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 | |
Mateusz Guzik | 5efc244 | 2016-08-23 16:20:39 +0200 | [diff] [blame] | 22 | #include <linux/file.h> |
Eric Paris | cfcad62 | 2009-06-11 14:31:36 -0400 | [diff] [blame] | 23 | #include <linux/kernel.h> |
| 24 | #include <linux/audit.h> |
| 25 | #include <linux/kthread.h> |
| 26 | #include <linux/mutex.h> |
| 27 | #include <linux/fs.h> |
Eric Paris | e9fd702 | 2009-12-17 20:12:04 -0500 | [diff] [blame] | 28 | #include <linux/fsnotify_backend.h> |
Eric Paris | cfcad62 | 2009-06-11 14:31:36 -0400 | [diff] [blame] | 29 | #include <linux/namei.h> |
| 30 | #include <linux/netlink.h> |
Elena Reshetova | bd120de | 2017-05-02 10:16:05 -0400 | [diff] [blame] | 31 | #include <linux/refcount.h> |
Eric Paris | cfcad62 | 2009-06-11 14:31:36 -0400 | [diff] [blame] | 32 | #include <linux/sched.h> |
Tejun Heo | 5a0e3ad | 2010-03-24 17:04:11 +0900 | [diff] [blame] | 33 | #include <linux/slab.h> |
Eric Paris | cfcad62 | 2009-06-11 14:31:36 -0400 | [diff] [blame] | 34 | #include <linux/security.h> |
| 35 | #include "audit.h" |
| 36 | |
| 37 | /* |
| 38 | * Reference counting: |
| 39 | * |
Eric Paris | e9fd702 | 2009-12-17 20:12:04 -0500 | [diff] [blame] | 40 | * 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] | 41 | * event. Each audit_watch holds a reference to its associated parent. |
| 42 | * |
| 43 | * audit_watch: if added to lists, lifetime is from audit_init_watch() to |
| 44 | * audit_remove_watch(). Additionally, an audit_watch may exist |
| 45 | * temporarily to assist in searching existing filter data. Each |
| 46 | * audit_krule holds a reference to its associated watch. |
| 47 | */ |
| 48 | |
| 49 | struct audit_watch { |
Elena Reshetova | bd120de | 2017-05-02 10:16:05 -0400 | [diff] [blame] | 50 | refcount_t count; /* reference count */ |
Eric Paris | cfcad62 | 2009-06-11 14:31:36 -0400 | [diff] [blame] | 51 | dev_t dev; /* associated superblock device */ |
Eric Paris | e08b061 | 2009-08-07 16:54:23 -0400 | [diff] [blame] | 52 | char *path; /* insertion path */ |
Eric Paris | cfcad62 | 2009-06-11 14:31:36 -0400 | [diff] [blame] | 53 | unsigned long ino; /* associated inode number */ |
| 54 | struct audit_parent *parent; /* associated parent */ |
| 55 | struct list_head wlist; /* entry in parent->watches list */ |
Eric Paris | ae7b8f4 | 2009-12-17 20:12:04 -0500 | [diff] [blame] | 56 | struct list_head rules; /* anchor for krule->rlist */ |
Eric Paris | cfcad62 | 2009-06-11 14:31:36 -0400 | [diff] [blame] | 57 | }; |
| 58 | |
| 59 | struct audit_parent { |
Eric Paris | ae7b8f4 | 2009-12-17 20:12:04 -0500 | [diff] [blame] | 60 | struct list_head watches; /* anchor for audit_watch->wlist */ |
Eric Paris | e61ce86 | 2009-12-17 21:24:24 -0500 | [diff] [blame] | 61 | struct fsnotify_mark mark; /* fsnotify mark on the inode */ |
Eric Paris | cfcad62 | 2009-06-11 14:31:36 -0400 | [diff] [blame] | 62 | }; |
| 63 | |
Eric Paris | e9fd702 | 2009-12-17 20:12:04 -0500 | [diff] [blame] | 64 | /* fsnotify handle. */ |
Stephen Hemminger | b8800aa | 2010-10-20 17:23:50 -0700 | [diff] [blame] | 65 | static struct fsnotify_group *audit_watch_group; |
Eric Paris | cfcad62 | 2009-06-11 14:31:36 -0400 | [diff] [blame] | 66 | |
Eric Paris | e9fd702 | 2009-12-17 20:12:04 -0500 | [diff] [blame] | 67 | /* fsnotify events we care about. */ |
| 68 | #define AUDIT_FS_WATCH (FS_MOVE | FS_CREATE | FS_DELETE | FS_DELETE_SELF |\ |
| 69 | FS_MOVE_SELF | FS_EVENT_ON_CHILD) |
Eric Paris | cfcad62 | 2009-06-11 14:31:36 -0400 | [diff] [blame] | 70 | |
Eric Paris | ae7b8f4 | 2009-12-17 20:12:04 -0500 | [diff] [blame] | 71 | static void audit_free_parent(struct audit_parent *parent) |
| 72 | { |
| 73 | WARN_ON(!list_empty(&parent->watches)); |
| 74 | kfree(parent); |
| 75 | } |
| 76 | |
Eric Paris | e61ce86 | 2009-12-17 21:24:24 -0500 | [diff] [blame] | 77 | static void audit_watch_free_mark(struct fsnotify_mark *entry) |
Eric Paris | cfcad62 | 2009-06-11 14:31:36 -0400 | [diff] [blame] | 78 | { |
