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Commit | Line | Data |
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457c8996 | 1 | // SPDX-License-Identifier: GPL-2.0-only |
1da177e4 LT |
2 | /* |
3 | * linux/fs/open.c | |
4 | * | |
5 | * Copyright (C) 1991, 1992 Linus Torvalds | |
6 | */ | |
7 | ||
8 | #include <linux/string.h> | |
9 | #include <linux/mm.h> | |
1da177e4 | 10 | #include <linux/file.h> |
9f3acc31 | 11 | #include <linux/fdtable.h> |
0eeca283 | 12 | #include <linux/fsnotify.h> |
1da177e4 | 13 | #include <linux/module.h> |
1da177e4 LT |
14 | #include <linux/tty.h> |
15 | #include <linux/namei.h> | |
16 | #include <linux/backing-dev.h> | |
16f7e0fe | 17 | #include <linux/capability.h> |
086f7316 | 18 | #include <linux/securebits.h> |
1da177e4 LT |
19 | #include <linux/security.h> |
20 | #include <linux/mount.h> | |
5590ff0d | 21 | #include <linux/fcntl.h> |
5a0e3ad6 | 22 | #include <linux/slab.h> |
7c0f6ba6 | 23 | #include <linux/uaccess.h> |
1da177e4 | 24 | #include <linux/fs.h> |
ef3daeda | 25 | #include <linux/personality.h> |
1da177e4 LT |
26 | #include <linux/pagemap.h> |
27 | #include <linux/syscalls.h> | |
ab2af1f5 | 28 | #include <linux/rcupdate.h> |
73241ccc | 29 | #include <linux/audit.h> |
97ac7350 | 30 | #include <linux/falloc.h> |
5ad4e53b | 31 | #include <linux/fs_struct.h> |
b65a9cfc | 32 | #include <linux/ima.h> |
2dfc1cae | 33 | #include <linux/dnotify.h> |
3f6d078d | 34 | #include <linux/compat.h> |
c7c91d8d | 35 | #include <linux/mnt_idmapping.h> |
1da177e4 | 36 | |
e81e3f4d EP |
37 | #include "internal.h" |
38 | ||
643fe55a CB |
39 | int do_truncate(struct user_namespace *mnt_userns, struct dentry *dentry, |
40 | loff_t length, unsigned int time_attrs, struct file *filp) | |
1da177e4 | 41 | { |
939a9421 | 42 | int ret; |
1da177e4 LT |
43 | struct iattr newattrs; |
44 | ||
45 | /* Not pretty: "inode->i_size" shouldn't really be signed. But it is. */ | |
46 | if (length < 0) | |
47 | return -EINVAL; | |
48 | ||
49 | newattrs.ia_size = length; | |
4a30131e | 50 | newattrs.ia_valid = ATTR_SIZE | time_attrs; |
cc4e69de MS |
51 | if (filp) { |
52 | newattrs.ia_file = filp; | |
53 | newattrs.ia_valid |= ATTR_FILE; | |
54 | } | |
1da177e4 | 55 | |
45f147a1 JK |
56 | /* Remove suid, sgid, and file capabilities on truncate too */ |
57 | ret = dentry_needs_remove_privs(dentry); | |
58 | if (ret < 0) | |
59 | return ret; | |
939a9421 AW |
60 | if (ret) |
61 | newattrs.ia_valid |= ret | ATTR_FORCE; | |
7b82dc0e | 62 | |
5955102c | 63 | inode_lock(dentry->d_inode); |
27ac0ffe | 64 | /* Note any delegations or leases have already been broken: */ |
643fe55a | 65 | ret = notify_change(mnt_userns, dentry, &newattrs, NULL); |
5955102c | 66 | inode_unlock(dentry->d_inode); |
939a9421 | 67 | return ret; |
1da177e4 | 68 | } |
7fea21ae | 69 | EXPORT_SYMBOL_GPL(do_truncate); |
1da177e4 | 70 | |
7df818b2 | 71 | long vfs_truncate(const struct path *path, loff_t length) |
1da177e4 | 72 | { |
643fe55a | 73 | struct user_namespace *mnt_userns; |
2d8f3038 | 74 | struct inode *inode; |
a02de960 | 75 | long error; |
1da177e4 | 76 | |
a02de960 | 77 | inode = path->dentry->d_inode; |
1da177e4 LT |
78 | |
79 | /* For directories it's -EISDIR, for other non-regulars - -EINVAL */ | |
1da177e4 | 80 | if (S_ISDIR(inode->i_mode)) |
a02de960 | 81 | return -EISDIR; |
1da177e4 | 82 | if (!S_ISREG(inode->i_mode)) |
a02de960 | 83 | return -EINVAL; |
1da177e4 | 84 | |
a02de960 | 85 | error = mnt_want_write(path->mnt); |
1da177e4 | 86 | if (error) |
a02de960 | 87 | goto out; |
1da177e4 | 88 | |
643fe55a CB |
89 | mnt_userns = mnt_user_ns(path->mnt); |
90 | error = inode_permission(mnt_userns, inode, MAY_WRITE); | |
9ac9b847 DH |
91 | if (error) |
92 | goto mnt_drop_write_and_out; | |
1da177e4 LT |
93 | |
94 | error = -EPERM; | |
c82e42da | 95 | if (IS_APPEND(inode)) |
9ac9b847 | 96 | goto mnt_drop_write_and_out; |
1da177e4 | 97 | |
8cf9ee50 | 98 | error = get_write_access(inode); |
1da177e4 | 99 | if (error) |
9ac9b847 | 100 | goto mnt_drop_write_and_out; |
1da177e4 | 101 | |
9700382c | 102 | /* |
103 | * Make sure that there are no leases. get_write_access() protects | |
104 | * against the truncate racing with a lease-granting setlease(). | |
105 | */ | |
8737c930 | 106 | error = break_lease(inode, O_WRONLY); |
1da177e4 | 107 | if (error) |
9700382c | 108 | goto put_write_and_out; |
1da177e4 | 109 | |
f7e33bdb | 110 | error = security_path_truncate(path); |
907f4554 | 111 | if (!error) |
643fe55a | 112 | error = do_truncate(mnt_userns, path->dentry, length, 0, NULL); |
1da177e4 | 113 | |
9700382c | 114 | put_write_and_out: |
8cf9ee50 | 115 | put_write_access(inode); |
9ac9b847 | 116 | mnt_drop_write_and_out: |
a02de960 | 117 | mnt_drop_write(path->mnt); |
1da177e4 LT |
118 | out: |
119 | return error; | |
120 | } | |
a02de960 DH |
121 | EXPORT_SYMBOL_GPL(vfs_truncate); |
122 | ||
df260e21 | 123 | long do_sys_truncate(const char __user *pathname, loff_t length) |
a02de960 | 124 | { |
48f7530d | 125 | unsigned int lookup_flags = LOOKUP_FOLLOW; |
a02de960 DH |
126 | struct path path; |
127 | int error; | |
128 | ||
129 | if (length < 0) /* sorry, but loff_t says... */ | |
130 | return -EINVAL; | |
131 | ||
48f7530d JL |
132 | retry: |
133 | error = user_path_at(AT_FDCWD, pathname, lookup_flags, &path); | |
a02de960 DH |
134 | if (!error) { |
135 | error = vfs_truncate(&path, length); | |
136 | path_put(&path); | |
137 | } | |
48f7530d JL |
138 | if (retry_estale(error, lookup_flags)) { |
139 | lookup_flags |= LOOKUP_REVAL; | |
140 | goto retry; | |
141 | } | |
a02de960 DH |
142 | return error; |
143 | } | |
1da177e4 | 144 | |
4fd8da8d | 145 | SYSCALL_DEFINE2(truncate, const char __user *, path, long, length) |
1da177e4 | 146 | { |
4fd8da8d | 147 | return do_sys_truncate(path, length); |
1da177e4 LT |
148 | } |
149 | ||
3f6d078d AV |
150 | #ifdef CONFIG_COMPAT |
151 | COMPAT_SYSCALL_DEFINE2(truncate, const char __user *, path, compat_off_t, length) | |
152 | { | |
153 | return do_sys_truncate(path, length); | |
154 | } | |
155 | #endif | |
156 | ||
411d9475 | 157 | long do_sys_ftruncate(unsigned int fd, loff_t length, int small) |
1da177e4 | 158 | { |
bf2965d5 | 159 | struct inode *inode; |
1da177e4 | 160 | struct dentry *dentry; |
2903ff01 | 161 | struct fd f; |
1da177e4 LT |
162 | int error; |
163 | ||
164 | error = -EINVAL; | |
165 | if (length < 0) | |
166 | goto out; | |
167 | error = -EBADF; | |
2903ff01 AV |
168 | f = fdget(fd); |
169 | if (!f.file) | |
1da177e4 LT |
170 | goto out; |
171 | ||
172 | /* explicitly opened as large or we are on 64-bit box */ | |
2903ff01 | 173 | if (f.file->f_flags & O_LARGEFILE) |
1da177e4 LT |
174 | small = 0; |
175 | ||
2903ff01 | 176 | dentry = f.file->f_path.dentry; |
1da177e4 LT |
177 | inode = dentry->d_inode; |
178 | error = -EINVAL; | |
2903ff01 | 179 | if (!S_ISREG(inode->i_mode) || !(f.file->f_mode & FMODE_WRITE)) |
1da177e4 LT |
