Commit | Line | Data |
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457c8996 | 1 | // SPDX-License-Identifier: GPL-2.0-only |
1da177e4 | 2 | /* |
5c8ebd57 | 3 | * Copyright (C) 2002,2003 by Andreas Gruenbacher <a.gruenbacher@computer.org> |
1da177e4 | 4 | * |
5c8ebd57 CH |
5 | * Fixes from William Schumacher incorporated on 15 March 2001. |
6 | * (Reported by Charles Bertsch, <CBertsch@microtest.com>). | |
1da177e4 LT |
7 | */ |
8 | ||
9 | /* | |
10 | * This file contains generic functions for manipulating | |
11 | * POSIX 1003.1e draft standard 17 ACLs. | |
12 | */ | |
13 | ||
14 | #include <linux/kernel.h> | |
15 | #include <linux/slab.h> | |
60063497 | 16 | #include <linux/atomic.h> |
1da177e4 LT |
17 | #include <linux/fs.h> |
18 | #include <linux/sched.h> | |
5b825c3a | 19 | #include <linux/cred.h> |
1da177e4 | 20 | #include <linux/posix_acl.h> |
5c8ebd57 | 21 | #include <linux/posix_acl_xattr.h> |
2aeccbe9 | 22 | #include <linux/xattr.h> |
630d9c47 | 23 | #include <linux/export.h> |
5c8ebd57 | 24 | #include <linux/user_namespace.h> |
332f606b | 25 | #include <linux/namei.h> |
a793d79e | 26 | #include <linux/mnt_idmapping.h> |
36f05cab | 27 | #include <linux/iversion.h> |
e4cc9163 CB |
28 | #include <linux/security.h> |
29 | #include <linux/evm.h> | |
30 | #include <linux/fsnotify.h> | |
31 | ||
32 | #include "internal.h" | |
1da177e4 | 33 | |
04c57f45 | 34 | static struct posix_acl **acl_by_type(struct inode *inode, int type) |
0afaa120 AM |
35 | { |
36 | switch (type) { | |
37 | case ACL_TYPE_ACCESS: | |
38 | return &inode->i_acl; | |
39 | case ACL_TYPE_DEFAULT: | |
40 | return &inode->i_default_acl; | |
41 | default: | |
42 | BUG(); | |
43 | } | |
44 | } | |
0afaa120 AM |
45 | |
46 | struct posix_acl *get_cached_acl(struct inode *inode, int type) | |
47 | { | |
48 | struct posix_acl **p = acl_by_type(inode, type); | |
b8a7a3a6 AG |
49 | struct posix_acl *acl; |
50 | ||
51 | for (;;) { | |
52 | rcu_read_lock(); | |
53 | acl = rcu_dereference(*p); | |
54 | if (!acl || is_uncached_acl(acl) || | |
66717260 | 55 | refcount_inc_not_zero(&acl->a_refcount)) |
b8a7a3a6 AG |
56 | break; |
57 | rcu_read_unlock(); | |
58 | cpu_relax(); | |
0afaa120 | 59 | } |
b8a7a3a6 | 60 | rcu_read_unlock(); |
0afaa120 AM |
61 | return acl; |
62 | } | |
63 | EXPORT_SYMBOL(get_cached_acl); | |
64 | ||
65 | struct posix_acl *get_cached_acl_rcu(struct inode *inode, int type) | |
66 | { | |
332f606b MS |
67 | struct posix_acl *acl = rcu_dereference(*acl_by_type(inode, type)); |
68 | ||
69 | if (acl == ACL_DONT_CACHE) { | |
70 | struct posix_acl *ret; | |
71 | ||
cac2f8b8 | 72 | ret = inode->i_op->get_inode_acl(inode, type, LOOKUP_RCU); |
332f606b MS |
73 | if (!IS_ERR(ret)) |
74 | acl = ret; | |
75 | } | |
76 | ||
77 | return acl; | |
0afaa120 AM |
78 | } |
79 | EXPORT_SYMBOL(get_cached_acl_rcu); | |
80 | ||
81 | void set_cached_acl(struct inode *inode, int type, struct posix_acl *acl) | |
82 | { | |
83 | struct posix_acl **p = acl_by_type(inode, type); | |
84 | struct posix_acl *old; | |
b8a7a3a6 AG |
85 | |
86 | old = xchg(p, posix_acl_dup(acl)); | |
87 | if (!is_uncached_acl(old)) | |
0afaa120 AM |
88 | posix_acl_release(old); |
89 | } | |
90 | EXPORT_SYMBOL(set_cached_acl); | |
91 | ||
b8a7a3a6 | 92 | static void __forget_cached_acl(struct posix_acl **p) |
0afaa120 | 93 | { |
0afaa120 | 94 | struct posix_acl *old; |
b8a7a3a6 AG |
95 | |
96 | old = xchg(p, ACL_NOT_CACHED); | |
97 | if (!is_uncached_acl(old)) | |
0afaa120 AM |
98 | posix_acl_release(old); |
99 | } | |
b8a7a3a6 AG |
100 | |
101 | void forget_cached_acl(struct inode *inode, int type) | |
102 | { | |
103 | __forget_cached_acl(acl_by_type(inode, type)); | |
104 | } | |
0afaa120 AM |
105 | EXPORT_SYMBOL(forget_cached_acl); |
106 | ||
107 | void forget_all_cached_acls(struct inode *inode) | |
108 | { | |
b8a7a3a6 AG |
109 | __forget_cached_acl(&inode->i_acl); |
110 | __forget_cached_acl(&inode->i_default_acl); | |
0afaa120 AM |
111 | } |
112 | EXPORT_SYMBOL(forget_all_cached_acls); | |
1da177e4 | 113 | |
4f353ba4 CB |
114 | static struct posix_acl *__get_acl(struct user_namespace *mnt_userns, |
115 | struct dentry *dentry, struct inode *inode, | |
116 | int type) | |
2982baa2 | 117 | { |
b8a7a3a6 AG |
118 | void *sentinel; |
119 | struct posix_acl **p; | |
2982baa2 CH |
120 | struct posix_acl *acl; |
121 | ||
b8a7a3a6 AG |
122 | /* |
123 | * The sentinel is used to detect when another operation like | |
cac2f8b8 | 124 | * set_cached_acl() or forget_cached_acl() races with get_inode_acl(). |
b8a7a3a6 AG |
125 | * It is guaranteed that is_uncached_acl(sentinel) is true. |
126 | */ | |
127 | ||
2982baa2 | 128 | acl = get_cached_acl(inode, type); |
b8a7a3a6 | 129 | if (!is_uncached_acl(acl)) |
2982baa2 CH |
130 | return acl; |
131 | ||
132 | if (!IS_POSIXACL(inode)) | |
133 | return NULL; | |
134 | ||
b8a7a3a6 AG |
135 | sentinel = uncached_acl_sentinel(current); |
136 | p = acl_by_type(inode, type); | |
137 | ||
138 | /* | |
139 | * If the ACL isn't being read yet, set our sentinel. Otherwise, the | |
140 | * current value of the ACL will not be ACL_NOT_CACHED and so our own | |
141 | * sentinel will not be set; another task will update the cache. We | |
142 | * could wait for that other task to complete its job, but it's easier | |
cac2f8b8 CB |
143 | * to just call ->get_inode_acl to fetch the ACL ourself. (This is |
144 | * going to be an unlikely race.) | |
b8a7a3a6 | 145 | */ |
d1cef29a | 146 | cmpxchg(p, ACL_NOT_CACHED, sentinel); |
b8a7a3a6 | 147 | |
2982baa2 | 148 | /* |
4f353ba4 | 149 | * Normally, the ACL returned by ->get{_inode}_acl will be cached. |
