Eric Paris | cfcad62 | 2009-06-11 14:31:36 -0400 | [diff] [blame] | 1 | /* audit_watch.c -- watching inodes |
| 2 | * |
| 3 | * Copyright 2003-2009 Red Hat, Inc. |
| 4 | * Copyright 2005 Hewlett-Packard Development Company, L.P. |
| 5 | * Copyright 2005 IBM Corporation |
| 6 | * |
| 7 | * This program is free software; you can redistribute it and/or modify |
| 8 | * it under the terms of the GNU General Public License as published by |
| 9 | * the Free Software Foundation; either version 2 of the License, or |
| 10 | * (at your option) any later version. |
| 11 | * |
| 12 | * This program is distributed in the hope that it will be useful, |
| 13 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 14 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 15 | * GNU General Public License for more details. |
| 16 | * |
| 17 | * You should have received a copy of the GNU General Public License |
| 18 | * along with this program; if not, write to the Free Software |
| 19 | * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA |
| 20 | */ |
| 21 | |
| 22 | #include <linux/kernel.h> |
| 23 | #include <linux/audit.h> |
| 24 | #include <linux/kthread.h> |
| 25 | #include <linux/mutex.h> |
| 26 | #include <linux/fs.h> |
Eric Paris | e9fd702 | 2009-12-17 20:12:04 -0500 | [diff] [blame] | 27 | #include <linux/fsnotify_backend.h> |
Eric Paris | cfcad62 | 2009-06-11 14:31:36 -0400 | [diff] [blame] | 28 | #include <linux/namei.h> |
| 29 | #include <linux/netlink.h> |
| 30 | #include <linux/sched.h> |
Tejun Heo | 5a0e3ad | 2010-03-24 17:04:11 +0900 | [diff] [blame] | 31 | #include <linux/slab.h> |
Eric Paris | cfcad62 | 2009-06-11 14:31:36 -0400 | [diff] [blame] | 32 | #include <linux/security.h> |
| 33 | #include "audit.h" |
| 34 | |
| 35 | /* |
| 36 | * Reference counting: |
| 37 | * |
Eric Paris | e9fd702 | 2009-12-17 20:12:04 -0500 | [diff] [blame] | 38 | * audit_parent: lifetime is from audit_init_parent() to receipt of an FS_IGNORED |
Eric Paris | cfcad62 | 2009-06-11 14:31:36 -0400 | [diff] [blame] | 39 | * event. Each audit_watch holds a reference to its associated parent. |
| 40 | * |
| 41 | * audit_watch: if added to lists, lifetime is from audit_init_watch() to |
| 42 | * audit_remove_watch(). Additionally, an audit_watch may exist |
| 43 | * temporarily to assist in searching existing filter data. Each |
| 44 | * audit_krule holds a reference to its associated watch. |
| 45 | */ |
| 46 | |
| 47 | struct audit_watch { |
| 48 | atomic_t count; /* reference count */ |
Eric Paris | cfcad62 | 2009-06-11 14:31:36 -0400 | [diff] [blame] | 49 | dev_t dev; /* associated superblock device */ |
Eric Paris | e08b061 | 2009-08-07 16:54:23 -0400 | [diff] [blame] | 50 | char *path; /* insertion path */ |
Eric Paris | cfcad62 | 2009-06-11 14:31:36 -0400 | [diff] [blame] | 51 | unsigned long ino; /* associated inode number */ |
| 52 | struct audit_parent *parent; /* associated parent */ |
| 53 | struct list_head wlist; /* entry in parent->watches list */ |
Eric Paris | ae7b8f4 | 2009-12-17 20:12:04 -0500 | [diff] [blame] | 54 | struct list_head rules; /* anchor for krule->rlist */ |
Eric Paris | cfcad62 | 2009-06-11 14:31:36 -0400 | [diff] [blame] | 55 | }; |
| 56 | |
| 57 | struct audit_parent { |
Eric Paris | ae7b8f4 | 2009-12-17 20:12:04 -0500 | [diff] [blame] | 58 | struct list_head watches; /* anchor for audit_watch->wlist */ |
Eric Paris | e61ce86 | 2009-12-17 21:24:24 -0500 | [diff] [blame] | 59 | struct fsnotify_mark mark; /* fsnotify mark on the inode */ |
Eric Paris | cfcad62 | 2009-06-11 14:31:36 -0400 | [diff] [blame] | 60 | }; |
| 61 | |
