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b2441318 | 1 | // SPDX-License-Identifier: GPL-2.0 |
33d3dfff | 2 | #include <linux/fanotify.h> |
11637e4b | 3 | #include <linux/fcntl.h> |
2a3edf86 | 4 | #include <linux/file.h> |
11637e4b | 5 | #include <linux/fs.h> |
52c923dd | 6 | #include <linux/anon_inodes.h> |
11637e4b | 7 | #include <linux/fsnotify_backend.h> |
2a3edf86 | 8 | #include <linux/init.h> |
a1014f10 | 9 | #include <linux/mount.h> |
2a3edf86 | 10 | #include <linux/namei.h> |
a1014f10 | 11 | #include <linux/poll.h> |
11637e4b EP |
12 | #include <linux/security.h> |
13 | #include <linux/syscalls.h> | |
e4e047a2 | 14 | #include <linux/slab.h> |
2a3edf86 | 15 | #include <linux/types.h> |
a1014f10 | 16 | #include <linux/uaccess.h> |
91c2e0bc | 17 | #include <linux/compat.h> |
174cd4b1 | 18 | #include <linux/sched/signal.h> |
d46eb14b | 19 | #include <linux/memcontrol.h> |
a8b13aa2 AG |
20 | #include <linux/statfs.h> |
21 | #include <linux/exportfs.h> | |
a1014f10 EP |
22 | |
23 | #include <asm/ioctls.h> | |
11637e4b | 24 | |
c63181e6 | 25 | #include "../../mount.h" |
be77196b | 26 | #include "../fdinfo.h" |
7053aee2 | 27 | #include "fanotify.h" |
c63181e6 | 28 | |
2529a0df | 29 | #define FANOTIFY_DEFAULT_MAX_EVENTS 16384 |
e7099d8a | 30 | #define FANOTIFY_DEFAULT_MAX_MARKS 8192 |
4afeff85 | 31 | #define FANOTIFY_DEFAULT_MAX_LISTENERS 128 |
2529a0df | 32 | |
48149e9d HS |
33 | /* |
34 | * All flags that may be specified in parameter event_f_flags of fanotify_init. | |
35 | * | |
36 | * Internal and external open flags are stored together in field f_flags of | |
37 | * struct file. Only external open flags shall be allowed in event_f_flags. | |
38 | * Internal flags like FMODE_NONOTIFY, FMODE_EXEC, FMODE_NOCMTIME shall be | |
39 | * excluded. | |
40 | */ | |
41 | #define FANOTIFY_INIT_ALL_EVENT_F_BITS ( \ | |
42 | O_ACCMODE | O_APPEND | O_NONBLOCK | \ | |
43 | __O_SYNC | O_DSYNC | O_CLOEXEC | \ | |
44 | O_LARGEFILE | O_NOATIME ) | |
45 | ||
33d3dfff | 46 | extern const struct fsnotify_ops fanotify_fsnotify_ops; |
11637e4b | 47 | |
054c636e | 48 | struct kmem_cache *fanotify_mark_cache __read_mostly; |
7053aee2 | 49 | struct kmem_cache *fanotify_event_cachep __read_mostly; |
f083441b | 50 | struct kmem_cache *fanotify_perm_event_cachep __read_mostly; |
2a3edf86 | 51 | |
5e469c83 AG |
52 | #define FANOTIFY_EVENT_ALIGN 4 |
53 | ||
54 | static int fanotify_event_info_len(struct fanotify_event *event) | |
55 | { | |
56 | if (!fanotify_event_has_fid(event)) | |
57 | return 0; | |
58 | ||
59 | return roundup(sizeof(struct fanotify_event_info_fid) + | |
60 | sizeof(struct file_handle) + event->fh_len, | |
61 | FANOTIFY_EVENT_ALIGN); | |
62 | } | |
63 | ||
a1014f10 EP |
64 | /* |
65 | * Get an fsnotify notification event if one exists and is small | |
66 | * enough to fit in "count". Return an error pointer if the count | |
67 | * is not large enough. | |
68 | * | |
c21dbe20 | 69 | * Called with the group->notification_lock held. |
a1014f10 EP |
70 | */ |
71 | static struct fsnotify_event *get_one_event(struct fsnotify_group *group, | |
72 | size_t count) | |
73 | { | |
5e469c83 AG |
74 | size_t event_size = FAN_EVENT_METADATA_LEN; |
75 | struct fanotify_event *event; | |
76 | ||
ed272640 | 77 | assert_spin_locked(&group->notification_lock); |
a1014f10 EP |
78 | |
79 | pr_debug("%s: group=%p count=%zd\n", __func__, group, count); | |
80 | ||
81 | if (fsnotify_notify_queue_is_empty(group)) | |
82 | return NULL; | |
83 | ||
5e469c83 AG |
84 | if (FAN_GROUP_FLAG(group, FAN_REPORT_FID)) { |
85 | event = FANOTIFY_E(fsnotify_peek_first_event(group)); | |
86 | event_size += fanotify_event_info_len(event); | |
87 | } | |
88 | ||
89 | if (event_size > count) | |
a1014f10 EP |
90 | return ERR_PTR(-EINVAL); |
91 | ||
5e469c83 AG |
92 | /* |
93 | * Held the notification_lock the whole time, so this is the | |
94 | * same event we peeked above | |
95 | */ | |
8ba8fa91 | 96 | return fsnotify_remove_first_event(group); |
a1014f10 EP |
97 | } |
98 | ||
352e3b24 | 99 | static int create_fd(struct fsnotify_group *group, |
33913997 | 100 | struct fanotify_event *event, |
7053aee2 | 101 | struct file **file) |
a1014f10 EP |
102 | { |
103 | int client_fd; | |
a1014f10 EP |
104 | struct file *new_file; |
105 | ||
22aa425d | 106 | pr_debug("%s: group=%p event=%p\n", __func__, group, event); |
a1014f10 | 107 | |
0b37e097 | 108 | client_fd = get_unused_fd_flags(group->fanotify_data.f_flags); |
a1014f10 EP |
109 | if (client_fd < 0) |
110 | return client_fd; | |
111 | ||
a1014f10 EP |
112 | /* |
113 | * we need a new file handle for the userspace program so it can read even if it was | |
114 | * originally opened O_WRONLY. | |
115 | */ | |
a1014f10 EP |
116 | /* it's possible this event was an overflow event. in that case dentry and mnt |
117 | * are NULL; That's fine, just don't call dentry open */ | |
765927b2 AV |
118 | if (event->path.dentry && event->path.mnt) |
119 | new_file = dentry_open(&event->path, | |
80af2588 | 120 | group->fanotify_data.f_flags | FMODE_NONOTIFY, |
a1014f10 EP |
121 | current_cred()); |
122 | else | |
123 | new_file = ERR_PTR(-EOVERFLOW); | |
124 | if (IS_ERR(new_file)) { | |
125 | /* | |
126 | * we still send an event even if we can't open the file. this | |