b8a7a3a6 | 150 | * A filesystem can prevent that by calling |
4f353ba4 | 151 | * forget_cached_acl(inode, type) in ->get{_inode}_acl. |
2982baa2 | 152 | * |
4f353ba4 | 153 | * If the filesystem doesn't have a get{_inode}_ acl() function at all, |
cac2f8b8 | 154 | * we'll just create the negative cache entry. |
2982baa2 | 155 | */ |
4f353ba4 CB |
156 | if (dentry && inode->i_op->get_acl) { |
157 | acl = inode->i_op->get_acl(mnt_userns, dentry, type); | |
158 | } else if (inode->i_op->get_inode_acl) { | |
159 | acl = inode->i_op->get_inode_acl(inode, type, false); | |
160 | } else { | |
2982baa2 CH |
161 | set_cached_acl(inode, type, NULL); |
162 | return NULL; | |
163 | } | |
b8a7a3a6 AG |
164 | if (IS_ERR(acl)) { |
165 | /* | |
166 | * Remove our sentinel so that we don't block future attempts | |
167 | * to cache the ACL. | |
168 | */ | |
169 | cmpxchg(p, sentinel, ACL_NOT_CACHED); | |
170 | return acl; | |
171 | } | |
172 | ||
173 | /* | |
174 | * Cache the result, but only if our sentinel is still in place. | |
175 | */ | |
176 | posix_acl_dup(acl); | |
177 | if (unlikely(cmpxchg(p, sentinel, acl) != sentinel)) | |
178 | posix_acl_release(acl); | |
179 | return acl; | |
2982baa2 | 180 | } |
4f353ba4 CB |
181 | |
182 | struct posix_acl *get_inode_acl(struct inode *inode, int type) | |
183 | { | |
184 | return __get_acl(&init_user_ns, NULL, inode, type); | |
185 | } | |
cac2f8b8 | 186 | EXPORT_SYMBOL(get_inode_acl); |
2982baa2 | 187 | |
f61f6da0 CL |
188 | /* |
189 | * Init a fresh posix_acl | |
190 | */ | |
191 | void | |
192 | posix_acl_init(struct posix_acl *acl, int count) | |
193 | { | |
66717260 | 194 | refcount_set(&acl->a_refcount, 1); |
f61f6da0 CL |
195 | acl->a_count = count; |
196 | } | |
0afaa120 | 197 | EXPORT_SYMBOL(posix_acl_init); |
f61f6da0 | 198 | |
1da177e4 LT |
199 | /* |
200 | * Allocate a new ACL with the specified number of entries. | |
201 | */ | |
202 | struct posix_acl * | |
dd0fc66f | 203 | posix_acl_alloc(int count, gfp_t flags) |
1da177e4 LT |
204 | { |
205 | const size_t size = sizeof(struct posix_acl) + | |
206 | count * sizeof(struct posix_acl_entry); | |
207 | struct posix_acl *acl = kmalloc(size, flags); | |
f61f6da0 CL |
208 | if (acl) |
209 | posix_acl_init(acl, count); | |
1da177e4 LT |
210 | return acl; |
211 | } | |
0afaa120 | 212 | EXPORT_SYMBOL(posix_acl_alloc); |
1da177e4 LT |
213 | |
214 | /* | |
215 | * Clone an ACL. | |
216 | */ | |
8043bffd | 217 | struct posix_acl * |
dd0fc66f | 218 | posix_acl_clone(const struct posix_acl *acl, gfp_t flags) |
1da177e4 LT |
219 | { |
220 | struct posix_acl *clone = NULL; | |
221 | ||
222 | if (acl) { | |
223 | int size = sizeof(struct posix_acl) + acl->a_count * | |
224 | sizeof(struct posix_acl_entry); | |
52978be6 AD |
225 | clone = kmemdup(acl, size, flags); |
226 | if (clone) | |
66717260 | 227 | refcount_set(&clone->a_refcount, 1); |
1da177e4 LT |
228 | } |
229 | return clone; | |
230 | } | |
8043bffd | 231 | EXPORT_SYMBOL_GPL(posix_acl_clone); |
1da177e4 LT |
232 | |
233 | /* | |
234 | * Check if an acl is valid. Returns 0 if it is, or -E... otherwise. | |
235 | */ | |
236 | int | |
0d4d717f | 237 | posix_acl_valid(struct user_namespace *user_ns, const struct posix_acl *acl) |
1da177e4 LT |
238 | { |
239 | const struct posix_acl_entry *pa, *pe; | |
240 | int state = ACL_USER_OBJ; | |
1da177e4 LT |
241 | int needs_mask = 0; |
242 | ||
243 | FOREACH_ACL_ENTRY(pa, acl, pe) { | |
244 | if (pa->e_perm & ~(ACL_READ|ACL_WRITE|ACL_EXECUTE)) | |
245 | return -EINVAL; | |
246 | switch (pa->e_tag) { | |
247 | case ACL_USER_OBJ: | |
248 | if (state == ACL_USER_OBJ) { | |
1da177e4 LT |
249 | state = ACL_USER; |
250 | break; | |
251 | } | |
252 | return -EINVAL; | |
253 | ||
254 | case ACL_USER: | |
255 | if (state != ACL_USER) | |
256 | return -EINVAL; | |
0d4d717f | 257 | if (!kuid_has_mapping(user_ns, pa->e_uid)) |
1da177e4 | 258 | return -EINVAL; |
1da177e4 LT |
259 | needs_mask = 1; |
260 | break; | |
261 | ||
262 | case ACL_GROUP_OBJ: | |
263 | if (state == ACL_USER) { | |
1da177e4 LT |
264 | state = ACL_GROUP; |
265 | break; | |
266 | } | |
267 | return -EINVAL; | |
268 | ||
269 | case ACL_GROUP: | |
270 | if (state != ACL_GROUP) | |
271 | return -EINVAL; | |
0d4d717f | 272 | if (!kgid_has_mapping(user_ns, pa->e_gid)) |
2f6f0654 | 273 | return -EINVAL; |
1da177e4 LT |
274 | needs_mask = 1; |
275 | break; | |
276 | ||
277 | case ACL_MASK: | |
278 | if (state != ACL_GROUP) | |
279 | return -EINVAL; | |
280 | state = ACL_OTHER; | |
281 | break; | |
282 | ||
283 | case ACL_OTHER: | |
284 | if (state == ACL_OTHER || | |
285 | (state == ACL_GROUP && !needs_mask)) { | |
286 | state = 0; | |
287 | break; | |
288 | } | |
289 | return -EINVAL; | |
290 | ||
291 | default: | |
292 | return -EINVAL; | |
293 | } | |
294 | } | |
295 | if (state == 0) | |
296 | return 0; | |
297 | return -EINVAL; | |
298 | } | |
0afaa120 | 299 | EXPORT_SYMBOL(posix_acl_valid); |
1da177e4 LT |
300 | |
301 | /* | |
302 | * Returns 0 if the acl can be exactly represented in the traditional | |
303 | * file mode permission bits, or else 1. Returns -E... on error. | |
304 | */ | |
305 | int | |
d6952123 | 306 | posix_acl_equiv_mode(const struct posix_acl *acl, umode_t *mode_p) |
1da177e4 LT |
307 | { |
308 | const struct posix_acl_entry *pa, *pe; | |
d6952123 | 309 | umode_t mode = 0; |
1da177e4 LT |
310 | int not_equiv = 0; |
311 | ||
50c6e282 CH |
312 | /* |
313 | * A null ACL can always be presented as mode bits. | |
314 | */ | |
315 | if (!acl) | |
316 | return 0; | |
317 | ||
1da177e4 LT |
318 | FOREACH_ACL_ENTRY(pa, acl, pe) { |
319 | switch (pa->e_tag) { | |
320 | case ACL_USER_OBJ: | |