| 79 | struct audit_parent *parent; |
| 80 | |
Eric Paris | e9fd702 | 2009-12-17 20:12:04 -0500 | [diff] [blame] | 81 | parent = container_of(entry, struct audit_parent, mark); |
Eric Paris | ae7b8f4 | 2009-12-17 20:12:04 -0500 | [diff] [blame] | 82 | audit_free_parent(parent); |
Eric Paris | cfcad62 | 2009-06-11 14:31:36 -0400 | [diff] [blame] | 83 | } |
| 84 | |
Eric Paris | e9fd702 | 2009-12-17 20:12:04 -0500 | [diff] [blame] | 85 | static void audit_get_parent(struct audit_parent *parent) |
| 86 | { |
| 87 | if (likely(parent)) |
| 88 | fsnotify_get_mark(&parent->mark); |
| 89 | } |
| 90 | |
| 91 | static void audit_put_parent(struct audit_parent *parent) |
| 92 | { |
| 93 | if (likely(parent)) |
| 94 | fsnotify_put_mark(&parent->mark); |
| 95 | } |
| 96 | |
| 97 | /* |
| 98 | * Find and return the audit_parent on the given inode. If found a reference |
| 99 | * is taken on this parent. |
| 100 | */ |
| 101 | static inline struct audit_parent *audit_find_parent(struct inode *inode) |
| 102 | { |
| 103 | struct audit_parent *parent = NULL; |
Eric Paris | e61ce86 | 2009-12-17 21:24:24 -0500 | [diff] [blame] | 104 | struct fsnotify_mark *entry; |
Eric Paris | e9fd702 | 2009-12-17 20:12:04 -0500 | [diff] [blame] | 105 | |
Jan Kara | b1362ed | 2016-12-21 16:28:45 +0100 | [diff] [blame] | 106 | entry = fsnotify_find_mark(&inode->i_fsnotify_marks, audit_watch_group); |
Eric Paris | e9fd702 | 2009-12-17 20:12:04 -0500 | [diff] [blame] | 107 | if (entry) |
| 108 | parent = container_of(entry, struct audit_parent, mark); |
| 109 | |
| 110 | return parent; |
| 111 | } |
| 112 | |
Eric Paris | cfcad62 | 2009-06-11 14:31:36 -0400 | [diff] [blame] | 113 | void audit_get_watch(struct audit_watch *watch) |
| 114 | { |
Elena Reshetova | bd120de | 2017-05-02 10:16:05 -0400 | [diff] [blame] | 115 | refcount_inc(&watch->count); |
Eric Paris | cfcad62 | 2009-06-11 14:31:36 -0400 | [diff] [blame] | 116 | } |
| 117 | |
| 118 | void audit_put_watch(struct audit_watch *watch) |
| 119 | { |
Elena Reshetova | bd120de | 2017-05-02 10:16:05 -0400 | [diff] [blame] | 120 | if (refcount_dec_and_test(&watch->count)) { |
Eric Paris | cfcad62 | 2009-06-11 14:31:36 -0400 | [diff] [blame] | 121 | WARN_ON(watch->parent); |
| 122 | WARN_ON(!list_empty(&watch->rules)); |
| 123 | kfree(watch->path); |
| 124 | kfree(watch); |
| 125 | } |
| 126 | } |
| 127 | |
Stephen Hemminger | b8800aa | 2010-10-20 17:23:50 -0700 | [diff] [blame] | 128 | static void audit_remove_watch(struct audit_watch *watch) |
Eric Paris | cfcad62 | 2009-06-11 14:31:36 -0400 | [diff] [blame] | 129 | { |
| 130 | list_del(&watch->wlist); |
Eric Paris | e9fd702 | 2009-12-17 20:12:04 -0500 | [diff] [blame] | 131 | audit_put_parent(watch->parent); |
Eric Paris | cfcad62 | 2009-06-11 14:31:36 -0400 | [diff] [blame] | 132 | watch->parent = NULL; |
| 133 | audit_put_watch(watch); /* match initial get */ |
| 134 | } |
| 135 | |
| 136 | char *audit_watch_path(struct audit_watch *watch) |
| 137 | { |
| 138 | return watch->path; |
| 139 | } |
| 140 | |
Eric Paris | ae7b8f4 | 2009-12-17 20:12:04 -0500 | [diff] [blame] | 141 | 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] | 142 | { |
Richard Guy Briggs | 84cb777 | 2015-08-05 23:48:20 -0400 | [diff] [blame] | 143 | return (watch->ino != AUDIT_INO_UNSET) && |
Eric Paris | ae7b8f4 | 2009-12-17 20:12:04 -0500 | [diff] [blame] | 144 | (watch->ino == ino) && |
| 145 | (watch->dev == dev); |
Eric Paris | cfcad62 | 2009-06-11 14:31:36 -0400 | [diff] [blame] | 146 | } |
| 147 | |
| 148 | /* Initialize a parent watch entry. */ |
Al Viro | 15a9155 | 2011-02-16 15:08:54 -0500 | [diff] [blame] | 149 | static struct audit_parent *audit_init_parent(struct path *path) |
Eric Paris | cfcad62 | 2009-06-11 14:31:36 -0400 | [diff] [blame] | 150 | { |
David Howells | 3b36215 | 2015-03-17 22:26:21 +0000 | [diff] [blame] | 151 | struct inode *inode = d_backing_inode(path->dentry); |