180 | goto out_putf; |
181 | ||
182 | error = -EINVAL; | |
183 | /* Cannot ftruncate over 2^31 bytes without large file support */ | |
184 | if (small && length > MAX_NON_LFS) | |
185 | goto out_putf; | |
186 | ||
187 | error = -EPERM; | |
78757af6 AG |
188 | /* Check IS_APPEND on real upper inode */ |
189 | if (IS_APPEND(file_inode(f.file))) | |
1da177e4 | 190 | goto out_putf; |
14da9200 | 191 | sb_start_write(inode->i_sb); |
f7e33bdb | 192 | error = security_path_truncate(&f.file->f_path); |
1da177e4 | 193 | if (!error) |
643fe55a CB |
194 | error = do_truncate(file_mnt_user_ns(f.file), dentry, length, |
195 | ATTR_MTIME | ATTR_CTIME, f.file); | |
14da9200 | 196 | sb_end_write(inode->i_sb); |
1da177e4 | 197 | out_putf: |
2903ff01 | 198 | fdput(f); |
1da177e4 LT |
199 | out: |
200 | return error; | |
201 | } | |
202 | ||
bdc480e3 | 203 | SYSCALL_DEFINE2(ftruncate, unsigned int, fd, unsigned long, length) |
1da177e4 | 204 | { |
2cf09666 | 205 | return do_sys_ftruncate(fd, length, 1); |
1da177e4 LT |
206 | } |
207 | ||
3f6d078d AV |
208 | #ifdef CONFIG_COMPAT |
209 | COMPAT_SYSCALL_DEFINE2(ftruncate, unsigned int, fd, compat_ulong_t, length) | |
210 | { | |
211 | return do_sys_ftruncate(fd, length, 1); | |
212 | } | |
213 | #endif | |
214 | ||
1da177e4 LT |
215 | /* LFS versions of truncate are only needed on 32 bit machines */ |
216 | #if BITS_PER_LONG == 32 | |
4a0fd5bf | 217 | SYSCALL_DEFINE2(truncate64, const char __user *, path, loff_t, length) |
1da177e4 LT |
218 | { |
219 | return do_sys_truncate(path, length); | |
220 | } | |
221 | ||
4a0fd5bf | 222 | SYSCALL_DEFINE2(ftruncate64, unsigned int, fd, loff_t, length) |
1da177e4 | 223 | { |
2cf09666 | 224 | return do_sys_ftruncate(fd, length, 0); |
1da177e4 | 225 | } |
6673e0c3 | 226 | #endif /* BITS_PER_LONG == 32 */ |
1da177e4 | 227 | |
3e63cbb1 | 228 | |
72c72bdf | 229 | int vfs_fallocate(struct file *file, int mode, loff_t offset, loff_t len) |
97ac7350 | 230 | { |
496ad9aa | 231 | struct inode *inode = file_inode(file); |
3e63cbb1 | 232 | long ret; |
97ac7350 AA |
233 | |
234 | if (offset < 0 || len <= 0) | |
3e63cbb1 | 235 | return -EINVAL; |
97ac7350 AA |
236 | |
237 | /* Return error if mode is not supported */ | |
dd46c787 | 238 | if (mode & ~FALLOC_FL_SUPPORTED_MASK) |
409332b6 LC |
239 | return -EOPNOTSUPP; |
240 | ||
241 | /* Punch hole and zero range are mutually exclusive */ | |
242 | if ((mode & (FALLOC_FL_PUNCH_HOLE | FALLOC_FL_ZERO_RANGE)) == | |
243 | (FALLOC_FL_PUNCH_HOLE | FALLOC_FL_ZERO_RANGE)) | |
79124f18 JB |
244 | return -EOPNOTSUPP; |
245 | ||
246 | /* Punch hole must have keep size set */ | |
247 | if ((mode & FALLOC_FL_PUNCH_HOLE) && | |
248 | !(mode & FALLOC_FL_KEEP_SIZE)) | |
3e63cbb1 | 249 | return -EOPNOTSUPP; |
97ac7350 | 250 | |
00f5e619 NJ |
251 | /* Collapse range should only be used exclusively. */ |
252 | if ((mode & FALLOC_FL_COLLAPSE_RANGE) && | |
253 | (mode & ~FALLOC_FL_COLLAPSE_RANGE)) | |
254 | return -EINVAL; | |
255 | ||
dd46c787 NJ |
256 | /* Insert range should only be used exclusively. */ |
257 | if ((mode & FALLOC_FL_INSERT_RANGE) && | |
258 | (mode & ~FALLOC_FL_INSERT_RANGE)) | |
259 | return -EINVAL; | |
260 | ||
71be6b49 DW |
261 | /* Unshare range should only be used with allocate mode. */ |
262 | if ((mode & FALLOC_FL_UNSHARE_RANGE) && | |
263 | (mode & ~(FALLOC_FL_UNSHARE_RANGE | FALLOC_FL_KEEP_SIZE))) | |
264 | return -EINVAL; | |
265 | ||
97ac7350 | 266 | if (!(file->f_mode & FMODE_WRITE)) |
3e63cbb1 | 267 | return -EBADF; |
1ca551c6 | 268 | |
00f5e619 | 269 | /* |
8fc61d92 | 270 | * We can only allow pure fallocate on append only files |
00f5e619 | 271 | */ |
8fc61d92 | 272 | if ((mode & ~FALLOC_FL_KEEP_SIZE) && IS_APPEND(inode)) |
1ca551c6 MS |
273 | return -EPERM; |
274 | ||
275 | if (IS_IMMUTABLE(inode)) | |
276 | return -EPERM; | |
277 | ||
0790b31b | 278 | /* |
6d2b6170 | 279 | * We cannot allow any fallocate operation on an active swapfile |
0790b31b LC |
280 | */ |
281 | if (IS_SWAPFILE(inode)) | |
6d2b6170 | 282 | return -ETXTBSY; |
0790b31b | 283 | |
97ac7350 AA |
284 | /* |
285 | * Revalidate the write permissions, in case security policy has | |
286 | * changed since the files were opened. | |
287 | */ | |
288 | ret = security_file_permission(file, MAY_WRITE); | |
289 | if (ret) | |
3e63cbb1 | 290 | return ret; |
97ac7350 | 291 | |
97ac7350 | 292 | if (S_ISFIFO(inode->i_mode)) |
3e63cbb1 | 293 | return -ESPIPE; |
97ac7350 | 294 | |
9e79b132 AG |
295 | if (S_ISDIR(inode->i_mode)) |
296 | return -EISDIR; | |
297 | ||
298 | if (!S_ISREG(inode->i_mode) && !S_ISBLK(inode->i_mode)) | |
3e63cbb1 | 299 | return -ENODEV; |
97ac7350 | 300 | |
97ac7350 AA |
301 | /* Check for wrap through zero too */ |
302 | if (((offset + len) > inode->i_sb->s_maxbytes) || ((offset + len) < 0)) | |
3e63cbb1 | 303 | return -EFBIG; |
97ac7350 | 304 | |
2fe17c10 | 305 | if (!file->f_op->fallocate) |
3e63cbb1 | 306 | return -EOPNOTSUPP; |
97ac7350 | 307 | |
bfe219d3 | 308 | file_start_write(file); |
14da9200 | 309 | ret = file->f_op->fallocate(file, mode, offset, len); |
820c12d5 HS |
310 | |
311 | /* | |
312 | * Create inotify and fanotify events. | |
313 | * | |
314 | * To keep the logic simple always create events if fallocate succeeds. | |
315 | * This implies that events are even created if the file size remains | |
316 | * unchanged, e.g. when using flag FALLOC_FL_KEEP_SIZE. | |
317 | */ | |
318 | if (ret == 0) | |
319 | fsnotify_modify(file); | |
320 | ||
bfe219d3 | 321 | file_end_write(file); |
14da9200 | 322 | return ret; |
3e63cbb1 | 323 | } |
72c72bdf | 324 | EXPORT_SYMBOL_GPL(vfs_fallocate); |
3e63cbb1 | 325 | |
edf292c7 | 326 | int ksys_fallocate(int fd, int mode, loff_t offset, loff_t len) |
3e63cbb1 | 327 | { |
2903ff01 | 328 | struct fd f = fdget(fd); |
3e63cbb1 AJ |
329 | int error = -EBADF; |
330 | ||
2903ff01 | 331 | if (f.file) { |
72c72bdf | 332 | error = vfs_fallocate(f.file, mode, offset, len); |
2903ff01 | 333 | fdput(f); |
3e63cbb1 | 334 | } |
3e63cbb1 | 335 | return error; |
97ac7350 | 336 | } |
3e63cbb1 | 337 | |
edf292c7 DB |
338 | SYSCALL_DEFINE4(fallocate, int, fd, int, mode, loff_t, offset, loff_t, len) |
339 | { | |
340 | return ksys_fallocate(fd, mode, offset, len); | |
341 | } | |
342 | ||
1da177e4 LT |
343 | /* |
344 | * access() needs to use the real uid/gid, not the effective uid/gid. | |
345 | * We do this by temporarily clearing all FS-related capabilities and | |
346 | * switching the fsuid/fsgid around to the real ones. | |
347 | */ | |
94704515 | 348 | static const struct cred *access_override_creds(void) |
1da177e4 | 349 | { |
d84f4f99 DH |
350 | const struct cred *old_cred; |
351 | struct cred *override_cred; | |
1da177e4 | 352 | |
d84f4f99 DH |
353 | override_cred = prepare_creds(); |
354 | if (!override_cred) | |
94704515 | 355 | return NULL; |
1da177e4 | 356 | |
d84f4f99 DH |
357 | override_cred->fsuid = override_cred->uid; |