Eric Paris | e9fd702 | 2009-12-17 20:12:04 -0500 | [diff] [blame] | 62 | /* fsnotify handle. */ |
Stephen Hemminger | b8800aa | 2010-10-20 17:23:50 -0700 | [diff] [blame] | 63 | static struct fsnotify_group *audit_watch_group; |
Eric Paris | cfcad62 | 2009-06-11 14:31:36 -0400 | [diff] [blame] | 64 | |
Eric Paris | e9fd702 | 2009-12-17 20:12:04 -0500 | [diff] [blame] | 65 | /* fsnotify events we care about. */ |
| 66 | #define AUDIT_FS_WATCH (FS_MOVE | FS_CREATE | FS_DELETE | FS_DELETE_SELF |\ |
| 67 | FS_MOVE_SELF | FS_EVENT_ON_CHILD) |
Eric Paris | cfcad62 | 2009-06-11 14:31:36 -0400 | [diff] [blame] | 68 | |
Eric Paris | ae7b8f4 | 2009-12-17 20:12:04 -0500 | [diff] [blame] | 69 | static void audit_free_parent(struct audit_parent *parent) |
| 70 | { |
| 71 | WARN_ON(!list_empty(&parent->watches)); |
| 72 | kfree(parent); |
| 73 | } |
| 74 | |
Eric Paris | e61ce86 | 2009-12-17 21:24:24 -0500 | [diff] [blame] | 75 | static void audit_watch_free_mark(struct fsnotify_mark *entry) |
Eric Paris | cfcad62 | 2009-06-11 14:31:36 -0400 | [diff] [blame] | 76 | { |
| 77 | struct audit_parent *parent; |
| 78 | |
Eric Paris | e9fd702 | 2009-12-17 20:12:04 -0500 | [diff] [blame] | 79 | parent = container_of(entry, struct audit_parent, mark); |
Eric Paris | ae7b8f4 | 2009-12-17 20:12:04 -0500 | [diff] [blame] | 80 | audit_free_parent(parent); |
Eric Paris | cfcad62 | 2009-06-11 14:31:36 -0400 | [diff] [blame] | 81 | } |
| 82 | |
Eric Paris | e9fd702 | 2009-12-17 20:12:04 -0500 | [diff] [blame] | 83 | static void audit_get_parent(struct audit_parent *parent) |
| 84 | { |
| 85 | if (likely(parent)) |
| 86 | fsnotify_get_mark(&parent->mark); |
| 87 | } |
| 88 | |
| 89 | static void audit_put_parent(struct audit_parent *parent) |
| 90 | { |
| 91 | if (likely(parent)) |
| 92 | fsnotify_put_mark(&parent->mark); |
| 93 | } |
| 94 | |
| 95 | /* |
| 96 | * Find and return the audit_parent on the given inode. If found a reference |
| 97 | * is taken on this parent. |
| 98 | */ |
| 99 | static inline struct audit_parent *audit_find_parent(struct inode *inode) |
| 100 | { |
| 101 | struct audit_parent *parent = NULL; |
Eric Paris | e61ce86 | 2009-12-17 21:24:24 -0500 | [diff] [blame] | 102 | struct fsnotify_mark *entry; |
Eric Paris | e9fd702 | 2009-12-17 20:12:04 -0500 | [diff] [blame] | 103 | |
Eric Paris | 5444e29 | 2009-12-17 21:24:27 -0500 | [diff] [blame] | 104 | entry = fsnotify_find_inode_mark(audit_watch_group, inode); |
Eric Paris | e9fd702 | 2009-12-17 20:12:04 -0500 | [diff] [blame] | 105 | if (entry) |
| 106 | parent = container_of(entry, struct audit_parent, mark); |
| 107 | |
| 108 | return parent; |
| 109 | } |
| 110 | |
Eric Paris | cfcad62 | 2009-06-11 14:31:36 -0400 | [diff] [blame] | 111 | void audit_get_watch(struct audit_watch *watch) |
| 112 | { |
| 113 | atomic_inc(&watch->count); |
| 114 | } |
| 115 | |
| 116 | void audit_put_watch(struct audit_watch *watch) |
| 117 | { |
| 118 | if (atomic_dec_and_test(&watch->count)) { |
| 119 | WARN_ON(watch->parent); |
| 120 | WARN_ON(!list_empty(&watch->rules)); |
| 121 | kfree(watch->path); |
| 122 | kfree(watch); |
| 123 | } |
| 124 | } |
| 125 | |
Stephen Hemminger | b8800aa | 2010-10-20 17:23:50 -0700 | [diff] [blame] | 126 | static void audit_remove_watch(struct audit_watch *watch) |
Eric Paris | cfcad62 | 2009-06-11 14:31:36 -0400 | [diff] [blame] | 127 | { |
| 128 | list_del(&watch->wlist); |
Eric Paris | e9fd702 | 2009-12-17 20:12:04 -0500 | [diff] [blame] | 129 | audit_put_parent(watch->parent); |
Eric Paris | cfcad62 | 2009-06-11 14:31:36 -0400 | [diff] [blame] | 130 | watch->parent = NULL; |