127 | * can happen when say tasks are gone and we try to open their | |
128 | * /proc files or we try to open a WRONLY file like in sysfs | |
129 | * we just send the errno to userspace since there isn't much | |
130 | * else we can do. | |
131 | */ | |
132 | put_unused_fd(client_fd); | |
133 | client_fd = PTR_ERR(new_file); | |
134 | } else { | |
352e3b24 | 135 | *file = new_file; |
a1014f10 EP |
136 | } |
137 | ||
22aa425d | 138 | return client_fd; |
a1014f10 EP |
139 | } |
140 | ||
33913997 | 141 | static struct fanotify_perm_event *dequeue_event( |
f083441b | 142 | struct fsnotify_group *group, int fd) |
b2d87909 | 143 | { |
33913997 | 144 | struct fanotify_perm_event *event, *return_e = NULL; |
b2d87909 | 145 | |
073f6552 | 146 | spin_lock(&group->notification_lock); |
f083441b JK |
147 | list_for_each_entry(event, &group->fanotify_data.access_list, |
148 | fae.fse.list) { | |
149 | if (event->fd != fd) | |
b2d87909 EP |
150 | continue; |
151 | ||
f083441b JK |
152 | list_del_init(&event->fae.fse.list); |
153 | return_e = event; | |
b2d87909 EP |
154 | break; |
155 | } | |
073f6552 | 156 | spin_unlock(&group->notification_lock); |
b2d87909 | 157 | |
f083441b | 158 | pr_debug("%s: found return_re=%p\n", __func__, return_e); |
b2d87909 | 159 | |
f083441b | 160 | return return_e; |
b2d87909 EP |
161 | } |
162 | ||
163 | static int process_access_response(struct fsnotify_group *group, | |
164 | struct fanotify_response *response_struct) | |
165 | { | |
33913997 | 166 | struct fanotify_perm_event *event; |
f083441b JK |
167 | int fd = response_struct->fd; |
168 | int response = response_struct->response; | |
b2d87909 EP |
169 | |
170 | pr_debug("%s: group=%p fd=%d response=%d\n", __func__, group, | |
171 | fd, response); | |
172 | /* | |
173 | * make sure the response is valid, if invalid we do nothing and either | |
25985edc | 174 | * userspace can send a valid response or we will clean it up after the |
b2d87909 EP |
175 | * timeout |
176 | */ | |
de8cd83e | 177 | switch (response & ~FAN_AUDIT) { |
b2d87909 EP |
178 | case FAN_ALLOW: |
179 | case FAN_DENY: | |
180 | break; | |
181 | default: | |
182 | return -EINVAL; | |
183 | } | |
184 | ||
185 | if (fd < 0) | |
186 | return -EINVAL; | |
187 | ||
96a71f21 | 188 | if ((response & FAN_AUDIT) && !FAN_GROUP_FLAG(group, FAN_ENABLE_AUDIT)) |
de8cd83e SG |
189 | return -EINVAL; |
190 | ||
f083441b JK |
191 | event = dequeue_event(group, fd); |
192 | if (!event) | |
b2d87909 EP |
193 | return -ENOENT; |
194 | ||
f083441b | 195 | event->response = response; |
b2d87909 EP |
196 | wake_up(&group->fanotify_data.access_waitq); |
197 | ||
b2d87909 EP |
198 | return 0; |
199 | } | |
b2d87909 | 200 | |
5e469c83 AG |
201 | static int copy_fid_to_user(struct fanotify_event *event, char __user *buf) |
202 | { | |
203 | struct fanotify_event_info_fid info = { }; | |
204 | struct file_handle handle = { }; | |
205 | size_t fh_len = event->fh_len; | |
206 | size_t len = fanotify_event_info_len(event); | |
207 | ||
208 | if (!len) | |
209 | return 0; | |
210 | ||
211 | if (WARN_ON_ONCE(len < sizeof(info) + sizeof(handle) + fh_len)) | |
212 | return -EFAULT; | |
213 | ||
214 | /* Copy event info fid header followed by vaiable sized file handle */ | |
215 | info.hdr.info_type = FAN_EVENT_INFO_TYPE_FID; | |
216 | info.hdr.len = len; | |
217 | info.fsid = event->fid.fsid; | |
218 | if (copy_to_user(buf, &info, sizeof(info))) | |
219 | return -EFAULT; | |
220 | ||
221 | buf += sizeof(info); | |
222 | len -= sizeof(info); | |
223 | handle.handle_type = event->fh_type; | |
224 | handle.handle_bytes = fh_len; | |
225 | if (copy_to_user(buf, &handle, sizeof(handle))) | |
226 | return -EFAULT; | |
227 | ||
228 | buf += sizeof(handle); | |
229 | len -= sizeof(handle); | |
230 | if (copy_to_user(buf, fanotify_event_fh(event), fh_len)) | |
231 | return -EFAULT; | |
232 | ||
233 | /* Pad with 0's */ | |
234 | buf += fh_len; | |
235 | len -= fh_len; | |
236 | WARN_ON_ONCE(len < 0 || len >= FANOTIFY_EVENT_ALIGN); | |
237 | if (len > 0 && clear_user(buf, len)) | |
238 | return -EFAULT; | |
239 | ||
240 | return 0; | |
241 | } | |
242 | ||
a1014f10 | 243 | static ssize_t copy_event_to_user(struct fsnotify_group *group, |
bb2f7b45 | 244 | struct fsnotify_event *fsn_event, |
5b03a472 | 245 | char __user *buf, size_t count) |
a1014f10 | 246 | { |
bb2f7b45 AG |
247 | struct fanotify_event_metadata metadata; |
248 | struct fanotify_event *event; | |
249 | struct file *f = NULL; | |
e9e0c890 | 250 | int ret, fd = FAN_NOFD; |
a1014f10 | 251 | |
bb2f7b45 | 252 | pr_debug("%s: group=%p event=%p\n", __func__, group, fsn_event); |
a1014f10 | 253 | |
bb2f7b45 AG |
254 | event = container_of(fsn_event, struct fanotify_event, fse); |
255 | metadata.event_len = FAN_EVENT_METADATA_LEN; | |
256 | metadata.metadata_len = FAN_EVENT_METADATA_LEN; | |
257 | metadata.vers = FANOTIFY_METADATA_VERSION; | |
258 | metadata.reserved = 0; | |
259 | metadata.mask = event->mask & FANOTIFY_OUTGOING_EVENTS; | |
260 | metadata.pid = pid_vnr(event->pid); | |
261 | ||
e9e0c890 | 262 | if (fanotify_event_has_path(event)) { |
bb2f7b45 AG |
263 | fd = create_fd(group, event, &f); |
264 | if (fd < 0) | |
265 | return fd; | |
5e469c83 AG |
266 | } else if (fanotify_event_has_fid(event)) { |
