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Commit | Line | Data |
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457c8996 | 1 | // SPDX-License-Identifier: GPL-2.0-only |
1da177e4 LT |
2 | /* |
3 | File: fs/xattr.c | |
4 | ||
5 | Extended attribute handling. | |
6 | ||
7 | Copyright (C) 2001 by Andreas Gruenbacher <a.gruenbacher@computer.org> | |
8 | Copyright (C) 2001 SGI - Silicon Graphics, Inc <linux-xfs@oss.sgi.com> | |
9 | Copyright (c) 2004 Red Hat, Inc., James Morris <jmorris@redhat.com> | |
10 | */ | |
11 | #include <linux/fs.h> | |
12 | #include <linux/slab.h> | |
1da177e4 LT |
13 | #include <linux/file.h> |
14 | #include <linux/xattr.h> | |
18f335af | 15 | #include <linux/mount.h> |
1da177e4 LT |
16 | #include <linux/namei.h> |
17 | #include <linux/security.h> | |
c7b87de2 | 18 | #include <linux/evm.h> |
1da177e4 | 19 | #include <linux/syscalls.h> |
630d9c47 | 20 | #include <linux/export.h> |
0eeca283 | 21 | #include <linux/fsnotify.h> |
73241ccc | 22 | #include <linux/audit.h> |
0d08d7b7 | 23 | #include <linux/vmalloc.h> |
2f6f0654 | 24 | #include <linux/posix_acl_xattr.h> |
1da177e4 | 25 | |
7c0f6ba6 | 26 | #include <linux/uaccess.h> |
5be196e5 | 27 | |
b6ba1177 AG |
28 | static const char * |
29 | strcmp_prefix(const char *a, const char *a_prefix) | |
30 | { | |
31 | while (*a_prefix && *a == *a_prefix) { | |
32 | a++; | |
33 | a_prefix++; | |
34 | } | |
35 | return *a_prefix ? NULL : a; | |
36 | } | |
37 | ||
38 | /* | |
39 | * In order to implement different sets of xattr operations for each xattr | |
6c6ef9f2 AG |
40 | * prefix, a filesystem should create a null-terminated array of struct |
41 | * xattr_handler (one for each prefix) and hang a pointer to it off of the | |
42 | * s_xattr field of the superblock. | |
b6ba1177 AG |
43 | */ |
44 | #define for_each_xattr_handler(handlers, handler) \ | |
45 | if (handlers) \ | |
46 | for ((handler) = *(handlers)++; \ | |
47 | (handler) != NULL; \ | |
48 | (handler) = *(handlers)++) | |
49 | ||
50 | /* | |
51 | * Find the xattr_handler with the matching prefix. | |
52 | */ | |
53 | static const struct xattr_handler * | |
d0a5b995 | 54 | xattr_resolve_name(struct inode *inode, const char **name) |
b6ba1177 | 55 | { |
d0a5b995 | 56 | const struct xattr_handler **handlers = inode->i_sb->s_xattr; |
b6ba1177 AG |
57 | const struct xattr_handler *handler; |
58 | ||
5f6e59ae AG |
59 | if (!(inode->i_opflags & IOP_XATTR)) { |
60 | if (unlikely(is_bad_inode(inode))) | |
61 | return ERR_PTR(-EIO); | |
d0a5b995 | 62 | return ERR_PTR(-EOPNOTSUPP); |
5f6e59ae | 63 | } |
b6ba1177 AG |
64 | for_each_xattr_handler(handlers, handler) { |
65 | const char *n; | |
66 | ||
67 | n = strcmp_prefix(*name, xattr_prefix(handler)); | |
68 | if (n) { | |
69 | if (!handler->prefix ^ !*n) { | |
70 | if (*n) | |
71 | continue; | |
72 | return ERR_PTR(-EINVAL); | |
73 | } | |
74 | *name = n; | |
75 | return handler; | |
76 | } | |
77 | } | |
78 | return ERR_PTR(-EOPNOTSUPP); | |
79 | } | |
80 | ||
e0ad7b07 | 81 | /* |
82 | * Check permissions for extended attribute access. This is a bit complicated | |
83 | * because different namespaces have very different rules. | |
84 | */ | |
85 | static int | |
c7c7a1a1 TA |
86 | xattr_permission(struct user_namespace *mnt_userns, struct inode *inode, |
87 | const char *name, int mask) | |
e0ad7b07 | 88 | { |
89 | /* | |
90 | * We can never set or remove an extended attribute on a read-only | |
91 | * filesystem or on an immutable / append-only inode. | |
92 | */ | |
93 | if (mask & MAY_WRITE) { | |
e0ad7b07 | 94 | if (IS_IMMUTABLE(inode) || IS_APPEND(inode)) |
95 | return -EPERM; | |
0bd23d09 EB |
96 | /* |
97 | * Updating an xattr will likely cause i_uid and i_gid | |
98 | * to be writen back improperly if their true value is | |
99 | * unknown to the vfs. | |
100 | */ | |
ba73d987 | 101 | if (HAS_UNMAPPED_ID(mnt_userns, inode)) |
0bd23d09 | 102 | return -EPERM; |
e0ad7b07 | 103 | } |
104 | ||
105 | /* | |
106 | * No restriction for security.* and system.* from the VFS. Decision | |
107 | * on these is left to the underlying filesystem / security module. | |
108 | */ | |
109 | if (!strncmp(name, XATTR_SECURITY_PREFIX, XATTR_SECURITY_PREFIX_LEN) || | |
110 | !strncmp(name, XATTR_SYSTEM_PREFIX, XATTR_SYSTEM_PREFIX_LEN)) | |
111 | return 0; | |
112 | ||
113 | /* | |
55b23bde | 114 | * The trusted.* namespace can only be accessed by privileged users. |
e0ad7b07 | 115 | */ |
55b23bde AG |
116 | if (!strncmp(name, XATTR_TRUSTED_PREFIX, XATTR_TRUSTED_PREFIX_LEN)) { |
117 | if (!capable(CAP_SYS_ADMIN)) | |
118 | return (mask & MAY_WRITE) ? -EPERM : -ENODATA; | |
119 | return 0; | |
120 | } | |
e0ad7b07 | 121 | |
55b23bde AG |
122 | /* |
123 | * In the user.* namespace, only regular files and directories can have | |
f1f2d871 | 124 | * extended attributes. For sticky directories, only the owner and |
55b23bde | 125 | * privileged users can write attributes. |
f1f2d871 | 126 | */ |
e0ad7b07 | 127 | if (!strncmp(name, XATTR_USER_PREFIX, XATTR_USER_PREFIX_LEN)) { |
f1f2d871 | 128 | if (!S_ISREG(inode->i_mode) && !S_ISDIR(inode->i_mode)) |
55b23bde | 129 | return (mask & MAY_WRITE) ? -EPERM : -ENODATA; |
f1f2d871 | 130 | if (S_ISDIR(inode->i_mode) && (inode->i_mode & S_ISVTX) && |
21cb47be | 131 | (mask & MAY_WRITE) && |
c7c7a1a1 | 132 | !inode_owner_or_capable(mnt_userns, inode)) |
e0ad7b07 | 133 | return -EPERM; |
134 | } | |