| 131 | audit_put_watch(watch); /* match initial get */ |
| 132 | } |
| 133 | |
| 134 | char *audit_watch_path(struct audit_watch *watch) |
| 135 | { |
| 136 | return watch->path; |
| 137 | } |
| 138 | |
Eric Paris | ae7b8f4 | 2009-12-17 20:12:04 -0500 | [diff] [blame] | 139 | int audit_watch_compare(struct audit_watch *watch, unsigned long ino, dev_t dev) |
Eric Paris | cfcad62 | 2009-06-11 14:31:36 -0400 | [diff] [blame] | 140 | { |
Eric Paris | ae7b8f4 | 2009-12-17 20:12:04 -0500 | [diff] [blame] | 141 | return (watch->ino != (unsigned long)-1) && |
| 142 | (watch->ino == ino) && |
| 143 | (watch->dev == dev); |
Eric Paris | cfcad62 | 2009-06-11 14:31:36 -0400 | [diff] [blame] | 144 | } |
| 145 | |
| 146 | /* Initialize a parent watch entry. */ |
Al Viro | 15a9155 | 2011-02-16 15:08:54 -0500 | [diff] [blame] | 147 | static struct audit_parent *audit_init_parent(struct path *path) |
Eric Paris | cfcad62 | 2009-06-11 14:31:36 -0400 | [diff] [blame] | 148 | { |
Al Viro | 15a9155 | 2011-02-16 15:08:54 -0500 | [diff] [blame] | 149 | struct inode *inode = path->dentry->d_inode; |
Eric Paris | cfcad62 | 2009-06-11 14:31:36 -0400 | [diff] [blame] | 150 | struct audit_parent *parent; |
Eric Paris | e9fd702 | 2009-12-17 20:12:04 -0500 | [diff] [blame] | 151 | int ret; |
Eric Paris | cfcad62 | 2009-06-11 14:31:36 -0400 | [diff] [blame] | 152 | |
| 153 | parent = kzalloc(sizeof(*parent), GFP_KERNEL); |
| 154 | if (unlikely(!parent)) |
| 155 | return ERR_PTR(-ENOMEM); |
| 156 | |
| 157 | INIT_LIST_HEAD(&parent->watches); |
Eric Paris | cfcad62 | 2009-06-11 14:31:36 -0400 | [diff] [blame] | 158 | |
Eric Paris | e9fd702 | 2009-12-17 20:12:04 -0500 | [diff] [blame] | 159 | fsnotify_init_mark(&parent->mark, audit_watch_free_mark); |
| 160 | parent->mark.mask = AUDIT_FS_WATCH; |
Eric Paris | 5444e29 | 2009-12-17 21:24:27 -0500 | [diff] [blame] | 161 | ret = fsnotify_add_mark(&parent->mark, audit_watch_group, inode, NULL, 0); |
Eric Paris | e9fd702 | 2009-12-17 20:12:04 -0500 | [diff] [blame] | 162 | if (ret < 0) { |
Eric Paris | ae7b8f4 | 2009-12-17 20:12:04 -0500 | [diff] [blame] | 163 | audit_free_parent(parent); |
Eric Paris | e9fd702 | 2009-12-17 20:12:04 -0500 | [diff] [blame] | 164 | return ERR_PTR(ret); |
Eric Paris | cfcad62 | 2009-06-11 14:31:36 -0400 | [diff] [blame] | 165 | } |
| 166 | |
| 167 | return parent; |
| 168 | } |
| 169 | |
| 170 | /* Initialize a watch entry. */ |
| 171 | static struct audit_watch *audit_init_watch(char *path) |
| 172 | { |
| 173 | struct audit_watch *watch; |
| 174 | |
| 175 | watch = kzalloc(sizeof(*watch), GFP_KERNEL); |
| 176 | if (unlikely(!watch)) |
| 177 | return ERR_PTR(-ENOMEM); |
| 178 | |
| 179 | INIT_LIST_HEAD(&watch->rules); |
| 180 | atomic_set(&watch->count, 1); |
| 181 | watch->path = path; |
| 182 | watch->dev = (dev_t)-1; |
| 183 | watch->ino = (unsigned long)-1; |
| 184 | |
| 185 | return watch; |
| 186 | } |
| 187 | |
| 188 | /* Translate a watch string to kernel respresentation. */ |
| 189 | int audit_to_watch(struct audit_krule *krule, char *path, int len, u32 op) |
| 190 | { |
| 191 | struct audit_watch *watch; |
| 192 | |
Eric Paris | e9fd702 | 2009-12-17 20:12:04 -0500 | [diff] [blame] | 193 | if (!audit_watch_group) |
Eric Paris | cfcad62 | 2009-06-11 14:31:36 -0400 | [diff] [blame] | 194 | return -EOPNOTSUPP; |
| 195 | |
| 196 | if (path[0] != '/' || path[len-1] == '/' || |
| 197 | krule->listnr != AUDIT_FILTER_EXIT || |
| 198 | op != Audit_equal || |
| 199 | krule->inode_f || krule->watch || krule->tree) |
| 200 | return -EINVAL; |
| 201 | |
| 202 | watch = audit_init_watch(path); |