358 | override_cred->fsgid = override_cred->gid; | |
1da177e4 | 359 | |
086f7316 | 360 | if (!issecure(SECURE_NO_SETUID_FIXUP)) { |
1cdcbec1 | 361 | /* Clear the capabilities if we switch to a non-root user */ |
18815a18 EB |
362 | kuid_t root_uid = make_kuid(override_cred->user_ns, 0); |
363 | if (!uid_eq(override_cred->uid, root_uid)) | |
d84f4f99 | 364 | cap_clear(override_cred->cap_effective); |
086f7316 | 365 | else |
d84f4f99 DH |
366 | override_cred->cap_effective = |
367 | override_cred->cap_permitted; | |
086f7316 | 368 | } |
1da177e4 | 369 | |
d7852fbd LT |
370 | /* |
371 | * The new set of credentials can *only* be used in | |
372 | * task-synchronous circumstances, and does not need | |
373 | * RCU freeing, unless somebody then takes a separate | |
374 | * reference to it. | |
375 | * | |
376 | * NOTE! This is _only_ true because this credential | |
377 | * is used purely for override_creds() that installs | |
378 | * it as the subjective cred. Other threads will be | |
379 | * accessing ->real_cred, not the subjective cred. | |
380 | * | |
381 | * If somebody _does_ make a copy of this (using the | |
382 | * 'get_current_cred()' function), that will clear the | |
383 | * non_rcu field, because now that other user may be | |
384 | * expecting RCU freeing. But normal thread-synchronous | |
385 | * cred accesses will keep things non-RCY. | |
386 | */ | |
387 | override_cred->non_rcu = 1; | |
388 | ||
d84f4f99 | 389 | old_cred = override_creds(override_cred); |
94704515 MS |
390 | |
391 | /* override_cred() gets its own ref */ | |
392 | put_cred(override_cred); | |
393 | ||
394 | return old_cred; | |
395 | } | |
396 | ||
eb9d7d39 | 397 | static long do_faccessat(int dfd, const char __user *filename, int mode, int flags) |
94704515 MS |
398 | { |
399 | struct path path; | |
400 | struct inode *inode; | |
401 | int res; | |
402 | unsigned int lookup_flags = LOOKUP_FOLLOW; | |
c8ffd8bc | 403 | const struct cred *old_cred = NULL; |
94704515 MS |
404 | |
405 | if (mode & ~S_IRWXO) /* where's F_OK, X_OK, W_OK, R_OK? */ | |
406 | return -EINVAL; | |
407 | ||
c8ffd8bc MS |
408 | if (flags & ~(AT_EACCESS | AT_SYMLINK_NOFOLLOW | AT_EMPTY_PATH)) |
409 | return -EINVAL; | |
410 | ||
411 | if (flags & AT_SYMLINK_NOFOLLOW) | |
412 | lookup_flags &= ~LOOKUP_FOLLOW; | |
413 | if (flags & AT_EMPTY_PATH) | |
414 | lookup_flags |= LOOKUP_EMPTY; | |
415 | ||
416 | if (!(flags & AT_EACCESS)) { | |
417 | old_cred = access_override_creds(); | |
418 | if (!old_cred) | |
419 | return -ENOMEM; | |
420 | } | |
94704515 | 421 | |
87fa5595 JL |
422 | retry: |
423 | res = user_path_at(dfd, filename, lookup_flags, &path); | |
6902d925 DH |
424 | if (res) |
425 | goto out; | |
426 | ||
63afdfc7 | 427 | inode = d_backing_inode(path.dentry); |
256984a8 AV |
428 | |
429 | if ((mode & MAY_EXEC) && S_ISREG(inode->i_mode)) { | |
30524472 AV |
430 | /* |
431 | * MAY_EXEC on regular files is denied if the fs is mounted | |
432 | * with the "noexec" flag. | |
433 | */ | |
434 | res = -EACCES; | |
90f8572b | 435 | if (path_noexec(&path)) |
30524472 AV |
436 | goto out_path_release; |
437 | } | |
438 | ||
b8b546a0 | 439 | res = inode_permission(mnt_user_ns(path.mnt), inode, mode | MAY_ACCESS); |
6902d925 | 440 | /* SuS v2 requires we report a read only fs too */ |
256984a8 | 441 | if (res || !(mode & S_IWOTH) || special_file(inode->i_mode)) |
6902d925 | 442 | goto out_path_release; |
2f676cbc DH |
443 | /* |
444 | * This is a rare case where using __mnt_is_readonly() | |
445 | * is OK without a mnt_want/drop_write() pair. Since | |
446 | * no actual write to the fs is performed here, we do | |
447 | * not need to telegraph to that to anyone. | |
448 | * | |
449 | * By doing this, we accept that this access is | |
450 | * inherently racy and know that the fs may change | |
451 | * state before we even see this result. | |
452 | */ | |
2d8f3038 | 453 | if (__mnt_is_readonly(path.mnt)) |
6902d925 | 454 | res = -EROFS; |
1da177e4 | 455 | |
6902d925 | 456 | out_path_release: |
2d8f3038 | 457 | path_put(&path); |
87fa5595 JL |
458 | if (retry_estale(res, lookup_flags)) { |
459 | lookup_flags |= LOOKUP_REVAL; | |
460 | goto retry; | |
461 | } | |
6902d925 | 462 | out: |
c8ffd8bc MS |
463 | if (old_cred) |
464 | revert_creds(old_cred); | |
465 | ||
1da177e4 LT |
466 | return res; |
467 | } | |
468 | ||
cbfe20f5 DB |
469 | SYSCALL_DEFINE3(faccessat, int, dfd, const char __user *, filename, int, mode) |
470 | { | |
c8ffd8bc MS |
471 | return do_faccessat(dfd, filename, mode, 0); |
472 | } | |
473 | ||
474 | SYSCALL_DEFINE4(faccessat2, int, dfd, const char __user *, filename, int, mode, | |
475 | int, flags) | |
476 | { | |
477 | return do_faccessat(dfd, filename, mode, flags); | |
cbfe20f5 DB |
478 | } |
479 | ||
ca013e94 | 480 | SYSCALL_DEFINE2(access, const char __user *, filename, int, mode) |
5590ff0d | 481 | { |
c8ffd8bc | 482 | return do_faccessat(AT_FDCWD, filename, mode, 0); |
5590ff0d UD |
483 | } |
484 | ||
db63f1e3 | 485 | SYSCALL_DEFINE1(chdir, const char __user *, filename) |
1da177e4 | 486 | { |
2d8f3038 | 487 | struct path path; |
1da177e4 | 488 | int error; |
0291c0a5 JL |
489 | unsigned int lookup_flags = LOOKUP_FOLLOW | LOOKUP_DIRECTORY; |
490 | retry: | |
491 | error = user_path_at(AT_FDCWD, filename, lookup_flags, &path); | |
1da177e4 LT |
492 | if (error) |
493 | goto out; | |
494 | ||
02f92b38 | 495 | error = path_permission(&path, MAY_EXEC | MAY_CHDIR); |
1da177e4 LT |
496 | if (error) |
497 | goto dput_and_out; | |
498 | ||
2d8f3038 | 499 | set_fs_pwd(current->fs, &path); |
1da177e4 LT |
500 | |
501 | dput_and_out: | |
2d8f3038 | 502 | path_put(&path); |
0291c0a5 JL |
503 | if (retry_estale(error, lookup_flags)) { |
504 | lookup_flags |= LOOKUP_REVAL; | |
505 | goto retry; | |
506 | } | |
1da177e4 LT |
507 | out: |
508 | return error; | |
509 | } | |
510 | ||
3cdad428 | 511 | SYSCALL_DEFINE1(fchdir, unsigned int, fd) |
1da177e4 | 512 | { |
2903ff01 | 513 | struct fd f = fdget_raw(fd); |
159b0956 | 514 | int error; |
1da177e4 LT |
515 | |
516 | error = -EBADF; | |
2903ff01 | 517 | if (!f.file) |
1da177e4 LT |
518 | goto out; |
519 | ||
1da177e4 | 520 | error = -ENOTDIR; |
159b0956 | 521 | if (!d_can_lookup(f.file->f_path.dentry)) |
1da177e4 LT |
522 | goto out_putf; |
523 | ||
02f92b38 | 524 | error = file_permission(f.file, MAY_EXEC | MAY_CHDIR); |
1da177e4 | 525 | if (!error) |
2903ff01 | 526 | set_fs_pwd(current->fs, &f.file->f_path); |
1da177e4 | 527 | out_putf: |
2903ff01 | 528 | fdput(f); |
1da177e4 LT |
529 | out: |
530 | return error; | |
531 | } | |
532 | ||
4b7ca501 | 533 | SYSCALL_DEFINE1(chroot, const char __user *, filename) |
1da177e4 | 534 | { |
2d8f3038 | 535 | struct path path; |
1da177e4 | 536 | int error; |
2771261e JL |
537 | unsigned int lookup_flags = LOOKUP_FOLLOW | LOOKUP_DIRECTORY; |
538 | retry: | |
539 | error = user_path_at(AT_FDCWD, filename, lookup_flags, &path); | |
1da177e4 LT |