135 | ||
c7c7a1a1 | 136 | return inode_permission(mnt_userns, inode, mask); |
e0ad7b07 | 137 | } |
138 | ||
cab8d289 FL |
139 | /* |
140 | * Look for any handler that deals with the specified namespace. | |
141 | */ | |
142 | int | |
143 | xattr_supported_namespace(struct inode *inode, const char *prefix) | |
144 | { | |
145 | const struct xattr_handler **handlers = inode->i_sb->s_xattr; | |
146 | const struct xattr_handler *handler; | |
147 | size_t preflen; | |
148 | ||
149 | if (!(inode->i_opflags & IOP_XATTR)) { | |
150 | if (unlikely(is_bad_inode(inode))) | |
151 | return -EIO; | |
152 | return -EOPNOTSUPP; | |
153 | } | |
154 | ||
155 | preflen = strlen(prefix); | |
156 | ||
157 | for_each_xattr_handler(handlers, handler) { | |
158 | if (!strncmp(xattr_prefix(handler), prefix, preflen)) | |
159 | return 0; | |
160 | } | |
161 | ||
162 | return -EOPNOTSUPP; | |
163 | } | |
164 | EXPORT_SYMBOL(xattr_supported_namespace); | |
165 | ||
5d6c3191 | 166 | int |
c7c7a1a1 TA |
167 | __vfs_setxattr(struct user_namespace *mnt_userns, struct dentry *dentry, |
168 | struct inode *inode, const char *name, const void *value, | |
169 | size_t size, int flags) | |
5d6c3191 | 170 | { |
6c6ef9f2 AG |
171 | const struct xattr_handler *handler; |
172 | ||
173 | handler = xattr_resolve_name(inode, &name); | |
174 | if (IS_ERR(handler)) | |
175 | return PTR_ERR(handler); | |
176 | if (!handler->set) | |
5d6c3191 | 177 | return -EOPNOTSUPP; |
6c6ef9f2 AG |
178 | if (size == 0) |
179 | value = ""; /* empty EA, do not remove */ | |
c7c7a1a1 | 180 | return handler->set(handler, mnt_userns, dentry, inode, name, value, |
e65ce2a5 | 181 | size, flags); |
5d6c3191 AG |
182 | } |
183 | EXPORT_SYMBOL(__vfs_setxattr); | |
184 | ||
b1ab7e4b DQ |
185 | /** |
186 | * __vfs_setxattr_noperm - perform setxattr operation without performing | |
187 | * permission checks. | |
188 | * | |
6961fed4 RD |
189 | * @mnt_userns: user namespace of the mount the inode was found from |
190 | * @dentry: object to perform setxattr on | |
191 | * @name: xattr name to set | |
192 | * @value: value to set @name to | |
193 | * @size: size of @value | |
194 | * @flags: flags to pass into filesystem operations | |
b1ab7e4b DQ |
195 | * |
196 | * returns the result of the internal setxattr or setsecurity operations. | |
197 | * | |
198 | * This function requires the caller to lock the inode's i_mutex before it | |
199 | * is executed. It also assumes that the caller will make the appropriate | |
200 | * permission checks. | |
201 | */ | |
c7c7a1a1 TA |
202 | int __vfs_setxattr_noperm(struct user_namespace *mnt_userns, |
203 | struct dentry *dentry, const char *name, | |
204 | const void *value, size_t size, int flags) | |
5be196e5 CH |
205 | { |
206 | struct inode *inode = dentry->d_inode; | |
4a590153 | 207 | int error = -EAGAIN; |
69b45732 AK |
208 | int issec = !strncmp(name, XATTR_SECURITY_PREFIX, |
209 | XATTR_SECURITY_PREFIX_LEN); | |
e0ad7b07 | 210 | |
69b45732 AK |
211 | if (issec) |
212 | inode->i_flags &= ~S_NOSEC; | |
6c6ef9f2 | 213 | if (inode->i_opflags & IOP_XATTR) { |
c7c7a1a1 TA |
214 | error = __vfs_setxattr(mnt_userns, dentry, inode, name, value, |
215 | size, flags); | |
5be196e5 CH |
216 | if (!error) { |
217 | fsnotify_xattr(dentry); | |
218 | security_inode_post_setxattr(dentry, name, value, | |
219 | size, flags); | |
220 | } | |
4a590153 | 221 | } else { |
5f6e59ae AG |
222 | if (unlikely(is_bad_inode(inode))) |
223 | return -EIO; | |
4a590153 AG |
224 | } |
225 | if (error == -EAGAIN) { | |
226 | error = -EOPNOTSUPP; | |
227 | ||
228 | if (issec) { | |
229 | const char *suffix = name + XATTR_SECURITY_PREFIX_LEN; | |
230 | ||
231 | error = security_inode_setsecurity(inode, suffix, value, | |
232 | size, flags); | |
233 | if (!error) | |
234 | fsnotify_xattr(dentry); | |
235 | } | |
5be196e5 | 236 | } |
b1ab7e4b DQ |
237 | |
238 | return error; | |
239 | } | |
3fb38c98 | 240 | EXPORT_SYMBOL_GPL(__vfs_setxattr_noperm); |
b1ab7e4b | 241 | |
08b5d501 | 242 | /** |
da5c1c0b | 243 | * __vfs_setxattr_locked - set an extended attribute while holding the inode |
08b5d501 FL |
244 | * lock |
245 | * | |
6961fed4 | 246 | * @mnt_userns: user namespace of the mount of the target inode |
da5c1c0b RD |
247 | * @dentry: object to perform setxattr on |
248 | * @name: xattr name to set | |
249 | * @value: value to set @name to | |
250 | * @size: size of @value | |
251 | * @flags: flags to pass into filesystem operations | |
252 | * @delegated_inode: on return, will contain an inode pointer that | |
08b5d501 FL |
253 | * a delegation was broken on, NULL if none. |
254 | */ | |
b1ab7e4b | 255 | int |
c7c7a1a1 TA |
256 | __vfs_setxattr_locked(struct user_namespace *mnt_userns, struct dentry *dentry, |
257 | const char *name, const void *value, size_t size, | |
258 | int flags, struct inode **delegated_inode) | |
b1ab7e4b DQ |
259 | { |
260 | struct inode *inode = dentry->d_inode; | |
261 | int error; | |
262 | ||
c7c7a1a1 | 263 | error = xattr_permission(mnt_userns, inode, name, MAY_WRITE); |
b1ab7e4b DQ |
264 | if (error) |
265 | return error; | |
266 | ||
71bc356f CB |
267 | error = security_inode_setxattr(mnt_userns, dentry, name, value, size, |
268 | flags); | |
b1ab7e4b DQ |
269 | if (error) |
270 | goto out; | |
271 | ||
08b5d501 FL |
272 | error = try_break_deleg(inode, delegated_inode); |
273 | if (error) | |
274 | goto out; | |
