| 1 | |
| 2 | |
| 3 | * linux/fs/attr.c
|
| 4 | *
|
| 5 | * Copyright (C) 1991, 1992 Linus Torvalds
|
| 6 | * changes by Thomas Schoebel-Theuer
|
| 7 |
|
| 8 |
|
| 9 | #include <linux/export.h>
|
| 10 | #include <linux/time.h>
|
| 11 | #include <linux/mm.h>
|
| 12 | #include <linux/string.h>
|
| 13 | #include <linux/sched/signal.h>
|
| 14 | #include <linux/capability.h>
|
| 15 | #include <linux/fsnotify.h>
|
| 16 | #include <linux/fcntl.h>
|
| 17 | #include <linux/filelock.h>
|
| 18 | #include <linux/security.h>
|
| 19 |
|
| 20 | |
| 21 | * setattr_should_drop_sgid - determine whether the setgid bit needs to be
|
| 22 | * removed
|
| 23 | * @idmap: idmap of the mount @inode was found from
|
| 24 | * @inode: inode to check
|
| 25 | *
|
| 26 | * This function determines whether the setgid bit needs to be removed.
|
| 27 | * We retain backwards compatibility and require setgid bit to be removed
|
| 28 | * unconditionally if S_IXGRP is set. Otherwise we have the exact same
|
| 29 | * requirements as setattr_prepare() and setattr_copy().
|
| 30 | *
|
| 31 | * Return: ATTR_KILL_SGID if setgid bit needs to be removed, 0 otherwise.
|
| 32 |
|
| 33 | int setattr_should_drop_sgid(struct mnt_idmap *idmap,
|
| 34 | const struct inode *inode)
|
| 35 | {
|
| 36 | umode_t mode = inode->i_mode;
|
| 37 |
|
| 38 | if (!(mode & S_ISGID))
|
| 39 | return 0;
|
| 40 | if (mode & S_IXGRP)
|
| 41 | return ATTR_KILL_SGID;
|
| 42 | if (!in_group_or_capable(idmap, inode, i_gid_into_vfsgid(idmap, inode)))
|
| 43 | return ATTR_KILL_SGID;
|
| 44 | return 0;
|
| 45 | }
|
| 46 | EXPORT_SYMBOL(setattr_should_drop_sgid);
|
| 47 |
|
| 48 | |
| 49 | * setattr_should_drop_suidgid - determine whether the set{g,u}id bit
|
| 50 | * needs to be dropped
|
| 51 | * @idmap: idmap of the mount @inode was found from
|
| 52 | * @inode: inode to check
|
| 53 | *
|
| 54 | * This function determines whether the set{g,u}id bits need to be removed.
|
| 55 | * If the setuid bit needs to be removed ATTR_KILL_SUID is returned. If the
|
| 56 | * setgid bit needs to be removed ATTR_KILL_SGID is returned. If both
|
| 57 | * set{g,u}id bits need to be removed the corresponding mask of both flags is
|
| 58 | * returned.
|
| 59 | *
|
| 60 | * Return: A mask of ATTR_KILL_S{G,U}ID indicating which - if any - setid bits
|
| 61 | * to remove, 0 otherwise.
|
| 62 |
|
| 63 | int setattr_should_drop_suidgid(struct mnt_idmap *idmap,
|
| 64 | struct inode *inode)
|
| 65 | {
|
| 66 | umode_t mode = inode->i_mode;
|
| 67 | int kill = 0;
|
| 68 |
|
| 69 |
|
| 70 | if (unlikely(mode & S_ISUID))
|
| 71 | kill = ATTR_KILL_SUID;
|
| 72 |
|
| 73 | kill |= setattr_should_drop_sgid(idmap, inode);
|
| 74 |
|
| 75 | if (unlikely(kill && !capable(CAP_FSETID) && S_ISREG(mode)))
|
| 76 | return kill;
|
| 77 |
|
| 78 | return 0;
|
| 79 | }
|
| 80 | EXPORT_SYMBOL(setattr_should_drop_suidgid);
|
| 81 |
|
| 82 | |
| 83 | * chown_ok - verify permissions to chown inode
|
| 84 | * @idmap: idmap of the mount @inode was found from
|
| 85 | * @inode: inode to check permissions on
|
| 86 | * @ia_vfsuid: uid to chown @inode to
|
| 87 | *
|
| 88 | * If the inode has been found through an idmapped mount the idmap of
|
| 89 | * the vfsmount must be passed through @idmap. This function will then
|
| 90 | * take care to map the inode according to @idmap before checking
|
| 91 | * permissions. On non-idmapped mounts or if permission checking is to be
|
| 92 | * performed on the raw inode simply pass @nop_mnt_idmap.