540 | if (error) |
541 | goto out; | |
542 | ||
02f92b38 | 543 | error = path_permission(&path, MAY_EXEC | MAY_CHDIR); |
1da177e4 LT |
544 | if (error) |
545 | goto dput_and_out; | |
546 | ||
547 | error = -EPERM; | |
c7b96acf | 548 | if (!ns_capable(current_user_ns(), CAP_SYS_CHROOT)) |
1da177e4 | 549 | goto dput_and_out; |
8b8efb44 TH |
550 | error = security_path_chroot(&path); |
551 | if (error) | |
552 | goto dput_and_out; | |
1da177e4 | 553 | |
2d8f3038 | 554 | set_fs_root(current->fs, &path); |
1da177e4 LT |
555 | error = 0; |
556 | dput_and_out: | |
2d8f3038 | 557 | path_put(&path); |
2771261e JL |
558 | if (retry_estale(error, lookup_flags)) { |
559 | lookup_flags |= LOOKUP_REVAL; | |
560 | goto retry; | |
561 | } | |
1da177e4 LT |
562 | out: |
563 | return error; | |
564 | } | |
565 | ||
1097742e | 566 | int chmod_common(const struct path *path, umode_t mode) |
1da177e4 | 567 | { |
e57712eb | 568 | struct inode *inode = path->dentry->d_inode; |
27ac0ffe | 569 | struct inode *delegated_inode = NULL; |
1da177e4 | 570 | struct iattr newattrs; |
e57712eb | 571 | int error; |
1da177e4 | 572 | |
e57712eb AV |
573 | error = mnt_want_write(path->mnt); |
574 | if (error) | |
575 | return error; | |
27ac0ffe | 576 | retry_deleg: |
5955102c | 577 | inode_lock(inode); |
cdcf116d | 578 | error = security_path_chmod(path, mode); |
e57712eb | 579 | if (error) |
fe542cf5 | 580 | goto out_unlock; |
1da177e4 LT |
581 | newattrs.ia_mode = (mode & S_IALLUGO) | (inode->i_mode & ~S_IALLUGO); |
582 | newattrs.ia_valid = ATTR_MODE | ATTR_CTIME; | |
b8b546a0 CB |
583 | error = notify_change(mnt_user_ns(path->mnt), path->dentry, |
584 | &newattrs, &delegated_inode); | |
fe542cf5 | 585 | out_unlock: |
5955102c | 586 | inode_unlock(inode); |
27ac0ffe BF |
587 | if (delegated_inode) { |
588 | error = break_deleg_wait(&delegated_inode); | |
589 | if (!error) | |
590 | goto retry_deleg; | |
591 | } | |
e57712eb AV |
592 | mnt_drop_write(path->mnt); |
593 | return error; | |
594 | } | |
595 | ||
9e96c8c0 CH |
596 | int vfs_fchmod(struct file *file, umode_t mode) |
597 | { | |
598 | audit_file(file); | |
599 | return chmod_common(&file->f_path, mode); | |
600 | } | |
601 | ||
b25ba7c3 | 602 | SYSCALL_DEFINE2(fchmod, unsigned int, fd, umode_t, mode) |
e57712eb | 603 | { |
173c8401 | 604 | struct fd f = fdget(fd); |
e57712eb AV |
605 | int err = -EBADF; |
606 | ||
173c8401 | 607 | if (f.file) { |
9e96c8c0 | 608 | err = vfs_fchmod(f.file, mode); |
173c8401 | 609 | fdput(f); |
e57712eb | 610 | } |
1da177e4 LT |
611 | return err; |
612 | } | |
613 | ||
1097742e | 614 | static int do_fchmodat(int dfd, const char __user *filename, umode_t mode) |
1da177e4 | 615 | { |
2d8f3038 | 616 | struct path path; |
1da177e4 | 617 | int error; |
14ff690c JL |
618 | unsigned int lookup_flags = LOOKUP_FOLLOW; |
619 | retry: | |
620 | error = user_path_at(dfd, filename, lookup_flags, &path); | |
e57712eb AV |
621 | if (!error) { |
622 | error = chmod_common(&path, mode); | |
623 | path_put(&path); | |
14ff690c JL |
624 | if (retry_estale(error, lookup_flags)) { |
625 | lookup_flags |= LOOKUP_REVAL; | |
626 | goto retry; | |
627 | } | |
e57712eb | 628 | } |
1da177e4 LT |
629 | return error; |
630 | } | |
631 | ||
03450e27 DB |
632 | SYSCALL_DEFINE3(fchmodat, int, dfd, const char __user *, filename, |
633 | umode_t, mode) | |
634 | { | |
635 | return do_fchmodat(dfd, filename, mode); | |
636 | } | |
637 | ||
49f0a076 | 638 | SYSCALL_DEFINE2(chmod, const char __user *, filename, umode_t, mode) |
5590ff0d | 639 | { |
03450e27 | 640 | return do_fchmodat(AT_FDCWD, filename, mode); |
5590ff0d UD |
641 | } |
642 | ||
b873498f | 643 | int chown_common(const struct path *path, uid_t user, gid_t group) |
1da177e4 | 644 | { |
911a39c1 | 645 | struct user_namespace *mnt_userns, *fs_userns; |
fe542cf5 | 646 | struct inode *inode = path->dentry->d_inode; |
27ac0ffe | 647 | struct inode *delegated_inode = NULL; |
1da177e4 LT |
648 | int error; |
649 | struct iattr newattrs; | |
52137abe EB |
650 | kuid_t uid; |
651 | kgid_t gid; | |
652 | ||
653 | uid = make_kuid(current_user_ns(), user); | |
654 | gid = make_kgid(current_user_ns(), group); | |
1da177e4 | 655 | |
b8b546a0 | 656 | mnt_userns = mnt_user_ns(path->mnt); |
911a39c1 CB |
657 | fs_userns = i_user_ns(inode); |
658 | uid = mapped_kuid_user(mnt_userns, fs_userns, uid); | |
659 | gid = mapped_kgid_user(mnt_userns, fs_userns, gid); | |
b8b546a0 | 660 | |
c1b8940b | 661 | retry_deleg: |
1da177e4 LT |
662 | newattrs.ia_valid = ATTR_CTIME; |
663 | if (user != (uid_t) -1) { | |
52137abe EB |
664 | if (!uid_valid(uid)) |
665 | return -EINVAL; | |
1da177e4 | 666 | newattrs.ia_valid |= ATTR_UID; |
52137abe | 667 | newattrs.ia_uid = uid; |
1da177e4 LT |
668 | } |
669 | if (group != (gid_t) -1) { | |
52137abe EB |
670 | if (!gid_valid(gid)) |
671 | return -EINVAL; | |
1da177e4 | 672 | newattrs.ia_valid |= ATTR_GID; |
52137abe | 673 | newattrs.ia_gid = gid; |
1da177e4 LT |
674 | } |
675 | if (!S_ISDIR(inode->i_mode)) | |
b5376771 SH |
676 | newattrs.ia_valid |= |
677 | ATTR_KILL_SUID | ATTR_KILL_SGID | ATTR_KILL_PRIV; | |
5955102c | 678 | inode_lock(inode); |
d2b31ca6 | 679 | error = security_path_chown(path, uid, gid); |
fe542cf5 | 680 | if (!error) |
b8b546a0 | 681 | error = notify_change(mnt_userns, path->dentry, &newattrs, |
2f221d6f | 682 | &delegated_inode); |
5955102c | 683 | inode_unlock(inode); |
27ac0ffe BF |
684 | if (delegated_inode) { |
685 | error = break_deleg_wait(&delegated_inode); | |
686 | if (!error) | |
687 | goto retry_deleg; | |
688 | } | |
1da177e4 LT |
689 | return error; |
690 | } | |
691 | ||
55731b3c DB |
692 | int do_fchownat(int dfd, const char __user *filename, uid_t user, gid_t group, |
693 | int flag) | |
5590ff0d | 694 | { |
2d8f3038 | 695 | struct path path; |
5590ff0d | 696 | int error = -EINVAL; |
65cfc672 | 697 | int lookup_flags; |
5590ff0d | 698 | |
65cfc672 | 699 | if ((flag & ~(AT_SYMLINK_NOFOLLOW | AT_EMPTY_PATH)) != 0) |
5590ff0d UD |
700 | goto out; |
701 | ||
65cfc672 AV |
702 | lookup_flags = (flag & AT_SYMLINK_NOFOLLOW) ? 0 : LOOKUP_FOLLOW; |
703 | if (flag & AT_EMPTY_PATH) | |
704 | lookup_flags |= LOOKUP_EMPTY; | |
99a5df37 | 705 | retry: |
65cfc672 | 706 | error = user_path_at(dfd, filename, lookup_flags, &path); |
6902d925 DH |
707 | if (error) |
708 | goto out; | |
2d8f3038 | 709 | error = mnt_want_write(path.mnt); |
2af482a7 DH |
710 | if (error) |
711 | goto out_release; | |
fe542cf5 | 712 | error = chown_common(&path, user, group); |
2d8f3038 | 713 | mnt_drop_write(path.mnt); |
2af482a7 | 714 | out_release: |
2d8f3038 | 715 | path_put(&path); |
99a5df37 JL |
716 | if (retry_estale(error, lookup_flags)) { |
717 | lookup_flags |= LOOKUP_REVAL; | |
718 | goto retry; | |
719 | } | |
5590ff0d UD |
720 | out: |
721 | return error; | |
722 | } | |
723 | ||
55731b3c DB |
724 | SYSCALL_DEFINE5(fchownat, int, dfd, const char __user *, filename, uid_t, user, |