267 | metadata.event_len += fanotify_event_info_len(event); | |
bb2f7b45 AG |
268 | } |
269 | metadata.fd = fd; | |
b2d87909 | 270 | |
b2d87909 | 271 | ret = -EFAULT; |
5b03a472 KC |
272 | /* |
273 | * Sanity check copy size in case get_one_event() and | |
274 | * fill_event_metadata() event_len sizes ever get out of sync. | |
275 | */ | |
bb2f7b45 | 276 | if (WARN_ON_ONCE(metadata.event_len > count)) |
5b03a472 | 277 | goto out_close_fd; |
bb2f7b45 | 278 | |
5e469c83 | 279 | if (copy_to_user(buf, &metadata, FAN_EVENT_METADATA_LEN)) |
352e3b24 AV |
280 | goto out_close_fd; |
281 | ||
bb2f7b45 AG |
282 | if (fanotify_is_perm_event(event->mask)) |
283 | FANOTIFY_PE(fsn_event)->fd = fd; | |
a1014f10 | 284 | |
5e469c83 | 285 | if (fanotify_event_has_path(event)) { |
3587b1b0 | 286 | fd_install(fd, f); |
5e469c83 AG |
287 | } else if (fanotify_event_has_fid(event)) { |
288 | ret = copy_fid_to_user(event, buf + FAN_EVENT_METADATA_LEN); | |
289 | if (ret < 0) | |
290 | return ret; | |
291 | } | |
292 | ||
bb2f7b45 | 293 | return metadata.event_len; |
b2d87909 | 294 | |
b2d87909 | 295 | out_close_fd: |
352e3b24 AV |
296 | if (fd != FAN_NOFD) { |
297 | put_unused_fd(fd); | |
298 | fput(f); | |
299 | } | |
b2d87909 | 300 | return ret; |
a1014f10 EP |
301 | } |
302 | ||
303 | /* intofiy userspace file descriptor functions */ | |
076ccb76 | 304 | static __poll_t fanotify_poll(struct file *file, poll_table *wait) |
a1014f10 EP |
305 | { |
306 | struct fsnotify_group *group = file->private_data; | |
076ccb76 | 307 | __poll_t ret = 0; |
a1014f10 EP |
308 | |
309 | poll_wait(file, &group->notification_waitq, wait); | |
c21dbe20 | 310 | spin_lock(&group->notification_lock); |
a1014f10 | 311 | if (!fsnotify_notify_queue_is_empty(group)) |
a9a08845 | 312 | ret = EPOLLIN | EPOLLRDNORM; |
c21dbe20 | 313 | spin_unlock(&group->notification_lock); |
a1014f10 EP |
314 | |
315 | return ret; | |
316 | } | |
317 | ||
318 | static ssize_t fanotify_read(struct file *file, char __user *buf, | |
319 | size_t count, loff_t *pos) | |
320 | { | |
321 | struct fsnotify_group *group; | |
322 | struct fsnotify_event *kevent; | |
323 | char __user *start; | |
324 | int ret; | |
536ebe9c | 325 | DEFINE_WAIT_FUNC(wait, woken_wake_function); |
a1014f10 EP |
326 | |
327 | start = buf; | |
328 | group = file->private_data; | |
329 | ||
330 | pr_debug("%s: group=%p\n", __func__, group); | |
331 | ||
536ebe9c | 332 | add_wait_queue(&group->notification_waitq, &wait); |
a1014f10 | 333 | while (1) { |
c21dbe20 | 334 | spin_lock(&group->notification_lock); |
a1014f10 | 335 | kevent = get_one_event(group, count); |
c21dbe20 | 336 | spin_unlock(&group->notification_lock); |
a1014f10 | 337 | |
d8aaab4f | 338 | if (IS_ERR(kevent)) { |
a1014f10 | 339 | ret = PTR_ERR(kevent); |
d8aaab4f JK |
340 | break; |
341 | } | |
342 | ||
343 | if (!kevent) { | |
344 | ret = -EAGAIN; | |
345 | if (file->f_flags & O_NONBLOCK) | |
a1014f10 | 346 | break; |
d8aaab4f JK |
347 | |
348 | ret = -ERESTARTSYS; | |
349 | if (signal_pending(current)) | |
350 | break; | |
351 | ||
352 | if (start != buf) | |
a1014f10 | 353 | break; |
536ebe9c PZ |
354 | |
355 | wait_woken(&wait, TASK_INTERRUPTIBLE, MAX_SCHEDULE_TIMEOUT); | |
a1014f10 EP |
356 | continue; |
357 | } | |
358 | ||
5b03a472 | 359 | ret = copy_event_to_user(group, kevent, buf, count); |
4ff33aaf AG |
360 | if (unlikely(ret == -EOPENSTALE)) { |
361 | /* | |
362 | * We cannot report events with stale fd so drop it. | |
363 | * Setting ret to 0 will continue the event loop and | |
364 | * do the right thing if there are no more events to | |
365 | * read (i.e. return bytes read, -EAGAIN or wait). | |
366 | */ | |
367 | ret = 0; | |
368 | } | |
369 | ||
d8aaab4f JK |
370 | /* |
371 | * Permission events get queued to wait for response. Other | |
372 | * events can be destroyed now. | |
373 | */ | |
a0a92d26 | 374 | if (!fanotify_is_perm_event(FANOTIFY_E(kevent)->mask)) { |
d8aaab4f | 375 | fsnotify_destroy_event(group, kevent); |
d507816b | 376 | } else { |
4ff33aaf | 377 | if (ret <= 0) { |
d507816b JK |
378 | FANOTIFY_PE(kevent)->response = FAN_DENY; |
379 | wake_up(&group->fanotify_data.access_waitq); | |
4ff33aaf AG |
380 | } else { |
381 | spin_lock(&group->notification_lock); | |
382 | list_add_tail(&kevent->list, | |
383 | &group->fanotify_data.access_list); | |
384 | spin_unlock(&group->notification_lock); | |
d507816b | 385 | } |
d507816b | 386 | } |
4ff33aaf AG |
387 | if (ret < 0) |
388 | break; | |
d8aaab4f JK |
389 | buf += ret; |
390 | count -= ret; | |
a1014f10 | 391 | } |
536ebe9c | 392 | remove_wait_queue(&group->notification_waitq, &wait); |
a1014f10 | 393 | |
a1014f10 EP |
394 | if (start != buf && ret != -EFAULT) |
395 | ret = buf - start; | |
396 | return ret; | |
397 | } | |
398 | ||
b2d87909 EP |
399 | static ssize_t fanotify_write(struct file *file, const char __user *buf, size_t count, loff_t *pos) |
400 | { | |
b2d87909 EP |
401 | struct fanotify_response response = { .fd = -1, .response = -1 }; |
402 | struct fsnotify_group *group; | |
403 | int ret; | |
404 | ||
6685df31 MS |
405 | if (!IS_ENABLED(CONFIG_FANOTIFY_ACCESS_PERMISSIONS)) |
406 | return -EINVAL; | |
407 | ||
b2d87909 EP |
408 | group = file->private_data; |
409 | ||
410 | if (count > sizeof(response)) | |
