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> | |
5970e15d | 31 | #include <linux/filelock.h> |
e4cc9163 CB |
32 | |
33 | #include "internal.h" | |
1da177e4 | 34 | |
04c57f45 | 35 | static struct posix_acl **acl_by_type(struct inode *inode, int type) |
0afaa120 AM |
36 | { |
37 | switch (type) { | |
38 | case ACL_TYPE_ACCESS: | |
39 | return &inode->i_acl; | |
40 | case ACL_TYPE_DEFAULT: | |
41 | return &inode->i_default_acl; | |
42 | default: | |
43 | BUG(); | |
44 | } | |
45 | } | |
0afaa120 AM |
46 | |
47 | struct posix_acl *get_cached_acl(struct inode *inode, int type) | |
48 | { | |
49 | struct posix_acl **p = acl_by_type(inode, type); | |
b8a7a3a6 AG |
50 | struct posix_acl *acl; |
51 | ||
52 | for (;;) { | |
53 | rcu_read_lock(); | |
54 | acl = rcu_dereference(*p); | |
55 | if (!acl || is_uncached_acl(acl) || | |
66717260 | 56 | refcount_inc_not_zero(&acl->a_refcount)) |
b8a7a3a6 AG |
57 | break; |
58 | rcu_read_unlock(); | |
59 | cpu_relax(); | |
0afaa120 | 60 | } |
b8a7a3a6 | 61 | rcu_read_unlock(); |
0afaa120 AM |
62 | return acl; |
63 | } | |
64 | EXPORT_SYMBOL(get_cached_acl); | |
65 | ||
66 | struct posix_acl *get_cached_acl_rcu(struct inode *inode, int type) | |
67 | { | |
332f606b MS |
68 | struct posix_acl *acl = rcu_dereference(*acl_by_type(inode, type)); |
69 | ||
70 | if (acl == ACL_DONT_CACHE) { | |
71 | struct posix_acl *ret; | |
72 | ||
cac2f8b8 | 73 | ret = inode->i_op->get_inode_acl(inode, type, LOOKUP_RCU); |
332f606b MS |
74 | if (!IS_ERR(ret)) |
75 | acl = ret; | |
76 | } | |
77 | ||
78 | return acl; | |
0afaa120 AM |
79 | } |
80 | EXPORT_SYMBOL(get_cached_acl_rcu); | |
81 | ||
82 | void set_cached_acl(struct inode *inode, int type, struct posix_acl *acl) | |
83 | { | |
84 | struct posix_acl **p = acl_by_type(inode, type); | |
85 | struct posix_acl *old; | |
b8a7a3a6 AG |
86 | |
87 | old = xchg(p, posix_acl_dup(acl)); | |
88 | if (!is_uncached_acl(old)) | |
0afaa120 AM |
89 | posix_acl_release(old); |
90 | } | |
91 | EXPORT_SYMBOL(set_cached_acl); | |
92 | ||
b8a7a3a6 | 93 | static void __forget_cached_acl(struct posix_acl **p) |
0afaa120 | 94 | { |
0afaa120 | 95 | struct posix_acl *old; |
b8a7a3a6 AG |
96 | |
97 | old = xchg(p, ACL_NOT_CACHED); | |
98 | if (!is_uncached_acl(old)) | |
0afaa120 AM |
99 | posix_acl_release(old); |
100 | } | |
b8a7a3a6 AG |
101 | |
102 | void forget_cached_acl(struct inode *inode, int type) | |
103 | { | |
104 | __forget_cached_acl(acl_by_type(inode, type)); | |
105 | } | |
0afaa120 AM |
106 | EXPORT_SYMBOL(forget_cached_acl); |
107 | ||
108 | void forget_all_cached_acls(struct inode *inode) | |
109 | { | |
b8a7a3a6 AG |
110 | __forget_cached_acl(&inode->i_acl); |
111 | __forget_cached_acl(&inode->i_default_acl); | |
0afaa120 AM |
112 | } |
113 | EXPORT_SYMBOL(forget_all_cached_acls); | |
1da177e4 | 114 | |
77435322 | 115 | static struct posix_acl *__get_acl(struct mnt_idmap *idmap, |
4f353ba4 CB |
116 | struct dentry *dentry, struct inode *inode, |
117 | int type) | |
2982baa2 | 118 | { |
d6fdf29f | 119 | struct posix_acl *sentinel; |
b8a7a3a6 | 120 | struct posix_acl **p; |
2982baa2 CH |
121 | struct posix_acl *acl; |
122 | ||
b8a7a3a6 AG |
123 | /* |
124 | * The sentinel is used to detect when another operation like | |
cac2f8b8 | 125 | * set_cached_acl() or forget_cached_acl() races with get_inode_acl(). |
b8a7a3a6 AG |
126 | * It is guaranteed that is_uncached_acl(sentinel) is true. |
127 | */ | |
128 | ||
2982baa2 | 129 | acl = get_cached_acl(inode, type); |
b8a7a3a6 | 130 | if (!is_uncached_acl(acl)) |
2982baa2 CH |
131 | return acl; |
132 | ||
133 | if (!IS_POSIXACL(inode)) | |
134 | return NULL; | |
135 | ||
b8a7a3a6 AG |
136 | sentinel = uncached_acl_sentinel(current); |
137 | p = acl_by_type(inode, type); | |
138 | ||
139 | /* | |
140 | * If the ACL isn't being read yet, set our sentinel. Otherwise, the | |
141 | * current value of the ACL will not be ACL_NOT_CACHED and so our own | |
142 | * sentinel will not be set; another task will update the cache. We | |
143 | * could wait for that other task to complete its job, but it's easier | |
cac2f8b8 CB |
144 | * to just call ->get_inode_acl to fetch the ACL ourself. (This is |
145 | * going to be an unlikely race.) | |
b8a7a3a6 | 146 | */ |
d1cef29a | 147 | cmpxchg(p, ACL_NOT_CACHED, sentinel); |
b8a7a3a6 | 148 | |
2982baa2 | 149 | /* |
4f353ba4 | 150 | * Normally, the ACL returned by ->get{_inode}_acl will be cached. |
b8a7a3a6 | 151 | * A filesystem can prevent that by calling |
4f353ba4 | 152 | * forget_cached_acl(inode, type) in ->get{_inode}_acl. |
2982baa2 | 153 | * |
4f353ba4 | 154 | * If the filesystem doesn't have a get{_inode}_ acl() function at all, |
cac2f8b8 | 155 | * we'll just create the negative cache entry. |
2982baa2 | 156 | */ |
4f353ba4 | 157 | if (dentry && inode->i_op->get_acl) { |
77435322 | 158 | acl = inode->i_op->get_acl(idmap, dentry, type); |
4f353ba4 CB |
159 | } else if (inode->i_op->get_inode_acl) { |
160 | acl = inode->i_op->get_inode_acl(inode, type, false); | |
161 | } else { | |
2982baa2 CH |
162 | set_cached_acl(inode, type, NULL); |
163 | return NULL; | |
164 | } | |
b8a7a3a6 AG |
165 | if (IS_ERR(acl)) { |
166 | /* | |
167 | * Remove our sentinel so that we don't block future attempts | |
168 | * to cache the ACL. | |
169 | */ | |
170 | cmpxchg(p, sentinel, ACL_NOT_CACHED); | |
171 | return acl; | |
172 | } | |
173 | ||
174 | /* | |
175 | * Cache the result, but only if our sentinel is still in place. | |
176 | */ | |
177 | posix_acl_dup(acl); | |
4e1da8fe | 178 | if (unlikely(!try_cmpxchg(p, &sentinel, acl))) |
b8a7a3a6 AG |
179 | posix_acl_release(acl); |
180 | return acl; | |
2982baa2 | 181 | } |