725 | gid_t, group, int, flag) | |
726 | { | |
727 | return do_fchownat(dfd, filename, user, group, flag); | |
728 | } | |
729 | ||
55e4def0 | 730 | SYSCALL_DEFINE3(chown, const char __user *, filename, uid_t, user, gid_t, group) |
1da177e4 | 731 | { |
55731b3c | 732 | return do_fchownat(AT_FDCWD, filename, user, group, 0); |
55e4def0 | 733 | } |
1da177e4 | 734 | |
55e4def0 DH |
735 | SYSCALL_DEFINE3(lchown, const char __user *, filename, uid_t, user, gid_t, group) |
736 | { | |
55731b3c DB |
737 | return do_fchownat(AT_FDCWD, filename, user, group, |
738 | AT_SYMLINK_NOFOLLOW); | |
1da177e4 LT |
739 | } |
740 | ||
c04011fe CH |
741 | int vfs_fchown(struct file *file, uid_t user, gid_t group) |
742 | { | |
743 | int error; | |
744 | ||
745 | error = mnt_want_write_file(file); | |
746 | if (error) | |
747 | return error; | |
748 | audit_file(file); | |
749 | error = chown_common(&file->f_path, user, group); | |
750 | mnt_drop_write_file(file); | |
751 | return error; | |
752 | } | |
753 | ||
55731b3c | 754 | int ksys_fchown(unsigned int fd, uid_t user, gid_t group) |
1da177e4 | 755 | { |
2903ff01 | 756 | struct fd f = fdget(fd); |
1da177e4 LT |
757 | int error = -EBADF; |
758 | ||
c04011fe CH |
759 | if (f.file) { |
760 | error = vfs_fchown(f.file, user, group); | |
761 | fdput(f); | |
762 | } | |
1da177e4 LT |
763 | return error; |
764 | } | |
765 | ||
55731b3c DB |
766 | SYSCALL_DEFINE3(fchown, unsigned int, fd, uid_t, user, gid_t, group) |
767 | { | |
768 | return ksys_fchown(fd, user, group); | |
769 | } | |
770 | ||
02e5180d | 771 | static int do_dentry_open(struct file *f, |
4bacc9c9 | 772 | struct inode *inode, |
ae2bb293 | 773 | int (*open)(struct inode *, struct file *)) |
1da177e4 | 774 | { |
1abf0c71 | 775 | static const struct file_operations empty_fops = {}; |
1da177e4 LT |
776 | int error; |
777 | ||
b5bcdda3 | 778 | path_get(&f->f_path); |
4bacc9c9 | 779 | f->f_inode = inode; |
1da177e4 | 780 | f->f_mapping = inode->i_mapping; |
5660e13d | 781 | f->f_wb_err = filemap_sample_wb_err(f->f_mapping); |
735e4ae5 | 782 | f->f_sb_err = file_sample_sb_err(f); |
5660e13d | 783 | |
3f4d5a00 | 784 | if (unlikely(f->f_flags & O_PATH)) { |
f5d11409 | 785 | f->f_mode = FMODE_PATH | FMODE_OPENED; |
1abf0c71 | 786 | f->f_op = &empty_fops; |
af04fadc | 787 | return 0; |
1abf0c71 AV |
788 | } |
789 | ||
dd20908a | 790 | if (f->f_mode & FMODE_WRITE && !special_file(inode->i_mode)) { |
0ccb2863 | 791 | error = get_write_access(inode); |
3f4d5a00 | 792 | if (unlikely(error)) |
1da177e4 | 793 | goto cleanup_file; |
0ccb2863 | 794 | error = __mnt_want_write(f->f_path.mnt); |
3f4d5a00 | 795 | if (unlikely(error)) { |
0ccb2863 AV |
796 | put_write_access(inode); |
797 | goto cleanup_file; | |
798 | } | |
83f936c7 | 799 | f->f_mode |= FMODE_WRITER; |
1da177e4 LT |
800 | } |
801 | ||
2be7d348 LT |
802 | /* POSIX.1-2008/SUSv4 Section XSI 2.9.7 */ |
803 | if (S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode)) | |
804 | f->f_mode |= FMODE_ATOMIC_POS; | |
805 | ||
1abf0c71 | 806 | f->f_op = fops_get(inode->i_fop); |
7159d544 | 807 | if (WARN_ON(!f->f_op)) { |
72c2d531 AV |
808 | error = -ENODEV; |
809 | goto cleanup_all; | |
810 | } | |
1abf0c71 | 811 | |
e3f20ae2 | 812 | error = security_file_open(f); |
788e7dd4 YN |
813 | if (error) |
814 | goto cleanup_all; | |
815 | ||
c568d683 | 816 | error = break_lease(locks_inode(f), f->f_flags); |
f3c7691e BF |
817 | if (error) |
818 | goto cleanup_all; | |
819 | ||
ea73ea72 AV |
820 | /* normally all 3 are set; ->open() can clear them if needed */ |
821 | f->f_mode |= FMODE_LSEEK | FMODE_PREAD | FMODE_PWRITE; | |
72c2d531 | 822 | if (!open) |
834f2a4a TM |
823 | open = f->f_op->open; |
824 | if (open) { | |
825 | error = open(inode, f); | |
1da177e4 LT |
826 | if (error) |
827 | goto cleanup_all; | |
828 | } | |
f5d11409 | 829 | f->f_mode |= FMODE_OPENED; |
890275b5 MZ |
830 | if ((f->f_mode & (FMODE_READ | FMODE_WRITE)) == FMODE_READ) |
831 | i_readcount_inc(inode); | |
293bc982 | 832 | if ((f->f_mode & FMODE_READ) && |
84363182 | 833 | likely(f->f_op->read || f->f_op->read_iter)) |
7f7f25e8 | 834 | f->f_mode |= FMODE_CAN_READ; |
293bc982 | 835 | if ((f->f_mode & FMODE_WRITE) && |
84363182 | 836 | likely(f->f_op->write || f->f_op->write_iter)) |
7f7f25e8 | 837 | f->f_mode |= FMODE_CAN_WRITE; |
834f2a4a | 838 | |
c75b1d94 | 839 | f->f_write_hint = WRITE_LIFE_NOT_SET; |
1da177e4 LT |
840 | f->f_flags &= ~(O_CREAT | O_EXCL | O_NOCTTY | O_TRUNC); |
841 | ||
842 | file_ra_state_init(&f->f_ra, f->f_mapping->host->i_mapping); | |
af04fadc | 843 | |
69527c55 AV |
844 | /* NB: we're sure to have correct a_ops only after f_op->open */ |
845 | if (f->f_flags & O_DIRECT) { | |
846 | if (!f->f_mapping->a_ops || !f->f_mapping->a_ops->direct_IO) | |
847 | return -EINVAL; | |
848 | } | |
09d91cda SL |
849 | |
850 | /* | |
851 | * XXX: Huge page cache doesn't support writing yet. Drop all page | |
852 | * cache for this file before processing writes. | |
853 | */ | |
eb6ecbed CF |
854 | if (f->f_mode & FMODE_WRITE) { |
855 | /* | |
856 | * Paired with smp_mb() in collapse_file() to ensure nr_thps | |
857 | * is up to date and the update to i_writecount by | |
858 | * get_write_access() is visible. Ensures subsequent insertion | |
859 | * of THPs into the page cache will fail. | |
860 | */ | |
861 | smp_mb(); | |
975e96f4 | 862 | if (filemap_nr_thps(inode->i_mapping)) { |
5de54df8 RW |
863 | struct address_space *mapping = inode->i_mapping; |
864 | ||
975e96f4 | 865 | filemap_invalidate_lock(inode->i_mapping); |
5de54df8 RW |
866 | /* |
867 | * unmap_mapping_range just need to be called once | |
868 | * here, because the private pages is not need to be | |
869 | * unmapped mapping (e.g. data segment of dynamic | |
870 | * shared libraries here). | |
871 | */ | |
872 | unmap_mapping_range(mapping, 0, 0, 0); | |
873 | truncate_inode_pages(mapping, 0); | |
975e96f4 RW |
874 | filemap_invalidate_unlock(inode->i_mapping); |
875 | } | |
eb6ecbed | 876 | } |
09d91cda | 877 | |
96b7e579 | 878 | return 0; |
1da177e4 LT |
879 | |
880 | cleanup_all: | |
6b4e8085 AV |
881 | if (WARN_ON_ONCE(error > 0)) |
882 | error = -EINVAL; | |
1da177e4 | 883 | fops_put(f->f_op); |
83f936c7 | 884 | if (f->f_mode & FMODE_WRITER) { |
1da177e4 | 885 | put_write_access(inode); |
83f936c7 | 886 | __mnt_drop_write(f->f_path.mnt); |
4a3fd211 | 887 | } |
1da177e4 | 888 | cleanup_file: |
02e5180d AV |
889 | path_put(&f->f_path); |
890 | f->f_path.mnt = NULL; | |
891 | f->f_path.dentry = NULL; | |
dd37978c | 892 | f->f_inode = NULL; |
96b7e579 | 893 | return error; |
1da177e4 LT |
894 | } |
895 | ||
d18e9008 MS |
896 | /** |
897 | * finish_open - finish opening a file | |
0854d450 | 898 | * @file: file pointer |
d18e9008 MS |
899 | * @dentry: pointer to dentry |
900 | * @open: open callback | |
0854d450 | 901 | * @opened: state of open |
d18e9008 MS |
902 | * |