|
| 93 |
|
| 94 | static bool chown_ok(struct mnt_idmap *idmap,
|
| 95 | const struct inode *inode, vfsuid_t ia_vfsuid)
|
| 96 | {
|
| 97 | vfsuid_t vfsuid = i_uid_into_vfsuid(idmap, inode);
|
| 98 | if (vfsuid_eq_kuid(vfsuid, current_fsuid()) &&
|
| 99 | vfsuid_eq(ia_vfsuid, vfsuid))
|
| 100 | return true;
|
| 101 | if (capable_wrt_inode_uidgid(idmap, inode, CAP_CHOWN))
|
| 102 | return true;
|
| 103 | if (!vfsuid_valid(vfsuid) &&
|
| 104 | ns_capable(inode->i_sb->s_user_ns, CAP_CHOWN))
|
| 105 | return true;
|
| 106 | return false;
|
| 107 | }
|
| 108 |
|
| 109 | |
| 110 | * chgrp_ok - verify permissions to chgrp inode
|
| 111 | * @idmap: idmap of the mount @inode was found from
|
| 112 | * @inode: inode to check permissions on
|
| 113 | * @ia_vfsgid: gid to chown @inode to
|
| 114 | *
|
| 115 | * If the inode has been found through an idmapped mount the idmap of
|
| 116 | * the vfsmount must be passed through @idmap. This function will then
|
| 117 | * take care to map the inode according to @idmap before checking
|
| 118 | * permissions. On non-idmapped mounts or if permission checking is to be
|
| 119 | * performed on the raw inode simply pass @nop_mnt_idmap.
|
| 120 |
|
| 121 | static bool chgrp_ok(struct mnt_idmap *idmap,
|
| 122 | const struct inode *inode, vfsgid_t ia_vfsgid)
|
| 123 | {
|
| 124 | vfsgid_t vfsgid = i_gid_into_vfsgid(idmap, inode);
|
| 125 | vfsuid_t vfsuid = i_uid_into_vfsuid(idmap, inode);
|
| 126 | if (vfsuid_eq_kuid(vfsuid, current_fsuid())) {
|
| 127 | if (vfsgid_eq(ia_vfsgid, vfsgid))
|
| 128 | return true;
|
| 129 | if (vfsgid_in_group_p(ia_vfsgid))
|
| 130 | return true;
|
| 131 | }
|
| 132 | if (capable_wrt_inode_uidgid(idmap, inode, CAP_CHOWN))
|
| 133 | return true;
|
| 134 | if (!vfsgid_valid(vfsgid) &&
|
| 135 | ns_capable(inode->i_sb->s_user_ns, CAP_CHOWN))
|
| 136 | return true;
|
| 137 | return false;
|
| 138 | }
|
| 139 |
|
| 140 | |
| 141 | * setattr_prepare - check if attribute changes to a dentry are allowed
|
| 142 | * @idmap: idmap of the mount the inode was found from
|
| 143 | * @dentry: dentry to check
|
| 144 | * @attr: attributes to change
|
| 145 | *
|
| 146 | * Check if we are allowed to change the attributes contained in @attr
|
| 147 | * in the given dentry. This includes the normal unix access permission
|
| 148 | * checks, as well as checks for rlimits and others. The function also clears
|
| 149 | * SGID bit from mode if user is not allowed to set it. Also file capabilities
|
| 150 | * and IMA extended attributes are cleared if ATTR_KILL_PRIV is set.