411 | count = sizeof(response); | |
412 | ||
413 | pr_debug("%s: group=%p count=%zu\n", __func__, group, count); | |
414 | ||
415 | if (copy_from_user(&response, buf, count)) | |
416 | return -EFAULT; | |
417 | ||
418 | ret = process_access_response(group, &response); | |
419 | if (ret < 0) | |
420 | count = ret; | |
421 | ||
422 | return count; | |
b2d87909 EP |
423 | } |
424 | ||
52c923dd EP |
425 | static int fanotify_release(struct inode *ignored, struct file *file) |
426 | { | |
427 | struct fsnotify_group *group = file->private_data; | |
33913997 | 428 | struct fanotify_perm_event *event, *next; |
96d41019 | 429 | struct fsnotify_event *fsn_event; |
19ba54f4 | 430 | |
5838d444 | 431 | /* |
96d41019 JK |
432 | * Stop new events from arriving in the notification queue. since |
433 | * userspace cannot use fanotify fd anymore, no event can enter or | |
434 | * leave access_list by now either. | |
5838d444 | 435 | */ |
96d41019 | 436 | fsnotify_group_stop_queueing(group); |
2eebf582 | 437 | |
96d41019 JK |
438 | /* |
439 | * Process all permission events on access_list and notification queue | |
440 | * and simulate reply from userspace. | |
441 | */ | |
073f6552 | 442 | spin_lock(&group->notification_lock); |
f083441b JK |
443 | list_for_each_entry_safe(event, next, &group->fanotify_data.access_list, |
444 | fae.fse.list) { | |
445 | pr_debug("%s: found group=%p event=%p\n", __func__, group, | |
446 | event); | |
2eebf582 | 447 | |
f083441b JK |
448 | list_del_init(&event->fae.fse.list); |
449 | event->response = FAN_ALLOW; | |
2eebf582 | 450 | } |
2eebf582 | 451 | |
5838d444 | 452 | /* |
96d41019 JK |
453 | * Destroy all non-permission events. For permission events just |
454 | * dequeue them and set the response. They will be freed once the | |
455 | * response is consumed and fanotify_get_response() returns. | |
5838d444 | 456 | */ |
96d41019 JK |
457 | while (!fsnotify_notify_queue_is_empty(group)) { |
458 | fsn_event = fsnotify_remove_first_event(group); | |
a0a92d26 | 459 | if (!(FANOTIFY_E(fsn_event)->mask & FANOTIFY_PERM_EVENTS)) { |
c21dbe20 | 460 | spin_unlock(&group->notification_lock); |
96d41019 | 461 | fsnotify_destroy_event(group, fsn_event); |
c21dbe20 | 462 | spin_lock(&group->notification_lock); |
6685df31 | 463 | } else { |
96d41019 | 464 | FANOTIFY_PE(fsn_event)->response = FAN_ALLOW; |
6685df31 | 465 | } |
96d41019 | 466 | } |
c21dbe20 | 467 | spin_unlock(&group->notification_lock); |
96d41019 JK |
468 | |
469 | /* Response for all permission events it set, wakeup waiters */ | |
2eebf582 | 470 | wake_up(&group->fanotify_data.access_waitq); |
0a6b6bd5 | 471 | |
52c923dd | 472 | /* matches the fanotify_init->fsnotify_alloc_group */ |
d8153d4d | 473 | fsnotify_destroy_group(group); |
52c923dd EP |
474 | |
475 | return 0; | |
476 | } | |
477 | ||
a1014f10 EP |
478 | static long fanotify_ioctl(struct file *file, unsigned int cmd, unsigned long arg) |
479 | { | |
480 | struct fsnotify_group *group; | |
7053aee2 | 481 | struct fsnotify_event *fsn_event; |
a1014f10 EP |
482 | void __user *p; |
483 | int ret = -ENOTTY; | |
484 | size_t send_len = 0; | |
485 | ||
486 | group = file->private_data; | |
487 | ||
488 | p = (void __user *) arg; | |
489 | ||
490 | switch (cmd) { | |
491 | case FIONREAD: | |
c21dbe20 | 492 | spin_lock(&group->notification_lock); |
7053aee2 | 493 | list_for_each_entry(fsn_event, &group->notification_list, list) |
a1014f10 | 494 | send_len += FAN_EVENT_METADATA_LEN; |
c21dbe20 | 495 | spin_unlock(&group->notification_lock); |
a1014f10 EP |
496 | ret = put_user(send_len, (int __user *) p); |
497 | break; | |
498 | } | |
499 | ||
500 | return ret; | |
501 | } | |
502 | ||
52c923dd | 503 | static const struct file_operations fanotify_fops = { |
be77196b | 504 | .show_fdinfo = fanotify_show_fdinfo, |
a1014f10 EP |
505 | .poll = fanotify_poll, |
506 | .read = fanotify_read, | |
b2d87909 | 507 | .write = fanotify_write, |
52c923dd EP |
508 | .fasync = NULL, |
509 | .release = fanotify_release, | |
a1014f10 EP |
510 | .unlocked_ioctl = fanotify_ioctl, |
511 | .compat_ioctl = fanotify_ioctl, | |
6038f373 | 512 | .llseek = noop_llseek, |
52c923dd EP |
513 | }; |
514 | ||
2a3edf86 EP |
515 | static int fanotify_find_path(int dfd, const char __user *filename, |
516 | struct path *path, unsigned int flags) | |
517 | { | |
518 | int ret; | |
519 | ||
520 | pr_debug("%s: dfd=%d filename=%p flags=%x\n", __func__, | |
521 | dfd, filename, flags); | |
522 | ||
523 | if (filename == NULL) { | |
2903ff01 | 524 | struct fd f = fdget(dfd); |
2a3edf86 EP |
525 | |
526 | ret = -EBADF; | |
2903ff01 | 527 | if (!f.file) |
2a3edf86 EP |
528 | goto out; |
529 | ||
530 | ret = -ENOTDIR; | |
531 | if ((flags & FAN_MARK_ONLYDIR) && | |
496ad9aa | 532 | !(S_ISDIR(file_inode(f.file)->i_mode))) { |
2903ff01 | 533 | fdput(f); |
2a3edf86 EP |
534 | goto out; |
535 | } | |
536 | ||
2903ff01 | 537 | *path = f.file->f_path; |
2a3edf86 | 538 | path_get(path); |
2903ff01 | 539 | fdput(f); |
2a3edf86 EP |
540 | } else { |
541 | unsigned int lookup_flags = 0; | |
542 | ||
543 | if (!(flags & FAN_MARK_DONT_FOLLOW)) | |
544 | lookup_flags |= LOOKUP_FOLLOW; | |
545 | if (flags & FAN_MARK_ONLYDIR) | |
546 | lookup_flags |= LOOKUP_DIRECTORY; | |
547 | ||
548 | ret = user_path_at(dfd, filename, lookup_flags, path); | |