903 | * This can be used to finish opening a file passed to i_op->atomic_open(). | |
904 | * | |
905 | * If the open callback is set to NULL, then the standard f_op->open() | |
906 | * filesystem callback is substituted. | |
0854d450 MS |
907 | * |
908 | * NB: the dentry reference is _not_ consumed. If, for example, the dentry is | |
909 | * the return value of d_splice_alias(), then the caller needs to perform dput() | |
910 | * on it after finish_open(). | |
911 | * | |
0854d450 | 912 | * Returns zero on success or -errno if the open failed. |
d18e9008 | 913 | */ |
30d90494 | 914 | int finish_open(struct file *file, struct dentry *dentry, |
be12af3e | 915 | int (*open)(struct inode *, struct file *)) |
d18e9008 | 916 | { |
aad888f8 | 917 | BUG_ON(file->f_mode & FMODE_OPENED); /* once it's opened, it's opened */ |
d18e9008 | 918 | |
b5bcdda3 | 919 | file->f_path.dentry = dentry; |
aad888f8 | 920 | return do_dentry_open(file, d_backing_inode(dentry), open); |
d18e9008 MS |
921 | } |
922 | EXPORT_SYMBOL(finish_open); | |
923 | ||
924 | /** | |
925 | * finish_no_open - finish ->atomic_open() without opening the file | |
926 | * | |
0854d450 | 927 | * @file: file pointer |
d18e9008 MS |
928 | * @dentry: dentry or NULL (as returned from ->lookup()) |
929 | * | |
930 | * This can be used to set the result of a successful lookup in ->atomic_open(). | |
0854d450 MS |
931 | * |
932 | * NB: unlike finish_open() this function does consume the dentry reference and | |
933 | * the caller need not dput() it. | |
934 | * | |
64e1ac4d | 935 | * Returns "0" which must be the return value of ->atomic_open() after having |
0854d450 | 936 | * called this function. |
d18e9008 | 937 | */ |
e45198a6 | 938 | int finish_no_open(struct file *file, struct dentry *dentry) |
d18e9008 | 939 | { |
30d90494 | 940 | file->f_path.dentry = dentry; |
64e1ac4d | 941 | return 0; |
d18e9008 MS |
942 | } |
943 | EXPORT_SYMBOL(finish_no_open); | |
944 | ||
9bf39ab2 MS |
945 | char *file_path(struct file *filp, char *buf, int buflen) |
946 | { | |
947 | return d_path(&filp->f_path, buf, buflen); | |
948 | } | |
949 | EXPORT_SYMBOL(file_path); | |
950 | ||
4bacc9c9 DH |
951 | /** |
952 | * vfs_open - open the file at the given path | |
953 | * @path: path to open | |
954 | * @file: newly allocated file with f_flag initialized | |
955 | * @cred: credentials to use | |
956 | */ | |
ae2bb293 | 957 | int vfs_open(const struct path *path, struct file *file) |
4bacc9c9 | 958 | { |
54d5ca87 | 959 | file->f_path = *path; |
a6518f73 | 960 | return do_dentry_open(file, d_backing_inode(path->dentry), NULL); |
4bacc9c9 DH |
961 | } |
962 | ||
765927b2 | 963 | struct file *dentry_open(const struct path *path, int flags, |
745ca247 | 964 | const struct cred *cred) |
a1a5b3d9 PS |
965 | { |
966 | int error; | |
967 | struct file *f; | |
968 | ||
e0e81739 DH |
969 | validate_creds(cred); |
970 | ||
c212f9aa | 971 | /* We must always pass in a valid mount pointer. */ |
765927b2 | 972 | BUG_ON(!path->mnt); |
322ee5b3 | 973 | |
ea73ea72 | 974 | f = alloc_empty_file(flags, cred); |
af04fadc | 975 | if (!IS_ERR(f)) { |
ae2bb293 | 976 | error = vfs_open(path, f); |
4d27f326 AV |
977 | if (error) { |
978 | fput(f); | |
af04fadc AV |
979 | f = ERR_PTR(error); |
980 | } | |
2a027e7a AV |
981 | } |
982 | return f; | |
a1a5b3d9 | 983 | } |
1da177e4 LT |
984 | EXPORT_SYMBOL(dentry_open); |
985 | ||
2abc77af AV |
986 | struct file *open_with_fake_path(const struct path *path, int flags, |
987 | struct inode *inode, const struct cred *cred) | |
988 | { | |
d3b1084d | 989 | struct file *f = alloc_empty_file_noaccount(flags, cred); |
2abc77af AV |
990 | if (!IS_ERR(f)) { |
991 | int error; | |
992 | ||
993 | f->f_path = *path; | |
994 | error = do_dentry_open(f, inode, NULL); | |
995 | if (error) { | |
996 | fput(f); | |
997 | f = ERR_PTR(error); | |
998 | } | |
999 | } | |
1000 | return f; | |
1001 | } | |
1002 | EXPORT_SYMBOL(open_with_fake_path); | |
1003 | ||
fddb5d43 AS |
1004 | #define WILL_CREATE(flags) (flags & (O_CREAT | __O_TMPFILE)) |
1005 | #define O_PATH_FLAGS (O_DIRECTORY | O_NOFOLLOW | O_PATH | O_CLOEXEC) | |
1006 | ||
35cb6d54 | 1007 | inline struct open_how build_open_how(int flags, umode_t mode) |
fddb5d43 AS |
1008 | { |
1009 | struct open_how how = { | |
1010 | .flags = flags & VALID_OPEN_FLAGS, | |
1011 | .mode = mode & S_IALLUGO, | |
1012 | }; | |
1013 | ||
1014 | /* O_PATH beats everything else. */ | |
1015 | if (how.flags & O_PATH) | |
1016 | how.flags &= O_PATH_FLAGS; | |
1017 | /* Modes should only be set for create-like flags. */ | |
1018 | if (!WILL_CREATE(how.flags)) | |
1019 | how.mode = 0; | |
1020 | return how; | |
1021 | } | |
1022 | ||
35cb6d54 | 1023 | inline int build_open_flags(const struct open_how *how, struct open_flags *op) |
47c805dc | 1024 | { |
cfe80306 CB |
1025 | u64 flags = how->flags; |
1026 | u64 strip = FMODE_NONOTIFY | O_CLOEXEC; | |
47c805dc | 1027 | int lookup_flags = 0; |
62fb4a15 | 1028 | int acc_mode = ACC_MODE(flags); |
47c805dc | 1029 | |
cfe80306 CB |
1030 | BUILD_BUG_ON_MSG(upper_32_bits(VALID_OPEN_FLAGS), |
1031 | "struct open_flags doesn't yet handle flags > 32 bits"); | |
1032 | ||
1033 | /* | |
1034 | * Strip flags that either shouldn't be set by userspace like | |
1035 | * FMODE_NONOTIFY or that aren't relevant in determining struct | |
1036 | * open_flags like O_CLOEXEC. | |
1037 | */ | |
1038 | flags &= ~strip; | |
fddb5d43 | 1039 | |
629e014b | 1040 | /* |
fddb5d43 AS |
1041 | * Older syscalls implicitly clear all of the invalid flags or argument |
1042 | * values before calling build_open_flags(), but openat2(2) checks all | |
1043 | * of its arguments. | |
629e014b | 1044 | */ |
fddb5d43 AS |
1045 | if (flags & ~VALID_OPEN_FLAGS) |
1046 | return -EINVAL; | |
1047 | if (how->resolve & ~VALID_RESOLVE_FLAGS) | |
1048 | return -EINVAL; | |
629e014b | 1049 | |
398840f8 AS |
1050 | /* Scoping flags are mutually exclusive. */ |
1051 | if ((how->resolve & RESOLVE_BENEATH) && (how->resolve & RESOLVE_IN_ROOT)) | |
1052 | return -EINVAL; | |
1053 | ||
fddb5d43 AS |
1054 | /* Deal with the mode. */ |
1055 | if (WILL_CREATE(flags)) { | |
1056 | if (how->mode & ~S_IALLUGO) | |
1057 | return -EINVAL; | |
1058 | op->mode = how->mode | S_IFREG; | |
1059 | } else { | |
1060 | if (how->mode != 0) | |
1061 | return -EINVAL; | |
e68726ff | 1062 | op->mode = 0; |
fddb5d43 | 1063 | } |
47c805dc AV |
1064 | |
1065 | /* | |
fddb5d43 AS |
1066 | * In order to ensure programs get explicit errors when trying to use |
1067 | * O_TMPFILE on old kernels, O_TMPFILE is implemented such that it | |
1068 | * looks like (O_DIRECTORY|O_RDWR & ~O_CREAT) to old kernels. But we | |
1069 | * have to require userspace to explicitly set it. | |
47c805dc | 1070 | */ |
bb458c64 AV |
1071 | if (flags & __O_TMPFILE) { |
1072 | if ((flags & O_TMPFILE_MASK) != O_TMPFILE) | |
60545d0d | 1073 | return -EINVAL; |
ba57ea64 AV |
1074 | if (!(acc_mode & MAY_WRITE)) |