| 203 | if (IS_ERR(watch)) |
| 204 | return PTR_ERR(watch); |
| 205 | |
| 206 | audit_get_watch(watch); |
| 207 | krule->watch = watch; |
| 208 | |
| 209 | return 0; |
| 210 | } |
| 211 | |
| 212 | /* Duplicate the given audit watch. The new watch's rules list is initialized |
| 213 | * to an empty list and wlist is undefined. */ |
| 214 | static struct audit_watch *audit_dupe_watch(struct audit_watch *old) |
| 215 | { |
| 216 | char *path; |
| 217 | struct audit_watch *new; |
| 218 | |
| 219 | path = kstrdup(old->path, GFP_KERNEL); |
| 220 | if (unlikely(!path)) |
| 221 | return ERR_PTR(-ENOMEM); |
| 222 | |
| 223 | new = audit_init_watch(path); |
| 224 | if (IS_ERR(new)) { |
| 225 | kfree(path); |
| 226 | goto out; |
| 227 | } |
| 228 | |
| 229 | new->dev = old->dev; |
| 230 | new->ino = old->ino; |
Eric Paris | e9fd702 | 2009-12-17 20:12:04 -0500 | [diff] [blame] | 231 | audit_get_parent(old->parent); |
Eric Paris | cfcad62 | 2009-06-11 14:31:36 -0400 | [diff] [blame] | 232 | new->parent = old->parent; |
| 233 | |
| 234 | out: |
| 235 | return new; |
| 236 | } |
| 237 | |
| 238 | static void audit_watch_log_rule_change(struct audit_krule *r, struct audit_watch *w, char *op) |
| 239 | { |
| 240 | if (audit_enabled) { |
| 241 | struct audit_buffer *ab; |
| 242 | ab = audit_log_start(NULL, GFP_NOFS, AUDIT_CONFIG_CHANGE); |
| 243 | audit_log_format(ab, "auid=%u ses=%u op=", |
Eric W. Biederman | e1760bd | 2012-09-10 22:39:43 -0700 | [diff] [blame] | 244 | from_kuid(&init_user_ns, audit_get_loginuid(current)), |
Eric Paris | cfcad62 | 2009-06-11 14:31:36 -0400 | [diff] [blame] | 245 | audit_get_sessionid(current)); |
| 246 | audit_log_string(ab, op); |
| 247 | audit_log_format(ab, " path="); |
| 248 | audit_log_untrustedstring(ab, w->path); |
Eric Paris | 9d96098 | 2009-06-11 14:31:37 -0400 | [diff] [blame] | 249 | audit_log_key(ab, r->filterkey); |
Eric Paris | cfcad62 | 2009-06-11 14:31:36 -0400 | [diff] [blame] | 250 | audit_log_format(ab, " list=%d res=1", r->listnr); |
| 251 | audit_log_end(ab); |
| 252 | } |
| 253 | } |
| 254 | |
| 255 | /* Update inode info in audit rules based on filesystem event. */ |
| 256 | static void audit_update_watch(struct audit_parent *parent, |
| 257 | const char *dname, dev_t dev, |
| 258 | unsigned long ino, unsigned invalidating) |
| 259 | { |
| 260 | struct audit_watch *owatch, *nwatch, *nextw; |
| 261 | struct audit_krule *r, *nextr; |
| 262 | struct audit_entry *oentry, *nentry; |
| 263 | |
| 264 | mutex_lock(&audit_filter_mutex); |
Eric Paris | ae7b8f4 | 2009-12-17 20:12:04 -0500 | [diff] [blame] | 265 | /* Run all of the watches on this parent looking for the one that |
| 266 | * matches the given dname */ |
Eric Paris | cfcad62 | 2009-06-11 14:31:36 -0400 | [diff] [blame] | 267 | list_for_each_entry_safe(owatch, nextw, &parent->watches, wlist) { |
Jeff Layton | e3d6b07 | 2012-10-10 15:25:25 -0400 | [diff] [blame] | 268 | if (audit_compare_dname_path(dname, owatch->path, |
| 269 | AUDIT_NAME_FULL)) |
Eric Paris | cfcad62 | 2009-06-11 14:31:36 -0400 | [diff] [blame] | 270 | continue; |
| 271 | |
| 272 | /* If the update involves invalidating rules, do the inode-based |
| 273 | * filtering now, so we don't omit records. */ |
Eric Paris | ae7b8f4 | 2009-12-17 20:12:04 -0500 | [diff] [blame] | 274 | if (invalidating && !audit_dummy_context()) |
Eric Paris | cfcad62 | 2009-06-11 14:31:36 -0400 | [diff] [blame] | 275 | audit_filter_inodes(current, current->audit_context); |
| 276 | |
Eric Paris | ae7b8f4 | 2009-12-17 20:12:04 -0500 | [diff] [blame] | 277 | /* updating ino will likely change which audit_hash_list we |