4f353ba4 CB |
182 | |
183 | struct posix_acl *get_inode_acl(struct inode *inode, int type) | |
184 | { | |
77435322 | 185 | return __get_acl(&nop_mnt_idmap, NULL, inode, type); |
4f353ba4 | 186 | } |
cac2f8b8 | 187 | EXPORT_SYMBOL(get_inode_acl); |
2982baa2 | 188 | |
f61f6da0 CL |
189 | /* |
190 | * Init a fresh posix_acl | |
191 | */ | |
192 | void | |
193 | posix_acl_init(struct posix_acl *acl, int count) | |
194 | { | |
66717260 | 195 | refcount_set(&acl->a_refcount, 1); |
f61f6da0 CL |
196 | acl->a_count = count; |
197 | } | |
0afaa120 | 198 | EXPORT_SYMBOL(posix_acl_init); |
f61f6da0 | 199 | |
1da177e4 LT |
200 | /* |
201 | * Allocate a new ACL with the specified number of entries. | |
202 | */ | |
203 | struct posix_acl * | |
dd0fc66f | 204 | posix_acl_alloc(int count, gfp_t flags) |
1da177e4 LT |
205 | { |
206 | const size_t size = sizeof(struct posix_acl) + | |
207 | count * sizeof(struct posix_acl_entry); | |
208 | struct posix_acl *acl = kmalloc(size, flags); | |
f61f6da0 CL |
209 | if (acl) |
210 | posix_acl_init(acl, count); | |
1da177e4 LT |
211 | return acl; |
212 | } | |
0afaa120 | 213 | EXPORT_SYMBOL(posix_acl_alloc); |
1da177e4 LT |
214 | |
215 | /* | |
216 | * Clone an ACL. | |
217 | */ | |
8043bffd | 218 | struct posix_acl * |
dd0fc66f | 219 | posix_acl_clone(const struct posix_acl *acl, gfp_t flags) |
1da177e4 LT |
220 | { |
221 | struct posix_acl *clone = NULL; | |
222 | ||
223 | if (acl) { | |
224 | int size = sizeof(struct posix_acl) + acl->a_count * | |
225 | sizeof(struct posix_acl_entry); | |
52978be6 AD |
226 | clone = kmemdup(acl, size, flags); |
227 | if (clone) | |
66717260 | 228 | refcount_set(&clone->a_refcount, 1); |
1da177e4 LT |
229 | } |
230 | return clone; | |
231 | } | |
8043bffd | 232 | EXPORT_SYMBOL_GPL(posix_acl_clone); |
1da177e4 LT |
233 | |
234 | /* | |
235 | * Check if an acl is valid. Returns 0 if it is, or -E... otherwise. | |
236 | */ | |
237 | int | |
0d4d717f | 238 | posix_acl_valid(struct user_namespace *user_ns, const struct posix_acl *acl) |
1da177e4 LT |
239 | { |
240 | const struct posix_acl_entry *pa, *pe; | |
241 | int state = ACL_USER_OBJ; | |
1da177e4 LT |
242 | int needs_mask = 0; |
243 | ||
244 | FOREACH_ACL_ENTRY(pa, acl, pe) { | |
245 | if (pa->e_perm & ~(ACL_READ|ACL_WRITE|ACL_EXECUTE)) | |
246 | return -EINVAL; | |
247 | switch (pa->e_tag) { | |
248 | case ACL_USER_OBJ: | |
249 | if (state == ACL_USER_OBJ) { | |
1da177e4 LT |
250 | state = ACL_USER; |
251 | break; | |
252 | } | |
253 | return -EINVAL; | |
254 | ||
255 | case ACL_USER: | |
256 | if (state != ACL_USER) | |
257 | return -EINVAL; | |
0d4d717f | 258 | if (!kuid_has_mapping(user_ns, pa->e_uid)) |
1da177e4 | 259 | return -EINVAL; |
1da177e4 LT |
260 | needs_mask = 1; |
261 | break; | |
262 | ||
263 | case ACL_GROUP_OBJ: | |
264 | if (state == ACL_USER) { | |
1da177e4 LT |
265 | state = ACL_GROUP; |
266 | break; | |
267 | } | |
268 | return -EINVAL; | |
269 | ||
270 | case ACL_GROUP: | |
271 | if (state != ACL_GROUP) | |
272 | return -EINVAL; | |
0d4d717f | 273 | if (!kgid_has_mapping(user_ns, pa->e_gid)) |
2f6f0654 | 274 | return -EINVAL; |
1da177e4 LT |
275 | needs_mask = 1; |
276 | break; | |
277 | ||
278 | case ACL_MASK: | |
279 | if (state != ACL_GROUP) | |
280 | return -EINVAL; | |
281 | state = ACL_OTHER; | |
282 | break; | |
283 | ||
284 | case ACL_OTHER: | |
285 | if (state == ACL_OTHER || | |
286 | (state == ACL_GROUP && !needs_mask)) { | |
287 | state = 0; | |
288 | break; | |
289 | } | |
290 | return -EINVAL; | |
291 | ||
292 | default: | |
293 | return -EINVAL; | |
294 | } | |
295 | } | |
296 | if (state == 0) | |
297 | return 0; | |
298 | return -EINVAL; | |
299 | } | |
0afaa120 | 300 | EXPORT_SYMBOL(posix_acl_valid); |
1da177e4 LT |
301 | |
302 | /* | |
303 | * Returns 0 if the acl can be exactly represented in the traditional | |
304 | * file mode permission bits, or else 1. Returns -E... on error. | |
305 | */ | |
306 | int | |
d6952123 | 307 | posix_acl_equiv_mode(const struct posix_acl *acl, umode_t *mode_p) |
1da177e4 LT |
308 | { |
309 | const struct posix_acl_entry *pa, *pe; | |
d6952123 | 310 | umode_t mode = 0; |
1da177e4 LT |
311 | int not_equiv = 0; |
312 | ||
50c6e282 CH |
313 | /* |
314 | * A null ACL can always be presented as mode bits. | |
315 | */ | |
316 | if (!acl) | |
317 | return 0; | |
318 | ||
1da177e4 LT |
319 | FOREACH_ACL_ENTRY(pa, acl, pe) { |
320 | switch (pa->e_tag) { | |
321 | case ACL_USER_OBJ: | |
322 | mode |= (pa->e_perm & S_IRWXO) << 6; | |
323 | break; | |
324 | case ACL_GROUP_OBJ: | |
325 | mode |= (pa->e_perm & S_IRWXO) << 3; | |
326 | break; | |
327 | case ACL_OTHER: | |
328 | mode |= pa->e_perm & S_IRWXO; | |
329 | break; | |
330 | case ACL_MASK: | |
331 | mode = (mode & ~S_IRWXG) | | |
332 | ((pa->e_perm & S_IRWXO) << 3); | |
333 | not_equiv = 1; | |
334 | break; | |
335 | case ACL_USER: | |
336 | case ACL_GROUP: | |
337 | not_equiv = 1; | |
338 | break; | |
339 | default: | |
340 | return -EINVAL; | |
341 | } | |
342 | } | |
343 | if (mode_p) | |
344 | *mode_p = (*mode_p & ~S_IRWXUGO) | mode; | |
345 | return not_equiv; | |
346 | } | |
0afaa120 | 347 | EXPORT_SYMBOL(posix_acl_equiv_mode); |
1da177e4 LT |
348 | |
349 | /* | |
350 | * Create an ACL representing the file mode permission bits of an inode. | |
351 | */ | |
352 | struct posix_acl * | |
3a5fba19 | 353 | posix_acl_from_mode(umode_t mode, gfp_t flags) |
1da177e4 LT |
354 | { |
355 | struct posix_acl *acl = posix_acl_alloc(3, flags); | |
356 | if (!acl) | |
357 | return ERR_PTR(-ENOMEM); | |
358 | ||
359 | acl->a_entries[0].e_tag = ACL_USER_OBJ; | |
1da177e4 LT |
360 | acl->a_entries[0].e_perm = (mode & S_IRWXU) >> 6; |