321 | mode |= (pa->e_perm & S_IRWXO) << 6; | |
322 | break; | |
323 | case ACL_GROUP_OBJ: | |
324 | mode |= (pa->e_perm & S_IRWXO) << 3; | |
325 | break; | |
326 | case ACL_OTHER: | |
327 | mode |= pa->e_perm & S_IRWXO; | |
328 | break; | |
329 | case ACL_MASK: | |
330 | mode = (mode & ~S_IRWXG) | | |
331 | ((pa->e_perm & S_IRWXO) << 3); | |
332 | not_equiv = 1; | |
333 | break; | |
334 | case ACL_USER: | |
335 | case ACL_GROUP: | |
336 | not_equiv = 1; | |
337 | break; | |
338 | default: | |
339 | return -EINVAL; | |
340 | } | |
341 | } | |
342 | if (mode_p) | |
343 | *mode_p = (*mode_p & ~S_IRWXUGO) | mode; | |
344 | return not_equiv; | |
345 | } | |
0afaa120 | 346 | EXPORT_SYMBOL(posix_acl_equiv_mode); |
1da177e4 LT |
347 | |
348 | /* | |
349 | * Create an ACL representing the file mode permission bits of an inode. | |
350 | */ | |
351 | struct posix_acl * | |
3a5fba19 | 352 | posix_acl_from_mode(umode_t mode, gfp_t flags) |
1da177e4 LT |
353 | { |
354 | struct posix_acl *acl = posix_acl_alloc(3, flags); | |
355 | if (!acl) | |
356 | return ERR_PTR(-ENOMEM); | |
357 | ||
358 | acl->a_entries[0].e_tag = ACL_USER_OBJ; | |
1da177e4 LT |
359 | acl->a_entries[0].e_perm = (mode & S_IRWXU) >> 6; |
360 | ||
361 | acl->a_entries[1].e_tag = ACL_GROUP_OBJ; | |
1da177e4 LT |
362 | acl->a_entries[1].e_perm = (mode & S_IRWXG) >> 3; |
363 | ||
364 | acl->a_entries[2].e_tag = ACL_OTHER; | |
1da177e4 LT |
365 | acl->a_entries[2].e_perm = (mode & S_IRWXO); |
366 | return acl; | |
367 | } | |
0afaa120 | 368 | EXPORT_SYMBOL(posix_acl_from_mode); |
1da177e4 LT |
369 | |
370 | /* | |
371 | * Return 0 if current is granted want access to the inode | |
372 | * by the acl. Returns -E... otherwise. | |
373 | */ | |
374 | int | |
47291baa CB |
375 | posix_acl_permission(struct user_namespace *mnt_userns, struct inode *inode, |
376 | const struct posix_acl *acl, int want) | |
1da177e4 LT |
377 | { |
378 | const struct posix_acl_entry *pa, *pe, *mask_obj; | |
abfcf55d | 379 | struct user_namespace *fs_userns = i_user_ns(inode); |
1da177e4 | 380 | int found = 0; |
e933c15f CB |
381 | vfsuid_t vfsuid; |
382 | vfsgid_t vfsgid; | |
1da177e4 | 383 | |
63d72b93 | 384 | want &= MAY_READ | MAY_WRITE | MAY_EXEC; |
d124b60a | 385 | |
1da177e4 LT |
386 | FOREACH_ACL_ENTRY(pa, acl, pe) { |
387 | switch(pa->e_tag) { | |
388 | case ACL_USER_OBJ: | |
389 | /* (May have been checked already) */ | |
e933c15f CB |
390 | vfsuid = i_uid_into_vfsuid(mnt_userns, inode); |
391 | if (vfsuid_eq_kuid(vfsuid, current_fsuid())) | |
1da177e4 LT |
392 | goto check_perm; |
393 | break; | |
394 | case ACL_USER: | |
abfcf55d | 395 | vfsuid = make_vfsuid(mnt_userns, fs_userns, |
bd303368 | 396 | pa->e_uid); |
e933c15f | 397 | if (vfsuid_eq_kuid(vfsuid, current_fsuid())) |
1da177e4 LT |
398 | goto mask; |
399 | break; | |
400 | case ACL_GROUP_OBJ: | |
e933c15f CB |
401 | vfsgid = i_gid_into_vfsgid(mnt_userns, inode); |
402 | if (vfsgid_in_group_p(vfsgid)) { | |
1da177e4 LT |
403 | found = 1; |
404 | if ((pa->e_perm & want) == want) | |
405 | goto mask; | |
406 | } | |
407 | break; | |
408 | case ACL_GROUP: | |
abfcf55d | 409 | vfsgid = make_vfsgid(mnt_userns, fs_userns, |
bd303368 | 410 | pa->e_gid); |
e933c15f | 411 | if (vfsgid_in_group_p(vfsgid)) { |
1da177e4 LT |
412 | found = 1; |
413 | if ((pa->e_perm & want) == want) | |
414 | goto mask; | |
415 | } | |
416 | break; | |
417 | case ACL_MASK: | |
418 | break; | |
419 | case ACL_OTHER: | |
420 | if (found) | |
421 | return -EACCES; | |
422 | else | |
423 | goto check_perm; | |
424 | default: | |
425 | return -EIO; | |
426 | } | |
427 | } | |
428 | return -EIO; | |
429 | ||
430 | mask: | |
431 | for (mask_obj = pa+1; mask_obj != pe; mask_obj++) { | |
432 | if (mask_obj->e_tag == ACL_MASK) { | |
433 | if ((pa->e_perm & mask_obj->e_perm & want) == want) | |
434 | return 0; | |
435 | return -EACCES; | |
436 | } | |
437 | } | |
438 | ||
439 | check_perm: | |
440 | if ((pa->e_perm & want) == want) | |
441 | return 0; | |
442 | return -EACCES; | |
443 | } | |
444 | ||
445 | /* | |
446 | * Modify acl when creating a new inode. The caller must ensure the acl is | |
447 | * only referenced once. | |
448 | * | |
449 | * mode_p initially must contain the mode parameter to the open() / creat() | |
450 | * system calls. All permissions that are not granted by the acl are removed. | |
451 | * The permissions in the acl are changed to reflect the mode_p parameter. | |
452 | */ | |
d3fb6120 | 453 | static int posix_acl_create_masq(struct posix_acl *acl, umode_t *mode_p) |
1da177e4 LT |
454 | { |
455 | struct posix_acl_entry *pa, *pe; | |
456 | struct posix_acl_entry *group_obj = NULL, *mask_obj = NULL; | |
d3fb6120 | 457 | umode_t mode = *mode_p; |
1da177e4 LT |
458 | int not_equiv = 0; |
459 | ||
460 | /* assert(atomic_read(acl->a_refcount) == 1); */ | |
461 | ||
462 | FOREACH_ACL_ENTRY(pa, acl, pe) { | |
463 | switch(pa->e_tag) { | |
464 | case ACL_USER_OBJ: | |
465 | pa->e_perm &= (mode >> 6) | ~S_IRWXO; | |
466 | mode &= (pa->e_perm << 6) | ~S_IRWXU; | |
467 | break; | |
468 | ||
469 | case ACL_USER: | |
470 | case ACL_GROUP: | |
471 | not_equiv = 1; | |
472 | break; | |
473 | ||
474 | case ACL_GROUP_OBJ: | |
475 | group_obj = pa; | |
476 | break; | |
477 | ||
478 | case ACL_OTHER: | |
479 | pa->e_perm &= mode | ~S_IRWXO; | |
480 | mode &= pa->e_perm | ~S_IRWXO; | |
481 | break; | |
482 | ||
483 | case ACL_MASK: | |
484 | mask_obj = pa; | |
485 | not_equiv = 1; | |
486 | break; | |
487 | ||
488 | default: | |
489 | return -EIO; | |
490 | } | |
491 | } | |
492 | ||
493 | if (mask_obj) { | |
494 | mask_obj->e_perm &= (mode >> 3) | ~S_IRWXO; | |