275 | ||
c7c7a1a1 TA |
276 | error = __vfs_setxattr_noperm(mnt_userns, dentry, name, value, |
277 | size, flags); | |
b1ab7e4b | 278 | |
5be196e5 | 279 | out: |
08b5d501 FL |
280 | return error; |
281 | } | |
282 | EXPORT_SYMBOL_GPL(__vfs_setxattr_locked); | |
283 | ||
284 | int | |
c7c7a1a1 TA |
285 | vfs_setxattr(struct user_namespace *mnt_userns, struct dentry *dentry, |
286 | const char *name, const void *value, size_t size, int flags) | |
08b5d501 FL |
287 | { |
288 | struct inode *inode = dentry->d_inode; | |
289 | struct inode *delegated_inode = NULL; | |
7c03e2cd | 290 | const void *orig_value = value; |
08b5d501 FL |
291 | int error; |
292 | ||
7c03e2cd | 293 | if (size && strcmp(name, XATTR_NAME_CAPS) == 0) { |
c7c7a1a1 | 294 | error = cap_convert_nscap(mnt_userns, dentry, &value, size); |
7c03e2cd MS |
295 | if (error < 0) |
296 | return error; | |
297 | size = error; | |
298 | } | |
299 | ||
08b5d501 FL |
300 | retry_deleg: |
301 | inode_lock(inode); | |
c7c7a1a1 TA |
302 | error = __vfs_setxattr_locked(mnt_userns, dentry, name, value, size, |
303 | flags, &delegated_inode); | |
5955102c | 304 | inode_unlock(inode); |
08b5d501 FL |
305 | |
306 | if (delegated_inode) { | |
307 | error = break_deleg_wait(&delegated_inode); | |
308 | if (!error) | |
309 | goto retry_deleg; | |
310 | } | |
7c03e2cd MS |
311 | if (value != orig_value) |
312 | kfree(value); | |
313 | ||
5be196e5 CH |
314 | return error; |
315 | } | |
316 | EXPORT_SYMBOL_GPL(vfs_setxattr); | |
317 | ||
2220c5b0 | 318 | static ssize_t |
71bc356f CB |
319 | xattr_getsecurity(struct user_namespace *mnt_userns, struct inode *inode, |
320 | const char *name, void *value, size_t size) | |
42492594 DQ |
321 | { |
322 | void *buffer = NULL; | |
323 | ssize_t len; | |
324 | ||
325 | if (!value || !size) { | |
71bc356f CB |
326 | len = security_inode_getsecurity(mnt_userns, inode, name, |
327 | &buffer, false); | |
42492594 DQ |
328 | goto out_noalloc; |
329 | } | |
330 | ||
71bc356f CB |
331 | len = security_inode_getsecurity(mnt_userns, inode, name, &buffer, |
332 | true); | |
42492594 DQ |
333 | if (len < 0) |
334 | return len; | |
335 | if (size < len) { | |
336 | len = -ERANGE; | |
337 | goto out; | |
338 | } | |
339 | memcpy(value, buffer, len); | |
340 | out: | |
57e7ba04 | 341 | kfree(buffer); |
42492594 DQ |
342 | out_noalloc: |
343 | return len; | |
344 | } | |
42492594 | 345 | |
1601fbad MZ |
346 | /* |
347 | * vfs_getxattr_alloc - allocate memory, if necessary, before calling getxattr | |
348 | * | |
349 | * Allocate memory, if not already allocated, or re-allocate correct size, | |
350 | * before retrieving the extended attribute. | |
351 | * | |
352 | * Returns the result of alloc, if failed, or the getxattr operation. | |
353 | */ | |
354 | ssize_t | |
c7c7a1a1 TA |
355 | vfs_getxattr_alloc(struct user_namespace *mnt_userns, struct dentry *dentry, |
356 | const char *name, char **xattr_value, size_t xattr_size, | |
357 | gfp_t flags) | |
1601fbad | 358 | { |
6c6ef9f2 | 359 | const struct xattr_handler *handler; |
1601fbad MZ |
360 | struct inode *inode = dentry->d_inode; |
361 | char *value = *xattr_value; | |
362 | int error; | |
363 | ||
c7c7a1a1 | 364 | error = xattr_permission(mnt_userns, inode, name, MAY_READ); |
1601fbad MZ |
365 | if (error) |
366 | return error; | |
367 | ||
6c6ef9f2 AG |
368 | handler = xattr_resolve_name(inode, &name); |
369 | if (IS_ERR(handler)) | |
370 | return PTR_ERR(handler); | |
371 | if (!handler->get) | |
1601fbad | 372 | return -EOPNOTSUPP; |
6c6ef9f2 | 373 | error = handler->get(handler, dentry, inode, name, NULL, 0); |
1601fbad MZ |
374 | if (error < 0) |
375 | return error; | |
376 | ||
377 | if (!value || (error > xattr_size)) { | |
378 | value = krealloc(*xattr_value, error + 1, flags); | |
379 | if (!value) | |
380 | return -ENOMEM; | |
381 | memset(value, 0, error + 1); | |
382 | } | |
383 | ||
6c6ef9f2 | 384 | error = handler->get(handler, dentry, inode, name, value, error); |
1601fbad MZ |
385 | *xattr_value = value; |
386 | return error; | |
387 | } | |
7fea21ae | 388 | EXPORT_SYMBOL_GPL(vfs_getxattr_alloc); |
1601fbad | 389 | |
5d6c3191 AG |
390 | ssize_t |
391 | __vfs_getxattr(struct dentry *dentry, struct inode *inode, const char *name, | |
392 | void *value, size_t size) | |
393 | { | |
6c6ef9f2 AG |
394 | const struct xattr_handler *handler; |
395 | ||
396 | handler = xattr_resolve_name(inode, &name); | |
397 | if (IS_ERR(handler)) | |
398 | return PTR_ERR(handler); | |
399 | if (!handler->get) | |
5d6c3191 | 400 | return -EOPNOTSUPP; |
6c6ef9f2 | 401 | return handler->get(handler, dentry, inode, name, value, size); |
5d6c3191 AG |
402 | } |
403 | EXPORT_SYMBOL(__vfs_getxattr); | |
404 | ||
5be196e5 | 405 | ssize_t |
c7c7a1a1 TA |
406 | vfs_getxattr(struct user_namespace *mnt_userns, struct dentry *dentry, |
407 | const char *name, void *value, size_t size) | |
5be196e5 CH |
408 | { |
409 | struct inode *inode = dentry->d_inode; | |
410 | int error; | |
411 | ||
c7c7a1a1 | 412 | error = xattr_permission(mnt_userns, inode, name, MAY_READ); |
e0ad7b07 | 413 | if (error) |
414 | return error; | |
415 | ||
5be196e5 CH |
416 | error = security_inode_getxattr(dentry, name); |
417 | if (error) | |
418 | return error; | |
419 | ||
5be196e5 | 420 | if (!strncmp(name, XATTR_SECURITY_PREFIX, |
e0ad7b07 | 421 | XATTR_SECURITY_PREFIX_LEN)) { |
422 | const char *suffix = name + XATTR_SECURITY_PREFIX_LEN; | |