Eric Paris | cfcad62 | 2009-06-11 14:31:36 -0400 | [diff] [blame] | 152 | struct audit_parent *parent; |
Eric Paris | e9fd702 | 2009-12-17 20:12:04 -0500 | [diff] [blame] | 153 | int ret; |
Eric Paris | cfcad62 | 2009-06-11 14:31:36 -0400 | [diff] [blame] | 154 | |
| 155 | parent = kzalloc(sizeof(*parent), GFP_KERNEL); |
| 156 | if (unlikely(!parent)) |
| 157 | return ERR_PTR(-ENOMEM); |
| 158 | |
| 159 | INIT_LIST_HEAD(&parent->watches); |
Eric Paris | cfcad62 | 2009-06-11 14:31:36 -0400 | [diff] [blame] | 160 | |
Jan Kara | 054c636 | 2016-12-21 18:06:12 +0100 | [diff] [blame] | 161 | fsnotify_init_mark(&parent->mark, audit_watch_group); |
Eric Paris | e9fd702 | 2009-12-17 20:12:04 -0500 | [diff] [blame] | 162 | parent->mark.mask = AUDIT_FS_WATCH; |
Jan Kara | 7b129323 | 2016-12-21 18:32:48 +0100 | [diff] [blame] | 163 | ret = fsnotify_add_mark(&parent->mark, inode, NULL, 0); |
Eric Paris | e9fd702 | 2009-12-17 20:12:04 -0500 | [diff] [blame] | 164 | if (ret < 0) { |
Eric Paris | ae7b8f4 | 2009-12-17 20:12:04 -0500 | [diff] [blame] | 165 | audit_free_parent(parent); |
Eric Paris | e9fd702 | 2009-12-17 20:12:04 -0500 | [diff] [blame] | 166 | return ERR_PTR(ret); |
Eric Paris | cfcad62 | 2009-06-11 14:31:36 -0400 | [diff] [blame] | 167 | } |
| 168 | |
| 169 | return parent; |
| 170 | } |
| 171 | |
| 172 | /* Initialize a watch entry. */ |
| 173 | static struct audit_watch *audit_init_watch(char *path) |
| 174 | { |
| 175 | struct audit_watch *watch; |
| 176 | |
| 177 | watch = kzalloc(sizeof(*watch), GFP_KERNEL); |
| 178 | if (unlikely(!watch)) |
| 179 | return ERR_PTR(-ENOMEM); |
| 180 | |
| 181 | INIT_LIST_HEAD(&watch->rules); |
Elena Reshetova | bd120de | 2017-05-02 10:16:05 -0400 | [diff] [blame] | 182 | refcount_set(&watch->count, 1); |
Eric Paris | cfcad62 | 2009-06-11 14:31:36 -0400 | [diff] [blame] | 183 | watch->path = path; |
Richard Guy Briggs | 84cb777 | 2015-08-05 23:48:20 -0400 | [diff] [blame] | 184 | watch->dev = AUDIT_DEV_UNSET; |
| 185 | watch->ino = AUDIT_INO_UNSET; |
Eric Paris | cfcad62 | 2009-06-11 14:31:36 -0400 | [diff] [blame] | 186 | |
| 187 | return watch; |
| 188 | } |
| 189 | |
Wei Yuan | fd97646 | 2016-02-06 15:39:47 +0800 | [diff] [blame] | 190 | /* Translate a watch string to kernel representation. */ |
Eric Paris | cfcad62 | 2009-06-11 14:31:36 -0400 | [diff] [blame] | 191 | int audit_to_watch(struct audit_krule *krule, char *path, int len, u32 op) |
| 192 | { |
| 193 | struct audit_watch *watch; |
| 194 | |
Eric Paris | e9fd702 | 2009-12-17 20:12:04 -0500 | [diff] [blame] | 195 | if (!audit_watch_group) |
Eric Paris | cfcad62 | 2009-06-11 14:31:36 -0400 | [diff] [blame] | 196 | return -EOPNOTSUPP; |
| 197 | |
| 198 | if (path[0] != '/' || path[len-1] == '/' || |
| 199 | krule->listnr != AUDIT_FILTER_EXIT || |
| 200 | op != Audit_equal || |
| 201 | krule->inode_f || krule->watch || krule->tree) |
| 202 | return -EINVAL; |
| 203 | |
| 204 | watch = audit_init_watch(path); |
| 205 | if (IS_ERR(watch)) |
| 206 | return PTR_ERR(watch); |
| 207 | |
Eric Paris | cfcad62 | 2009-06-11 14:31:36 -0400 | [diff] [blame] | 208 | krule->watch = watch; |
| 209 | |
| 210 | return 0; |
| 211 | } |
| 212 | |
| 213 | /* Duplicate the given audit watch. The new watch's rules list is initialized |
| 214 | * to an empty list and wlist is undefined. */ |
| 215 | static struct audit_watch *audit_dupe_watch(struct audit_watch *old) |
| 216 | { |
| 217 | char *path; |
| 218 | struct audit_watch *new; |
| 219 | |
| 220 | path = kstrdup(old->path, GFP_KERNEL); |
| 221 | if (unlikely(!path)) |
| 222 | return ERR_PTR(-ENOMEM); |
| 223 | |
| 224 | new = audit_init_watch(path); |
| 225 | if (IS_ERR(new)) { |
| 226 | kfree(path); |
| 227 | goto out; |
| 228 | } |
| 229 | |
| 230 | new->dev = old->dev; |
| 231 | new->ino = old->ino; |
Eric Paris | e9fd702 | 2009-12-17 20:12:04 -0500 | [diff] [blame] | 232 | audit_get_parent(old->parent); |
Eric Paris | cfcad62 | 2009-06-11 14:31:36 -0400 | [diff] [blame] | 233 | new->parent = old->parent; |
| 234 | |