| 278 | * are on so we need a new watch for the new list */ |
Eric Paris | cfcad62 | 2009-06-11 14:31:36 -0400 | [diff] [blame] | 279 | nwatch = audit_dupe_watch(owatch); |
| 280 | if (IS_ERR(nwatch)) { |
| 281 | mutex_unlock(&audit_filter_mutex); |
| 282 | audit_panic("error updating watch, skipping"); |
| 283 | return; |
| 284 | } |
| 285 | nwatch->dev = dev; |
| 286 | nwatch->ino = ino; |
| 287 | |
| 288 | list_for_each_entry_safe(r, nextr, &owatch->rules, rlist) { |
| 289 | |
| 290 | oentry = container_of(r, struct audit_entry, rule); |
| 291 | list_del(&oentry->rule.rlist); |
| 292 | list_del_rcu(&oentry->list); |
| 293 | |
Eric Paris | ae7b8f4 | 2009-12-17 20:12:04 -0500 | [diff] [blame] | 294 | nentry = audit_dupe_rule(&oentry->rule); |
Eric Paris | cfcad62 | 2009-06-11 14:31:36 -0400 | [diff] [blame] | 295 | if (IS_ERR(nentry)) { |
| 296 | list_del(&oentry->rule.list); |
| 297 | audit_panic("error updating watch, removing"); |
| 298 | } else { |
| 299 | int h = audit_hash_ino((u32)ino); |
Eric Paris | ae7b8f4 | 2009-12-17 20:12:04 -0500 | [diff] [blame] | 300 | |
| 301 | /* |
| 302 | * nentry->rule.watch == oentry->rule.watch so |
| 303 | * we must drop that reference and set it to our |
| 304 | * new watch. |
| 305 | */ |
| 306 | audit_put_watch(nentry->rule.watch); |
| 307 | audit_get_watch(nwatch); |
| 308 | nentry->rule.watch = nwatch; |
Eric Paris | cfcad62 | 2009-06-11 14:31:36 -0400 | [diff] [blame] | 309 | list_add(&nentry->rule.rlist, &nwatch->rules); |
| 310 | list_add_rcu(&nentry->list, &audit_inode_hash[h]); |
| 311 | list_replace(&oentry->rule.list, |
| 312 | &nentry->rule.list); |
| 313 | } |
| 314 | |
| 315 | audit_watch_log_rule_change(r, owatch, "updated rules"); |
| 316 | |
| 317 | call_rcu(&oentry->rcu, audit_free_rule_rcu); |
| 318 | } |
| 319 | |
| 320 | audit_remove_watch(owatch); |
| 321 | goto add_watch_to_parent; /* event applies to a single watch */ |
| 322 | } |
| 323 | mutex_unlock(&audit_filter_mutex); |
| 324 | return; |
| 325 | |
| 326 | add_watch_to_parent: |
| 327 | list_add(&nwatch->wlist, &parent->watches); |
| 328 | mutex_unlock(&audit_filter_mutex); |
| 329 | return; |
| 330 | } |
| 331 | |
| 332 | /* Remove all watches & rules associated with a parent that is going away. */ |
| 333 | static void audit_remove_parent_watches(struct audit_parent *parent) |
| 334 | { |
| 335 | struct audit_watch *w, *nextw; |
| 336 | struct audit_krule *r, *nextr; |
| 337 | struct audit_entry *e; |
| 338 | |
| 339 | mutex_lock(&audit_filter_mutex); |
Eric Paris | cfcad62 | 2009-06-11 14:31:36 -0400 | [diff] [blame] | 340 | list_for_each_entry_safe(w, nextw, &parent->watches, wlist) { |
| 341 | list_for_each_entry_safe(r, nextr, &w->rules, rlist) { |
| 342 | e = container_of(r, struct audit_entry, rule); |
| 343 | audit_watch_log_rule_change(r, w, "remove rule"); |
| 344 | list_del(&r->rlist); |
| 345 | list_del(&r->list); |
| 346 | list_del_rcu(&e->list); |
| 347 | call_rcu(&e->rcu, audit_free_rule_rcu); |
| 348 | } |
| 349 | audit_remove_watch(w); |
| 350 | } |
| 351 | mutex_unlock(&audit_filter_mutex); |
Eric Paris | e9fd702 | 2009-12-17 20:12:04 -0500 | [diff] [blame] | 352 | |
Lino Sanfilippo | e2a2994 | 2011-06-14 17:29:51 +0200 | [diff] [blame] | 353 | fsnotify_destroy_mark(&parent->mark, audit_watch_group); |
Eric Paris | cfcad62 | 2009-06-11 14:31:36 -0400 | [diff] [blame] | 354 | } |
| 355 | |
Eric Paris | cfcad62 | 2009-06-11 14:31:36 -0400 | [diff] [blame] | 356 | /* Get path information necessary for adding watches. */ |
Al Viro | 15a9155 | 2011-02-16 15:08:54 -0500 | [diff] [blame] | 357 | static int audit_get_nd(struct audit_watch *watch, struct path *parent) |