71bc356f CB |
423 | int ret = xattr_getsecurity(mnt_userns, inode, suffix, value, |
424 | size); | |
5be196e5 CH |
425 | /* |
426 | * Only overwrite the return value if a security module | |
427 | * is actually active. | |
428 | */ | |
4bea5805 DQ |
429 | if (ret == -EOPNOTSUPP) |
430 | goto nolsm; | |
431 | return ret; | |
5be196e5 | 432 | } |
4bea5805 | 433 | nolsm: |
5d6c3191 | 434 | return __vfs_getxattr(dentry, inode, name, value, size); |
5be196e5 CH |
435 | } |
436 | EXPORT_SYMBOL_GPL(vfs_getxattr); | |
437 | ||
659564c8 | 438 | ssize_t |
bf3ee713 | 439 | vfs_listxattr(struct dentry *dentry, char *list, size_t size) |
659564c8 | 440 | { |
bf3ee713 | 441 | struct inode *inode = d_inode(dentry); |
659564c8 BN |
442 | ssize_t error; |
443 | ||
bf3ee713 | 444 | error = security_inode_listxattr(dentry); |
659564c8 BN |
445 | if (error) |
446 | return error; | |
bf3ee713 | 447 | if (inode->i_op->listxattr && (inode->i_opflags & IOP_XATTR)) { |
bf3ee713 | 448 | error = inode->i_op->listxattr(dentry, list, size); |
659564c8 | 449 | } else { |
bf3ee713 | 450 | error = security_inode_listsecurity(inode, list, size); |
659564c8 BN |
451 | if (size && error > size) |
452 | error = -ERANGE; | |
453 | } | |
454 | return error; | |
455 | } | |
456 | EXPORT_SYMBOL_GPL(vfs_listxattr); | |
457 | ||
5be196e5 | 458 | int |
c7c7a1a1 TA |
459 | __vfs_removexattr(struct user_namespace *mnt_userns, struct dentry *dentry, |
460 | const char *name) | |
5be196e5 | 461 | { |
6c6ef9f2 AG |
462 | struct inode *inode = d_inode(dentry); |
463 | const struct xattr_handler *handler; | |
5be196e5 | 464 | |
6c6ef9f2 AG |
465 | handler = xattr_resolve_name(inode, &name); |
466 | if (IS_ERR(handler)) | |
467 | return PTR_ERR(handler); | |
468 | if (!handler->set) | |
5be196e5 | 469 | return -EOPNOTSUPP; |
c7c7a1a1 TA |
470 | return handler->set(handler, mnt_userns, dentry, inode, name, NULL, 0, |
471 | XATTR_REPLACE); | |
5d6c3191 AG |
472 | } |
473 | EXPORT_SYMBOL(__vfs_removexattr); | |
474 | ||
3fb38c98 SF |
475 | /** |
476 | * __vfs_removexattr_noperm - perform removexattr operation without | |
477 | * performing permission checks. | |
478 | * | |
479 | * @dentry - object to perform setxattr on | |
480 | * @name - xattr name to set | |
481 | * | |
482 | * returns the result of the internal setxattr or setsecurity operations. | |
483 | * | |
484 | * This function requires the caller to lock the inode's i_mutex before it | |
485 | * is executed. It also assumes that the caller will make the appropriate | |
486 | * permission checks. | |
487 | */ | |
488 | int | |
489 | __vfs_removexattr_noperm(struct user_namespace *mnt_userns, | |
490 | struct dentry *dentry, const char *name) | |
491 | { | |
492 | int error; | |
493 | ||
494 | error =__vfs_removexattr(mnt_userns, dentry, name); | |
495 | if (!error) { | |
496 | fsnotify_xattr(dentry); | |
497 | evm_inode_post_removexattr(dentry, name); | |
498 | } | |
499 | return error; | |
500 | } | |
501 | EXPORT_SYMBOL_GPL(__vfs_removexattr_noperm); | |
502 | ||
08b5d501 | 503 | /** |
da5c1c0b | 504 | * __vfs_removexattr_locked - set an extended attribute while holding the inode |
08b5d501 FL |
505 | * lock |
506 | * | |
6961fed4 | 507 | * @mnt_userns: user namespace of the mount of the target inode |
da5c1c0b RD |
508 | * @dentry: object to perform setxattr on |
509 | * @name: name of xattr to remove | |
510 | * @delegated_inode: on return, will contain an inode pointer that | |
08b5d501 FL |
511 | * a delegation was broken on, NULL if none. |
512 | */ | |
5d6c3191 | 513 | int |
c7c7a1a1 TA |
514 | __vfs_removexattr_locked(struct user_namespace *mnt_userns, |
515 | struct dentry *dentry, const char *name, | |
516 | struct inode **delegated_inode) | |
5d6c3191 AG |
517 | { |
518 | struct inode *inode = dentry->d_inode; | |
519 | int error; | |
5be196e5 | 520 | |
c7c7a1a1 | 521 | error = xattr_permission(mnt_userns, inode, name, MAY_WRITE); |
e0ad7b07 | 522 | if (error) |
523 | return error; | |
524 | ||
71bc356f | 525 | error = security_inode_removexattr(mnt_userns, dentry, name); |
7c51bb00 DK |
526 | if (error) |
527 | goto out; | |
5be196e5 | 528 | |
08b5d501 FL |
529 | error = try_break_deleg(inode, delegated_inode); |
530 | if (error) | |
531 | goto out; | |
532 | ||
3fb38c98 | 533 | error = __vfs_removexattr_noperm(mnt_userns, dentry, name); |
7c51bb00 DK |
534 | |
535 | out: | |
08b5d501 FL |
536 | return error; |
537 | } | |
538 | EXPORT_SYMBOL_GPL(__vfs_removexattr_locked); | |
539 | ||
540 | int | |
c7c7a1a1 TA |
541 | vfs_removexattr(struct user_namespace *mnt_userns, struct dentry *dentry, |
542 | const char *name) | |
08b5d501 FL |
543 | { |
544 | struct inode *inode = dentry->d_inode; | |
545 | struct inode *delegated_inode = NULL; | |
546 | int error; | |
547 | ||
548 | retry_deleg: | |
549 | inode_lock(inode); | |
c7c7a1a1 TA |
550 | error = __vfs_removexattr_locked(mnt_userns, dentry, |
551 | name, &delegated_inode); | |
5955102c | 552 | inode_unlock(inode); |
08b5d501 FL |
553 | |
554 | if (delegated_inode) { | |
555 | error = break_deleg_wait(&delegated_inode); | |
556 | if (!error) | |
557 | goto retry_deleg; | |
558 | } | |
559 | ||
5be196e5 CH |
560 | return error; |
561 | } | |
562 | EXPORT_SYMBOL_GPL(vfs_removexattr); | |
563 | ||
1da177e4 LT |
564 | /* |
565 | * Extended attribute SET operations | |
566 | */ | |
567 | static long | |
