { |
| 799 | trim_marked(tree); |
| 800 | } |
| 801 | |
| 802 | put_tree(tree); |
| 803 | mutex_lock(&audit_filter_mutex); |
| 804 | } |
| 805 | list_del(&barrier); |
| 806 | list_del(&cursor); |
Al Viro | 74c3cbe | 2007-07-22 08:04:18 -0400 | [diff] [blame] | 807 | mutex_unlock(&audit_filter_mutex); |
Al Viro | 2096f75 | 2010-01-30 13:16:21 -0500 | [diff] [blame] | 808 | path_put(&path1); |
Al Viro | 74c3cbe | 2007-07-22 08:04:18 -0400 | [diff] [blame] | 809 | drop_collected_mounts(tagged); |
| 810 | return failed; |
| 811 | } |
| 812 | |
| 813 | /* |
| 814 | * That gets run when evict_chunk() ends up needing to kill audit_tree. |
Al Viro | 916d757 | 2009-06-24 00:02:38 -0400 | [diff] [blame] | 815 | * Runs from a separate thread. |
Al Viro | 74c3cbe | 2007-07-22 08:04:18 -0400 | [diff] [blame] | 816 | */ |
Al Viro | 916d757 | 2009-06-24 00:02:38 -0400 | [diff] [blame] | 817 | static int prune_tree_thread(void *unused) |
Al Viro | 74c3cbe | 2007-07-22 08:04:18 -0400 | [diff] [blame] | 818 | { |
Al Viro | 916d757 | 2009-06-24 00:02:38 -0400 | [diff] [blame] | 819 | mutex_lock(&audit_cmd_mutex); |
Al Viro | 74c3cbe | 2007-07-22 08:04:18 -0400 | [diff] [blame] | 820 | mutex_lock(&audit_filter_mutex); |
| 821 | |
| 822 | while (!list_empty(&prune_list)) { |
| 823 | struct audit_tree *victim; |
| 824 | |
| 825 | victim = list_entry(prune_list.next, struct audit_tree, list); |
| 826 | list_del_init(&victim->list); |
| 827 | |
| 828 | mutex_unlock(&audit_filter_mutex); |
| 829 | |
| 830 | prune_one(victim); |
| 831 | |
| 832 | mutex_lock(&audit_filter_mutex); |
| 833 | } |
| 834 | |
| 835 | mutex_unlock(&audit_filter_mutex); |
Al Viro | 916d757 | 2009-06-24 00:02:38 -0400 | [diff] [blame] | 836 | mutex_unlock(&audit_cmd_mutex); |
| 837 | return 0; |
| 838 | } |
| 839 | |
| 840 | static void audit_schedule_prune(void) |
| 841 | { |
| 842 | kthread_run(prune_tree_thread, NULL, "audit_prune_tree"); |
| 843 | } |
| 844 | |
| 845 | /* |
| 846 | * ... and that one is done if evict_chunk() decides to delay until the end |
| 847 | * of syscall. Runs synchronously. |
| 848 | */ |
| 849 | void audit_kill_trees(struct list_head *list) |
| 850 | { |
| 851 | mutex_lock(&audit_cmd_mutex); |
| 852 | mutex_lock(&audit_filter_mutex); |
| 853 | |
| 854 | while (!list_empty(list)) { |
| 855 | struct audit_tree *victim; |
| 856 | |
| 857 | victim = list_entry(list->next, struct audit_tree, list); |
| 858 | kill_rules(victim); |
| 859 | list_del_init(&victim->list); |
| 860 | |
| 861 | mutex_unlock(&audit_filter_mutex); |
| 862 | |
| 863 | prune_one(victim); |
| 864 | |
| 865 | mutex_lock(&audit_filter_mutex); |
| 866 | } |
| 867 | |
| 868 | mutex_unlock(&audit_filter_mutex); |
| 869 | mutex_unlock(&audit_cmd_mutex); |
Al Viro | 74c3cbe | 2007-07-22 08:04:18 -0400 | [diff] [blame] | 870 | } |
| 871 | |
| 872 | /* |
| 873 | * Here comes the stuff asynchronous to auditctl operations |
| 874 | */ |
| 875 | |
Al Viro | 74c3cbe | 2007-07-22 08:04:18 -0400 | [diff] [blame] | 876 | static void evict_chunk(struct audit_chunk *chunk) |
| 877 | { |
| 878 | struct audit_tree *owner; |
Al Viro | 916d757 | 2009-06-24 00:02:38 -0400 | [diff] [blame] | 879 | struct list_head *postponed = audit_killed_trees(); |
| 880 | int need_prune = 0; |
Al Viro | 74c3cbe | 2007-07-22 08:04:18 -0400 | [diff] [blame] | 881 | int n; |
| 882 | |
| 883 | if (chunk->dead) |
| 884 | return; |
| 885 | |
| 886 | chunk->dead = 1; |
| 887 | mutex_lock(&audit_filter_mutex); |
| 888 | spin_lock(&hash_lock); |
| 889 | while (!list_empty(&chunk->trees)) { |
| 890 | owner = list_entry(chunk->trees.next, |
| 891 | struct audit_tree, same_root); |
| 892 | owner->goner = 1; |
| 893 | owner->root = NULL; |
| 894 | list_del_init(&owner->same_root); |
| 895 | spin_unlock(&hash_lock); |
Al Viro | 916d757 | 2009-06-24 00:02:38 -0400 | [diff] [blame] | 896 | if (!postponed) { |
| 897 | kill_rules(owner); |
| 898 | list_move(&owner->list, &prune_list); |