Eric Paris | cfcad62 | 2009-06-11 14:31:36 -0400 | [diff] [blame] | 358 | { |
Al Viro | 79714f7 | 2012-06-15 03:01:42 +0400 | [diff] [blame] | 359 | struct dentry *d = kern_path_locked(watch->path, parent); |
| 360 | if (IS_ERR(d)) |
Al Viro | 15a9155 | 2011-02-16 15:08:54 -0500 | [diff] [blame] | 361 | return PTR_ERR(d); |
Al Viro | 79714f7 | 2012-06-15 03:01:42 +0400 | [diff] [blame] | 362 | mutex_unlock(&parent->dentry->d_inode->i_mutex); |
Al Viro | 15a9155 | 2011-02-16 15:08:54 -0500 | [diff] [blame] | 363 | if (d->d_inode) { |
| 364 | /* update watch filter fields */ |
| 365 | watch->dev = d->d_inode->i_sb->s_dev; |
| 366 | watch->ino = d->d_inode->i_ino; |
| 367 | } |
Al Viro | 15a9155 | 2011-02-16 15:08:54 -0500 | [diff] [blame] | 368 | dput(d); |
Eric Paris | cfcad62 | 2009-06-11 14:31:36 -0400 | [diff] [blame] | 369 | return 0; |
| 370 | } |
| 371 | |
Eric Paris | e9fd702 | 2009-12-17 20:12:04 -0500 | [diff] [blame] | 372 | /* Associate the given rule with an existing parent. |
Eric Paris | cfcad62 | 2009-06-11 14:31:36 -0400 | [diff] [blame] | 373 | * Caller must hold audit_filter_mutex. */ |
| 374 | static void audit_add_to_parent(struct audit_krule *krule, |
| 375 | struct audit_parent *parent) |
| 376 | { |
| 377 | struct audit_watch *w, *watch = krule->watch; |
| 378 | int watch_found = 0; |
| 379 | |
Eric Paris | e9fd702 | 2009-12-17 20:12:04 -0500 | [diff] [blame] | 380 | BUG_ON(!mutex_is_locked(&audit_filter_mutex)); |
| 381 | |
Eric Paris | cfcad62 | 2009-06-11 14:31:36 -0400 | [diff] [blame] | 382 | list_for_each_entry(w, &parent->watches, wlist) { |
| 383 | if (strcmp(watch->path, w->path)) |
| 384 | continue; |
| 385 | |
| 386 | watch_found = 1; |
| 387 | |
| 388 | /* put krule's and initial refs to temporary watch */ |
| 389 | audit_put_watch(watch); |
| 390 | audit_put_watch(watch); |
| 391 | |
| 392 | audit_get_watch(w); |
| 393 | krule->watch = watch = w; |
| 394 | break; |
| 395 | } |
| 396 | |
| 397 | if (!watch_found) { |
Eric Paris | e9fd702 | 2009-12-17 20:12:04 -0500 | [diff] [blame] | 398 | audit_get_parent(parent); |
Eric Paris | cfcad62 | 2009-06-11 14:31:36 -0400 | [diff] [blame] | 399 | watch->parent = parent; |
| 400 | |
| 401 | list_add(&watch->wlist, &parent->watches); |
| 402 | } |
| 403 | list_add(&krule->rlist, &watch->rules); |
| 404 | } |
| 405 | |
| 406 | /* Find a matching watch entry, or add this one. |
| 407 | * Caller must hold audit_filter_mutex. */ |
Eric Paris | ae7b8f4 | 2009-12-17 20:12:04 -0500 | [diff] [blame] | 408 | int audit_add_watch(struct audit_krule *krule, struct list_head **list) |
Eric Paris | cfcad62 | 2009-06-11 14:31:36 -0400 | [diff] [blame] | 409 | { |
| 410 | struct audit_watch *watch = krule->watch; |
Eric Paris | cfcad62 | 2009-06-11 14:31:36 -0400 | [diff] [blame] | 411 | struct audit_parent *parent; |
Al Viro | 15a9155 | 2011-02-16 15:08:54 -0500 | [diff] [blame] | 412 | struct path parent_path; |
Eric Paris | ae7b8f4 | 2009-12-17 20:12:04 -0500 | [diff] [blame] | 413 | int h, ret = 0; |
Eric Paris | cfcad62 | 2009-06-11 14:31:36 -0400 | [diff] [blame] | 414 | |
Eric Paris | 35fe4d0 | 2009-06-11 14:31:36 -0400 | [diff] [blame] | 415 | mutex_unlock(&audit_filter_mutex); |
| 416 | |
| 417 | /* Avoid calling path_lookup under audit_filter_mutex. */ |
Al Viro | 15a9155 | 2011-02-16 15:08:54 -0500 | [diff] [blame] | 418 | ret = audit_get_nd(watch, &parent_path); |
Eric Paris | 35fe4d0 | 2009-06-11 14:31:36 -0400 | [diff] [blame] | 419 | |
Al Viro | 15a9155 | 2011-02-16 15:08:54 -0500 | [diff] [blame] | 420 | /* caller expects mutex locked */ |