495 | mode &= (mask_obj->e_perm << 3) | ~S_IRWXG; | |
496 | } else { | |
497 | if (!group_obj) | |
498 | return -EIO; | |
499 | group_obj->e_perm &= (mode >> 3) | ~S_IRWXO; | |
500 | mode &= (group_obj->e_perm << 3) | ~S_IRWXG; | |
501 | } | |
502 | ||
503 | *mode_p = (*mode_p & ~S_IRWXUGO) | mode; | |
504 | return not_equiv; | |
505 | } | |
506 | ||
507 | /* | |
508 | * Modify the ACL for the chmod syscall. | |
509 | */ | |
5bf3258f | 510 | static int __posix_acl_chmod_masq(struct posix_acl *acl, umode_t mode) |
1da177e4 LT |
511 | { |
512 | struct posix_acl_entry *group_obj = NULL, *mask_obj = NULL; | |
513 | struct posix_acl_entry *pa, *pe; | |
514 | ||
515 | /* assert(atomic_read(acl->a_refcount) == 1); */ | |
516 | ||
517 | FOREACH_ACL_ENTRY(pa, acl, pe) { | |
518 | switch(pa->e_tag) { | |
519 | case ACL_USER_OBJ: | |
520 | pa->e_perm = (mode & S_IRWXU) >> 6; | |
521 | break; | |
522 | ||
523 | case ACL_USER: | |
524 | case ACL_GROUP: | |
525 | break; | |
526 | ||
527 | case ACL_GROUP_OBJ: | |
528 | group_obj = pa; | |
529 | break; | |
530 | ||
531 | case ACL_MASK: | |
532 | mask_obj = pa; | |
533 | break; | |
534 | ||
535 | case ACL_OTHER: | |
536 | pa->e_perm = (mode & S_IRWXO); | |
537 | break; | |
538 | ||
539 | default: | |
540 | return -EIO; | |
541 | } | |
542 | } | |
543 | ||
544 | if (mask_obj) { | |
545 | mask_obj->e_perm = (mode & S_IRWXG) >> 3; | |
546 | } else { | |
547 | if (!group_obj) | |
548 | return -EIO; | |
549 | group_obj->e_perm = (mode & S_IRWXG) >> 3; | |
550 | } | |
551 | ||
552 | return 0; | |
553 | } | |
bc26ab5f | 554 | |
826cae2f | 555 | int |
37bc1539 | 556 | __posix_acl_create(struct posix_acl **acl, gfp_t gfp, umode_t *mode_p) |
826cae2f AV |
557 | { |
558 | struct posix_acl *clone = posix_acl_clone(*acl, gfp); | |
559 | int err = -ENOMEM; | |
560 | if (clone) { | |
561 | err = posix_acl_create_masq(clone, mode_p); | |
562 | if (err < 0) { | |
563 | posix_acl_release(clone); | |
564 | clone = NULL; | |
565 | } | |
566 | } | |
567 | posix_acl_release(*acl); | |
568 | *acl = clone; | |
569 | return err; | |
570 | } | |
37bc1539 | 571 | EXPORT_SYMBOL(__posix_acl_create); |
826cae2f | 572 | |
bc26ab5f | 573 | int |
5bf3258f | 574 | __posix_acl_chmod(struct posix_acl **acl, gfp_t gfp, umode_t mode) |
bc26ab5f AV |
575 | { |
576 | struct posix_acl *clone = posix_acl_clone(*acl, gfp); | |
577 | int err = -ENOMEM; | |
578 | if (clone) { | |
5bf3258f | 579 | err = __posix_acl_chmod_masq(clone, mode); |
bc26ab5f AV |
580 | if (err) { |
581 | posix_acl_release(clone); | |
582 | clone = NULL; | |
583 | } | |
584 | } | |
585 | posix_acl_release(*acl); | |
586 | *acl = clone; | |
587 | return err; | |
588 | } | |
5bf3258f CH |
589 | EXPORT_SYMBOL(__posix_acl_chmod); |
590 | ||
e65ce2a5 CB |
591 | /** |
592 | * posix_acl_chmod - chmod a posix acl | |
593 | * | |
594 | * @mnt_userns: user namespace of the mount @inode was found from | |
138060ba | 595 | * @dentry: dentry to check permissions on |
e65ce2a5 CB |
596 | * @mode: the new mode of @inode |
597 | * | |
138060ba | 598 | * If the dentry has been found through an idmapped mount the user namespace of |
e65ce2a5 CB |
599 | * the vfsmount must be passed through @mnt_userns. This function will then |
600 | * take care to map the inode according to @mnt_userns before checking | |
601 | * permissions. On non-idmapped mounts or if permission checking is to be | |
602 | * performed on the raw inode simply passs init_user_ns. | |
603 | */ | |
5bf3258f | 604 | int |
138060ba | 605 | posix_acl_chmod(struct user_namespace *mnt_userns, struct dentry *dentry, |
e65ce2a5 | 606 | umode_t mode) |
5bf3258f | 607 | { |
138060ba | 608 | struct inode *inode = d_inode(dentry); |
5bf3258f CH |
609 | struct posix_acl *acl; |
610 | int ret = 0; | |
611 | ||
612 | if (!IS_POSIXACL(inode)) | |
613 | return 0; | |
614 | if (!inode->i_op->set_acl) | |
615 | return -EOPNOTSUPP; | |
616 | ||
cac2f8b8 | 617 | acl = get_inode_acl(inode, ACL_TYPE_ACCESS); |
789b663a TM |
618 | if (IS_ERR_OR_NULL(acl)) { |
619 | if (acl == ERR_PTR(-EOPNOTSUPP)) | |
620 | return 0; | |
5bf3258f | 621 | return PTR_ERR(acl); |
789b663a | 622 | } |
5bf3258f | 623 | |
37bc1539 | 624 | ret = __posix_acl_chmod(&acl, GFP_KERNEL, mode); |
5bf3258f CH |
625 | if (ret) |
626 | return ret; | |
138060ba | 627 | ret = inode->i_op->set_acl(mnt_userns, dentry, acl, ACL_TYPE_ACCESS); |
5bf3258f CH |
628 | posix_acl_release(acl); |
629 | return ret; | |
630 | } | |
bc26ab5f | 631 | EXPORT_SYMBOL(posix_acl_chmod); |
5c8ebd57 | 632 | |
37bc1539 CH |
633 | int |
634 | posix_acl_create(struct inode *dir, umode_t *mode, | |
635 | struct posix_acl **default_acl, struct posix_acl **acl) | |
636 | { | |
637 | struct posix_acl *p; | |
c0c3a718 | 638 | struct posix_acl *clone; |
37bc1539 CH |
639 | int ret; |
640 | ||
c0c3a718 DC |
641 | *acl = NULL; |
642 | *default_acl = NULL; | |
643 | ||
37bc1539 | 644 | if (S_ISLNK(*mode) || !IS_POSIXACL(dir)) |
c0c3a718 | 645 | return 0; |
37bc1539 | 646 | |
cac2f8b8 | 647 | p = get_inode_acl(dir, ACL_TYPE_DEFAULT); |
c0c3a718 DC |
648 | if (!p || p == ERR_PTR(-EOPNOTSUPP)) { |
649 | *mode &= ~current_umask(); | |
650 | return 0; | |
37bc1539 | 651 | } |
c0c3a718 DC |
652 | if (IS_ERR(p)) |
653 | return PTR_ERR(p); | |
37bc1539 | 654 | |
beaf226b | 655 | ret = -ENOMEM; |
c0c3a718 DC |
656 | clone = posix_acl_clone(p, GFP_NOFS); |
657 | if (!clone) | |
beaf226b | 658 | goto err_release; |
37bc1539 | 659 | |
c0c3a718 | 660 | ret = posix_acl_create_masq(clone, mode); |
fed0b588 | 661 | if (ret < 0) |
beaf226b | 662 | goto err_release_clone; |
37bc1539 | 663 | |
c0c3a718 DC |