361 | ||
362 | acl->a_entries[1].e_tag = ACL_GROUP_OBJ; | |
1da177e4 LT |
363 | acl->a_entries[1].e_perm = (mode & S_IRWXG) >> 3; |
364 | ||
365 | acl->a_entries[2].e_tag = ACL_OTHER; | |
1da177e4 LT |
366 | acl->a_entries[2].e_perm = (mode & S_IRWXO); |
367 | return acl; | |
368 | } | |
0afaa120 | 369 | EXPORT_SYMBOL(posix_acl_from_mode); |
1da177e4 LT |
370 | |
371 | /* | |
372 | * Return 0 if current is granted want access to the inode | |
373 | * by the acl. Returns -E... otherwise. | |
374 | */ | |
375 | int | |
700b7940 | 376 | posix_acl_permission(struct mnt_idmap *idmap, struct inode *inode, |
47291baa | 377 | const struct posix_acl *acl, int want) |
1da177e4 LT |
378 | { |
379 | const struct posix_acl_entry *pa, *pe, *mask_obj; | |
abfcf55d | 380 | struct user_namespace *fs_userns = i_user_ns(inode); |
1da177e4 | 381 | int found = 0; |
e933c15f CB |
382 | vfsuid_t vfsuid; |
383 | vfsgid_t vfsgid; | |
1da177e4 | 384 | |
63d72b93 | 385 | want &= MAY_READ | MAY_WRITE | MAY_EXEC; |
d124b60a | 386 | |
1da177e4 LT |
387 | FOREACH_ACL_ENTRY(pa, acl, pe) { |
388 | switch(pa->e_tag) { | |
389 | case ACL_USER_OBJ: | |
390 | /* (May have been checked already) */ | |
e67fe633 | 391 | vfsuid = i_uid_into_vfsuid(idmap, inode); |
e933c15f | 392 | if (vfsuid_eq_kuid(vfsuid, current_fsuid())) |
1da177e4 LT |
393 | goto check_perm; |
394 | break; | |
395 | case ACL_USER: | |
4d7ca409 | 396 | vfsuid = make_vfsuid(idmap, fs_userns, |
bd303368 | 397 | pa->e_uid); |
e933c15f | 398 | if (vfsuid_eq_kuid(vfsuid, current_fsuid())) |
1da177e4 LT |
399 | goto mask; |
400 | break; | |
401 | case ACL_GROUP_OBJ: | |
e67fe633 | 402 | vfsgid = i_gid_into_vfsgid(idmap, inode); |
e933c15f | 403 | if (vfsgid_in_group_p(vfsgid)) { |
1da177e4 LT |
404 | found = 1; |
405 | if ((pa->e_perm & want) == want) | |
406 | goto mask; | |
407 | } | |
408 | break; | |
409 | case ACL_GROUP: | |
4d7ca409 | 410 | vfsgid = make_vfsgid(idmap, fs_userns, |
bd303368 | 411 | pa->e_gid); |
e933c15f | 412 | if (vfsgid_in_group_p(vfsgid)) { |
1da177e4 LT |
413 | found = 1; |
414 | if ((pa->e_perm & want) == want) | |
415 | goto mask; | |
416 | } | |
417 | break; | |
418 | case ACL_MASK: | |
419 | break; | |
420 | case ACL_OTHER: | |
421 | if (found) | |
422 | return -EACCES; | |
423 | else | |
424 | goto check_perm; | |
425 | default: | |
426 | return -EIO; | |
427 | } | |
428 | } | |
429 | return -EIO; | |
430 | ||
431 | mask: | |
432 | for (mask_obj = pa+1; mask_obj != pe; mask_obj++) { | |
433 | if (mask_obj->e_tag == ACL_MASK) { | |
434 | if ((pa->e_perm & mask_obj->e_perm & want) == want) | |
435 | return 0; | |
436 | return -EACCES; | |
437 | } | |
438 | } | |
439 | ||
440 | check_perm: | |
441 | if ((pa->e_perm & want) == want) | |
442 | return 0; | |
443 | return -EACCES; | |
444 | } | |
445 | ||
446 | /* | |
447 | * Modify acl when creating a new inode. The caller must ensure the acl is | |
448 | * only referenced once. | |
449 | * | |
450 | * mode_p initially must contain the mode parameter to the open() / creat() | |
451 | * system calls. All permissions that are not granted by the acl are removed. | |
452 | * The permissions in the acl are changed to reflect the mode_p parameter. | |
453 | */ | |
d3fb6120 | 454 | static int posix_acl_create_masq(struct posix_acl *acl, umode_t *mode_p) |
1da177e4 LT |
455 | { |
456 | struct posix_acl_entry *pa, *pe; | |
457 | struct posix_acl_entry *group_obj = NULL, *mask_obj = NULL; | |
d3fb6120 | 458 | umode_t mode = *mode_p; |
1da177e4 LT |
459 | int not_equiv = 0; |
460 | ||
461 | /* assert(atomic_read(acl->a_refcount) == 1); */ | |
462 | ||
463 | FOREACH_ACL_ENTRY(pa, acl, pe) { | |
464 | switch(pa->e_tag) { | |
465 | case ACL_USER_OBJ: | |
466 | pa->e_perm &= (mode >> 6) | ~S_IRWXO; | |
467 | mode &= (pa->e_perm << 6) | ~S_IRWXU; | |
468 | break; | |
469 | ||
470 | case ACL_USER: | |
471 | case ACL_GROUP: | |
472 | not_equiv = 1; | |
473 | break; | |
474 | ||
475 | case ACL_GROUP_OBJ: | |
476 | group_obj = pa; | |
477 | break; | |
478 | ||
479 | case ACL_OTHER: | |
480 | pa->e_perm &= mode | ~S_IRWXO; | |
481 | mode &= pa->e_perm | ~S_IRWXO; | |
482 | break; | |
483 | ||
484 | case ACL_MASK: | |
485 | mask_obj = pa; | |
486 | not_equiv = 1; | |
487 | break; | |
488 | ||
489 | default: | |
490 | return -EIO; | |
491 | } | |
492 | } | |
493 | ||
494 | if (mask_obj) { | |
495 | mask_obj->e_perm &= (mode >> 3) | ~S_IRWXO; | |
496 | mode &= (mask_obj->e_perm << 3) | ~S_IRWXG; | |
497 | } else { | |
498 | if (!group_obj) | |
499 | return -EIO; | |
500 | group_obj->e_perm &= (mode >> 3) | ~S_IRWXO; | |
501 | mode &= (group_obj->e_perm << 3) | ~S_IRWXG; | |
502 | } | |
503 | ||
504 | *mode_p = (*mode_p & ~S_IRWXUGO) | mode; | |
505 | return not_equiv; | |
506 | } | |
507 | ||
508 | /* | |
509 | * Modify the ACL for the chmod syscall. | |
510 | */ | |
5bf3258f | 511 | static int __posix_acl_chmod_masq(struct posix_acl *acl, umode_t mode) |
1da177e4 LT |
512 | { |
513 | struct posix_acl_entry *group_obj = NULL, *mask_obj = NULL; | |
514 | struct posix_acl_entry *pa, *pe; | |
515 | ||
516 | /* assert(atomic_read(acl->a_refcount) == 1); */ | |
517 | ||
518 | FOREACH_ACL_ENTRY(pa, acl, pe) { | |
519 | switch(pa->e_tag) { | |
520 | case ACL_USER_OBJ: | |
521 | pa->e_perm = (mode & S_IRWXU) >> 6; | |
522 | break; | |
523 | ||
524 | case ACL_USER: | |
525 | case ACL_GROUP: | |
526 | break; | |
527 | ||
528 | case ACL_GROUP_OBJ: | |
529 | group_obj = pa; | |
530 | break; | |
531 | ||
532 | case ACL_MASK: | |
533 | mask_obj = pa; | |
534 | break; | |
535 | ||
536 | case ACL_OTHER: | |
537 | pa->e_perm = (mode & S_IRWXO); | |
538 | break; | |
539 | ||