549 | if (ret) | |
550 | goto out; | |
551 | } | |
552 | ||
553 | /* you can only watch an inode if you have read permissions on it */ | |
554 | ret = inode_permission(path->dentry->d_inode, MAY_READ); | |
555 | if (ret) | |
556 | path_put(path); | |
557 | out: | |
558 | return ret; | |
559 | } | |
560 | ||
b9e4e3bd EP |
561 | static __u32 fanotify_mark_remove_from_mask(struct fsnotify_mark *fsn_mark, |
562 | __u32 mask, | |
6dfbd149 LS |
563 | unsigned int flags, |
564 | int *destroy) | |
088b09b0 | 565 | { |
d2c1874c | 566 | __u32 oldmask = 0; |
088b09b0 AG |
567 | |
568 | spin_lock(&fsn_mark->lock); | |
b9e4e3bd EP |
569 | if (!(flags & FAN_MARK_IGNORED_MASK)) { |
570 | oldmask = fsn_mark->mask; | |
a72fd224 | 571 | fsn_mark->mask &= ~mask; |
b9e4e3bd | 572 | } else { |
a72fd224 | 573 | fsn_mark->ignored_mask &= ~mask; |
b9e4e3bd | 574 | } |
a118449a | 575 | *destroy = !(fsn_mark->mask | fsn_mark->ignored_mask); |
088b09b0 AG |
576 | spin_unlock(&fsn_mark->lock); |
577 | ||
088b09b0 AG |
578 | return mask & oldmask; |
579 | } | |
580 | ||
eaa2c6b0 AG |
581 | static int fanotify_remove_mark(struct fsnotify_group *group, |
582 | fsnotify_connp_t *connp, __u32 mask, | |
583 | unsigned int flags) | |
88826276 EP |
584 | { |
585 | struct fsnotify_mark *fsn_mark = NULL; | |
088b09b0 | 586 | __u32 removed; |
6dfbd149 | 587 | int destroy_mark; |
88826276 | 588 | |
7b18527c | 589 | mutex_lock(&group->mark_mutex); |
eaa2c6b0 | 590 | fsn_mark = fsnotify_find_mark(connp, group); |
7b18527c LS |
591 | if (!fsn_mark) { |
592 | mutex_unlock(&group->mark_mutex); | |
f3640192 | 593 | return -ENOENT; |
7b18527c | 594 | } |
88826276 | 595 | |
6dfbd149 LS |
596 | removed = fanotify_mark_remove_from_mask(fsn_mark, mask, flags, |
597 | &destroy_mark); | |
3ac70bfc AG |
598 | if (removed & fsnotify_conn_mask(fsn_mark->connector)) |
599 | fsnotify_recalc_mask(fsn_mark->connector); | |
6dfbd149 | 600 | if (destroy_mark) |
4712e722 | 601 | fsnotify_detach_mark(fsn_mark); |
7b18527c | 602 | mutex_unlock(&group->mark_mutex); |
4712e722 JK |
603 | if (destroy_mark) |
604 | fsnotify_free_mark(fsn_mark); | |
6dfbd149 | 605 | |
eaa2c6b0 | 606 | /* matches the fsnotify_find_mark() */ |
f3640192 | 607 | fsnotify_put_mark(fsn_mark); |
f3640192 AG |
608 | return 0; |
609 | } | |
2a3edf86 | 610 | |
eaa2c6b0 AG |
611 | static int fanotify_remove_vfsmount_mark(struct fsnotify_group *group, |
612 | struct vfsmount *mnt, __u32 mask, | |
613 | unsigned int flags) | |
614 | { | |
615 | return fanotify_remove_mark(group, &real_mount(mnt)->mnt_fsnotify_marks, | |
616 | mask, flags); | |
617 | } | |
618 | ||
d54f4fba AG |
619 | static int fanotify_remove_sb_mark(struct fsnotify_group *group, |
620 | struct super_block *sb, __u32 mask, | |
621 | unsigned int flags) | |
622 | { | |
623 | return fanotify_remove_mark(group, &sb->s_fsnotify_marks, mask, flags); | |
624 | } | |
625 | ||
f3640192 | 626 | static int fanotify_remove_inode_mark(struct fsnotify_group *group, |
b9e4e3bd EP |
627 | struct inode *inode, __u32 mask, |
628 | unsigned int flags) | |
f3640192 | 629 | { |
eaa2c6b0 AG |
630 | return fanotify_remove_mark(group, &inode->i_fsnotify_marks, mask, |
631 | flags); | |
2a3edf86 EP |
632 | } |
633 | ||
b9e4e3bd EP |
634 | static __u32 fanotify_mark_add_to_mask(struct fsnotify_mark *fsn_mark, |
635 | __u32 mask, | |
636 | unsigned int flags) | |
912ee394 | 637 | { |
192ca4d1 | 638 | __u32 oldmask = -1; |
912ee394 AG |
639 | |
640 | spin_lock(&fsn_mark->lock); | |
b9e4e3bd EP |
641 | if (!(flags & FAN_MARK_IGNORED_MASK)) { |
642 | oldmask = fsn_mark->mask; | |
a72fd224 | 643 | fsn_mark->mask |= mask; |
b9e4e3bd | 644 | } else { |
a72fd224 | 645 | fsn_mark->ignored_mask |= mask; |
c9778a98 EP |
646 | if (flags & FAN_MARK_IGNORED_SURV_MODIFY) |
647 | fsn_mark->flags |= FSNOTIFY_MARK_FLAG_IGNORED_SURV_MODIFY; | |
b9e4e3bd | 648 | } |
912ee394 AG |
649 | spin_unlock(&fsn_mark->lock); |
650 | ||
651 | return mask & ~oldmask; | |
652 | } | |
653 | ||
5e9c070c | 654 | static struct fsnotify_mark *fanotify_add_new_mark(struct fsnotify_group *group, |
b812a9f5 | 655 | fsnotify_connp_t *connp, |
77115225 AG |
656 | unsigned int type, |
657 | __kernel_fsid_t *fsid) | |
5e9c070c LS |
658 | { |
659 | struct fsnotify_mark *mark; | |
660 | int ret; | |
661 | ||
662 | if (atomic_read(&group->num_marks) > group->fanotify_data.max_marks) | |
663 | return ERR_PTR(-ENOSPC); | |
664 | ||
665 | mark = kmem_cache_alloc(fanotify_mark_cache, GFP_KERNEL); | |
666 | if (!mark) | |
667 | return ERR_PTR(-ENOMEM); | |
668 | ||
054c636e | 669 | fsnotify_init_mark(mark, group); |
77115225 | 670 | ret = fsnotify_add_mark_locked(mark, connp, type, 0, fsid); |
5e9c070c LS |
671 | if (ret) { |
672 | fsnotify_put_mark(mark); | |
673 | return ERR_PTR(ret); | |
674 | } | |
675 | ||
676 | return mark; | |
677 | } | |
678 | ||
679 | ||
eaa2c6b0 AG |
680 | static int fanotify_add_mark(struct fsnotify_group *group, |
681 | fsnotify_connp_t *connp, unsigned int type, | |
77115225 AG |
682 | __u32 mask, unsigned int flags, |
683 | __kernel_fsid_t *fsid) | |
2a3edf86 EP |
684 | { |
685 | struct fsnotify_mark *fsn_mark; | |
912ee394 | 686 | __u32 added; |
2a3edf86 | 687 | |
7b18527c | 688 | mutex_lock(&group->mark_mutex); |