Eric Paris | e118e9c | 2009-12-17 20:12:04 -0500 | [diff] [blame] | 421 | mutex_lock(&audit_filter_mutex); |
| 422 | |
Al Viro | 15a9155 | 2011-02-16 15:08:54 -0500 | [diff] [blame] | 423 | if (ret) |
| 424 | return ret; |
Eric Paris | cfcad62 | 2009-06-11 14:31:36 -0400 | [diff] [blame] | 425 | |
Eric Paris | e118e9c | 2009-12-17 20:12:04 -0500 | [diff] [blame] | 426 | /* either find an old parent or attach a new one */ |
Al Viro | 15a9155 | 2011-02-16 15:08:54 -0500 | [diff] [blame] | 427 | parent = audit_find_parent(parent_path.dentry->d_inode); |
Eric Paris | e9fd702 | 2009-12-17 20:12:04 -0500 | [diff] [blame] | 428 | if (!parent) { |
Al Viro | 15a9155 | 2011-02-16 15:08:54 -0500 | [diff] [blame] | 429 | parent = audit_init_parent(&parent_path); |
Eric Paris | cfcad62 | 2009-06-11 14:31:36 -0400 | [diff] [blame] | 430 | if (IS_ERR(parent)) { |
Eric Paris | 35fe4d0 | 2009-06-11 14:31:36 -0400 | [diff] [blame] | 431 | ret = PTR_ERR(parent); |
| 432 | goto error; |
Eric Paris | cfcad62 | 2009-06-11 14:31:36 -0400 | [diff] [blame] | 433 | } |
Eric Paris | e9fd702 | 2009-12-17 20:12:04 -0500 | [diff] [blame] | 434 | } |
Eric Paris | cfcad62 | 2009-06-11 14:31:36 -0400 | [diff] [blame] | 435 | |
Eric Paris | e118e9c | 2009-12-17 20:12:04 -0500 | [diff] [blame] | 436 | audit_add_to_parent(krule, parent); |
Eric Paris | cfcad62 | 2009-06-11 14:31:36 -0400 | [diff] [blame] | 437 | |
Eric Paris | e9fd702 | 2009-12-17 20:12:04 -0500 | [diff] [blame] | 438 | /* match get in audit_find_parent or audit_init_parent */ |
| 439 | audit_put_parent(parent); |
Eric Paris | 35fe4d0 | 2009-06-11 14:31:36 -0400 | [diff] [blame] | 440 | |
Eric Paris | ae7b8f4 | 2009-12-17 20:12:04 -0500 | [diff] [blame] | 441 | h = audit_hash_ino((u32)watch->ino); |
| 442 | *list = &audit_inode_hash[h]; |
Eric Paris | 35fe4d0 | 2009-06-11 14:31:36 -0400 | [diff] [blame] | 443 | error: |
Al Viro | 15a9155 | 2011-02-16 15:08:54 -0500 | [diff] [blame] | 444 | path_put(&parent_path); |
Eric Paris | cfcad62 | 2009-06-11 14:31:36 -0400 | [diff] [blame] | 445 | return ret; |
Eric Paris | cfcad62 | 2009-06-11 14:31:36 -0400 | [diff] [blame] | 446 | } |
| 447 | |
Eric Paris | a05fb6c | 2009-12-17 20:12:05 -0500 | [diff] [blame] | 448 | void audit_remove_watch_rule(struct audit_krule *krule) |
Eric Paris | cfcad62 | 2009-06-11 14:31:36 -0400 | [diff] [blame] | 449 | { |
| 450 | struct audit_watch *watch = krule->watch; |
| 451 | struct audit_parent *parent = watch->parent; |
| 452 | |
| 453 | list_del(&krule->rlist); |
| 454 | |
| 455 | if (list_empty(&watch->rules)) { |
| 456 | audit_remove_watch(watch); |
| 457 | |
| 458 | if (list_empty(&parent->watches)) { |
Eric Paris | e9fd702 | 2009-12-17 20:12:04 -0500 | [diff] [blame] | 459 | audit_get_parent(parent); |
Lino Sanfilippo | e2a2994 | 2011-06-14 17:29:51 +0200 | [diff] [blame] | 460 | fsnotify_destroy_mark(&parent->mark, audit_watch_group); |
Eric Paris | a05fb6c | 2009-12-17 20:12:05 -0500 | [diff] [blame] | 461 | audit_put_parent(parent); |
Eric Paris | cfcad62 | 2009-06-11 14:31:36 -0400 | [diff] [blame] | 462 | } |
| 463 | } |
| 464 | } |
| 465 | |
Eric Paris | 7b0a04f | 2009-12-17 21:24:21 -0500 | [diff] [blame] | 466 | static bool audit_watch_should_send_event(struct fsnotify_group *group, struct inode *inode, |
Eric Paris | 1968f5e | 2010-07-28 10:18:39 -0400 | [diff] [blame] | 467 | struct fsnotify_mark *inode_mark, |
Eric Paris | ce8f76f | 2010-07-28 10:18:39 -0400 | [diff] [blame] | 468 | struct fsnotify_mark *vfsmount_mark, |
Eric Paris | 3a9b16b | 2010-07-28 10:18:38 -0400 | [diff] [blame] | 469 | __u32 mask, void *data, int data_type) |