1075 | return -EINVAL; | |
fddb5d43 AS |
1076 | } |
1077 | if (flags & O_PATH) { | |
1078 | /* O_PATH only permits certain other flags to be set. */ | |
1079 | if (flags & ~O_PATH_FLAGS) | |
1080 | return -EINVAL; | |
1abf0c71 | 1081 | acc_mode = 0; |
1abf0c71 | 1082 | } |
47c805dc | 1083 | |
fddb5d43 AS |
1084 | /* |
1085 | * O_SYNC is implemented as __O_SYNC|O_DSYNC. As many places only | |
1086 | * check for O_DSYNC if the need any syncing at all we enforce it's | |
1087 | * always set instead of having to deal with possibly weird behaviour | |
1088 | * for malicious applications setting only __O_SYNC. | |
1089 | */ | |
1090 | if (flags & __O_SYNC) | |
1091 | flags |= O_DSYNC; | |
1092 | ||
1abf0c71 | 1093 | op->open_flag = flags; |
47c805dc AV |
1094 | |
1095 | /* O_TRUNC implies we need access checks for write permissions */ | |
1096 | if (flags & O_TRUNC) | |
1097 | acc_mode |= MAY_WRITE; | |
1098 | ||
1099 | /* Allow the LSM permission hook to distinguish append | |
1100 | access from general write access. */ | |
1101 | if (flags & O_APPEND) | |
1102 | acc_mode |= MAY_APPEND; | |
1103 | ||
1104 | op->acc_mode = acc_mode; | |
1105 | ||
1abf0c71 AV |
1106 | op->intent = flags & O_PATH ? 0 : LOOKUP_OPEN; |
1107 | ||
47c805dc AV |
1108 | if (flags & O_CREAT) { |
1109 | op->intent |= LOOKUP_CREATE; | |
31d1726d | 1110 | if (flags & O_EXCL) { |
47c805dc | 1111 | op->intent |= LOOKUP_EXCL; |
31d1726d AV |
1112 | flags |= O_NOFOLLOW; |
1113 | } | |
47c805dc AV |
1114 | } |
1115 | ||
1116 | if (flags & O_DIRECTORY) | |
1117 | lookup_flags |= LOOKUP_DIRECTORY; | |
1118 | if (!(flags & O_NOFOLLOW)) | |
1119 | lookup_flags |= LOOKUP_FOLLOW; | |
fddb5d43 AS |
1120 | |
1121 | if (how->resolve & RESOLVE_NO_XDEV) | |
1122 | lookup_flags |= LOOKUP_NO_XDEV; | |
1123 | if (how->resolve & RESOLVE_NO_MAGICLINKS) | |
1124 | lookup_flags |= LOOKUP_NO_MAGICLINKS; | |
1125 | if (how->resolve & RESOLVE_NO_SYMLINKS) | |
1126 | lookup_flags |= LOOKUP_NO_SYMLINKS; | |
1127 | if (how->resolve & RESOLVE_BENEATH) | |
1128 | lookup_flags |= LOOKUP_BENEATH; | |
1129 | if (how->resolve & RESOLVE_IN_ROOT) | |
1130 | lookup_flags |= LOOKUP_IN_ROOT; | |
99668f61 JA |
1131 | if (how->resolve & RESOLVE_CACHED) { |
1132 | /* Don't bother even trying for create/truncate/tmpfile open */ | |
1133 | if (flags & (O_TRUNC | O_CREAT | O_TMPFILE)) | |
1134 | return -EAGAIN; | |
1135 | lookup_flags |= LOOKUP_CACHED; | |
1136 | } | |
fddb5d43 | 1137 | |
f9652e10 AV |
1138 | op->lookup_flags = lookup_flags; |
1139 | return 0; | |
47c805dc AV |
1140 | } |
1141 | ||
669abf4e JL |
1142 | /** |
1143 | * file_open_name - open file and return file pointer | |
1144 | * | |
1145 | * @name: struct filename containing path to open | |
1146 | * @flags: open flags as per the open(2) second argument | |
1147 | * @mode: mode for the new file if O_CREAT is set, else ignored | |
1148 | * | |
1149 | * This is the helper to open a file from kernelspace if you really | |
1150 | * have to. But in generally you should not do this, so please move | |
1151 | * along, nothing to see here.. | |
1152 | */ | |
1153 | struct file *file_open_name(struct filename *name, int flags, umode_t mode) | |
1154 | { | |
1155 | struct open_flags op; | |
fddb5d43 AS |
1156 | struct open_how how = build_open_how(flags, mode); |
1157 | int err = build_open_flags(&how, &op); | |
1158 | if (err) | |
1159 | return ERR_PTR(err); | |
1160 | return do_filp_open(AT_FDCWD, name, &op); | |
669abf4e JL |
1161 | } |
1162 | ||
47c805dc AV |
1163 | /** |
1164 | * filp_open - open file and return file pointer | |
1165 | * | |
1166 | * @filename: path to open | |
1167 | * @flags: open flags as per the open(2) second argument | |
1168 | * @mode: mode for the new file if O_CREAT is set, else ignored | |
1169 | * | |
1170 | * This is the helper to open a file from kernelspace if you really | |
1171 | * have to. But in generally you should not do this, so please move | |
1172 | * along, nothing to see here.. | |
1173 | */ | |
a218d0fd | 1174 | struct file *filp_open(const char *filename, int flags, umode_t mode) |
47c805dc | 1175 | { |
51689104 PM |
1176 | struct filename *name = getname_kernel(filename); |
1177 | struct file *file = ERR_CAST(name); | |
1178 | ||
1179 | if (!IS_ERR(name)) { | |
1180 | file = file_open_name(name, flags, mode); | |
1181 | putname(name); | |
1182 | } | |
1183 | return file; | |
47c805dc AV |
1184 | } |
1185 | EXPORT_SYMBOL(filp_open); | |
1186 | ||
ffb37ca3 | 1187 | struct file *file_open_root(const struct path *root, |
378c6520 | 1188 | const char *filename, int flags, umode_t mode) |
73d049a4 AV |
1189 | { |
1190 | struct open_flags op; | |
fddb5d43 AS |
1191 | struct open_how how = build_open_how(flags, mode); |
1192 | int err = build_open_flags(&how, &op); | |
f9652e10 AV |
1193 | if (err) |
1194 | return ERR_PTR(err); | |
ffb37ca3 | 1195 | return do_file_open_root(root, filename, &op); |
73d049a4 AV |
1196 | } |
1197 | EXPORT_SYMBOL(file_open_root); | |
1198 | ||
fddb5d43 AS |
1199 | static long do_sys_openat2(int dfd, const char __user *filename, |
1200 | struct open_how *how) | |
1da177e4 | 1201 | { |
47c805dc | 1202 | struct open_flags op; |
fddb5d43 | 1203 | int fd = build_open_flags(how, &op); |
f9652e10 AV |
1204 | struct filename *tmp; |
1205 | ||
1206 | if (fd) | |
1207 | return fd; | |
1208 | ||
1209 | tmp = getname(filename); | |
1210 | if (IS_ERR(tmp)) | |
1211 | return PTR_ERR(tmp); | |
1212 | ||
fddb5d43 | 1213 | fd = get_unused_fd_flags(how->flags); |
f9652e10 AV |
1214 | if (fd >= 0) { |
1215 | struct file *f = do_filp_open(dfd, tmp, &op); | |
1216 | if (IS_ERR(f)) { | |
1217 | put_unused_fd(fd); | |
1218 | fd = PTR_ERR(f); | |
1219 | } else { | |
1220 | fsnotify_open(f); | |
1221 | fd_install(fd, f); | |
1da177e4 | 1222 | } |
1da177e4 | 1223 | } |
f9652e10 | 1224 | putname(tmp); |
1da177e4 | 1225 | return fd; |
1da177e4 | 1226 | } |
e922efc3 | 1227 | |
fddb5d43 | 1228 | long do_sys_open(int dfd, const char __user *filename, int flags, umode_t mode) |
e922efc3 | 1229 | { |
fddb5d43 AS |
1230 | struct open_how how = build_open_how(flags, mode); |
1231 | return do_sys_openat2(dfd, filename, &how); | |
1232 | } | |
e922efc3 | 1233 | |
fddb5d43 AS |
1234 | |
1235 | SYSCALL_DEFINE3(open, const char __user *, filename, int, flags, umode_t, mode) | |
1236 | { | |
166e07c3 CH |
1237 | if (force_o_largefile()) |
1238 | flags |= O_LARGEFILE; | |
1239 | return do_sys_open(AT_FDCWD, filename, flags, mode); | |
e922efc3 | 1240 | } |
1da177e4 | 1241 | |
6559eed8 | 1242 | SYSCALL_DEFINE4(openat, int, dfd, const char __user *, filename, int, flags, |
a218d0fd | 1243 | umode_t, mode) |
5590ff0d UD |
1244 | { |
1245 | if (force_o_largefile()) | |
1246 | flags |= O_LARGEFILE; | |
2cf09666 | 1247 | return do_sys_open(dfd, filename, flags, mode); |
5590ff0d | 1248 | } |
5590ff0d | 1249 | |
fddb5d43 AS |
1250 | SYSCALL_DEFINE4(openat2, int, dfd, const char __user *, filename, |