| 235 | out: |
| 236 | return new; |
| 237 | } |
| 238 | |
| 239 | static void audit_watch_log_rule_change(struct audit_krule *r, struct audit_watch *w, char *op) |
| 240 | { |
| 241 | if (audit_enabled) { |
| 242 | struct audit_buffer *ab; |
| 243 | ab = audit_log_start(NULL, GFP_NOFS, AUDIT_CONFIG_CHANGE); |
Kees Cook | 0644ec0 | 2013-01-11 14:32:07 -0800 | [diff] [blame] | 244 | if (unlikely(!ab)) |
| 245 | return; |
Steve Grubb | c1e8f06 | 2016-11-16 16:14:33 -0500 | [diff] [blame] | 246 | audit_log_format(ab, "auid=%u ses=%u op=%s", |
Eric W. Biederman | e1760bd | 2012-09-10 22:39:43 -0700 | [diff] [blame] | 247 | from_kuid(&init_user_ns, audit_get_loginuid(current)), |
Steve Grubb | c1e8f06 | 2016-11-16 16:14:33 -0500 | [diff] [blame] | 248 | audit_get_sessionid(current), op); |
Eric Paris | cfcad62 | 2009-06-11 14:31:36 -0400 | [diff] [blame] | 249 | audit_log_format(ab, " path="); |
| 250 | audit_log_untrustedstring(ab, w->path); |
Eric Paris | 9d96098 | 2009-06-11 14:31:37 -0400 | [diff] [blame] | 251 | audit_log_key(ab, r->filterkey); |
Eric Paris | cfcad62 | 2009-06-11 14:31:36 -0400 | [diff] [blame] | 252 | audit_log_format(ab, " list=%d res=1", r->listnr); |
| 253 | audit_log_end(ab); |
| 254 | } |
| 255 | } |
| 256 | |
| 257 | /* Update inode info in audit rules based on filesystem event. */ |
| 258 | static void audit_update_watch(struct audit_parent *parent, |
| 259 | const char *dname, dev_t dev, |
| 260 | unsigned long ino, unsigned invalidating) |
| 261 | { |
| 262 | struct audit_watch *owatch, *nwatch, *nextw; |
| 263 | struct audit_krule *r, *nextr; |
| 264 | struct audit_entry *oentry, *nentry; |
| 265 | |
| 266 | mutex_lock(&audit_filter_mutex); |
Eric Paris | ae7b8f4 | 2009-12-17 20:12:04 -0500 | [diff] [blame] | 267 | /* Run all of the watches on this parent looking for the one that |
| 268 | * matches the given dname */ |
Eric Paris | cfcad62 | 2009-06-11 14:31:36 -0400 | [diff] [blame] | 269 | list_for_each_entry_safe(owatch, nextw, &parent->watches, wlist) { |
Jeff Layton | e3d6b07 | 2012-10-10 15:25:25 -0400 | [diff] [blame] | 270 | if (audit_compare_dname_path(dname, owatch->path, |
| 271 | AUDIT_NAME_FULL)) |
Eric Paris | cfcad62 | 2009-06-11 14:31:36 -0400 | [diff] [blame] | 272 | continue; |
| 273 | |
| 274 | /* If the update involves invalidating rules, do the inode-based |
| 275 | * filtering now, so we don't omit records. */ |
Eric Paris | ae7b8f4 | 2009-12-17 20:12:04 -0500 | [diff] [blame] | 276 | if (invalidating && !audit_dummy_context()) |
Eric Paris | cfcad62 | 2009-06-11 14:31:36 -0400 | [diff] [blame] | 277 | audit_filter_inodes(current, current->audit_context); |
| 278 | |
Eric Paris | ae7b8f4 | 2009-12-17 20:12:04 -0500 | [diff] [blame] | 279 | /* updating ino will likely change which audit_hash_list we |
| 280 | * are on so we need a new watch for the new list */ |
Eric Paris | cfcad62 | 2009-06-11 14:31:36 -0400 | [diff] [blame] | 281 | nwatch = audit_dupe_watch(owatch); |
| 282 | if (IS_ERR(nwatch)) { |
| 283 | mutex_unlock(&audit_filter_mutex); |
| 284 | audit_panic("error updating watch, skipping"); |
| 285 | return; |
| 286 | } |
| 287 | nwatch->dev = dev; |
| 288 | nwatch->ino = ino; |
| 289 | |
| 290 | list_for_each_entry_safe(r, nextr, &owatch->rules, rlist) { |
| 291 | |
| 292 | oentry = container_of(r, struct audit_entry, rule); |
| 293 | list_del(&oentry->rule.rlist); |
| 294 | list_del_rcu(&oentry->list); |
| 295 | |
Eric Paris | ae7b8f4 | 2009-12-17 20:12:04 -0500 | [diff] [blame] | 296 | nentry = audit_dupe_rule(&oentry->rule); |
Eric Paris | cfcad62 | 2009-06-11 14:31:36 -0400 | [diff] [blame] | 297 | if (IS_ERR(nentry)) { |
| 298 | list_del(&oentry->rule.list); |
| 299 | audit_panic("error updating watch, removing"); |
| 300 | } else { |
| 301 | int h = audit_hash_ino((u32)ino); |
Eric Paris | ae7b8f4 | 2009-12-17 20:12:04 -0500 | [diff] [blame] | 302 | |
| 303 | /* |
| 304 | * nentry->rule.watch == oentry->rule.watch so |