b812a9f5 | 689 | fsn_mark = fsnotify_find_mark(connp, group); |
88826276 | 690 | if (!fsn_mark) { |
77115225 | 691 | fsn_mark = fanotify_add_new_mark(group, connp, type, fsid); |
5e9c070c | 692 | if (IS_ERR(fsn_mark)) { |
7b18527c | 693 | mutex_unlock(&group->mark_mutex); |
5e9c070c | 694 | return PTR_ERR(fsn_mark); |
7b18527c | 695 | } |
88826276 | 696 | } |
b9e4e3bd | 697 | added = fanotify_mark_add_to_mask(fsn_mark, mask, flags); |
3ac70bfc AG |
698 | if (added & ~fsnotify_conn_mask(fsn_mark->connector)) |
699 | fsnotify_recalc_mask(fsn_mark->connector); | |
c9747640 | 700 | mutex_unlock(&group->mark_mutex); |
5e9c070c | 701 | |
fa218ab9 | 702 | fsnotify_put_mark(fsn_mark); |
5e9c070c | 703 | return 0; |
88826276 EP |
704 | } |
705 | ||
eaa2c6b0 AG |
706 | static int fanotify_add_vfsmount_mark(struct fsnotify_group *group, |
707 | struct vfsmount *mnt, __u32 mask, | |
77115225 | 708 | unsigned int flags, __kernel_fsid_t *fsid) |
eaa2c6b0 AG |
709 | { |
710 | return fanotify_add_mark(group, &real_mount(mnt)->mnt_fsnotify_marks, | |
77115225 | 711 | FSNOTIFY_OBJ_TYPE_VFSMOUNT, mask, flags, fsid); |
eaa2c6b0 AG |
712 | } |
713 | ||
d54f4fba | 714 | static int fanotify_add_sb_mark(struct fsnotify_group *group, |
77115225 AG |
715 | struct super_block *sb, __u32 mask, |
716 | unsigned int flags, __kernel_fsid_t *fsid) | |
d54f4fba AG |
717 | { |
718 | return fanotify_add_mark(group, &sb->s_fsnotify_marks, | |
77115225 | 719 | FSNOTIFY_OBJ_TYPE_SB, mask, flags, fsid); |
d54f4fba AG |
720 | } |
721 | ||
52202dfb | 722 | static int fanotify_add_inode_mark(struct fsnotify_group *group, |
b9e4e3bd | 723 | struct inode *inode, __u32 mask, |
77115225 | 724 | unsigned int flags, __kernel_fsid_t *fsid) |
88826276 | 725 | { |
88826276 | 726 | pr_debug("%s: group=%p inode=%p\n", __func__, group, inode); |
2a3edf86 | 727 | |
5322a59f EP |
728 | /* |
729 | * If some other task has this inode open for write we should not add | |
730 | * an ignored mark, unless that ignored mark is supposed to survive | |
731 | * modification changes anyway. | |
732 | */ | |
733 | if ((flags & FAN_MARK_IGNORED_MASK) && | |
734 | !(flags & FAN_MARK_IGNORED_SURV_MODIFY) && | |
ac9498d6 | 735 | inode_is_open_for_write(inode)) |
5322a59f EP |
736 | return 0; |
737 | ||
eaa2c6b0 | 738 | return fanotify_add_mark(group, &inode->i_fsnotify_marks, |
77115225 | 739 | FSNOTIFY_OBJ_TYPE_INODE, mask, flags, fsid); |
88826276 | 740 | } |
2a3edf86 | 741 | |
52c923dd | 742 | /* fanotify syscalls */ |
08ae8938 | 743 | SYSCALL_DEFINE2(fanotify_init, unsigned int, flags, unsigned int, event_f_flags) |
11637e4b | 744 | { |
52c923dd EP |
745 | struct fsnotify_group *group; |
746 | int f_flags, fd; | |
4afeff85 | 747 | struct user_struct *user; |
33913997 | 748 | struct fanotify_event *oevent; |
52c923dd | 749 | |
96a71f21 AG |
750 | pr_debug("%s: flags=%x event_f_flags=%x\n", |
751 | __func__, flags, event_f_flags); | |
52c923dd | 752 | |
52c923dd | 753 | if (!capable(CAP_SYS_ADMIN)) |
a2f13ad0 | 754 | return -EPERM; |
52c923dd | 755 | |
de8cd83e | 756 | #ifdef CONFIG_AUDITSYSCALL |
23c9deeb | 757 | if (flags & ~(FANOTIFY_INIT_FLAGS | FAN_ENABLE_AUDIT)) |
de8cd83e | 758 | #else |
23c9deeb | 759 | if (flags & ~FANOTIFY_INIT_FLAGS) |
de8cd83e | 760 | #endif |
52c923dd EP |
761 | return -EINVAL; |
762 | ||
48149e9d HS |
763 | if (event_f_flags & ~FANOTIFY_INIT_ALL_EVENT_F_BITS) |
764 | return -EINVAL; | |
765 | ||
766 | switch (event_f_flags & O_ACCMODE) { | |
767 | case O_RDONLY: | |
768 | case O_RDWR: | |
769 | case O_WRONLY: | |
770 | break; | |
771 | default: | |
772 | return -EINVAL; | |
773 | } | |
774 | ||
a8b13aa2 AG |
775 | if ((flags & FAN_REPORT_FID) && |
776 | (flags & FANOTIFY_CLASS_BITS) != FAN_CLASS_NOTIF) | |
777 | return -EINVAL; | |
778 | ||
4afeff85 EP |
779 | user = get_current_user(); |
780 | if (atomic_read(&user->fanotify_listeners) > FANOTIFY_DEFAULT_MAX_LISTENERS) { | |
781 | free_uid(user); | |
782 | return -EMFILE; | |
783 | } | |
784 | ||
b2d87909 | 785 | f_flags = O_RDWR | FMODE_NONOTIFY; |
52c923dd EP |
786 | if (flags & FAN_CLOEXEC) |
787 | f_flags |= O_CLOEXEC; | |
788 | if (flags & FAN_NONBLOCK) | |
789 | f_flags |= O_NONBLOCK; | |
790 | ||
791 | /* fsnotify_alloc_group takes a ref. Dropped in fanotify_release */ | |
792 | group = fsnotify_alloc_group(&fanotify_fsnotify_ops); | |
26379198 EP |
793 | if (IS_ERR(group)) { |
794 | free_uid(user); | |
52c923dd | 795 | return PTR_ERR(group); |
26379198 | 796 | } |
52c923dd | 797 | |
4afeff85 | 798 | group->fanotify_data.user = user; |
96a71f21 | 799 | group->fanotify_data.flags = flags; |
4afeff85 | 800 | atomic_inc(&user->fanotify_listeners); |
d46eb14b | 801 | group->memcg = get_mem_cgroup_from_mm(current->mm); |
4afeff85 | 802 | |
77115225 | 803 | oevent = fanotify_alloc_event(group, NULL, FS_Q_OVERFLOW, NULL, NULL); |
ff57cd58 JK |
804 | if (unlikely(!oevent)) { |
805 | fd = -ENOMEM; | |
806 | goto out_destroy_group; | |
807 | } | |
808 | group->overflow_event = &oevent->fse; | |
ff57cd58 | 809 | |
1e2ee49f WW |
810 | if (force_o_largefile()) |
811 | event_f_flags |= O_LARGEFILE; | |
80af2588 | 812 | group->fanotify_data.f_flags = event_f_flags; |
9e66e423 EP |
813 | init_waitqueue_head(&group->fanotify_data.access_waitq); |