540 | default: | |
541 | return -EIO; | |
542 | } | |
543 | } | |
544 | ||
545 | if (mask_obj) { | |
546 | mask_obj->e_perm = (mode & S_IRWXG) >> 3; | |
547 | } else { | |
548 | if (!group_obj) | |
549 | return -EIO; | |
550 | group_obj->e_perm = (mode & S_IRWXG) >> 3; | |
551 | } | |
552 | ||
553 | return 0; | |
554 | } | |
bc26ab5f | 555 | |
826cae2f | 556 | int |
37bc1539 | 557 | __posix_acl_create(struct posix_acl **acl, gfp_t gfp, umode_t *mode_p) |
826cae2f AV |
558 | { |
559 | struct posix_acl *clone = posix_acl_clone(*acl, gfp); | |
560 | int err = -ENOMEM; | |
561 | if (clone) { | |
562 | err = posix_acl_create_masq(clone, mode_p); | |
563 | if (err < 0) { | |
564 | posix_acl_release(clone); | |
565 | clone = NULL; | |
566 | } | |
567 | } | |
568 | posix_acl_release(*acl); | |
569 | *acl = clone; | |
570 | return err; | |
571 | } | |
37bc1539 | 572 | EXPORT_SYMBOL(__posix_acl_create); |
826cae2f | 573 | |
bc26ab5f | 574 | int |
5bf3258f | 575 | __posix_acl_chmod(struct posix_acl **acl, gfp_t gfp, umode_t mode) |
bc26ab5f AV |
576 | { |
577 | struct posix_acl *clone = posix_acl_clone(*acl, gfp); | |
578 | int err = -ENOMEM; | |
579 | if (clone) { | |
5bf3258f | 580 | err = __posix_acl_chmod_masq(clone, mode); |
bc26ab5f AV |
581 | if (err) { |
582 | posix_acl_release(clone); | |
583 | clone = NULL; | |
584 | } | |
585 | } | |
586 | posix_acl_release(*acl); | |
587 | *acl = clone; | |
588 | return err; | |
589 | } | |
5bf3258f CH |
590 | EXPORT_SYMBOL(__posix_acl_chmod); |
591 | ||
e65ce2a5 CB |
592 | /** |
593 | * posix_acl_chmod - chmod a posix acl | |
594 | * | |
13e83a49 | 595 | * @idmap: idmap of the mount @inode was found from |
138060ba | 596 | * @dentry: dentry to check permissions on |
e65ce2a5 CB |
597 | * @mode: the new mode of @inode |
598 | * | |
13e83a49 CB |
599 | * If the dentry has been found through an idmapped mount the idmap of |
600 | * the vfsmount must be passed through @idmap. This function will then | |
601 | * take care to map the inode according to @idmap before checking | |
e65ce2a5 | 602 | * permissions. On non-idmapped mounts or if permission checking is to be |
13e83a49 | 603 | * performed on the raw inode simply passs @nop_mnt_idmap. |
e65ce2a5 | 604 | */ |
5bf3258f | 605 | int |
13e83a49 | 606 | posix_acl_chmod(struct mnt_idmap *idmap, struct dentry *dentry, |
e65ce2a5 | 607 | umode_t mode) |
5bf3258f | 608 | { |
138060ba | 609 | struct inode *inode = d_inode(dentry); |
5bf3258f CH |
610 | struct posix_acl *acl; |
611 | int ret = 0; | |
612 | ||
613 | if (!IS_POSIXACL(inode)) | |
614 | return 0; | |
615 | if (!inode->i_op->set_acl) | |
616 | return -EOPNOTSUPP; | |
617 | ||
cac2f8b8 | 618 | acl = get_inode_acl(inode, ACL_TYPE_ACCESS); |
789b663a TM |
619 | if (IS_ERR_OR_NULL(acl)) { |
620 | if (acl == ERR_PTR(-EOPNOTSUPP)) | |
621 | return 0; | |
5bf3258f | 622 | return PTR_ERR(acl); |
789b663a | 623 | } |
5bf3258f | 624 | |
37bc1539 | 625 | ret = __posix_acl_chmod(&acl, GFP_KERNEL, mode); |
5bf3258f CH |
626 | if (ret) |
627 | return ret; | |
13e83a49 | 628 | ret = inode->i_op->set_acl(idmap, dentry, acl, ACL_TYPE_ACCESS); |
5bf3258f CH |
629 | posix_acl_release(acl); |
630 | return ret; | |
631 | } | |
bc26ab5f | 632 | EXPORT_SYMBOL(posix_acl_chmod); |
5c8ebd57 | 633 | |
37bc1539 CH |
634 | int |
635 | posix_acl_create(struct inode *dir, umode_t *mode, | |
636 | struct posix_acl **default_acl, struct posix_acl **acl) | |
637 | { | |
638 | struct posix_acl *p; | |
c0c3a718 | 639 | struct posix_acl *clone; |
37bc1539 CH |
640 | int ret; |
641 | ||
c0c3a718 DC |
642 | *acl = NULL; |
643 | *default_acl = NULL; | |
644 | ||
37bc1539 | 645 | if (S_ISLNK(*mode) || !IS_POSIXACL(dir)) |
c0c3a718 | 646 | return 0; |
37bc1539 | 647 | |
cac2f8b8 | 648 | p = get_inode_acl(dir, ACL_TYPE_DEFAULT); |
c0c3a718 DC |
649 | if (!p || p == ERR_PTR(-EOPNOTSUPP)) { |
650 | *mode &= ~current_umask(); | |
651 | return 0; | |
37bc1539 | 652 | } |
c0c3a718 DC |
653 | if (IS_ERR(p)) |
654 | return PTR_ERR(p); | |
37bc1539 | 655 | |
beaf226b | 656 | ret = -ENOMEM; |
c0c3a718 DC |
657 | clone = posix_acl_clone(p, GFP_NOFS); |
658 | if (!clone) | |
beaf226b | 659 | goto err_release; |
37bc1539 | 660 | |
c0c3a718 | 661 | ret = posix_acl_create_masq(clone, mode); |
fed0b588 | 662 | if (ret < 0) |
beaf226b | 663 | goto err_release_clone; |
37bc1539 | 664 | |
c0c3a718 DC |
665 | if (ret == 0) |
666 | posix_acl_release(clone); | |
667 | else | |
668 | *acl = clone; | |
37bc1539 | 669 | |
c0c3a718 | 670 | if (!S_ISDIR(*mode)) |
37bc1539 | 671 | posix_acl_release(p); |
c0c3a718 | 672 | else |
37bc1539 | 673 | *default_acl = p; |
37bc1539 | 674 | |
37bc1539 | 675 | return 0; |
fed0b588 | 676 | |
beaf226b | 677 | err_release_clone: |
c0c3a718 | 678 | posix_acl_release(clone); |
beaf226b | 679 | err_release: |
fed0b588 | 680 | posix_acl_release(p); |
beaf226b | 681 | return ret; |
37bc1539 CH |
682 | } |
683 | EXPORT_SYMBOL_GPL(posix_acl_create); | |
684 | ||
07393101 JK |
685 | /** |
686 | * posix_acl_update_mode - update mode in set_acl | |
700b7940 | 687 | * @idmap: idmap of the mount @inode was found from |
e65ce2a5 CB |
688 | * @inode: target inode |
689 | * @mode_p: mode (pointer) for update | |
690 | * @acl: acl pointer | |
07393101 JK |
691 | * |
692 | * Update the file mode when setting an ACL: compute the new file permission | |
693 | * bits based on the ACL. In addition, if the ACL is equivalent to the new | |
e39e773a | 694 | * file mode, set *@acl to NULL to indicate that no ACL should be set. |
07393101 | 695 | * |
e39e773a | 696 | * As with chmod, clear the setgid bit if the caller is not in the owning group |
07393101 JK |