664 | if (ret == 0) |
665 | posix_acl_release(clone); | |
666 | else | |
667 | *acl = clone; | |
37bc1539 | 668 | |
c0c3a718 | 669 | if (!S_ISDIR(*mode)) |
37bc1539 | 670 | posix_acl_release(p); |
c0c3a718 | 671 | else |
37bc1539 | 672 | *default_acl = p; |
37bc1539 | 673 | |
37bc1539 | 674 | return 0; |
fed0b588 | 675 | |
beaf226b | 676 | err_release_clone: |
c0c3a718 | 677 | posix_acl_release(clone); |
beaf226b | 678 | err_release: |
fed0b588 | 679 | posix_acl_release(p); |
beaf226b | 680 | return ret; |
37bc1539 CH |
681 | } |
682 | EXPORT_SYMBOL_GPL(posix_acl_create); | |
683 | ||
07393101 JK |
684 | /** |
685 | * posix_acl_update_mode - update mode in set_acl | |
e65ce2a5 CB |
686 | * @mnt_userns: user namespace of the mount @inode was found from |
687 | * @inode: target inode | |
688 | * @mode_p: mode (pointer) for update | |
689 | * @acl: acl pointer | |
07393101 JK |
690 | * |
691 | * Update the file mode when setting an ACL: compute the new file permission | |
692 | * bits based on the ACL. In addition, if the ACL is equivalent to the new | |
e39e773a | 693 | * file mode, set *@acl to NULL to indicate that no ACL should be set. |
07393101 | 694 | * |
e39e773a | 695 | * As with chmod, clear the setgid bit if the caller is not in the owning group |
07393101 JK |
696 | * or capable of CAP_FSETID (see inode_change_ok). |
697 | * | |
e65ce2a5 CB |
698 | * If the inode has been found through an idmapped mount the user namespace of |
699 | * the vfsmount must be passed through @mnt_userns. This function will then | |
700 | * take care to map the inode according to @mnt_userns before checking | |
701 | * permissions. On non-idmapped mounts or if permission checking is to be | |
702 | * performed on the raw inode simply passs init_user_ns. | |
703 | * | |
07393101 JK |
704 | * Called from set_acl inode operations. |
705 | */ | |
e65ce2a5 CB |
706 | int posix_acl_update_mode(struct user_namespace *mnt_userns, |
707 | struct inode *inode, umode_t *mode_p, | |
07393101 JK |
708 | struct posix_acl **acl) |
709 | { | |
710 | umode_t mode = inode->i_mode; | |
711 | int error; | |
712 | ||
713 | error = posix_acl_equiv_mode(*acl, &mode); | |
714 | if (error < 0) | |
715 | return error; | |
716 | if (error == 0) | |
717 | *acl = NULL; | |
e933c15f | 718 | if (!vfsgid_in_group_p(i_gid_into_vfsgid(mnt_userns, inode)) && |
e65ce2a5 | 719 | !capable_wrt_inode_uidgid(mnt_userns, inode, CAP_FSETID)) |
07393101 JK |
720 | mode &= ~S_ISGID; |
721 | *mode_p = mode; | |
722 | return 0; | |
723 | } | |
724 | EXPORT_SYMBOL(posix_acl_update_mode); | |
725 | ||
5c8ebd57 CH |
726 | /* |
727 | * Fix up the uids and gids in posix acl extended attributes in place. | |
728 | */ | |
985a6d0b | 729 | static int posix_acl_fix_xattr_common(const void *value, size_t size) |
0c5fd887 | 730 | { |
985a6d0b | 731 | const struct posix_acl_xattr_header *header = value; |
0c5fd887 CB |
732 | int count; |
733 | ||
734 | if (!header) | |
735 | return -EINVAL; | |
736 | if (size < sizeof(struct posix_acl_xattr_header)) | |
737 | return -EINVAL; | |
738 | if (header->a_version != cpu_to_le32(POSIX_ACL_XATTR_VERSION)) | |
985a6d0b | 739 | return -EOPNOTSUPP; |
0c5fd887 CB |
740 | |
741 | count = posix_acl_xattr_count(size); | |
742 | if (count < 0) | |
743 | return -EINVAL; | |
744 | if (count == 0) | |
985a6d0b | 745 | return 0; |
0c5fd887 CB |
746 | |
747 | return count; | |
748 | } | |
749 | ||
6b70fe06 | 750 | /** |
0a26bde2 CB |
751 | * posix_acl_from_xattr - convert POSIX ACLs from backing store to VFS format |
752 | * @userns: the filesystem's idmapping | |
6b70fe06 CB |
753 | * @value: the uapi representation of POSIX ACLs |
754 | * @size: the size of @void | |
6b70fe06 | 755 | * |
0a26bde2 CB |
756 | * Filesystems that store POSIX ACLs in the unaltered uapi format should use |
757 | * posix_acl_from_xattr() when reading them from the backing store and | |
758 | * converting them into the struct posix_acl VFS format. The helper is | |
759 | * specifically intended to be called from the acl inode operation. | |
760 | * | |
761 | * The posix_acl_from_xattr() function will map the raw {g,u}id values stored | |
762 | * in ACL_{GROUP,USER} entries into idmapping in @userns. | |
763 | * | |
764 | * Note that posix_acl_from_xattr() does not take idmapped mounts into account. | |
765 | * If it did it calling it from the get acl inode operation would return POSIX | |
766 | * ACLs mapped according to an idmapped mount which would mean that the value | |
767 | * couldn't be cached for the filesystem. Idmapped mounts are taken into | |
768 | * account on the fly during permission checking or right at the VFS - | |
769 | * userspace boundary before reporting them to the user. | |
6b70fe06 CB |
770 | * |
771 | * Return: Allocated struct posix_acl on success, NULL for a valid header but | |
772 | * without actual POSIX ACL entries, or ERR_PTR() encoded error code. | |
5c8ebd57 | 773 | */ |
0a26bde2 CB |
774 | struct posix_acl *posix_acl_from_xattr(struct user_namespace *userns, |
775 | const void *value, size_t size) | |
5c8ebd57 | 776 | { |
2211d5ba AG |
777 | const struct posix_acl_xattr_header *header = value; |
778 | const struct posix_acl_xattr_entry *entry = (const void *)(header + 1), *end; | |
5c8ebd57 CH |
779 | int count; |
780 | struct posix_acl *acl; | |
781 | struct posix_acl_entry *acl_e; | |
782 | ||
985a6d0b | 783 | count = posix_acl_fix_xattr_common(value, size); |
5c8ebd57 | 784 | if (count < 0) |
985a6d0b | 785 | return ERR_PTR(count); |
5c8ebd57 CH |
786 | if (count == 0) |
787 | return NULL; | |
788 | ||
789 | acl = posix_acl_alloc(count, GFP_NOFS); | |