c7c7a1a1 TA |
568 | setxattr(struct user_namespace *mnt_userns, struct dentry *d, |
569 | const char __user *name, const void __user *value, size_t size, | |
570 | int flags) | |
1da177e4 LT |
571 | { |
572 | int error; | |
573 | void *kvalue = NULL; | |
574 | char kname[XATTR_NAME_MAX + 1]; | |
575 | ||
576 | if (flags & ~(XATTR_CREATE|XATTR_REPLACE)) | |
577 | return -EINVAL; | |
578 | ||
579 | error = strncpy_from_user(kname, name, sizeof(kname)); | |
580 | if (error == 0 || error == sizeof(kname)) | |
581 | error = -ERANGE; | |
582 | if (error < 0) | |
583 | return error; | |
584 | ||
585 | if (size) { | |
586 | if (size > XATTR_SIZE_MAX) | |
587 | return -E2BIG; | |
752ade68 MH |
588 | kvalue = kvmalloc(size, GFP_KERNEL); |
589 | if (!kvalue) | |
590 | return -ENOMEM; | |
44c82498 AM |
591 | if (copy_from_user(kvalue, value, size)) { |
592 | error = -EFAULT; | |
593 | goto out; | |
594 | } | |
2f6f0654 EB |
595 | if ((strcmp(kname, XATTR_NAME_POSIX_ACL_ACCESS) == 0) || |
596 | (strcmp(kname, XATTR_NAME_POSIX_ACL_DEFAULT) == 0)) | |
c7c7a1a1 | 597 | posix_acl_fix_xattr_from_user(mnt_userns, kvalue, size); |
1da177e4 LT |
598 | } |
599 | ||
c7c7a1a1 | 600 | error = vfs_setxattr(mnt_userns, d, kname, kvalue, size, flags); |
44c82498 | 601 | out: |
0b2a6f23 RW |
602 | kvfree(kvalue); |
603 | ||
1da177e4 LT |
604 | return error; |
605 | } | |
606 | ||
8cc43116 EB |
607 | static int path_setxattr(const char __user *pathname, |
608 | const char __user *name, const void __user *value, | |
609 | size_t size, int flags, unsigned int lookup_flags) | |
1da177e4 | 610 | { |
2d8f3038 | 611 | struct path path; |
1da177e4 | 612 | int error; |
c7c7a1a1 | 613 | |
68f1bb8b JL |
614 | retry: |
615 | error = user_path_at(AT_FDCWD, pathname, lookup_flags, &path); | |
1da177e4 LT |
616 | if (error) |
617 | return error; | |
2d8f3038 | 618 | error = mnt_want_write(path.mnt); |
18f335af | 619 | if (!error) { |
c7c7a1a1 TA |
620 | error = setxattr(mnt_user_ns(path.mnt), path.dentry, name, |
621 | value, size, flags); | |
2d8f3038 | 622 | mnt_drop_write(path.mnt); |
18f335af | 623 | } |
2d8f3038 | 624 | path_put(&path); |
68f1bb8b JL |
625 | if (retry_estale(error, lookup_flags)) { |
626 | lookup_flags |= LOOKUP_REVAL; | |
627 | goto retry; | |
628 | } | |
1da177e4 LT |
629 | return error; |
630 | } | |
631 | ||
8cc43116 EB |
632 | SYSCALL_DEFINE5(setxattr, const char __user *, pathname, |
633 | const char __user *, name, const void __user *, value, | |
634 | size_t, size, int, flags) | |
635 | { | |
636 | return path_setxattr(pathname, name, value, size, flags, LOOKUP_FOLLOW); | |
637 | } | |
638 | ||
64fd1de3 HC |
639 | SYSCALL_DEFINE5(lsetxattr, const char __user *, pathname, |
640 | const char __user *, name, const void __user *, value, | |
641 | size_t, size, int, flags) | |
1da177e4 | 642 | { |
8cc43116 | 643 | return path_setxattr(pathname, name, value, size, flags, 0); |
1da177e4 LT |
644 | } |
645 | ||
64fd1de3 HC |
646 | SYSCALL_DEFINE5(fsetxattr, int, fd, const char __user *, name, |
647 | const void __user *,value, size_t, size, int, flags) | |
1da177e4 | 648 | { |
2903ff01 | 649 | struct fd f = fdget(fd); |
1da177e4 LT |
650 | int error = -EBADF; |
651 | ||
2903ff01 | 652 | if (!f.file) |
1da177e4 | 653 | return error; |
9f45f5bf | 654 | audit_file(f.file); |
6742cee0 | 655 | error = mnt_want_write_file(f.file); |
18f335af | 656 | if (!error) { |
c7c7a1a1 TA |
657 | error = setxattr(file_mnt_user_ns(f.file), |
658 | f.file->f_path.dentry, name, | |
659 | value, size, flags); | |
6742cee0 | 660 | mnt_drop_write_file(f.file); |
18f335af | 661 | } |
2903ff01 | 662 | fdput(f); |
1da177e4 LT |
663 | return error; |
664 | } | |
665 | ||
666 | /* | |
667 | * Extended attribute GET operations | |
668 | */ | |
669 | static ssize_t | |
c7c7a1a1 TA |
670 | getxattr(struct user_namespace *mnt_userns, struct dentry *d, |
671 | const char __user *name, void __user *value, size_t size) | |
1da177e4 LT |
672 | { |
673 | ssize_t error; | |
674 | void *kvalue = NULL; | |
675 | char kname[XATTR_NAME_MAX + 1]; | |
676 | ||
677 | error = strncpy_from_user(kname, name, sizeof(kname)); | |
678 | if (error == 0 || error == sizeof(kname)) | |
679 | error = -ERANGE; | |
680 | if (error < 0) | |
681 | return error; | |
682 | ||
683 | if (size) { | |
684 | if (size > XATTR_SIZE_MAX) | |
685 | size = XATTR_SIZE_MAX; | |
752ade68 MH |
686 | kvalue = kvzalloc(size, GFP_KERNEL); |
687 | if (!kvalue) | |
688 | return -ENOMEM; | |
1da177e4 LT |
689 | } |
690 | ||
c7c7a1a1 | 691 | error = vfs_getxattr(mnt_userns, d, kname, kvalue, size); |
f549d6c1 | 692 | if (error > 0) { |
2f6f0654 EB |
693 | if ((strcmp(kname, XATTR_NAME_POSIX_ACL_ACCESS) == 0) || |
694 | (strcmp(kname, XATTR_NAME_POSIX_ACL_DEFAULT) == 0)) | |
c7c7a1a1 | 695 | posix_acl_fix_xattr_to_user(mnt_userns, kvalue, error); |
f549d6c1 SS |
696 | if (size && copy_to_user(value, kvalue, error)) |
697 | error = -EFAULT; | |
698 | } else if (error == -ERANGE && size >= XATTR_SIZE_MAX) { | |
699 | /* The file system tried to returned a value bigger | |
700 | than XATTR_SIZE_MAX bytes. Not possible. */ | |
701 | error = -E2BIG; | |
1da177e4 | 702 | } |
0b2a6f23 RW |
703 | |
704 | kvfree(kvalue); | |
705 | ||
1da177e4 LT |
706 | return error; |
707 | } | |
708 | ||
8cc43116 EB |
709 | static ssize_t path_getxattr(const char __user *pathname, |
710 | const char __user *name, void __user *value, | |