697 | * or capable of CAP_FSETID (see inode_change_ok). |
698 | * | |
700b7940 CB |
699 | * If the inode has been found through an idmapped mount the idmap of |
700 | * the vfsmount must be passed through @idmap. This function will then | |
701 | * take care to map the inode according to @idmap before checking | |
e65ce2a5 | 702 | * permissions. On non-idmapped mounts or if permission checking is to be |
700b7940 | 703 | * performed on the raw inode simply passs @nop_mnt_idmap. |
e65ce2a5 | 704 | * |
07393101 JK |
705 | * Called from set_acl inode operations. |
706 | */ | |
700b7940 | 707 | int posix_acl_update_mode(struct mnt_idmap *idmap, |
e65ce2a5 | 708 | struct inode *inode, umode_t *mode_p, |
07393101 JK |
709 | struct posix_acl **acl) |
710 | { | |
711 | umode_t mode = inode->i_mode; | |
712 | int error; | |
713 | ||
714 | error = posix_acl_equiv_mode(*acl, &mode); | |
715 | if (error < 0) | |
716 | return error; | |
717 | if (error == 0) | |
718 | *acl = NULL; | |
e67fe633 | 719 | if (!vfsgid_in_group_p(i_gid_into_vfsgid(idmap, inode)) && |
9452e93e | 720 | !capable_wrt_inode_uidgid(idmap, inode, CAP_FSETID)) |
07393101 JK |
721 | mode &= ~S_ISGID; |
722 | *mode_p = mode; | |
723 | return 0; | |
724 | } | |
725 | EXPORT_SYMBOL(posix_acl_update_mode); | |
726 | ||
5c8ebd57 CH |
727 | /* |
728 | * Fix up the uids and gids in posix acl extended attributes in place. | |
729 | */ | |
985a6d0b | 730 | static int posix_acl_fix_xattr_common(const void *value, size_t size) |
0c5fd887 | 731 | { |
985a6d0b | 732 | const struct posix_acl_xattr_header *header = value; |
0c5fd887 CB |
733 | int count; |
734 | ||
735 | if (!header) | |
736 | return -EINVAL; | |
737 | if (size < sizeof(struct posix_acl_xattr_header)) | |
738 | return -EINVAL; | |
739 | if (header->a_version != cpu_to_le32(POSIX_ACL_XATTR_VERSION)) | |
985a6d0b | 740 | return -EOPNOTSUPP; |
0c5fd887 CB |
741 | |
742 | count = posix_acl_xattr_count(size); | |
743 | if (count < 0) | |
744 | return -EINVAL; | |
745 | if (count == 0) | |
985a6d0b | 746 | return 0; |
0c5fd887 CB |
747 | |
748 | return count; | |
749 | } | |
750 | ||
6b70fe06 | 751 | /** |
0a26bde2 CB |
752 | * posix_acl_from_xattr - convert POSIX ACLs from backing store to VFS format |
753 | * @userns: the filesystem's idmapping | |
6b70fe06 CB |
754 | * @value: the uapi representation of POSIX ACLs |
755 | * @size: the size of @void | |
6b70fe06 | 756 | * |
0a26bde2 CB |
757 | * Filesystems that store POSIX ACLs in the unaltered uapi format should use |
758 | * posix_acl_from_xattr() when reading them from the backing store and | |
759 | * converting them into the struct posix_acl VFS format. The helper is | |
760 | * specifically intended to be called from the acl inode operation. | |
761 | * | |
762 | * The posix_acl_from_xattr() function will map the raw {g,u}id values stored | |
763 | * in ACL_{GROUP,USER} entries into idmapping in @userns. | |
764 | * | |
765 | * Note that posix_acl_from_xattr() does not take idmapped mounts into account. | |
766 | * If it did it calling it from the get acl inode operation would return POSIX | |
767 | * ACLs mapped according to an idmapped mount which would mean that the value | |
768 | * couldn't be cached for the filesystem. Idmapped mounts are taken into | |
769 | * account on the fly during permission checking or right at the VFS - | |
770 | * userspace boundary before reporting them to the user. | |
6b70fe06 CB |
771 | * |
772 | * Return: Allocated struct posix_acl on success, NULL for a valid header but | |
773 | * without actual POSIX ACL entries, or ERR_PTR() encoded error code. | |
5c8ebd57 | 774 | */ |
0a26bde2 CB |
775 | struct posix_acl *posix_acl_from_xattr(struct user_namespace *userns, |
776 | const void *value, size_t size) | |
5c8ebd57 | 777 | { |
2211d5ba AG |
778 | const struct posix_acl_xattr_header *header = value; |
779 | const struct posix_acl_xattr_entry *entry = (const void *)(header + 1), *end; | |
5c8ebd57 CH |
780 | int count; |
781 | struct posix_acl *acl; | |
782 | struct posix_acl_entry *acl_e; | |
783 | ||
985a6d0b | 784 | count = posix_acl_fix_xattr_common(value, size); |
5c8ebd57 | 785 | if (count < 0) |
985a6d0b | 786 | return ERR_PTR(count); |
5c8ebd57 CH |
787 | if (count == 0) |
788 | return NULL; | |
789 | ||
790 | acl = posix_acl_alloc(count, GFP_NOFS); | |
791 | if (!acl) | |
792 | return ERR_PTR(-ENOMEM); | |
793 | acl_e = acl->a_entries; | |
794 | ||
795 | for (end = entry + count; entry != end; acl_e++, entry++) { | |
796 | acl_e->e_tag = le16_to_cpu(entry->e_tag); | |
797 | acl_e->e_perm = le16_to_cpu(entry->e_perm); | |
798 | ||
799 | switch(acl_e->e_tag) { | |
800 | case ACL_USER_OBJ: | |
801 | case ACL_GROUP_OBJ: | |
802 | case ACL_MASK: | |
803 | case ACL_OTHER: | |
804 | break; | |
805 | ||
806 | case ACL_USER: | |
0a26bde2 CB |
807 | acl_e->e_uid = make_kuid(userns, |
808 | le32_to_cpu(entry->e_id)); | |
5c8ebd57 CH |
809 | if (!uid_valid(acl_e->e_uid)) |
810 | goto fail; | |
811 | break; | |
812 | case ACL_GROUP: | |
0a26bde2 CB |
813 | acl_e->e_gid = make_kgid(userns, |
814 | le32_to_cpu(entry->e_id)); | |
5c8ebd57 CH |
815 | if (!gid_valid(acl_e->e_gid)) |
816 | goto fail; | |
817 | break; | |
818 | ||
819 | default: | |
820 | goto fail; | |
821 | } | |
822 | } | |
823 | return acl; | |
824 | ||
825 | fail: | |
826 | posix_acl_release(acl); | |
827 | return ERR_PTR(-EINVAL); | |
828 | } | |
829 | EXPORT_SYMBOL (posix_acl_from_xattr); | |
830 | ||
831 | /* | |
832 | * Convert from in-memory to extended attribute representation. | |
833 | */ | |
834 | int | |
835 | posix_acl_to_xattr(struct user_namespace *user_ns, const struct posix_acl *acl, | |