790 | if (!acl) | |
791 | return ERR_PTR(-ENOMEM); | |
792 | acl_e = acl->a_entries; | |
793 | ||
794 | for (end = entry + count; entry != end; acl_e++, entry++) { | |
795 | acl_e->e_tag = le16_to_cpu(entry->e_tag); | |
796 | acl_e->e_perm = le16_to_cpu(entry->e_perm); | |
797 | ||
798 | switch(acl_e->e_tag) { | |
799 | case ACL_USER_OBJ: | |
800 | case ACL_GROUP_OBJ: | |
801 | case ACL_MASK: | |
802 | case ACL_OTHER: | |
803 | break; | |
804 | ||
805 | case ACL_USER: | |
0a26bde2 CB |
806 | acl_e->e_uid = make_kuid(userns, |
807 | le32_to_cpu(entry->e_id)); | |
5c8ebd57 CH |
808 | if (!uid_valid(acl_e->e_uid)) |
809 | goto fail; | |
810 | break; | |
811 | case ACL_GROUP: | |
0a26bde2 CB |
812 | acl_e->e_gid = make_kgid(userns, |
813 | le32_to_cpu(entry->e_id)); | |
5c8ebd57 CH |
814 | if (!gid_valid(acl_e->e_gid)) |
815 | goto fail; | |
816 | break; | |
817 | ||
818 | default: | |
819 | goto fail; | |
820 | } | |
821 | } | |
822 | return acl; | |
823 | ||
824 | fail: | |
825 | posix_acl_release(acl); | |
826 | return ERR_PTR(-EINVAL); | |
827 | } | |
828 | EXPORT_SYMBOL (posix_acl_from_xattr); | |
829 | ||
830 | /* | |
831 | * Convert from in-memory to extended attribute representation. | |
832 | */ | |
833 | int | |
834 | posix_acl_to_xattr(struct user_namespace *user_ns, const struct posix_acl *acl, | |
835 | void *buffer, size_t size) | |
836 | { | |
2211d5ba AG |
837 | struct posix_acl_xattr_header *ext_acl = buffer; |
838 | struct posix_acl_xattr_entry *ext_entry; | |
5c8ebd57 CH |
839 | int real_size, n; |
840 | ||
841 | real_size = posix_acl_xattr_size(acl->a_count); | |
842 | if (!buffer) | |
843 | return real_size; | |
844 | if (real_size > size) | |
845 | return -ERANGE; | |
47ba9734 | 846 | |
2211d5ba | 847 | ext_entry = (void *)(ext_acl + 1); |
5c8ebd57 CH |
848 | ext_acl->a_version = cpu_to_le32(POSIX_ACL_XATTR_VERSION); |
849 | ||
850 | for (n=0; n < acl->a_count; n++, ext_entry++) { | |
851 | const struct posix_acl_entry *acl_e = &acl->a_entries[n]; | |
852 | ext_entry->e_tag = cpu_to_le16(acl_e->e_tag); | |
853 | ext_entry->e_perm = cpu_to_le16(acl_e->e_perm); | |
854 | switch(acl_e->e_tag) { | |
855 | case ACL_USER: | |
856 | ext_entry->e_id = | |
857 | cpu_to_le32(from_kuid(user_ns, acl_e->e_uid)); | |
858 | break; | |
859 | case ACL_GROUP: | |
860 | ext_entry->e_id = | |
861 | cpu_to_le32(from_kgid(user_ns, acl_e->e_gid)); | |
862 | break; | |
863 | default: | |
864 | ext_entry->e_id = cpu_to_le32(ACL_UNDEFINED_ID); | |
865 | break; | |
866 | } | |
867 | } | |
868 | return real_size; | |
869 | } | |
870 | EXPORT_SYMBOL (posix_acl_to_xattr); | |
2aeccbe9 | 871 | |
4f353ba4 CB |
872 | /** |
873 | * vfs_posix_acl_to_xattr - convert from kernel to userspace representation | |
874 | * @mnt_userns: user namespace of the mount | |
875 | * @inode: inode the posix acls are set on | |
876 | * @acl: the posix acls as represented by the vfs | |
877 | * @buffer: the buffer into which to convert @acl | |
878 | * @size: size of @buffer | |
879 | * | |
880 | * This converts @acl from the VFS representation in the filesystem idmapping | |
881 | * to the uapi form reportable to userspace. And mount and caller idmappings | |
882 | * are handled appropriately. | |
883 | * | |
884 | * Return: On success, the size of the stored uapi posix acls, on error a | |
885 | * negative errno. | |
886 | */ | |
a351b1f4 CB |
887 | static ssize_t vfs_posix_acl_to_xattr(struct user_namespace *mnt_userns, |
888 | struct inode *inode, | |
889 | const struct posix_acl *acl, void *buffer, | |
890 | size_t size) | |
4f353ba4 CB |
891 | |
892 | { | |
893 | struct posix_acl_xattr_header *ext_acl = buffer; | |
894 | struct posix_acl_xattr_entry *ext_entry; | |
895 | struct user_namespace *fs_userns, *caller_userns; | |
896 | ssize_t real_size, n; | |
897 | vfsuid_t vfsuid; | |
898 | vfsgid_t vfsgid; | |
899 | ||
900 | real_size = posix_acl_xattr_size(acl->a_count); | |
901 | if (!buffer) | |
902 | return real_size; | |
903 | if (real_size > size) | |
904 | return -ERANGE; | |
905 | ||
906 | ext_entry = (void *)(ext_acl + 1); | |
907 | ext_acl->a_version = cpu_to_le32(POSIX_ACL_XATTR_VERSION); | |
908 | ||
909 | fs_userns = i_user_ns(inode); | |
910 | caller_userns = current_user_ns(); | |
911 | for (n=0; n < acl->a_count; n++, ext_entry++) { | |
912 | const struct posix_acl_entry *acl_e = &acl->a_entries[n]; | |
913 | ext_entry->e_tag = cpu_to_le16(acl_e->e_tag); | |
914 | ext_entry->e_perm = cpu_to_le16(acl_e->e_perm); | |
915 | switch(acl_e->e_tag) { | |
916 | case ACL_USER: | |
917 | vfsuid = make_vfsuid(mnt_userns, fs_userns, acl_e->e_uid); | |
918 | ext_entry->e_id = cpu_to_le32(from_kuid( | |
919 | caller_userns, vfsuid_into_kuid(vfsuid))); | |
920 | break; | |
921 | case ACL_GROUP: | |
922 | vfsgid = make_vfsgid(mnt_userns, fs_userns, acl_e->e_gid); | |
923 | ext_entry->e_id = cpu_to_le32(from_kgid( | |
924 | caller_userns, vfsgid_into_kgid(vfsgid))); | |
925 | break; | |
926 | default: | |
927 | ext_entry->e_id = cpu_to_le32(ACL_UNDEFINED_ID); | |
928 | break; | |
929 | } | |
930 | } | |
931 | return real_size; | |
932 | } | |
933 | ||
485e71e8 | 934 | int |
138060ba | 935 | set_posix_acl(struct user_namespace *mnt_userns, struct dentry *dentry, |
e65ce2a5 | 936 | int type, struct posix_acl *acl) |
2aeccbe9 | 937 | { |
138060ba CB |
938 | struct inode *inode = d_inode(dentry); |
939 | ||
2aeccbe9 CH |
940 | if (!IS_POSIXACL(inode)) |
941 | return -EOPNOTSUPP; | |
942 | if (!inode->i_op->set_acl) | |
943 | return -EOPNOTSUPP; | |
944 | ||
485e71e8 AG |
945 | if (type == ACL_TYPE_DEFAULT && !S_ISDIR(inode->i_mode)) |