| 305 | * we must drop that reference and set it to our |
| 306 | * new watch. |
| 307 | */ |
| 308 | audit_put_watch(nentry->rule.watch); |
| 309 | audit_get_watch(nwatch); |
| 310 | nentry->rule.watch = nwatch; |
Eric Paris | cfcad62 | 2009-06-11 14:31:36 -0400 | [diff] [blame] | 311 | list_add(&nentry->rule.rlist, &nwatch->rules); |
| 312 | list_add_rcu(&nentry->list, &audit_inode_hash[h]); |
| 313 | list_replace(&oentry->rule.list, |
| 314 | &nentry->rule.list); |
| 315 | } |
Richard Guy Briggs | 34d99af5 | 2015-08-05 16:29:37 -0400 | [diff] [blame] | 316 | if (oentry->rule.exe) |
| 317 | audit_remove_mark(oentry->rule.exe); |
Eric Paris | cfcad62 | 2009-06-11 14:31:36 -0400 | [diff] [blame] | 318 | |
Burn Alting | e7df61f | 2014-04-04 16:00:38 +1100 | [diff] [blame] | 319 | audit_watch_log_rule_change(r, owatch, "updated_rules"); |
Eric Paris | cfcad62 | 2009-06-11 14:31:36 -0400 | [diff] [blame] | 320 | |
| 321 | call_rcu(&oentry->rcu, audit_free_rule_rcu); |
| 322 | } |
| 323 | |
| 324 | audit_remove_watch(owatch); |
| 325 | goto add_watch_to_parent; /* event applies to a single watch */ |
| 326 | } |
| 327 | mutex_unlock(&audit_filter_mutex); |
| 328 | return; |
| 329 | |
| 330 | add_watch_to_parent: |
| 331 | list_add(&nwatch->wlist, &parent->watches); |
| 332 | mutex_unlock(&audit_filter_mutex); |
| 333 | return; |
| 334 | } |
| 335 | |
| 336 | /* Remove all watches & rules associated with a parent that is going away. */ |
| 337 | static void audit_remove_parent_watches(struct audit_parent *parent) |
| 338 | { |
| 339 | struct audit_watch *w, *nextw; |
| 340 | struct audit_krule *r, *nextr; |
| 341 | struct audit_entry *e; |
| 342 | |
| 343 | mutex_lock(&audit_filter_mutex); |
Eric Paris | cfcad62 | 2009-06-11 14:31:36 -0400 | [diff] [blame] | 344 | list_for_each_entry_safe(w, nextw, &parent->watches, wlist) { |
| 345 | list_for_each_entry_safe(r, nextr, &w->rules, rlist) { |
| 346 | e = container_of(r, struct audit_entry, rule); |
Burn Alting | e7df61f | 2014-04-04 16:00:38 +1100 | [diff] [blame] | 347 | audit_watch_log_rule_change(r, w, "remove_rule"); |
Richard Guy Briggs | 34d99af5 | 2015-08-05 16:29:37 -0400 | [diff] [blame] | 348 | if (e->rule.exe) |
| 349 | audit_remove_mark(e->rule.exe); |
Eric Paris | cfcad62 | 2009-06-11 14:31:36 -0400 | [diff] [blame] | 350 | list_del(&r->rlist); |
| 351 | list_del(&r->list); |
| 352 | list_del_rcu(&e->list); |
| 353 | call_rcu(&e->rcu, audit_free_rule_rcu); |
| 354 | } |
| 355 | audit_remove_watch(w); |
| 356 | } |
| 357 | mutex_unlock(&audit_filter_mutex); |
Eric Paris | e9fd702 | 2009-12-17 20:12:04 -0500 | [diff] [blame] | 358 | |
Lino Sanfilippo | e2a2994 | 2011-06-14 17:29:51 +0200 | [diff] [blame] | 359 | fsnotify_destroy_mark(&parent->mark, audit_watch_group); |
Eric Paris | cfcad62 | 2009-06-11 14:31:36 -0400 | [diff] [blame] | 360 | } |
| 361 | |
Eric Paris | cfcad62 | 2009-06-11 14:31:36 -0400 | [diff] [blame] | 362 | /* Get path information necessary for adding watches. */ |
Al Viro | 15a9155 | 2011-02-16 15:08:54 -0500 | [diff] [blame] | 363 | static int audit_get_nd(struct audit_watch *watch, struct path *parent) |
Eric Paris | cfcad62 | 2009-06-11 14:31:36 -0400 | [diff] [blame] | 364 | { |
Al Viro | 79714f7 | 2012-06-15 03:01:42 +0400 | [diff] [blame] | 365 | struct dentry *d = kern_path_locked(watch->path, parent); |
| 366 | if (IS_ERR(d)) |
Al Viro | 15a9155 | 2011-02-16 15:08:54 -0500 | [diff] [blame] | 367 | return PTR_ERR(d); |
Al Viro | 5955102 | 2016-01-22 15:40:57 -0500 | [diff] [blame] | 368 | inode_unlock(d_backing_inode(parent->dentry)); |
David Howells | 3b36215 | 2015-03-17 22:26:21 +0000 | [diff] [blame] | 369 | if (d_is_positive(d)) { |
Al Viro | 15a9155 | 2011-02-16 15:08:54 -0500 | [diff] [blame] | 370 | /* update watch filter fields */ |
Al Viro | fc64005 | 2016-04-10 01:33:30 -0400 | [diff] [blame] | 371 | watch->dev = d->d_sb->s_dev; |
David Howells | 3b36215 | 2015-03-17 22:26:21 +0000 | [diff] [blame] | 372 | watch->ino = d_backing_inode(d)->i_ino; |