836 | void *buffer, size_t size) | |
837 | { | |
2211d5ba AG |
838 | struct posix_acl_xattr_header *ext_acl = buffer; |
839 | struct posix_acl_xattr_entry *ext_entry; | |
5c8ebd57 CH |
840 | int real_size, n; |
841 | ||
842 | real_size = posix_acl_xattr_size(acl->a_count); | |
843 | if (!buffer) | |
844 | return real_size; | |
845 | if (real_size > size) | |
846 | return -ERANGE; | |
47ba9734 | 847 | |
2211d5ba | 848 | ext_entry = (void *)(ext_acl + 1); |
5c8ebd57 CH |
849 | ext_acl->a_version = cpu_to_le32(POSIX_ACL_XATTR_VERSION); |
850 | ||
851 | for (n=0; n < acl->a_count; n++, ext_entry++) { | |
852 | const struct posix_acl_entry *acl_e = &acl->a_entries[n]; | |
853 | ext_entry->e_tag = cpu_to_le16(acl_e->e_tag); | |
854 | ext_entry->e_perm = cpu_to_le16(acl_e->e_perm); | |
855 | switch(acl_e->e_tag) { | |
856 | case ACL_USER: | |
857 | ext_entry->e_id = | |
858 | cpu_to_le32(from_kuid(user_ns, acl_e->e_uid)); | |
859 | break; | |
860 | case ACL_GROUP: | |
861 | ext_entry->e_id = | |
862 | cpu_to_le32(from_kgid(user_ns, acl_e->e_gid)); | |
863 | break; | |
864 | default: | |
865 | ext_entry->e_id = cpu_to_le32(ACL_UNDEFINED_ID); | |
866 | break; | |
867 | } | |
868 | } | |
869 | return real_size; | |
870 | } | |
871 | EXPORT_SYMBOL (posix_acl_to_xattr); | |
2aeccbe9 | 872 | |
4f353ba4 CB |
873 | /** |
874 | * vfs_posix_acl_to_xattr - convert from kernel to userspace representation | |
5a6f52d2 | 875 | * @idmap: idmap of the mount |
4f353ba4 CB |
876 | * @inode: inode the posix acls are set on |
877 | * @acl: the posix acls as represented by the vfs | |
878 | * @buffer: the buffer into which to convert @acl | |
879 | * @size: size of @buffer | |
880 | * | |
881 | * This converts @acl from the VFS representation in the filesystem idmapping | |
882 | * to the uapi form reportable to userspace. And mount and caller idmappings | |
883 | * are handled appropriately. | |
884 | * | |
885 | * Return: On success, the size of the stored uapi posix acls, on error a | |
886 | * negative errno. | |
887 | */ | |
5a6f52d2 | 888 | static ssize_t vfs_posix_acl_to_xattr(struct mnt_idmap *idmap, |
a351b1f4 CB |
889 | struct inode *inode, |
890 | const struct posix_acl *acl, void *buffer, | |
891 | size_t size) | |
4f353ba4 CB |
892 | |
893 | { | |
894 | struct posix_acl_xattr_header *ext_acl = buffer; | |
895 | struct posix_acl_xattr_entry *ext_entry; | |
896 | struct user_namespace *fs_userns, *caller_userns; | |
897 | ssize_t real_size, n; | |
898 | vfsuid_t vfsuid; | |
899 | vfsgid_t vfsgid; | |
900 | ||
901 | real_size = posix_acl_xattr_size(acl->a_count); | |
902 | if (!buffer) | |
903 | return real_size; | |
904 | if (real_size > size) | |
905 | return -ERANGE; | |
906 | ||
907 | ext_entry = (void *)(ext_acl + 1); | |
908 | ext_acl->a_version = cpu_to_le32(POSIX_ACL_XATTR_VERSION); | |
909 | ||
910 | fs_userns = i_user_ns(inode); | |
911 | caller_userns = current_user_ns(); | |
912 | for (n=0; n < acl->a_count; n++, ext_entry++) { | |
913 | const struct posix_acl_entry *acl_e = &acl->a_entries[n]; | |
914 | ext_entry->e_tag = cpu_to_le16(acl_e->e_tag); | |
915 | ext_entry->e_perm = cpu_to_le16(acl_e->e_perm); | |
916 | switch(acl_e->e_tag) { | |
917 | case ACL_USER: | |
4d7ca409 | 918 | vfsuid = make_vfsuid(idmap, fs_userns, acl_e->e_uid); |
4f353ba4 CB |
919 | ext_entry->e_id = cpu_to_le32(from_kuid( |
920 | caller_userns, vfsuid_into_kuid(vfsuid))); | |
921 | break; | |
922 | case ACL_GROUP: | |
4d7ca409 | 923 | vfsgid = make_vfsgid(idmap, fs_userns, acl_e->e_gid); |
4f353ba4 CB |
924 | ext_entry->e_id = cpu_to_le32(from_kgid( |
925 | caller_userns, vfsgid_into_kgid(vfsgid))); | |
926 | break; | |
927 | default: | |
928 | ext_entry->e_id = cpu_to_le32(ACL_UNDEFINED_ID); | |
929 | break; | |
930 | } | |
931 | } | |
932 | return real_size; | |
933 | } | |
934 | ||
485e71e8 | 935 | int |
13e83a49 | 936 | set_posix_acl(struct mnt_idmap *idmap, struct dentry *dentry, |
e65ce2a5 | 937 | int type, struct posix_acl *acl) |
2aeccbe9 | 938 | { |
138060ba CB |
939 | struct inode *inode = d_inode(dentry); |
940 | ||
2aeccbe9 CH |
941 | if (!IS_POSIXACL(inode)) |
942 | return -EOPNOTSUPP; | |
943 | if (!inode->i_op->set_acl) | |
944 | return -EOPNOTSUPP; | |
945 | ||
485e71e8 AG |
946 | if (type == ACL_TYPE_DEFAULT && !S_ISDIR(inode->i_mode)) |
947 | return acl ? -EACCES : 0; | |
01beba79 | 948 | if (!inode_owner_or_capable(idmap, inode)) |
2aeccbe9 CH |
949 | return -EPERM; |
950 | ||
485e71e8 | 951 | if (acl) { |
a867d734 | 952 | int ret = posix_acl_valid(inode->i_sb->s_user_ns, acl); |
485e71e8 AG |
953 | if (ret) |
954 | return ret; | |
955 | } | |
13e83a49 | 956 | return inode->i_op->set_acl(idmap, dentry, acl, type); |
485e71e8 AG |
957 | } |
958 | EXPORT_SYMBOL(set_posix_acl); | |
959 | ||
f2620f16 CB |
960 | int posix_acl_listxattr(struct inode *inode, char **buffer, |
961 | ssize_t *remaining_size) | |
962 | { | |
963 | int err; | |
964 | ||
965 | if (!IS_POSIXACL(inode)) | |
966 | return 0; | |
967 | ||
968 | if (inode->i_acl) { | |
969 | err = xattr_list_one(buffer, remaining_size, | |
970 | XATTR_NAME_POSIX_ACL_ACCESS); | |
971 | if (err) | |
972 | return err; | |
973 | } | |
974 | ||
975 | if (inode->i_default_acl) { | |
976 | err = xattr_list_one(buffer, remaining_size, | |
977 | XATTR_NAME_POSIX_ACL_DEFAULT); | |
978 | if (err) | |
979 | return err; | |
980 | } | |
981 | ||
982 | return 0; | |
983 | } | |
984 | ||
764a5c6b AG |
985 | static bool |
986 | posix_acl_xattr_list(struct dentry *dentry) | |
2aeccbe9 | 987 | { |
764a5c6b | 988 | return IS_POSIXACL(d_backing_inode(dentry)); |
2aeccbe9 CH |
989 | } |
990 | ||
d549b741 CB |
991 | /* |