814 | INIT_LIST_HEAD(&group->fanotify_data.access_list); | |
23c9deeb | 815 | switch (flags & FANOTIFY_CLASS_BITS) { |
4231a235 EP |
816 | case FAN_CLASS_NOTIF: |
817 | group->priority = FS_PRIO_0; | |
818 | break; | |
819 | case FAN_CLASS_CONTENT: | |
820 | group->priority = FS_PRIO_1; | |
821 | break; | |
822 | case FAN_CLASS_PRE_CONTENT: | |
823 | group->priority = FS_PRIO_2; | |
824 | break; | |
825 | default: | |
826 | fd = -EINVAL; | |
d8153d4d | 827 | goto out_destroy_group; |
4231a235 | 828 | } |
cb2d429f | 829 | |
5dd03f55 EP |
830 | if (flags & FAN_UNLIMITED_QUEUE) { |
831 | fd = -EPERM; | |
832 | if (!capable(CAP_SYS_ADMIN)) | |
d8153d4d | 833 | goto out_destroy_group; |
5dd03f55 EP |
834 | group->max_events = UINT_MAX; |
835 | } else { | |
836 | group->max_events = FANOTIFY_DEFAULT_MAX_EVENTS; | |
837 | } | |
2529a0df | 838 | |
ac7e22dc EP |
839 | if (flags & FAN_UNLIMITED_MARKS) { |
840 | fd = -EPERM; | |
841 | if (!capable(CAP_SYS_ADMIN)) | |
d8153d4d | 842 | goto out_destroy_group; |
ac7e22dc EP |
843 | group->fanotify_data.max_marks = UINT_MAX; |
844 | } else { | |
845 | group->fanotify_data.max_marks = FANOTIFY_DEFAULT_MAX_MARKS; | |
846 | } | |
e7099d8a | 847 | |
de8cd83e SG |
848 | if (flags & FAN_ENABLE_AUDIT) { |
849 | fd = -EPERM; | |
850 | if (!capable(CAP_AUDIT_WRITE)) | |
851 | goto out_destroy_group; | |
de8cd83e SG |
852 | } |
853 | ||
52c923dd EP |
854 | fd = anon_inode_getfd("[fanotify]", &fanotify_fops, group, f_flags); |
855 | if (fd < 0) | |
d8153d4d | 856 | goto out_destroy_group; |
52c923dd EP |
857 | |
858 | return fd; | |
859 | ||
d8153d4d LS |
860 | out_destroy_group: |
861 | fsnotify_destroy_group(group); | |
52c923dd | 862 | return fd; |
11637e4b | 863 | } |
bbaa4168 | 864 | |
a8b13aa2 | 865 | /* Check if filesystem can encode a unique fid */ |
77115225 | 866 | static int fanotify_test_fid(struct path *path, struct kstatfs *stat) |
a8b13aa2 | 867 | { |
77115225 | 868 | struct kstatfs root_stat; |
a8b13aa2 AG |
869 | struct path root = { |
870 | .mnt = path->mnt, | |
871 | .dentry = path->dentry->d_sb->s_root, | |
872 | }; | |
873 | int err; | |
874 | ||
875 | /* | |
876 | * Make sure path is not in filesystem with zero fsid (e.g. tmpfs). | |
877 | */ | |
77115225 | 878 | err = vfs_statfs(path, stat); |
a8b13aa2 AG |
879 | if (err) |
880 | return err; | |
881 | ||
77115225 | 882 | if (!stat->f_fsid.val[0] && !stat->f_fsid.val[1]) |
a8b13aa2 AG |
883 | return -ENODEV; |
884 | ||
885 | /* | |
886 | * Make sure path is not inside a filesystem subvolume (e.g. btrfs) | |
887 | * which uses a different fsid than sb root. | |
888 | */ | |
889 | err = vfs_statfs(&root, &root_stat); | |
890 | if (err) | |
891 | return err; | |
892 | ||
77115225 AG |
893 | if (root_stat.f_fsid.val[0] != stat->f_fsid.val[0] || |
894 | root_stat.f_fsid.val[1] != stat->f_fsid.val[1]) | |
a8b13aa2 AG |
895 | return -EXDEV; |
896 | ||
897 | /* | |
898 | * We need to make sure that the file system supports at least | |
899 | * encoding a file handle so user can use name_to_handle_at() to | |
900 | * compare fid returned with event to the file handle of watched | |
901 | * objects. However, name_to_handle_at() requires that the | |
902 | * filesystem also supports decoding file handles. | |
903 | */ | |
904 | if (!path->dentry->d_sb->s_export_op || | |
905 | !path->dentry->d_sb->s_export_op->fh_to_dentry) | |
906 | return -EOPNOTSUPP; | |
907 | ||
908 | return 0; | |
909 | } | |
910 | ||
183caa3c DB |
911 | static int do_fanotify_mark(int fanotify_fd, unsigned int flags, __u64 mask, |
912 | int dfd, const char __user *pathname) | |
bbaa4168 | 913 | { |
0ff21db9 EP |
914 | struct inode *inode = NULL; |
915 | struct vfsmount *mnt = NULL; | |
2a3edf86 | 916 | struct fsnotify_group *group; |
2903ff01 | 917 | struct fd f; |
2a3edf86 | 918 | struct path path; |
77115225 AG |
919 | struct kstatfs stat; |
920 | __kernel_fsid_t *fsid = NULL; | |
bdd5a46f | 921 | u32 valid_mask = FANOTIFY_EVENTS | FANOTIFY_EVENT_FLAGS; |
23c9deeb | 922 | unsigned int mark_type = flags & FANOTIFY_MARK_TYPE_BITS; |
2903ff01 | 923 | int ret; |
2a3edf86 EP |
924 | |
925 | pr_debug("%s: fanotify_fd=%d flags=%x dfd=%d pathname=%p mask=%llx\n", | |
926 | __func__, fanotify_fd, flags, dfd, pathname, mask); | |
927 | ||
928 | /* we only use the lower 32 bits as of right now. */ | |
929 | if (mask & ((__u64)0xffffffff << 32)) | |
930 | return -EINVAL; | |
931 | ||
23c9deeb | 932 | if (flags & ~FANOTIFY_MARK_FLAGS) |
88380fe6 | 933 | return -EINVAL; |
d54f4fba AG |
934 | |
935 | switch (mark_type) { | |
936 | case FAN_MARK_INODE: | |
937 | case FAN_MARK_MOUNT: | |
938 | case FAN_MARK_FILESYSTEM: | |
939 | break; | |
940 | default: | |
941 | return -EINVAL; | |
942 | } | |
943 | ||
4d92604c | 944 | switch (flags & (FAN_MARK_ADD | FAN_MARK_REMOVE | FAN_MARK_FLUSH)) { |
1734dee4 | 945 | case FAN_MARK_ADD: /* fallthrough */ |
88380fe6 | 946 | case FAN_MARK_REMOVE: |
1734dee4 LS |
947 | if (!mask) |
948 | return -EINVAL; | |
cc299a98 | 949 | break; |
4d92604c | 950 | case FAN_MARK_FLUSH: |
23c9deeb | 951 | if (flags & ~(FANOTIFY_MARK_TYPE_BITS | FAN_MARK_FLUSH)) |
cc299a98 | 952 | return -EINVAL; |
88380fe6 AG |
953 | break; |
954 | default: | |
955 | return -EINVAL; | |
956 | } | |
8fcd6528 | 957 | |
6685df31 | 958 | if (IS_ENABLED(CONFIG_FANOTIFY_ACCESS_PERMISSIONS)) |