1251 | struct open_how __user *, how, size_t, usize) | |
1252 | { | |
1253 | int err; | |
1254 | struct open_how tmp; | |
1255 | ||
1256 | BUILD_BUG_ON(sizeof(struct open_how) < OPEN_HOW_SIZE_VER0); | |
1257 | BUILD_BUG_ON(sizeof(struct open_how) != OPEN_HOW_SIZE_LATEST); | |
1258 | ||
1259 | if (unlikely(usize < OPEN_HOW_SIZE_VER0)) | |
1260 | return -EINVAL; | |
1261 | ||
1262 | err = copy_struct_from_user(&tmp, sizeof(tmp), how, usize); | |
1263 | if (err) | |
1264 | return err; | |
1265 | ||
1266 | /* O_LARGEFILE is only allowed for non-O_PATH. */ | |
1267 | if (!(tmp.flags & O_PATH) && force_o_largefile()) | |
1268 | tmp.flags |= O_LARGEFILE; | |
1269 | ||
1270 | return do_sys_openat2(dfd, filename, &tmp); | |
1271 | } | |
1272 | ||
e35d49f6 AV |
1273 | #ifdef CONFIG_COMPAT |
1274 | /* | |
1275 | * Exactly like sys_open(), except that it doesn't set the | |
1276 | * O_LARGEFILE flag. | |
1277 | */ | |
1278 | COMPAT_SYSCALL_DEFINE3(open, const char __user *, filename, int, flags, umode_t, mode) | |
1279 | { | |
1280 | return do_sys_open(AT_FDCWD, filename, flags, mode); | |
1281 | } | |
1282 | ||
1283 | /* | |
1284 | * Exactly like sys_openat(), except that it doesn't set the | |
1285 | * O_LARGEFILE flag. | |
1286 | */ | |
1287 | COMPAT_SYSCALL_DEFINE4(openat, int, dfd, const char __user *, filename, int, flags, umode_t, mode) | |
1288 | { | |
1289 | return do_sys_open(dfd, filename, flags, mode); | |
1290 | } | |
1291 | #endif | |
1292 | ||
1da177e4 LT |
1293 | #ifndef __alpha__ |
1294 | ||
1295 | /* | |
1296 | * For backward compatibility? Maybe this should be moved | |
1297 | * into arch/i386 instead? | |
1298 | */ | |
a218d0fd | 1299 | SYSCALL_DEFINE2(creat, const char __user *, pathname, umode_t, mode) |
1da177e4 | 1300 | { |
166e07c3 | 1301 | int flags = O_CREAT | O_WRONLY | O_TRUNC; |
1da177e4 | 1302 | |
166e07c3 CH |
1303 | if (force_o_largefile()) |
1304 | flags |= O_LARGEFILE; | |
1305 | return do_sys_open(AT_FDCWD, pathname, flags, mode); | |
1306 | } | |
1da177e4 LT |
1307 | #endif |
1308 | ||
1309 | /* | |
1310 | * "id" is the POSIX thread ID. We use the | |
1311 | * files pointer for this.. | |
1312 | */ | |
1313 | int filp_close(struct file *filp, fl_owner_t id) | |
1314 | { | |
45778ca8 | 1315 | int retval = 0; |
1da177e4 LT |
1316 | |
1317 | if (!file_count(filp)) { | |
1318 | printk(KERN_ERR "VFS: Close: file count is 0\n"); | |
45778ca8 | 1319 | return 0; |
1da177e4 LT |
1320 | } |
1321 | ||
72c2d531 | 1322 | if (filp->f_op->flush) |
75e1fcc0 | 1323 | retval = filp->f_op->flush(filp, id); |
1da177e4 | 1324 | |
1abf0c71 AV |
1325 | if (likely(!(filp->f_mode & FMODE_PATH))) { |
1326 | dnotify_flush(filp, id); | |
1327 | locks_remove_posix(filp, id); | |
1328 | } | |
1da177e4 LT |
1329 | fput(filp); |
1330 | return retval; | |
1331 | } | |
1332 | ||
1333 | EXPORT_SYMBOL(filp_close); | |
1334 | ||
1335 | /* | |
1336 | * Careful here! We test whether the file pointer is NULL before | |
1337 | * releasing the fd. This ensures that one clone task can't release | |
1338 | * an fd while another clone is opening it. | |
1339 | */ | |
ca013e94 | 1340 | SYSCALL_DEFINE1(close, unsigned int, fd) |
1da177e4 | 1341 | { |
8760c909 | 1342 | int retval = close_fd(fd); |
ee731f4f EP |
1343 | |
1344 | /* can't restart close syscall because file table entry was cleared */ | |
1345 | if (unlikely(retval == -ERESTARTSYS || | |
1346 | retval == -ERESTARTNOINTR || | |
1347 | retval == -ERESTARTNOHAND || | |
1348 | retval == -ERESTART_RESTARTBLOCK)) | |
1349 | retval = -EINTR; | |
1350 | ||
1351 | return retval; | |
1da177e4 | 1352 | } |
1da177e4 | 1353 | |
278a5fba CB |
1354 | /** |
1355 | * close_range() - Close all file descriptors in a given range. | |
1356 | * | |
1357 | * @fd: starting file descriptor to close | |
1358 | * @max_fd: last file descriptor to close | |
1359 | * @flags: reserved for future extensions | |
1360 | * | |
1361 | * This closes a range of file descriptors. All file descriptors | |
1362 | * from @fd up to and including @max_fd are closed. | |
1363 | * Currently, errors to close a given file descriptor are ignored. | |
1364 | */ | |
1365 | SYSCALL_DEFINE3(close_range, unsigned int, fd, unsigned int, max_fd, | |
1366 | unsigned int, flags) | |
1367 | { | |
60997c3d | 1368 | return __close_range(fd, max_fd, flags); |
278a5fba CB |
1369 | } |
1370 | ||
1da177e4 LT |
1371 | /* |
1372 | * This routine simulates a hangup on the tty, to arrange that users | |
1373 | * are given clean terminals at login time. | |
1374 | */ | |
ca013e94 | 1375 | SYSCALL_DEFINE0(vhangup) |
1da177e4 LT |
1376 | { |
1377 | if (capable(CAP_SYS_TTY_CONFIG)) { | |
2cb5998b | 1378 | tty_vhangup_self(); |
1da177e4 LT |
1379 | return 0; |
1380 | } | |
1381 | return -EPERM; | |
1382 | } | |
1383 | ||
1384 | /* | |
1385 | * Called when an inode is about to be open. | |
1386 | * We use this to disallow opening large files on 32bit systems if | |
1387 | * the caller didn't specify O_LARGEFILE. On 64bit systems we force | |
1388 | * on this flag in sys_open. | |
1389 | */ | |
1390 | int generic_file_open(struct inode * inode, struct file * filp) | |
1391 | { | |
1392 | if (!(filp->f_flags & O_LARGEFILE) && i_size_read(inode) > MAX_NON_LFS) | |
a9c62a18 | 1393 | return -EOVERFLOW; |
1da177e4 LT |
1394 | return 0; |
1395 | } | |
1396 | ||
1397 | EXPORT_SYMBOL(generic_file_open); | |
1398 | ||
1399 | /* | |
1400 | * This is used by subsystems that don't want seekable | |
06b1e104 DT |
1401 | * file descriptors. The function is not supposed to ever fail, the only |
1402 | * reason it returns an 'int' and not 'void' is so that it can be plugged | |
1403 | * directly into file_operations structure. | |
1da177e4 LT |
1404 | */ |
1405 | int nonseekable_open(struct inode *inode, struct file *filp) | |
1406 | { | |
1407 | filp->f_mode &= ~(FMODE_LSEEK | FMODE_PREAD | FMODE_PWRITE); | |
1408 | return 0; | |
1409 | } | |
1410 | ||
1411 | EXPORT_SYMBOL(nonseekable_open); | |
10dce8af KS |
1412 | |
1413 | /* | |
1414 | * stream_open is used by subsystems that want stream-like file descriptors. | |
1415 | * Such file descriptors are not seekable and don't have notion of position | |
438ab720 KS |
1416 | * (file.f_pos is always 0 and ppos passed to .read()/.write() is always NULL). |
1417 | * Contrary to file descriptors of other regular files, .read() and .write() | |
1418 | * can run simultaneously. | |
10dce8af KS |
1419 | * |
1420 | * stream_open never fails and is marked to return int so that it could be | |
1421 | * directly used as file_operations.open . | |
1422 | */ | |
1423 | int stream_open(struct inode *inode, struct file *filp) | |
1424 | { | |
2be7d348 | 1425 | filp->f_mode &= ~(FMODE_LSEEK | FMODE_PREAD | FMODE_PWRITE | FMODE_ATOMIC_POS); |
10dce8af KS |
1426 | filp->f_mode |= FMODE_STREAM; |
1427 | return 0; | |
1428 | } | |
1429 | ||
1430 | EXPORT_SYMBOL(stream_open); |