711 | size_t size, unsigned int lookup_flags) | |
1da177e4 | 712 | { |
2d8f3038 | 713 | struct path path; |
1da177e4 | 714 | ssize_t error; |
60e66b48 JL |
715 | retry: |
716 | error = user_path_at(AT_FDCWD, pathname, lookup_flags, &path); | |
1da177e4 LT |
717 | if (error) |
718 | return error; | |
c7c7a1a1 | 719 | error = getxattr(mnt_user_ns(path.mnt), path.dentry, name, value, size); |
2d8f3038 | 720 | path_put(&path); |
60e66b48 JL |
721 | if (retry_estale(error, lookup_flags)) { |
722 | lookup_flags |= LOOKUP_REVAL; | |
723 | goto retry; | |
724 | } | |
1da177e4 LT |
725 | return error; |
726 | } | |
727 | ||
8cc43116 EB |
728 | SYSCALL_DEFINE4(getxattr, const char __user *, pathname, |
729 | const char __user *, name, void __user *, value, size_t, size) | |
730 | { | |
731 | return path_getxattr(pathname, name, value, size, LOOKUP_FOLLOW); | |
732 | } | |
733 | ||
64fd1de3 HC |
734 | SYSCALL_DEFINE4(lgetxattr, const char __user *, pathname, |
735 | const char __user *, name, void __user *, value, size_t, size) | |
1da177e4 | 736 | { |
8cc43116 | 737 | return path_getxattr(pathname, name, value, size, 0); |
1da177e4 LT |
738 | } |
739 | ||
64fd1de3 HC |
740 | SYSCALL_DEFINE4(fgetxattr, int, fd, const char __user *, name, |
741 | void __user *, value, size_t, size) | |
1da177e4 | 742 | { |
2903ff01 | 743 | struct fd f = fdget(fd); |
1da177e4 LT |
744 | ssize_t error = -EBADF; |
745 | ||
2903ff01 | 746 | if (!f.file) |
1da177e4 | 747 | return error; |
9f45f5bf | 748 | audit_file(f.file); |
c7c7a1a1 TA |
749 | error = getxattr(file_mnt_user_ns(f.file), f.file->f_path.dentry, |
750 | name, value, size); | |
2903ff01 | 751 | fdput(f); |
1da177e4 LT |
752 | return error; |
753 | } | |
754 | ||
755 | /* | |
756 | * Extended attribute LIST operations | |
757 | */ | |
758 | static ssize_t | |
759 | listxattr(struct dentry *d, char __user *list, size_t size) | |
760 | { | |
761 | ssize_t error; | |
762 | char *klist = NULL; | |
763 | ||
764 | if (size) { | |
765 | if (size > XATTR_LIST_MAX) | |
766 | size = XATTR_LIST_MAX; | |
752ade68 MH |
767 | klist = kvmalloc(size, GFP_KERNEL); |
768 | if (!klist) | |
769 | return -ENOMEM; | |
1da177e4 LT |
770 | } |
771 | ||
659564c8 | 772 | error = vfs_listxattr(d, klist, size); |
f549d6c1 SS |
773 | if (error > 0) { |
774 | if (size && copy_to_user(list, klist, error)) | |
775 | error = -EFAULT; | |
776 | } else if (error == -ERANGE && size >= XATTR_LIST_MAX) { | |
777 | /* The file system tried to returned a list bigger | |
778 | than XATTR_LIST_MAX bytes. Not possible. */ | |
779 | error = -E2BIG; | |
1da177e4 | 780 | } |
0b2a6f23 RW |
781 | |
782 | kvfree(klist); | |
783 | ||
1da177e4 LT |
784 | return error; |
785 | } | |
786 | ||
8cc43116 EB |
787 | static ssize_t path_listxattr(const char __user *pathname, char __user *list, |
788 | size_t size, unsigned int lookup_flags) | |
1da177e4 | 789 | { |
2d8f3038 | 790 | struct path path; |
1da177e4 | 791 | ssize_t error; |
10a90cf3 JL |
792 | retry: |
793 | error = user_path_at(AT_FDCWD, pathname, lookup_flags, &path); | |
1da177e4 LT |
794 | if (error) |
795 | return error; | |
2d8f3038 AV |
796 | error = listxattr(path.dentry, list, size); |
797 | path_put(&path); | |
10a90cf3 JL |
798 | if (retry_estale(error, lookup_flags)) { |
799 | lookup_flags |= LOOKUP_REVAL; | |
800 | goto retry; | |
801 | } | |
1da177e4 LT |
802 | return error; |
803 | } | |
804 | ||
8cc43116 EB |
805 | SYSCALL_DEFINE3(listxattr, const char __user *, pathname, char __user *, list, |
806 | size_t, size) | |
807 | { | |
808 | return path_listxattr(pathname, list, size, LOOKUP_FOLLOW); | |
809 | } | |
810 | ||
64fd1de3 HC |
811 | SYSCALL_DEFINE3(llistxattr, const char __user *, pathname, char __user *, list, |
812 | size_t, size) | |
1da177e4 | 813 | { |
8cc43116 | 814 | return path_listxattr(pathname, list, size, 0); |
1da177e4 LT |
815 | } |
816 | ||
64fd1de3 | 817 | SYSCALL_DEFINE3(flistxattr, int, fd, char __user *, list, size_t, size) |
1da177e4 | 818 | { |
2903ff01 | 819 | struct fd f = fdget(fd); |
1da177e4 LT |
820 | ssize_t error = -EBADF; |
821 | ||
2903ff01 | 822 | if (!f.file) |
1da177e4 | 823 | return error; |
9f45f5bf | 824 | audit_file(f.file); |
2903ff01 AV |
825 | error = listxattr(f.file->f_path.dentry, list, size); |
826 | fdput(f); | |
1da177e4 LT |
827 | return error; |
828 | } | |
829 | ||
830 | /* | |
831 | * Extended attribute REMOVE operations | |
832 | */ | |
833 | static long | |
c7c7a1a1 TA |
834 | removexattr(struct user_namespace *mnt_userns, struct dentry *d, |
835 | const char __user *name) | |
1da177e4 LT |
836 | { |
837 | int error; | |
838 | char kname[XATTR_NAME_MAX + 1]; | |
839 | ||
840 | error = strncpy_from_user(kname, name, sizeof(kname)); | |
841 | if (error == 0 || error == sizeof(kname)) | |
842 | error = -ERANGE; | |
843 | if (error < 0) | |
844 | return error; | |
845 | ||
c7c7a1a1 | 846 | return vfs_removexattr(mnt_userns, d, kname); |
1da177e4 LT |
847 | } |
848 | ||
8cc43116 EB |
849 | static int path_removexattr(const char __user *pathname, |
850 | const char __user *name, unsigned int lookup_flags) | |
1da177e4 | 851 | { |
2d8f3038 | 852 | struct path path; |
1da177e4 | 853 | int error; |
12f06212 JL |
854 | retry: |
855 | error = user_path_at(AT_FDCWD, pathname, lookup_flags, &path); | |
1da177e4 LT |
856 | if (error) |
857 | return error; | |