992 | * nop_posix_acl_access - legacy xattr handler for access POSIX ACLs | |
993 | * | |
994 | * This is the legacy POSIX ACL access xattr handler. It is used by some | |
995 | * filesystems to implement their ->listxattr() inode operation. New code | |
996 | * should never use them. | |
997 | */ | |
998 | const struct xattr_handler nop_posix_acl_access = { | |
98e9cb57 | 999 | .name = XATTR_NAME_POSIX_ACL_ACCESS, |
2aeccbe9 | 1000 | .list = posix_acl_xattr_list, |
2aeccbe9 | 1001 | }; |
d549b741 | 1002 | EXPORT_SYMBOL_GPL(nop_posix_acl_access); |
2aeccbe9 | 1003 | |
d549b741 CB |
1004 | /* |
1005 | * nop_posix_acl_default - legacy xattr handler for default POSIX ACLs | |
1006 | * | |
1007 | * This is the legacy POSIX ACL default xattr handler. It is used by some | |
1008 | * filesystems to implement their ->listxattr() inode operation. New code | |
1009 | * should never use them. | |
1010 | */ | |
1011 | const struct xattr_handler nop_posix_acl_default = { | |
98e9cb57 | 1012 | .name = XATTR_NAME_POSIX_ACL_DEFAULT, |
2aeccbe9 | 1013 | .list = posix_acl_xattr_list, |
2aeccbe9 | 1014 | }; |
d549b741 | 1015 | EXPORT_SYMBOL_GPL(nop_posix_acl_default); |
feda821e | 1016 | |
13e83a49 | 1017 | int simple_set_acl(struct mnt_idmap *idmap, struct dentry *dentry, |
549c7297 | 1018 | struct posix_acl *acl, int type) |
feda821e CH |
1019 | { |
1020 | int error; | |
138060ba | 1021 | struct inode *inode = d_inode(dentry); |
feda821e CH |
1022 | |
1023 | if (type == ACL_TYPE_ACCESS) { | |
700b7940 | 1024 | error = posix_acl_update_mode(idmap, inode, |
497de07d GZ |
1025 | &inode->i_mode, &acl); |
1026 | if (error) | |
1027 | return error; | |
feda821e CH |
1028 | } |
1029 | ||
2276e5ba | 1030 | inode_set_ctime_current(inode); |
36f05cab JL |
1031 | if (IS_I_VERSION(inode)) |
1032 | inode_inc_iversion(inode); | |
feda821e CH |
1033 | set_cached_acl(inode, type, acl); |
1034 | return 0; | |
1035 | } | |
1036 | ||
1037 | int simple_acl_create(struct inode *dir, struct inode *inode) | |
1038 | { | |
1039 | struct posix_acl *default_acl, *acl; | |
1040 | int error; | |
1041 | ||
1042 | error = posix_acl_create(dir, &inode->i_mode, &default_acl, &acl); | |
1043 | if (error) | |
1044 | return error; | |
1045 | ||
1046 | set_cached_acl(inode, ACL_TYPE_DEFAULT, default_acl); | |
1047 | set_cached_acl(inode, ACL_TYPE_ACCESS, acl); | |
1048 | ||
1049 | if (default_acl) | |
1050 | posix_acl_release(default_acl); | |
1051 | if (acl) | |
1052 | posix_acl_release(acl); | |
1053 | return 0; | |
1054 | } | |
e4cc9163 | 1055 | |
700b7940 | 1056 | static int vfs_set_acl_idmapped_mnt(struct mnt_idmap *idmap, |
e4cc9163 CB |
1057 | struct user_namespace *fs_userns, |
1058 | struct posix_acl *acl) | |
1059 | { | |
1060 | for (int n = 0; n < acl->a_count; n++) { | |
1061 | struct posix_acl_entry *acl_e = &acl->a_entries[n]; | |
1062 | ||
1063 | switch (acl_e->e_tag) { | |
1064 | case ACL_USER: | |
4d7ca409 | 1065 | acl_e->e_uid = from_vfsuid(idmap, fs_userns, |
e4cc9163 CB |
1066 | VFSUIDT_INIT(acl_e->e_uid)); |
1067 | break; | |
1068 | case ACL_GROUP: | |
4d7ca409 | 1069 | acl_e->e_gid = from_vfsgid(idmap, fs_userns, |
e4cc9163 CB |
1070 | VFSGIDT_INIT(acl_e->e_gid)); |
1071 | break; | |
1072 | } | |
1073 | } | |
1074 | ||
1075 | return 0; | |
1076 | } | |
1077 | ||
1078 | /** | |
1079 | * vfs_set_acl - set posix acls | |
13e83a49 | 1080 | * @idmap: idmap of the mount |
e4cc9163 CB |
1081 | * @dentry: the dentry based on which to set the posix acls |
1082 | * @acl_name: the name of the posix acl | |
1083 | * @kacl: the posix acls in the appropriate VFS format | |
1084 | * | |
1085 | * This function sets @kacl. The caller must all posix_acl_release() on @kacl | |
1086 | * afterwards. | |
1087 | * | |
1088 | * Return: On success 0, on error negative errno. | |
1089 | */ | |
13e83a49 | 1090 | int vfs_set_acl(struct mnt_idmap *idmap, struct dentry *dentry, |
e4cc9163 CB |
1091 | const char *acl_name, struct posix_acl *kacl) |
1092 | { | |
1093 | int acl_type; | |
1094 | int error; | |
1095 | struct inode *inode = d_inode(dentry); | |
1096 | struct inode *delegated_inode = NULL; | |
1097 | ||
1098 | acl_type = posix_acl_type(acl_name); | |
1099 | if (acl_type < 0) | |
1100 | return -EINVAL; | |
1101 | ||
1102 | if (kacl) { | |
1103 | /* | |
1104 | * If we're on an idmapped mount translate from mount specific | |
1105 | * vfs{g,u}id_t into global filesystem k{g,u}id_t. | |
1106 | * Afterwards we can cache the POSIX ACLs filesystem wide and - | |
1107 | * if this is a filesystem with a backing store - ultimately | |
1108 | * translate them to backing store values. | |
1109 | */ | |
700b7940 | 1110 | error = vfs_set_acl_idmapped_mnt(idmap, i_user_ns(inode), kacl); |
e4cc9163 CB |
1111 | if (error) |
1112 | return error; | |
1113 | } | |
1114 | ||
1115 | retry_deleg: | |
1116 | inode_lock(inode); | |
1117 | ||
1118 | /* | |
1119 | * We only care about restrictions the inode struct itself places upon | |
1120 | * us otherwise POSIX ACLs aren't subject to any VFS restrictions. | |
1121 | */ | |
4609e1f1 | 1122 | error = may_write_xattr(idmap, inode); |
e4cc9163 CB |
1123 | if (error) |
1124 | goto out_inode_unlock; | |
1125 | ||
700b7940 | 1126 | error = security_inode_set_acl(idmap, dentry, acl_name, kacl); |
e4cc9163 CB |
1127 | if (error) |
1128 | goto out_inode_unlock; | |
1129 | ||
1130 | error = try_break_deleg(inode, &delegated_inode); | |
1131 | if (error) | |
1132 | goto out_inode_unlock; | |
1133 | ||
e499214c | 1134 | if (likely(!is_bad_inode(inode))) |
13e83a49 | 1135 | error = set_posix_acl(idmap, dentry, acl_type, kacl); |
e4cc9163 | 1136 | else |
e499214c | 1137 | error = -EIO; |
e4cc9163 CB |
1138 | if (!error) { |