Al Viro | 15a9155 | 2011-02-16 15:08:54 -0500 | [diff] [blame] | 373 | } |
Al Viro | 15a9155 | 2011-02-16 15:08:54 -0500 | [diff] [blame] | 374 | dput(d); |
Eric Paris | cfcad62 | 2009-06-11 14:31:36 -0400 | [diff] [blame] | 375 | return 0; |
| 376 | } |
| 377 | |
Eric Paris | e9fd702 | 2009-12-17 20:12:04 -0500 | [diff] [blame] | 378 | /* Associate the given rule with an existing parent. |
Eric Paris | cfcad62 | 2009-06-11 14:31:36 -0400 | [diff] [blame] | 379 | * Caller must hold audit_filter_mutex. */ |
| 380 | static void audit_add_to_parent(struct audit_krule *krule, |
| 381 | struct audit_parent *parent) |
| 382 | { |
| 383 | struct audit_watch *w, *watch = krule->watch; |
| 384 | int watch_found = 0; |
| 385 | |
Eric Paris | e9fd702 | 2009-12-17 20:12:04 -0500 | [diff] [blame] | 386 | BUG_ON(!mutex_is_locked(&audit_filter_mutex)); |
| 387 | |
Eric Paris | cfcad62 | 2009-06-11 14:31:36 -0400 | [diff] [blame] | 388 | list_for_each_entry(w, &parent->watches, wlist) { |
| 389 | if (strcmp(watch->path, w->path)) |
| 390 | continue; |
| 391 | |
| 392 | watch_found = 1; |
| 393 | |
Richard Guy Briggs | f8259b2 | 2015-08-01 15:41:12 -0400 | [diff] [blame] | 394 | /* put krule's ref to temporary watch */ |
Eric Paris | cfcad62 | 2009-06-11 14:31:36 -0400 | [diff] [blame] | 395 | audit_put_watch(watch); |
| 396 | |
| 397 | audit_get_watch(w); |
| 398 | krule->watch = watch = w; |
Richard Guy Briggs | aa7c043 | 2015-08-01 15:41:13 -0400 | [diff] [blame] | 399 | |
| 400 | audit_put_parent(parent); |
Eric Paris | cfcad62 | 2009-06-11 14:31:36 -0400 | [diff] [blame] | 401 | break; |
| 402 | } |
| 403 | |
| 404 | if (!watch_found) { |
Eric Paris | cfcad62 | 2009-06-11 14:31:36 -0400 | [diff] [blame] | 405 | watch->parent = parent; |
| 406 | |
Richard Guy Briggs | f8259b2 | 2015-08-01 15:41:12 -0400 | [diff] [blame] | 407 | audit_get_watch(watch); |
Eric Paris | cfcad62 | 2009-06-11 14:31:36 -0400 | [diff] [blame] | 408 | list_add(&watch->wlist, &parent->watches); |
| 409 | } |
| 410 | list_add(&krule->rlist, &watch->rules); |
| 411 | } |
| 412 | |
| 413 | /* Find a matching watch entry, or add this one. |
| 414 | * Caller must hold audit_filter_mutex. */ |
Eric Paris | ae7b8f4 | 2009-12-17 20:12:04 -0500 | [diff] [blame] | 415 | int audit_add_watch(struct audit_krule *krule, struct list_head **list) |
Eric Paris | cfcad62 | 2009-06-11 14:31:36 -0400 | [diff] [blame] | 416 | { |
| 417 | struct audit_watch *watch = krule->watch; |
Eric Paris | cfcad62 | 2009-06-11 14:31:36 -0400 | [diff] [blame] | 418 | struct audit_parent *parent; |
Al Viro | 15a9155 | 2011-02-16 15:08:54 -0500 | [diff] [blame] | 419 | struct path parent_path; |
Eric Paris | ae7b8f4 | 2009-12-17 20:12:04 -0500 | [diff] [blame] | 420 | int h, ret = 0; |
Eric Paris | cfcad62 | 2009-06-11 14:31:36 -0400 | [diff] [blame] | 421 | |
Eric Paris | 35fe4d0 | 2009-06-11 14:31:36 -0400 | [diff] [blame] | 422 | mutex_unlock(&audit_filter_mutex); |
| 423 | |
| 424 | /* Avoid calling path_lookup under audit_filter_mutex. */ |
Al Viro | 15a9155 | 2011-02-16 15:08:54 -0500 | [diff] [blame] | 425 | ret = audit_get_nd(watch, &parent_path); |
Eric Paris | 35fe4d0 | 2009-06-11 14:31:36 -0400 | [diff] [blame] | 426 | |
Al Viro | 15a9155 | 2011-02-16 15:08:54 -0500 | [diff] [blame] | 427 | /* caller expects mutex locked */ |
Eric Paris | e118e9c | 2009-12-17 20:12:04 -0500 | [diff] [blame] | 428 | mutex_lock(&audit_filter_mutex); |
| 429 | |
Al Viro | 15a9155 | 2011-02-16 15:08:54 -0500 | [diff] [blame] | 430 | if (ret) |
| 431 | return ret; |
Eric Paris | cfcad62 | 2009-06-11 14:31:36 -0400 | [diff] [blame] | 432 | |
Eric Paris | e118e9c | 2009-12-17 20:12:04 -0500 | [diff] [blame] | 433 | /* either find an old parent or attach a new one */ |
David Howells | 3b36215 | 2015-03-17 22:26:21 +0000 | [diff] [blame] | 434 | parent = audit_find_parent(d_backing_inode(parent_path.dentry)); |
Eric Paris | e9fd702 | 2009-12-17 20:12:04 -0500 | [diff] [blame] | 435 | if (!parent) { |