23c9deeb | 959 | valid_mask |= FANOTIFY_PERM_EVENTS; |
6685df31 MS |
960 | |
961 | if (mask & ~valid_mask) | |
2a3edf86 EP |
962 | return -EINVAL; |
963 | ||
2903ff01 AV |
964 | f = fdget(fanotify_fd); |
965 | if (unlikely(!f.file)) | |
2a3edf86 EP |
966 | return -EBADF; |
967 | ||
968 | /* verify that this is indeed an fanotify instance */ | |
969 | ret = -EINVAL; | |
2903ff01 | 970 | if (unlikely(f.file->f_op != &fanotify_fops)) |
2a3edf86 | 971 | goto fput_and_out; |
2903ff01 | 972 | group = f.file->private_data; |
4231a235 EP |
973 | |
974 | /* | |
975 | * group->priority == FS_PRIO_0 == FAN_CLASS_NOTIF. These are not | |
976 | * allowed to set permissions events. | |
977 | */ | |
978 | ret = -EINVAL; | |
23c9deeb | 979 | if (mask & FANOTIFY_PERM_EVENTS && |
4231a235 EP |
980 | group->priority == FS_PRIO_0) |
981 | goto fput_and_out; | |
2a3edf86 | 982 | |
0a8dd2db HS |
983 | if (flags & FAN_MARK_FLUSH) { |
984 | ret = 0; | |
d54f4fba | 985 | if (mark_type == FAN_MARK_MOUNT) |
0a8dd2db | 986 | fsnotify_clear_vfsmount_marks_by_group(group); |
d54f4fba AG |
987 | else if (mark_type == FAN_MARK_FILESYSTEM) |
988 | fsnotify_clear_sb_marks_by_group(group); | |
0a8dd2db HS |
989 | else |
990 | fsnotify_clear_inode_marks_by_group(group); | |
991 | goto fput_and_out; | |
992 | } | |
993 | ||
2a3edf86 EP |
994 | ret = fanotify_find_path(dfd, pathname, &path, flags); |
995 | if (ret) | |
996 | goto fput_and_out; | |
997 | ||
a8b13aa2 | 998 | if (FAN_GROUP_FLAG(group, FAN_REPORT_FID)) { |
77115225 | 999 | ret = fanotify_test_fid(&path, &stat); |
a8b13aa2 AG |
1000 | if (ret) |
1001 | goto path_put_and_out; | |
77115225 AG |
1002 | |
1003 | fsid = &stat.f_fsid; | |
a8b13aa2 AG |
1004 | } |
1005 | ||
2a3edf86 | 1006 | /* inode held in place by reference to path; group by fget on fd */ |
d54f4fba | 1007 | if (mark_type == FAN_MARK_INODE) |
0ff21db9 EP |
1008 | inode = path.dentry->d_inode; |
1009 | else | |
1010 | mnt = path.mnt; | |
2a3edf86 EP |
1011 | |
1012 | /* create/update an inode mark */ | |
0a8dd2db | 1013 | switch (flags & (FAN_MARK_ADD | FAN_MARK_REMOVE)) { |
c6223f46 | 1014 | case FAN_MARK_ADD: |
d54f4fba | 1015 | if (mark_type == FAN_MARK_MOUNT) |
77115225 AG |
1016 | ret = fanotify_add_vfsmount_mark(group, mnt, mask, |
1017 | flags, fsid); | |
d54f4fba | 1018 | else if (mark_type == FAN_MARK_FILESYSTEM) |
77115225 AG |
1019 | ret = fanotify_add_sb_mark(group, mnt->mnt_sb, mask, |
1020 | flags, fsid); | |
0ff21db9 | 1021 | else |
77115225 AG |
1022 | ret = fanotify_add_inode_mark(group, inode, mask, |
1023 | flags, fsid); | |
c6223f46 AG |
1024 | break; |
1025 | case FAN_MARK_REMOVE: | |
d54f4fba | 1026 | if (mark_type == FAN_MARK_MOUNT) |
77115225 AG |
1027 | ret = fanotify_remove_vfsmount_mark(group, mnt, mask, |
1028 | flags); | |
d54f4fba | 1029 | else if (mark_type == FAN_MARK_FILESYSTEM) |
77115225 AG |
1030 | ret = fanotify_remove_sb_mark(group, mnt->mnt_sb, mask, |
1031 | flags); | |
f3640192 | 1032 | else |
77115225 AG |
1033 | ret = fanotify_remove_inode_mark(group, inode, mask, |
1034 | flags); | |
c6223f46 AG |
1035 | break; |
1036 | default: | |
1037 | ret = -EINVAL; | |
1038 | } | |
2a3edf86 | 1039 | |
a8b13aa2 | 1040 | path_put_and_out: |
2a3edf86 EP |
1041 | path_put(&path); |
1042 | fput_and_out: | |
2903ff01 | 1043 | fdput(f); |
2a3edf86 EP |
1044 | return ret; |
1045 | } | |
1046 | ||
183caa3c DB |
1047 | SYSCALL_DEFINE5(fanotify_mark, int, fanotify_fd, unsigned int, flags, |
1048 | __u64, mask, int, dfd, | |
1049 | const char __user *, pathname) | |
1050 | { | |
1051 | return do_fanotify_mark(fanotify_fd, flags, mask, dfd, pathname); | |
1052 | } | |
1053 | ||
91c2e0bc AV |
1054 | #ifdef CONFIG_COMPAT |
1055 | COMPAT_SYSCALL_DEFINE6(fanotify_mark, | |
1056 | int, fanotify_fd, unsigned int, flags, | |
1057 | __u32, mask0, __u32, mask1, int, dfd, | |
1058 | const char __user *, pathname) | |
1059 | { | |
183caa3c | 1060 | return do_fanotify_mark(fanotify_fd, flags, |
91c2e0bc | 1061 | #ifdef __BIG_ENDIAN |
91c2e0bc | 1062 | ((__u64)mask0 << 32) | mask1, |
592f6b84 HC |
1063 | #else |
1064 | ((__u64)mask1 << 32) | mask0, | |
91c2e0bc AV |
1065 | #endif |
1066 | dfd, pathname); | |
1067 | } | |
1068 | #endif | |
1069 | ||
2a3edf86 | 1070 | /* |
ae0e47f0 | 1071 | * fanotify_user_setup - Our initialization function. Note that we cannot return |
2a3edf86 EP |
1072 | * error because we have compiled-in VFS hooks. So an (unlikely) failure here |
1073 | * must result in panic(). | |
1074 | */ | |
1075 | static int __init fanotify_user_setup(void) | |
1076 | { | |
a8b13aa2 | 1077 | BUILD_BUG_ON(HWEIGHT32(FANOTIFY_INIT_FLAGS) != 8); |
bdd5a46f AG |
1078 | BUILD_BUG_ON(HWEIGHT32(FANOTIFY_MARK_FLAGS) != 9); |
1079 | ||
d46eb14b SB |
1080 | fanotify_mark_cache = KMEM_CACHE(fsnotify_mark, |
1081 | SLAB_PANIC|SLAB_ACCOUNT); | |
33913997 | 1082 | fanotify_event_cachep = KMEM_CACHE(fanotify_event, SLAB_PANIC); |
6685df31 MS |
1083 | if (IS_ENABLED(CONFIG_FANOTIFY_ACCESS_PERMISSIONS)) { |
1084 | fanotify_perm_event_cachep = | |
33913997 | 1085 | KMEM_CACHE(fanotify_perm_event, SLAB_PANIC); |
6685df31 | 1086 | } |
2a3edf86 EP |
1087 | |
1088 | return 0; | |
bbaa4168 | 1089 | } |
2a3edf86 | 1090 | device_initcall(fanotify_user_setup); |