1139 | fsnotify_xattr(dentry); | |
1140 | evm_inode_post_set_acl(dentry, acl_name, kacl); | |
1141 | } | |
1142 | ||
1143 | out_inode_unlock: | |
1144 | inode_unlock(inode); | |
1145 | ||
1146 | if (delegated_inode) { | |
1147 | error = break_deleg_wait(&delegated_inode); | |
1148 | if (!error) | |
1149 | goto retry_deleg; | |
1150 | } | |
1151 | ||
1152 | return error; | |
1153 | } | |
1154 | EXPORT_SYMBOL_GPL(vfs_set_acl); | |
4f353ba4 CB |
1155 | |
1156 | /** | |
1157 | * vfs_get_acl - get posix acls | |
77435322 | 1158 | * @idmap: idmap of the mount |
4f353ba4 CB |
1159 | * @dentry: the dentry based on which to retrieve the posix acls |
1160 | * @acl_name: the name of the posix acl | |
1161 | * | |
1162 | * This function retrieves @kacl from the filesystem. The caller must all | |
1163 | * posix_acl_release() on @kacl. | |
1164 | * | |
1165 | * Return: On success POSIX ACLs in VFS format, on error negative errno. | |
1166 | */ | |
77435322 | 1167 | struct posix_acl *vfs_get_acl(struct mnt_idmap *idmap, |
4f353ba4 CB |
1168 | struct dentry *dentry, const char *acl_name) |
1169 | { | |
1170 | struct inode *inode = d_inode(dentry); | |
1171 | struct posix_acl *acl; | |
1172 | int acl_type, error; | |
1173 | ||
1174 | acl_type = posix_acl_type(acl_name); | |
1175 | if (acl_type < 0) | |
1176 | return ERR_PTR(-EINVAL); | |
1177 | ||
1178 | /* | |
1179 | * The VFS has no restrictions on reading POSIX ACLs so calling | |
1180 | * something like xattr_permission() isn't needed. Only LSMs get a say. | |
1181 | */ | |
700b7940 | 1182 | error = security_inode_get_acl(idmap, dentry, acl_name); |
4f353ba4 CB |
1183 | if (error) |
1184 | return ERR_PTR(error); | |
1185 | ||
1186 | if (!IS_POSIXACL(inode)) | |
1187 | return ERR_PTR(-EOPNOTSUPP); | |
1188 | if (S_ISLNK(inode->i_mode)) | |
1189 | return ERR_PTR(-EOPNOTSUPP); | |
1190 | ||
77435322 | 1191 | acl = __get_acl(idmap, dentry, inode, acl_type); |
4f353ba4 CB |
1192 | if (IS_ERR(acl)) |
1193 | return acl; | |
1194 | if (!acl) | |
1195 | return ERR_PTR(-ENODATA); | |
1196 | ||
1197 | return acl; | |
1198 | } | |
1199 | EXPORT_SYMBOL_GPL(vfs_get_acl); | |
aeb7f005 CB |
1200 | |
1201 | /** | |
1202 | * vfs_remove_acl - remove posix acls | |
13e83a49 | 1203 | * @idmap: idmap of the mount |
aeb7f005 CB |
1204 | * @dentry: the dentry based on which to retrieve the posix acls |
1205 | * @acl_name: the name of the posix acl | |
1206 | * | |
1207 | * This function removes posix acls. | |
1208 | * | |
1209 | * Return: On success 0, on error negative errno. | |
1210 | */ | |
13e83a49 | 1211 | int vfs_remove_acl(struct mnt_idmap *idmap, struct dentry *dentry, |
aeb7f005 CB |
1212 | const char *acl_name) |
1213 | { | |
1214 | int acl_type; | |
1215 | int error; | |
1216 | struct inode *inode = d_inode(dentry); | |
1217 | struct inode *delegated_inode = NULL; | |
1218 | ||
1219 | acl_type = posix_acl_type(acl_name); | |
1220 | if (acl_type < 0) | |
1221 | return -EINVAL; | |
1222 | ||
1223 | retry_deleg: | |
1224 | inode_lock(inode); | |
1225 | ||
1226 | /* | |
1227 | * We only care about restrictions the inode struct itself places upon | |
1228 | * us otherwise POSIX ACLs aren't subject to any VFS restrictions. | |
1229 | */ | |
4609e1f1 | 1230 | error = may_write_xattr(idmap, inode); |
aeb7f005 CB |
1231 | if (error) |
1232 | goto out_inode_unlock; | |
1233 | ||
700b7940 | 1234 | error = security_inode_remove_acl(idmap, dentry, acl_name); |
aeb7f005 CB |
1235 | if (error) |
1236 | goto out_inode_unlock; | |
1237 | ||
1238 | error = try_break_deleg(inode, &delegated_inode); | |
1239 | if (error) | |
1240 | goto out_inode_unlock; | |
1241 | ||
e499214c | 1242 | if (likely(!is_bad_inode(inode))) |
13e83a49 | 1243 | error = set_posix_acl(idmap, dentry, acl_type, NULL); |
aeb7f005 | 1244 | else |
e499214c | 1245 | error = -EIO; |
aeb7f005 CB |
1246 | if (!error) { |
1247 | fsnotify_xattr(dentry); | |
700b7940 | 1248 | evm_inode_post_remove_acl(idmap, dentry, acl_name); |
aeb7f005 CB |
1249 | } |
1250 | ||
1251 | out_inode_unlock: | |
1252 | inode_unlock(inode); | |
1253 | ||
1254 | if (delegated_inode) { | |
1255 | error = break_deleg_wait(&delegated_inode); | |
1256 | if (!error) | |
1257 | goto retry_deleg; | |
1258 | } | |
1259 | ||
1260 | return error; | |
1261 | } | |
1262 | EXPORT_SYMBOL_GPL(vfs_remove_acl); | |
318e6685 | 1263 | |
5a6f52d2 | 1264 | int do_set_acl(struct mnt_idmap *idmap, struct dentry *dentry, |
318e6685 CB |
1265 | const char *acl_name, const void *kvalue, size_t size) |
1266 | { | |
1267 | int error; | |
1268 | struct posix_acl *acl = NULL; | |
1269 | ||
1270 | if (size) { | |
1271 | /* | |
1272 | * Note that posix_acl_from_xattr() uses GFP_NOFS when it | |
1273 | * probably doesn't need to here. | |
1274 | */ | |
1275 | acl = posix_acl_from_xattr(current_user_ns(), kvalue, size); | |
1276 | if (IS_ERR(acl)) | |
1277 | return PTR_ERR(acl); | |
1278 | } | |
1279 | ||
13e83a49 | 1280 | error = vfs_set_acl(idmap, dentry, acl_name, acl); |
318e6685 CB |
1281 | posix_acl_release(acl); |
1282 | return error; | |
1283 | } | |
1284 | ||
5a6f52d2 | 1285 | ssize_t do_get_acl(struct mnt_idmap *idmap, struct dentry *dentry, |
318e6685 CB |
1286 | const char *acl_name, void *kvalue, size_t size) |
1287 | { | |
1288 | ssize_t error; | |
1289 | struct posix_acl *acl; | |
1290 | ||
77435322 | 1291 | acl = vfs_get_acl(idmap, dentry, acl_name); |
318e6685 CB |
1292 | if (IS_ERR(acl)) |
1293 | return PTR_ERR(acl); | |
1294 | ||
5a6f52d2 | 1295 | error = vfs_posix_acl_to_xattr(idmap, d_inode(dentry), |
318e6685 CB |
1296 | acl, kvalue, size); |
1297 | posix_acl_release(acl); | |
1298 | return error; | |
1299 | } |