2d8f3038 | 858 | error = mnt_want_write(path.mnt); |
18f335af | 859 | if (!error) { |
c7c7a1a1 | 860 | error = removexattr(mnt_user_ns(path.mnt), path.dentry, name); |
2d8f3038 | 861 | mnt_drop_write(path.mnt); |
18f335af | 862 | } |
2d8f3038 | 863 | path_put(&path); |
12f06212 JL |
864 | if (retry_estale(error, lookup_flags)) { |
865 | lookup_flags |= LOOKUP_REVAL; | |
866 | goto retry; | |
867 | } | |
1da177e4 LT |
868 | return error; |
869 | } | |
870 | ||
8cc43116 EB |
871 | SYSCALL_DEFINE2(removexattr, const char __user *, pathname, |
872 | const char __user *, name) | |
873 | { | |
874 | return path_removexattr(pathname, name, LOOKUP_FOLLOW); | |
875 | } | |
876 | ||
6a6160a7 HC |
877 | SYSCALL_DEFINE2(lremovexattr, const char __user *, pathname, |
878 | const char __user *, name) | |
1da177e4 | 879 | { |
8cc43116 | 880 | return path_removexattr(pathname, name, 0); |
1da177e4 LT |
881 | } |
882 | ||
6a6160a7 | 883 | SYSCALL_DEFINE2(fremovexattr, int, fd, const char __user *, name) |
1da177e4 | 884 | { |
2903ff01 | 885 | struct fd f = fdget(fd); |
1da177e4 LT |
886 | int error = -EBADF; |
887 | ||
2903ff01 | 888 | if (!f.file) |
1da177e4 | 889 | return error; |
9f45f5bf | 890 | audit_file(f.file); |
6742cee0 | 891 | error = mnt_want_write_file(f.file); |
18f335af | 892 | if (!error) { |
c7c7a1a1 TA |
893 | error = removexattr(file_mnt_user_ns(f.file), |
894 | f.file->f_path.dentry, name); | |
6742cee0 | 895 | mnt_drop_write_file(f.file); |
18f335af | 896 | } |
2903ff01 | 897 | fdput(f); |
1da177e4 LT |
898 | return error; |
899 | } | |
900 | ||
1da177e4 LT |
901 | /* |
902 | * Combine the results of the list() operation from every xattr_handler in the | |
903 | * list. | |
904 | */ | |
905 | ssize_t | |
906 | generic_listxattr(struct dentry *dentry, char *buffer, size_t buffer_size) | |
907 | { | |
bb435453 | 908 | const struct xattr_handler *handler, **handlers = dentry->d_sb->s_xattr; |
1da177e4 LT |
909 | unsigned int size = 0; |
910 | ||
911 | if (!buffer) { | |
431547b3 | 912 | for_each_xattr_handler(handlers, handler) { |
764a5c6b AG |
913 | if (!handler->name || |
914 | (handler->list && !handler->list(dentry))) | |
c4803c49 | 915 | continue; |
764a5c6b | 916 | size += strlen(handler->name) + 1; |
431547b3 | 917 | } |
1da177e4 LT |
918 | } else { |
919 | char *buf = buffer; | |
764a5c6b | 920 | size_t len; |
1da177e4 LT |
921 | |
922 | for_each_xattr_handler(handlers, handler) { | |
764a5c6b AG |
923 | if (!handler->name || |
924 | (handler->list && !handler->list(dentry))) | |
c4803c49 | 925 | continue; |
764a5c6b AG |
926 | len = strlen(handler->name); |
927 | if (len + 1 > buffer_size) | |
1da177e4 | 928 | return -ERANGE; |
764a5c6b AG |
929 | memcpy(buf, handler->name, len + 1); |
930 | buf += len + 1; | |
931 | buffer_size -= len + 1; | |
1da177e4 LT |
932 | } |
933 | size = buf - buffer; | |
934 | } | |
935 | return size; | |
936 | } | |
1da177e4 | 937 | EXPORT_SYMBOL(generic_listxattr); |
38f38657 | 938 | |
e409de99 AG |
939 | /** |
940 | * xattr_full_name - Compute full attribute name from suffix | |
941 | * | |
942 | * @handler: handler of the xattr_handler operation | |
943 | * @name: name passed to the xattr_handler operation | |
944 | * | |
945 | * The get and set xattr handler operations are called with the remainder of | |
946 | * the attribute name after skipping the handler's prefix: for example, "foo" | |
947 | * is passed to the get operation of a handler with prefix "user." to get | |
948 | * attribute "user.foo". The full name is still "there" in the name though. | |
949 | * | |
950 | * Note: the list xattr handler operation when called from the vfs is passed a | |
951 | * NULL name; some file systems use this operation internally, with varying | |
952 | * semantics. | |
953 | */ | |
954 | const char *xattr_full_name(const struct xattr_handler *handler, | |
955 | const char *name) | |
956 | { | |
98e9cb57 | 957 | size_t prefix_len = strlen(xattr_prefix(handler)); |
e409de99 AG |
958 | |
959 | return name - prefix_len; | |
960 | } | |
961 | EXPORT_SYMBOL(xattr_full_name); | |
962 | ||
38f38657 AR |
963 | /* |
964 | * Allocate new xattr and copy in the value; but leave the name to callers. | |
965 | */ | |
966 | struct simple_xattr *simple_xattr_alloc(const void *value, size_t size) | |
967 | { | |
968 | struct simple_xattr *new_xattr; | |
969 | size_t len; | |
970 | ||
971 | /* wrap around? */ | |
972 | len = sizeof(*new_xattr) + size; | |
4e66d445 | 973 | if (len < sizeof(*new_xattr)) |
38f38657 AR |
974 | return NULL; |
975 | ||
fdc85222 | 976 | new_xattr = kvmalloc(len, GFP_KERNEL); |
38f38657 AR |
977 | if (!new_xattr) |
978 | return NULL; | |
979 | ||
980 | new_xattr->size = size; | |
981 | memcpy(new_xattr->value, value, size); | |
982 | return new_xattr; | |
983 | } | |
984 | ||
985 | /* | |
986 | * xattr GET operation for in-memory/pseudo filesystems | |
987 | */ | |
988 | int simple_xattr_get(struct simple_xattrs *xattrs, const char *name, | |
989 | void *buffer, size_t size) | |
990 | { | |
991 | struct simple_xattr *xattr; | |
992 | int ret = -ENODATA; | |
993 | ||
994 | spin_lock(&xattrs->lock); | |
995 | list_for_each_entry(xattr, &xattrs->head, list) { | |
996 | if (strcmp(name, xattr->name)) | |
997 | continue; | |
998 | ||
999 | ret = xattr->size; | |
1000 | if (buffer) { | |
1001 | if (size < xattr->size) | |
1002 | ret = -ERANGE; | |
1003 | else | |