946 | return acl ? -EACCES : 0; | |
e65ce2a5 | 947 | if (!inode_owner_or_capable(mnt_userns, inode)) |
2aeccbe9 CH |
948 | return -EPERM; |
949 | ||
485e71e8 | 950 | if (acl) { |
a867d734 | 951 | int ret = posix_acl_valid(inode->i_sb->s_user_ns, acl); |
485e71e8 AG |
952 | if (ret) |
953 | return ret; | |
954 | } | |
138060ba | 955 | return inode->i_op->set_acl(mnt_userns, dentry, acl, type); |
485e71e8 AG |
956 | } |
957 | EXPORT_SYMBOL(set_posix_acl); | |
958 | ||
764a5c6b AG |
959 | static bool |
960 | posix_acl_xattr_list(struct dentry *dentry) | |
2aeccbe9 | 961 | { |
764a5c6b | 962 | return IS_POSIXACL(d_backing_inode(dentry)); |
2aeccbe9 CH |
963 | } |
964 | ||
965 | const struct xattr_handler posix_acl_access_xattr_handler = { | |
98e9cb57 | 966 | .name = XATTR_NAME_POSIX_ACL_ACCESS, |
2aeccbe9 CH |
967 | .flags = ACL_TYPE_ACCESS, |
968 | .list = posix_acl_xattr_list, | |
2aeccbe9 CH |
969 | }; |
970 | EXPORT_SYMBOL_GPL(posix_acl_access_xattr_handler); | |
971 | ||
972 | const struct xattr_handler posix_acl_default_xattr_handler = { | |
98e9cb57 | 973 | .name = XATTR_NAME_POSIX_ACL_DEFAULT, |
2aeccbe9 CH |
974 | .flags = ACL_TYPE_DEFAULT, |
975 | .list = posix_acl_xattr_list, | |
2aeccbe9 CH |
976 | }; |
977 | EXPORT_SYMBOL_GPL(posix_acl_default_xattr_handler); | |
feda821e | 978 | |
138060ba | 979 | int simple_set_acl(struct user_namespace *mnt_userns, struct dentry *dentry, |
549c7297 | 980 | struct posix_acl *acl, int type) |
feda821e CH |
981 | { |
982 | int error; | |
138060ba | 983 | struct inode *inode = d_inode(dentry); |
feda821e CH |
984 | |
985 | if (type == ACL_TYPE_ACCESS) { | |
549c7297 | 986 | error = posix_acl_update_mode(mnt_userns, inode, |
497de07d GZ |
987 | &inode->i_mode, &acl); |
988 | if (error) | |
989 | return error; | |
feda821e CH |
990 | } |
991 | ||
078cd827 | 992 | inode->i_ctime = current_time(inode); |
36f05cab JL |
993 | if (IS_I_VERSION(inode)) |
994 | inode_inc_iversion(inode); | |
feda821e CH |
995 | set_cached_acl(inode, type, acl); |
996 | return 0; | |
997 | } | |
998 | ||
999 | int simple_acl_create(struct inode *dir, struct inode *inode) | |
1000 | { | |
1001 | struct posix_acl *default_acl, *acl; | |
1002 | int error; | |
1003 | ||
1004 | error = posix_acl_create(dir, &inode->i_mode, &default_acl, &acl); | |
1005 | if (error) | |
1006 | return error; | |
1007 | ||
1008 | set_cached_acl(inode, ACL_TYPE_DEFAULT, default_acl); | |
1009 | set_cached_acl(inode, ACL_TYPE_ACCESS, acl); | |
1010 | ||
1011 | if (default_acl) | |
1012 | posix_acl_release(default_acl); | |
1013 | if (acl) | |
1014 | posix_acl_release(acl); | |
1015 | return 0; | |
1016 | } | |
e4cc9163 CB |
1017 | |
1018 | static int vfs_set_acl_idmapped_mnt(struct user_namespace *mnt_userns, | |
1019 | struct user_namespace *fs_userns, | |
1020 | struct posix_acl *acl) | |
1021 | { | |
1022 | for (int n = 0; n < acl->a_count; n++) { | |
1023 | struct posix_acl_entry *acl_e = &acl->a_entries[n]; | |
1024 | ||
1025 | switch (acl_e->e_tag) { | |
1026 | case ACL_USER: | |
1027 | acl_e->e_uid = from_vfsuid(mnt_userns, fs_userns, | |
1028 | VFSUIDT_INIT(acl_e->e_uid)); | |
1029 | break; | |
1030 | case ACL_GROUP: | |
1031 | acl_e->e_gid = from_vfsgid(mnt_userns, fs_userns, | |
1032 | VFSGIDT_INIT(acl_e->e_gid)); | |
1033 | break; | |
1034 | } | |
1035 | } | |
1036 | ||
1037 | return 0; | |
1038 | } | |
1039 | ||
1040 | /** | |
1041 | * vfs_set_acl - set posix acls | |
1042 | * @mnt_userns: user namespace of the mount | |
1043 | * @dentry: the dentry based on which to set the posix acls | |
1044 | * @acl_name: the name of the posix acl | |
1045 | * @kacl: the posix acls in the appropriate VFS format | |
1046 | * | |
1047 | * This function sets @kacl. The caller must all posix_acl_release() on @kacl | |
1048 | * afterwards. | |
1049 | * | |
1050 | * Return: On success 0, on error negative errno. | |
1051 | */ | |
1052 | int vfs_set_acl(struct user_namespace *mnt_userns, struct dentry *dentry, | |
1053 | const char *acl_name, struct posix_acl *kacl) | |
1054 | { | |
1055 | int acl_type; | |
1056 | int error; | |
1057 | struct inode *inode = d_inode(dentry); | |
1058 | struct inode *delegated_inode = NULL; | |
1059 | ||
1060 | acl_type = posix_acl_type(acl_name); | |
1061 | if (acl_type < 0) | |
1062 | return -EINVAL; | |
1063 | ||
1064 | if (kacl) { | |
1065 | /* | |
1066 | * If we're on an idmapped mount translate from mount specific | |
1067 | * vfs{g,u}id_t into global filesystem k{g,u}id_t. | |
1068 | * Afterwards we can cache the POSIX ACLs filesystem wide and - | |
1069 | * if this is a filesystem with a backing store - ultimately | |
1070 | * translate them to backing store values. | |
1071 | */ | |
1072 | error = vfs_set_acl_idmapped_mnt(mnt_userns, i_user_ns(inode), kacl); | |
1073 | if (error) | |
1074 | return error; | |
1075 | } | |
1076 | ||
1077 | retry_deleg: | |
1078 | inode_lock(inode); | |
1079 | ||
1080 | /* | |
1081 | * We only care about restrictions the inode struct itself places upon | |
1082 | * us otherwise POSIX ACLs aren't subject to any VFS restrictions. | |
1083 | */ | |
1084 | error = may_write_xattr(mnt_userns, inode); | |
1085 | if (error) | |
1086 | goto out_inode_unlock; | |
1087 | ||
1088 | error = security_inode_set_acl(mnt_userns, dentry, acl_name, kacl); | |
1089 | if (error) | |
1090 | goto out_inode_unlock; | |
1091 | ||
1092 | error = try_break_deleg(inode, &delegated_inode); | |
1093 | if (error) | |
1094 | goto out_inode_unlock; | |
1095 | ||
1096 | if (inode->i_opflags & IOP_XATTR) | |
1097 | error = set_posix_acl(mnt_userns, dentry, acl_type, kacl); | |
1098 | else if (unlikely(is_bad_inode(inode))) | |