Al Viro | 15a9155 | 2011-02-16 15:08:54 -0500 | [diff] [blame] | 436 | parent = audit_init_parent(&parent_path); |
Eric Paris | cfcad62 | 2009-06-11 14:31:36 -0400 | [diff] [blame] | 437 | if (IS_ERR(parent)) { |
Eric Paris | 35fe4d0 | 2009-06-11 14:31:36 -0400 | [diff] [blame] | 438 | ret = PTR_ERR(parent); |
| 439 | goto error; |
Eric Paris | cfcad62 | 2009-06-11 14:31:36 -0400 | [diff] [blame] | 440 | } |
Eric Paris | e9fd702 | 2009-12-17 20:12:04 -0500 | [diff] [blame] | 441 | } |
Eric Paris | cfcad62 | 2009-06-11 14:31:36 -0400 | [diff] [blame] | 442 | |
Eric Paris | e118e9c | 2009-12-17 20:12:04 -0500 | [diff] [blame] | 443 | audit_add_to_parent(krule, parent); |
Eric Paris | cfcad62 | 2009-06-11 14:31:36 -0400 | [diff] [blame] | 444 | |
Eric Paris | ae7b8f4 | 2009-12-17 20:12:04 -0500 | [diff] [blame] | 445 | h = audit_hash_ino((u32)watch->ino); |
| 446 | *list = &audit_inode_hash[h]; |
Eric Paris | 35fe4d0 | 2009-06-11 14:31:36 -0400 | [diff] [blame] | 447 | error: |
Al Viro | 15a9155 | 2011-02-16 15:08:54 -0500 | [diff] [blame] | 448 | path_put(&parent_path); |
Eric Paris | cfcad62 | 2009-06-11 14:31:36 -0400 | [diff] [blame] | 449 | return ret; |
Eric Paris | cfcad62 | 2009-06-11 14:31:36 -0400 | [diff] [blame] | 450 | } |
| 451 | |
Eric Paris | a05fb6c | 2009-12-17 20:12:05 -0500 | [diff] [blame] | 452 | void audit_remove_watch_rule(struct audit_krule *krule) |
Eric Paris | cfcad62 | 2009-06-11 14:31:36 -0400 | [diff] [blame] | 453 | { |
| 454 | struct audit_watch *watch = krule->watch; |
| 455 | struct audit_parent *parent = watch->parent; |
| 456 | |
| 457 | list_del(&krule->rlist); |
| 458 | |
| 459 | if (list_empty(&watch->rules)) { |
| 460 | audit_remove_watch(watch); |
| 461 | |
| 462 | if (list_empty(&parent->watches)) { |
Eric Paris | e9fd702 | 2009-12-17 20:12:04 -0500 | [diff] [blame] | 463 | audit_get_parent(parent); |
Lino Sanfilippo | e2a2994 | 2011-06-14 17:29:51 +0200 | [diff] [blame] | 464 | fsnotify_destroy_mark(&parent->mark, audit_watch_group); |
Eric Paris | a05fb6c | 2009-12-17 20:12:05 -0500 | [diff] [blame] | 465 | audit_put_parent(parent); |
Eric Paris | cfcad62 | 2009-06-11 14:31:36 -0400 | [diff] [blame] | 466 | } |
| 467 | } |
| 468 | } |
| 469 | |
Eric Paris | e9fd702 | 2009-12-17 20:12:04 -0500 | [diff] [blame] | 470 | /* Update watch data in audit rules based on fsnotify events. */ |
Eric Paris | 3a9b16b | 2010-07-28 10:18:38 -0400 | [diff] [blame] | 471 | static int audit_watch_handle_event(struct fsnotify_group *group, |
Jan Kara | 7053aee | 2014-01-21 15:48:14 -0800 | [diff] [blame] | 472 | struct inode *to_tell, |
Eric Paris | ce8f76f | 2010-07-28 10:18:39 -0400 | [diff] [blame] | 473 | struct fsnotify_mark *inode_mark, |
| 474 | struct fsnotify_mark *vfsmount_mark, |
Al Viro | 3cd5eca | 2016-11-20 20:19:09 -0500 | [diff] [blame] | 475 | u32 mask, const void *data, int data_type, |
Jan Kara | 9385a84 | 2016-11-10 17:51:50 +0100 | [diff] [blame] | 476 | const unsigned char *dname, u32 cookie, |
| 477 | struct fsnotify_iter_info *iter_info) |
Eric Paris | e9fd702 | 2009-12-17 20:12:04 -0500 | [diff] [blame] | 478 | { |
Al Viro | 3cd5eca | 2016-11-20 20:19:09 -0500 | [diff] [blame] | 479 | const struct inode *inode; |
Eric Paris | e9fd702 | 2009-12-17 20:12:04 -0500 | [diff] [blame] | 480 | struct audit_parent *parent; |
| 481 | |
Eric Paris | ce8f76f | 2010-07-28 10:18:39 -0400 | [diff] [blame] | 482 | parent = container_of(inode_mark, struct audit_parent, mark); |
Eric Paris | e9fd702 | 2009-12-17 20:12:04 -0500 | [diff] [blame] | 483 | |
Eric Paris | 4cd76a4 | 2010-07-28 10:18:38 -0400 | [diff] [blame] | 484 | BUG_ON(group != audit_watch_group); |
Eric Paris | e9fd702 | 2009-12-17 20:12:04 -0500 | [diff] [blame] | 485 | |
Jan Kara | 7053aee | 2014-01-21 15:48:14 -0800 | [diff] [blame] | 486 | switch (data_type) { |
Linus Torvalds | 2069601 | 2010-08-12 14:23:04 -0700 | [diff] [blame] | 487 | case (FSNOTIFY_EVENT_PATH): |