| 899 | need_prune = 1; |
| 900 | } else { |
| 901 | list_move(&owner->list, postponed); |
| 902 | } |
Al Viro | 74c3cbe | 2007-07-22 08:04:18 -0400 | [diff] [blame] | 903 | spin_lock(&hash_lock); |
| 904 | } |
| 905 | list_del_rcu(&chunk->hash); |
| 906 | for (n = 0; n < chunk->count; n++) |
| 907 | list_del_init(&chunk->owners[n].list); |
| 908 | spin_unlock(&hash_lock); |
Al Viro | 916d757 | 2009-06-24 00:02:38 -0400 | [diff] [blame] | 909 | if (need_prune) |
| 910 | audit_schedule_prune(); |
Al Viro | 74c3cbe | 2007-07-22 08:04:18 -0400 | [diff] [blame] | 911 | mutex_unlock(&audit_filter_mutex); |
| 912 | } |
| 913 | |
Eric Paris | 3a9b16b | 2010-07-28 10:18:38 -0400 | [diff] [blame] | 914 | static int audit_tree_handle_event(struct fsnotify_group *group, |
Eric Paris | ce8f76f | 2010-07-28 10:18:39 -0400 | [diff] [blame] | 915 | struct fsnotify_mark *inode_mark, |
| 916 | struct fsnotify_mark *vfsmonut_mark, |
Eric Paris | 3a9b16b | 2010-07-28 10:18:38 -0400 | [diff] [blame] | 917 | struct fsnotify_event *event) |
Al Viro | 74c3cbe | 2007-07-22 08:04:18 -0400 | [diff] [blame] | 918 | { |
Eric Paris | 28a3a7e | 2009-12-17 20:12:05 -0500 | [diff] [blame] | 919 | BUG(); |
| 920 | return -EOPNOTSUPP; |
Al Viro | 74c3cbe | 2007-07-22 08:04:18 -0400 | [diff] [blame] | 921 | } |
| 922 | |
Eric Paris | e61ce86 | 2009-12-17 21:24:24 -0500 | [diff] [blame] | 923 | static void audit_tree_freeing_mark(struct fsnotify_mark *entry, struct fsnotify_group *group) |
Al Viro | 74c3cbe | 2007-07-22 08:04:18 -0400 | [diff] [blame] | 924 | { |
Eric Paris | 28a3a7e | 2009-12-17 20:12:05 -0500 | [diff] [blame] | 925 | struct audit_chunk *chunk = container_of(entry, struct audit_chunk, mark); |
| 926 | |
| 927 | evict_chunk(chunk); |
Miklos Szeredi | b3e8692 | 2012-08-15 12:55:22 +0200 | [diff] [blame] | 928 | |
| 929 | /* |
| 930 | * We are guaranteed to have at least one reference to the mark from |
| 931 | * either the inode or the caller of fsnotify_destroy_mark(). |
| 932 | */ |
| 933 | BUG_ON(atomic_read(&entry->refcnt) < 1); |
Al Viro | 74c3cbe | 2007-07-22 08:04:18 -0400 | [diff] [blame] | 934 | } |
| 935 | |
Eric Paris | 7b0a04f | 2009-12-17 21:24:21 -0500 | [diff] [blame] | 936 | static bool audit_tree_send_event(struct fsnotify_group *group, struct inode *inode, |
Eric Paris | 1968f5e | 2010-07-28 10:18:39 -0400 | [diff] [blame] | 937 | struct fsnotify_mark *inode_mark, |
Eric Paris | ce8f76f | 2010-07-28 10:18:39 -0400 | [diff] [blame] | 938 | struct fsnotify_mark *vfsmount_mark, |
Eric Paris | 3a9b16b | 2010-07-28 10:18:38 -0400 | [diff] [blame] | 939 | __u32 mask, void *data, int data_type) |
Eric Paris | 28a3a7e | 2009-12-17 20:12:05 -0500 | [diff] [blame] | 940 | { |
Eric Paris | 2612abb | 2010-07-28 10:18:39 -0400 | [diff] [blame] | 941 | return false; |
Eric Paris | 28a3a7e | 2009-12-17 20:12:05 -0500 | [diff] [blame] | 942 | } |
| 943 | |
| 944 | static const struct fsnotify_ops audit_tree_ops = { |
| 945 | .handle_event = audit_tree_handle_event, |
| 946 | .should_send_event = audit_tree_send_event, |
| 947 | .free_group_priv = NULL, |
| 948 | .free_event_priv = NULL, |
| 949 | .freeing_mark = audit_tree_freeing_mark, |
Al Viro | 74c3cbe | 2007-07-22 08:04:18 -0400 | [diff] [blame] | 950 | }; |
| 951 | |
| 952 | static int __init audit_tree_init(void) |
| 953 | { |
| 954 | int i; |
| 955 | |
Eric Paris | 0d2e2a1 | 2009-12-17 21:24:22 -0500 | [diff] [blame] | 956 | audit_tree_group = fsnotify_alloc_group(&audit_tree_ops); |
Eric Paris | 28a3a7e | 2009-12-17 20:12:05 -0500 | [diff] [blame] | 957 | if (IS_ERR(audit_tree_group)) |
| 958 | audit_panic("cannot initialize fsnotify group for rectree watches"); |
Al Viro | 74c3cbe | 2007-07-22 08:04:18 -0400 | [diff] [blame] | 959 | |
| 960 | for (i = 0; i < HASH_SIZE; i++) |
| 961 | INIT_LIST_HEAD(&chunk_hash_heads[i]); |
| 962 | |
| 963 | return 0; |
| 964 | } |
| 965 | __initcall(audit_tree_init); |