1099 | error = -EIO; | |
1100 | else | |
1101 | error = -EOPNOTSUPP; | |
1102 | if (!error) { | |
1103 | fsnotify_xattr(dentry); | |
1104 | evm_inode_post_set_acl(dentry, acl_name, kacl); | |
1105 | } | |
1106 | ||
1107 | out_inode_unlock: | |
1108 | inode_unlock(inode); | |
1109 | ||
1110 | if (delegated_inode) { | |
1111 | error = break_deleg_wait(&delegated_inode); | |
1112 | if (!error) | |
1113 | goto retry_deleg; | |
1114 | } | |
1115 | ||
1116 | return error; | |
1117 | } | |
1118 | EXPORT_SYMBOL_GPL(vfs_set_acl); | |
4f353ba4 CB |
1119 | |
1120 | /** | |
1121 | * vfs_get_acl - get posix acls | |
1122 | * @mnt_userns: user namespace of the mount | |
1123 | * @dentry: the dentry based on which to retrieve the posix acls | |
1124 | * @acl_name: the name of the posix acl | |
1125 | * | |
1126 | * This function retrieves @kacl from the filesystem. The caller must all | |
1127 | * posix_acl_release() on @kacl. | |
1128 | * | |
1129 | * Return: On success POSIX ACLs in VFS format, on error negative errno. | |
1130 | */ | |
1131 | struct posix_acl *vfs_get_acl(struct user_namespace *mnt_userns, | |
1132 | struct dentry *dentry, const char *acl_name) | |
1133 | { | |
1134 | struct inode *inode = d_inode(dentry); | |
1135 | struct posix_acl *acl; | |
1136 | int acl_type, error; | |
1137 | ||
1138 | acl_type = posix_acl_type(acl_name); | |
1139 | if (acl_type < 0) | |
1140 | return ERR_PTR(-EINVAL); | |
1141 | ||
1142 | /* | |
1143 | * The VFS has no restrictions on reading POSIX ACLs so calling | |
1144 | * something like xattr_permission() isn't needed. Only LSMs get a say. | |
1145 | */ | |
1146 | error = security_inode_get_acl(mnt_userns, dentry, acl_name); | |
1147 | if (error) | |
1148 | return ERR_PTR(error); | |
1149 | ||
1150 | if (!IS_POSIXACL(inode)) | |
1151 | return ERR_PTR(-EOPNOTSUPP); | |
1152 | if (S_ISLNK(inode->i_mode)) | |
1153 | return ERR_PTR(-EOPNOTSUPP); | |
1154 | ||
1155 | acl = __get_acl(mnt_userns, dentry, inode, acl_type); | |
1156 | if (IS_ERR(acl)) | |
1157 | return acl; | |
1158 | if (!acl) | |
1159 | return ERR_PTR(-ENODATA); | |
1160 | ||
1161 | return acl; | |
1162 | } | |
1163 | EXPORT_SYMBOL_GPL(vfs_get_acl); | |
aeb7f005 CB |
1164 | |
1165 | /** | |
1166 | * vfs_remove_acl - remove posix acls | |
1167 | * @mnt_userns: user namespace of the mount | |
1168 | * @dentry: the dentry based on which to retrieve the posix acls | |
1169 | * @acl_name: the name of the posix acl | |
1170 | * | |
1171 | * This function removes posix acls. | |
1172 | * | |
1173 | * Return: On success 0, on error negative errno. | |
1174 | */ | |
1175 | int vfs_remove_acl(struct user_namespace *mnt_userns, struct dentry *dentry, | |
1176 | const char *acl_name) | |
1177 | { | |
1178 | int acl_type; | |
1179 | int error; | |
1180 | struct inode *inode = d_inode(dentry); | |
1181 | struct inode *delegated_inode = NULL; | |
1182 | ||
1183 | acl_type = posix_acl_type(acl_name); | |
1184 | if (acl_type < 0) | |
1185 | return -EINVAL; | |
1186 | ||
1187 | retry_deleg: | |
1188 | inode_lock(inode); | |
1189 | ||
1190 | /* | |
1191 | * We only care about restrictions the inode struct itself places upon | |
1192 | * us otherwise POSIX ACLs aren't subject to any VFS restrictions. | |
1193 | */ | |
1194 | error = may_write_xattr(mnt_userns, inode); | |
1195 | if (error) | |
1196 | goto out_inode_unlock; | |
1197 | ||
1198 | error = security_inode_remove_acl(mnt_userns, dentry, acl_name); | |
1199 | if (error) | |
1200 | goto out_inode_unlock; | |
1201 | ||
1202 | error = try_break_deleg(inode, &delegated_inode); | |
1203 | if (error) | |
1204 | goto out_inode_unlock; | |
1205 | ||
1206 | if (inode->i_opflags & IOP_XATTR) | |
1207 | error = set_posix_acl(mnt_userns, dentry, acl_type, NULL); | |
1208 | else if (unlikely(is_bad_inode(inode))) | |
1209 | error = -EIO; | |
1210 | else | |
1211 | error = -EOPNOTSUPP; | |
1212 | if (!error) { | |
1213 | fsnotify_xattr(dentry); | |
1214 | evm_inode_post_remove_acl(mnt_userns, dentry, acl_name); | |
1215 | } | |
1216 | ||
1217 | out_inode_unlock: | |
1218 | inode_unlock(inode); | |
1219 | ||
1220 | if (delegated_inode) { | |
1221 | error = break_deleg_wait(&delegated_inode); | |
1222 | if (!error) | |
1223 | goto retry_deleg; | |
1224 | } | |
1225 | ||
1226 | return error; | |
1227 | } | |
1228 | EXPORT_SYMBOL_GPL(vfs_remove_acl); | |
318e6685 CB |
1229 | |
1230 | int do_set_acl(struct user_namespace *mnt_userns, struct dentry *dentry, | |
1231 | const char *acl_name, const void *kvalue, size_t size) | |
1232 | { | |
1233 | int error; | |
1234 | struct posix_acl *acl = NULL; | |
1235 | ||
1236 | if (size) { | |
1237 | /* | |
1238 | * Note that posix_acl_from_xattr() uses GFP_NOFS when it | |
1239 | * probably doesn't need to here. | |
1240 | */ | |
1241 | acl = posix_acl_from_xattr(current_user_ns(), kvalue, size); | |
1242 | if (IS_ERR(acl)) | |
1243 | return PTR_ERR(acl); | |
1244 | } | |
1245 | ||
1246 | error = vfs_set_acl(mnt_userns, dentry, acl_name, acl); | |
1247 | posix_acl_release(acl); | |
1248 | return error; | |
1249 | } | |
1250 | ||
1251 | ssize_t do_get_acl(struct user_namespace *mnt_userns, struct dentry *dentry, | |
1252 | const char *acl_name, void *kvalue, size_t size) | |
1253 | { | |
1254 | ssize_t error; | |
1255 | struct posix_acl *acl; | |
1256 | ||
1257 | acl = vfs_get_acl(mnt_userns, dentry, acl_name); | |
1258 | if (IS_ERR(acl)) | |
1259 | return PTR_ERR(acl); | |
1260 | ||
1261 | error = vfs_posix_acl_to_xattr(mnt_userns, d_inode(dentry), | |
1262 | acl, kvalue, size); | |
1263 | posix_acl_release(acl); | |
1264 | return error; | |
1265 | } |