Eric Paris | e9fd702 | 2009-12-17 20:12:04 -0500 | [diff] [blame] | 470 | { |
Eric Paris | 2612abb | 2010-07-28 10:18:39 -0400 | [diff] [blame] | 471 | return true; |
Eric Paris | e9fd702 | 2009-12-17 20:12:04 -0500 | [diff] [blame] | 472 | } |
| 473 | |
| 474 | /* Update watch data in audit rules based on fsnotify events. */ |
Eric Paris | 3a9b16b | 2010-07-28 10:18:38 -0400 | [diff] [blame] | 475 | static int audit_watch_handle_event(struct fsnotify_group *group, |
Eric Paris | ce8f76f | 2010-07-28 10:18:39 -0400 | [diff] [blame] | 476 | struct fsnotify_mark *inode_mark, |
| 477 | struct fsnotify_mark *vfsmount_mark, |
Eric Paris | 3a9b16b | 2010-07-28 10:18:38 -0400 | [diff] [blame] | 478 | struct fsnotify_event *event) |
Eric Paris | e9fd702 | 2009-12-17 20:12:04 -0500 | [diff] [blame] | 479 | { |
| 480 | struct inode *inode; |
| 481 | __u32 mask = event->mask; |
| 482 | const char *dname = event->file_name; |
| 483 | struct audit_parent *parent; |
| 484 | |
Eric Paris | ce8f76f | 2010-07-28 10:18:39 -0400 | [diff] [blame] | 485 | parent = container_of(inode_mark, struct audit_parent, mark); |
Eric Paris | e9fd702 | 2009-12-17 20:12:04 -0500 | [diff] [blame] | 486 | |
Eric Paris | 4cd76a4 | 2010-07-28 10:18:38 -0400 | [diff] [blame] | 487 | BUG_ON(group != audit_watch_group); |
Eric Paris | e9fd702 | 2009-12-17 20:12:04 -0500 | [diff] [blame] | 488 | |
| 489 | switch (event->data_type) { |
Linus Torvalds | 2069601 | 2010-08-12 14:23:04 -0700 | [diff] [blame] | 490 | case (FSNOTIFY_EVENT_PATH): |
| 491 | inode = event->path.dentry->d_inode; |
Eric Paris | e9fd702 | 2009-12-17 20:12:04 -0500 | [diff] [blame] | 492 | break; |
| 493 | case (FSNOTIFY_EVENT_INODE): |
| 494 | inode = event->inode; |
| 495 | break; |
| 496 | default: |
| 497 | BUG(); |
| 498 | inode = NULL; |
| 499 | break; |
| 500 | }; |
| 501 | |
| 502 | if (mask & (FS_CREATE|FS_MOVED_TO) && inode) |
| 503 | audit_update_watch(parent, dname, inode->i_sb->s_dev, inode->i_ino, 0); |
| 504 | else if (mask & (FS_DELETE|FS_MOVED_FROM)) |
| 505 | audit_update_watch(parent, dname, (dev_t)-1, (unsigned long)-1, 1); |
| 506 | else if (mask & (FS_DELETE_SELF|FS_UNMOUNT|FS_MOVE_SELF)) |
| 507 | audit_remove_parent_watches(parent); |
Eric Paris | e9fd702 | 2009-12-17 20:12:04 -0500 | [diff] [blame] | 508 | |
| 509 | return 0; |
| 510 | } |
| 511 | |
Eric Paris | e9fd702 | 2009-12-17 20:12:04 -0500 | [diff] [blame] | 512 | static const struct fsnotify_ops audit_watch_fsnotify_ops = { |
| 513 | .should_send_event = audit_watch_should_send_event, |
| 514 | .handle_event = audit_watch_handle_event, |
| 515 | .free_group_priv = NULL, |
Eric Paris | e118e9c | 2009-12-17 20:12:04 -0500 | [diff] [blame] | 516 | .freeing_mark = NULL, |
Eric Paris | e9fd702 | 2009-12-17 20:12:04 -0500 | [diff] [blame] | 517 | .free_event_priv = NULL, |
Eric Paris | cfcad62 | 2009-06-11 14:31:36 -0400 | [diff] [blame] | 518 | }; |
| 519 | |
| 520 | static int __init audit_watch_init(void) |
| 521 | { |
Eric Paris | 0d2e2a1 | 2009-12-17 21:24:22 -0500 | [diff] [blame] | 522 | audit_watch_group = fsnotify_alloc_group(&audit_watch_fsnotify_ops); |
Eric Paris | e9fd702 | 2009-12-17 20:12:04 -0500 | [diff] [blame] | 523 | if (IS_ERR(audit_watch_group)) { |
| 524 | audit_watch_group = NULL; |
| 525 | audit_panic("cannot create audit fsnotify group"); |
| 526 | } |
Eric Paris | cfcad62 | 2009-06-11 14:31:36 -0400 | [diff] [blame] | 527 | return 0; |
| 528 | } |
Eric Paris | 1a3aedb | 2009-12-17 20:12:06 -0500 | [diff] [blame] | 529 | device_initcall(audit_watch_init); |