Al Viro | 3cd5eca | 2016-11-20 20:19:09 -0500 | [diff] [blame] | 488 | inode = d_backing_inode(((const struct path *)data)->dentry); |
Eric Paris | e9fd702 | 2009-12-17 20:12:04 -0500 | [diff] [blame] | 489 | break; |
| 490 | case (FSNOTIFY_EVENT_INODE): |
Al Viro | 3cd5eca | 2016-11-20 20:19:09 -0500 | [diff] [blame] | 491 | inode = (const struct inode *)data; |
Eric Paris | e9fd702 | 2009-12-17 20:12:04 -0500 | [diff] [blame] | 492 | break; |
| 493 | default: |
| 494 | BUG(); |
| 495 | inode = NULL; |
| 496 | break; |
Nicholas Mc Guire | 9aab4f4 | 2017-05-02 10:16:04 -0400 | [diff] [blame] | 497 | } |
Eric Paris | e9fd702 | 2009-12-17 20:12:04 -0500 | [diff] [blame] | 498 | |
| 499 | if (mask & (FS_CREATE|FS_MOVED_TO) && inode) |
| 500 | audit_update_watch(parent, dname, inode->i_sb->s_dev, inode->i_ino, 0); |
| 501 | else if (mask & (FS_DELETE|FS_MOVED_FROM)) |
Richard Guy Briggs | 84cb777 | 2015-08-05 23:48:20 -0400 | [diff] [blame] | 502 | audit_update_watch(parent, dname, AUDIT_DEV_UNSET, AUDIT_INO_UNSET, 1); |
Eric Paris | e9fd702 | 2009-12-17 20:12:04 -0500 | [diff] [blame] | 503 | else if (mask & (FS_DELETE_SELF|FS_UNMOUNT|FS_MOVE_SELF)) |
| 504 | audit_remove_parent_watches(parent); |
Eric Paris | e9fd702 | 2009-12-17 20:12:04 -0500 | [diff] [blame] | 505 | |
| 506 | return 0; |
| 507 | } |
| 508 | |
Eric Paris | e9fd702 | 2009-12-17 20:12:04 -0500 | [diff] [blame] | 509 | static const struct fsnotify_ops audit_watch_fsnotify_ops = { |
Eric Paris | e9fd702 | 2009-12-17 20:12:04 -0500 | [diff] [blame] | 510 | .handle_event = audit_watch_handle_event, |
Jan Kara | 054c636 | 2016-12-21 18:06:12 +0100 | [diff] [blame] | 511 | .free_mark = audit_watch_free_mark, |
Eric Paris | cfcad62 | 2009-06-11 14:31:36 -0400 | [diff] [blame] | 512 | }; |
| 513 | |
| 514 | static int __init audit_watch_init(void) |
| 515 | { |
Eric Paris | 0d2e2a1 | 2009-12-17 21:24:22 -0500 | [diff] [blame] | 516 | audit_watch_group = fsnotify_alloc_group(&audit_watch_fsnotify_ops); |
Eric Paris | e9fd702 | 2009-12-17 20:12:04 -0500 | [diff] [blame] | 517 | if (IS_ERR(audit_watch_group)) { |
| 518 | audit_watch_group = NULL; |
| 519 | audit_panic("cannot create audit fsnotify group"); |
| 520 | } |
Eric Paris | cfcad62 | 2009-06-11 14:31:36 -0400 | [diff] [blame] | 521 | return 0; |
| 522 | } |
Eric Paris | 1a3aedb | 2009-12-17 20:12:06 -0500 | [diff] [blame] | 523 | device_initcall(audit_watch_init); |
Richard Guy Briggs | 34d99af5 | 2015-08-05 16:29:37 -0400 | [diff] [blame] | 524 | |
| 525 | int audit_dupe_exe(struct audit_krule *new, struct audit_krule *old) |
| 526 | { |
| 527 | struct audit_fsnotify_mark *audit_mark; |
| 528 | char *pathname; |
| 529 | |
| 530 | pathname = kstrdup(audit_mark_path(old->exe), GFP_KERNEL); |
| 531 | if (!pathname) |
| 532 | return -ENOMEM; |
| 533 | |
| 534 | audit_mark = audit_alloc_mark(new, pathname, strlen(pathname)); |
| 535 | if (IS_ERR(audit_mark)) { |
| 536 | kfree(pathname); |
| 537 | return PTR_ERR(audit_mark); |
| 538 | } |
| 539 | new->exe = audit_mark; |
| 540 | |
| 541 | return 0; |
| 542 | } |
| 543 | |
| 544 | int audit_exe_compare(struct task_struct *tsk, struct audit_fsnotify_mark *mark) |
| 545 | { |
Richard Guy Briggs | 15ce414 | 2015-08-08 10:20:25 -0400 | [diff] [blame] | 546 | struct file *exe_file; |
| 547 | unsigned long ino; |
| 548 | dev_t dev; |
Richard Guy Briggs | 34d99af5 | 2015-08-05 16:29:37 -0400 | [diff] [blame] | 549 | |
Mateusz Guzik | 5efc244 | 2016-08-23 16:20:39 +0200 | [diff] [blame] | 550 | exe_file = get_task_exe_file(tsk); |
| 551 | if (!exe_file) |
| 552 | return 0; |
Al Viro | 4506309 | 2016-12-04 18:24:56 -0500 | [diff] [blame] | 553 | ino = file_inode(exe_file)->i_ino; |
| 554 | dev = file_inode(exe_file)->i_sb->s_dev; |
Mateusz Guzik | 5efc244 | 2016-08-23 16:20:39 +0200 | [diff] [blame] | 555 | fput(exe_file); |
Richard Guy Briggs | 34d99af5 | 2015-08-05 16:29:37 -0400 | [diff] [blame] | 556 | return audit_mark_compare(mark, ino, dev); |
| 557 | } |