1004 | memcpy(buffer, xattr->value, xattr->size); | |
1005 | } | |
1006 | break; | |
1007 | } | |
1008 | spin_unlock(&xattrs->lock); | |
1009 | return ret; | |
1010 | } | |
1011 | ||
aa7c5241 AG |
1012 | /** |
1013 | * simple_xattr_set - xattr SET operation for in-memory/pseudo filesystems | |
1014 | * @xattrs: target simple_xattr list | |
1015 | * @name: name of the extended attribute | |
1016 | * @value: value of the xattr. If %NULL, will remove the attribute. | |
1017 | * @size: size of the new xattr | |
1018 | * @flags: %XATTR_{CREATE|REPLACE} | |
a46a2295 | 1019 | * @removed_size: returns size of the removed xattr, -1 if none removed |
aa7c5241 AG |
1020 | * |
1021 | * %XATTR_CREATE is set, the xattr shouldn't exist already; otherwise fails | |
1022 | * with -EEXIST. If %XATTR_REPLACE is set, the xattr should exist; | |
1023 | * otherwise, fails with -ENODATA. | |
1024 | * | |
1025 | * Returns 0 on success, -errno on failure. | |
1026 | */ | |
1027 | int simple_xattr_set(struct simple_xattrs *xattrs, const char *name, | |
a46a2295 DX |
1028 | const void *value, size_t size, int flags, |
1029 | ssize_t *removed_size) | |
38f38657 AR |
1030 | { |
1031 | struct simple_xattr *xattr; | |
43385846 | 1032 | struct simple_xattr *new_xattr = NULL; |
38f38657 AR |
1033 | int err = 0; |
1034 | ||
772b3140 DX |
1035 | if (removed_size) |
1036 | *removed_size = -1; | |
1037 | ||
38f38657 AR |
1038 | /* value == NULL means remove */ |
1039 | if (value) { | |
1040 | new_xattr = simple_xattr_alloc(value, size); | |
1041 | if (!new_xattr) | |
1042 | return -ENOMEM; | |
1043 | ||
1044 | new_xattr->name = kstrdup(name, GFP_KERNEL); | |
1045 | if (!new_xattr->name) { | |
fdc85222 | 1046 | kvfree(new_xattr); |
38f38657 AR |
1047 | return -ENOMEM; |
1048 | } | |
1049 | } | |
1050 | ||
1051 | spin_lock(&xattrs->lock); | |
1052 | list_for_each_entry(xattr, &xattrs->head, list) { | |
1053 | if (!strcmp(name, xattr->name)) { | |
1054 | if (flags & XATTR_CREATE) { | |
1055 | xattr = new_xattr; | |
1056 | err = -EEXIST; | |
1057 | } else if (new_xattr) { | |
1058 | list_replace(&xattr->list, &new_xattr->list); | |
a46a2295 DX |
1059 | if (removed_size) |
1060 | *removed_size = xattr->size; | |
38f38657 AR |
1061 | } else { |
1062 | list_del(&xattr->list); | |
a46a2295 DX |
1063 | if (removed_size) |
1064 | *removed_size = xattr->size; | |
38f38657 AR |
1065 | } |
1066 | goto out; | |
1067 | } | |
1068 | } | |
1069 | if (flags & XATTR_REPLACE) { | |
1070 | xattr = new_xattr; | |
1071 | err = -ENODATA; | |
1072 | } else { | |
1073 | list_add(&new_xattr->list, &xattrs->head); | |
1074 | xattr = NULL; | |
1075 | } | |
1076 | out: | |
1077 | spin_unlock(&xattrs->lock); | |
1078 | if (xattr) { | |
1079 | kfree(xattr->name); | |
fdc85222 | 1080 | kvfree(xattr); |
38f38657 AR |
1081 | } |
1082 | return err; | |
1083 | ||
1084 | } | |
1085 | ||
38f38657 AR |
1086 | static bool xattr_is_trusted(const char *name) |
1087 | { | |
1088 | return !strncmp(name, XATTR_TRUSTED_PREFIX, XATTR_TRUSTED_PREFIX_LEN); | |
1089 | } | |
1090 | ||
786534b9 AG |
1091 | static int xattr_list_one(char **buffer, ssize_t *remaining_size, |
1092 | const char *name) | |
1093 | { | |
1094 | size_t len = strlen(name) + 1; | |
1095 | if (*buffer) { | |
1096 | if (*remaining_size < len) | |
1097 | return -ERANGE; | |
1098 | memcpy(*buffer, name, len); | |
1099 | *buffer += len; | |
1100 | } | |
1101 | *remaining_size -= len; | |
1102 | return 0; | |
1103 | } | |
1104 | ||
38f38657 AR |
1105 | /* |
1106 | * xattr LIST operation for in-memory/pseudo filesystems | |
1107 | */ | |
786534b9 AG |
1108 | ssize_t simple_xattr_list(struct inode *inode, struct simple_xattrs *xattrs, |
1109 | char *buffer, size_t size) | |
38f38657 AR |
1110 | { |
1111 | bool trusted = capable(CAP_SYS_ADMIN); | |
1112 | struct simple_xattr *xattr; | |
786534b9 | 1113 | ssize_t remaining_size = size; |
0e9a7da5 | 1114 | int err = 0; |
786534b9 AG |
1115 | |
1116 | #ifdef CONFIG_FS_POSIX_ACL | |
ffc4c922 AG |
1117 | if (IS_POSIXACL(inode)) { |
1118 | if (inode->i_acl) { | |
1119 | err = xattr_list_one(&buffer, &remaining_size, | |
1120 | XATTR_NAME_POSIX_ACL_ACCESS); | |
1121 | if (err) | |
1122 | return err; | |
1123 | } | |
1124 | if (inode->i_default_acl) { | |
1125 | err = xattr_list_one(&buffer, &remaining_size, | |
1126 | XATTR_NAME_POSIX_ACL_DEFAULT); | |
1127 | if (err) | |
1128 | return err; | |
1129 | } | |
786534b9 AG |
1130 | } |
1131 | #endif | |
38f38657 AR |
1132 | |
1133 | spin_lock(&xattrs->lock); | |
1134 | list_for_each_entry(xattr, &xattrs->head, list) { | |
38f38657 AR |
1135 | /* skip "trusted." attributes for unprivileged callers */ |
1136 | if (!trusted && xattr_is_trusted(xattr->name)) | |
1137 | continue; | |
1138 | ||
786534b9 AG |
1139 | err = xattr_list_one(&buffer, &remaining_size, xattr->name); |
1140 | if (err) | |
0e9a7da5 | 1141 | break; |
38f38657 AR |
1142 | } |
1143 | spin_unlock(&xattrs->lock); | |
1144 | ||
0e9a7da5 | 1145 | return err ? err : size - remaining_size; |
38f38657 AR |
1146 | } |
1147 | ||
4895768b AR |
1148 | /* |
1149 | * Adds an extended attribute to the list | |
1150 | */ | |
38f38657 AR |
1151 | void simple_xattr_list_add(struct simple_xattrs *xattrs, |
1152 | struct simple_xattr *new_xattr) | |
1153 | { | |
1154 | spin_lock(&xattrs->lock); | |
1155 | list_add(&new_xattr->list, &xattrs->head); | |
1156 | spin_unlock(&xattrs->lock); | |
1157 | } |