|
| 151 | *
|
| 152 | * If the inode has been found through an idmapped mount the idmap of
|
| 153 | * the vfsmount must be passed through @idmap. This function will then
|
| 154 | * take care to map the inode according to @idmap before checking
|
| 155 | * permissions. On non-idmapped mounts or if permission checking is to be
|
| 156 | * performed on the raw inode simply pass @nop_mnt_idmap.
|
| 157 | *
|
| 158 | * Should be called as the first thing in ->setattr implementations,
|
| 159 | * possibly after taking additional locks.
|
| 160 |
|
| 161 | int setattr_prepare(struct mnt_idmap *idmap, struct dentry *dentry,
|
| 162 | struct iattr *attr)
|
| 163 | {
|
| 164 | struct inode *inode = d_inode(dentry);
|
| 165 | unsigned int ia_valid = attr->ia_valid;
|
| 166 |
|
| 167 | |
| 168 | * First check size constraints. These can't be overridden using
|
| 169 | * ATTR_FORCE.
|
| 170 |
|
| 171 | if (ia_valid & ATTR_SIZE) {
|
| 172 | int error;
|
| 173 |
|
| 174 | |
| 175 | * Verity files are immutable, so deny truncates. This isn't
|
| 176 | * covered by the open-time check because sys_truncate() takes a
|
| 177 | * path, not an open file.
|
| 178 |
|
| 179 | if (IS_VERITY(inode))
|
| 180 | return -EPERM;
|
| 181 |
|
| 182 | error = inode_newsize_ok(inode, attr->ia_size);
|
| 183 | if (error)
|
| 184 | return error;
|
| 185 | }
|
| 186 |
|
| 187 |
|
| 188 | if (ia_valid & ATTR_FORCE)
|
| 189 | goto kill_priv;
|
| 190 |
|
| 191 |
|
| 192 | if ((ia_valid & ATTR_UID) &&
|
| 193 | !chown_ok(idmap, inode, attr->ia_vfsuid))
|
| 194 | return -EPERM;
|
| 195 |
|
| 196 |
|
| 197 | if ((ia_valid & ATTR_GID) &&
|
| 198 | !chgrp_ok(idmap, inode, attr->ia_vfsgid))
|
| 199 | return -EPERM;
|
| 200 |
|
| 201 |
|
| 202 | if (ia_valid & ATTR_MODE) {
|
| 203 | vfsgid_t vfsgid;
|
| 204 |
|
| 205 | if (!inode_owner_or_capable(idmap, inode))
|
| 206 | return -EPERM;
|
| 207 |
|
| 208 | if (ia_valid & ATTR_GID)
|
| 209 | vfsgid = attr->ia_vfsgid;
|
| 210 | else
|
| 211 | vfsgid = i_gid_into_vfsgid(idmap, inode);
|
| 212 |
|
| 213 |
|
| 214 | if (!in_group_or_capable(idmap, inode, vfsgid))
|
| 215 | attr->ia_mode &= ~S_ISGID;
|
| 216 | }
|
| 217 |
|
| 218 |
|
| 219 | if (ia_valid & (ATTR_MTIME_SET | ATTR_ATIME_SET | ATTR_TIMES_SET)) {
|
| 220 | if (!inode_owner_or_capable(idmap, inode))
|
| 221 | return -EPERM;
|
| 222 | }
|
| 223 |
|
| 224 | kill_priv:
|
| 225 |
|
| 226 | if (ia_valid & ATTR_KILL_PRIV) {
|
| 227 | int error;
|
| 228 |
|
| 229 | error = security_inode_killpriv(idmap, dentry);
|
| 230 | if (error)
|
| 231 | return error;
|
| 232 | }
|
| 233 |
|
| 234 | return 0;
|
| 235 | }
|
| 236 | EXPORT_SYMBOL(setattr_prepare);
|
| 237 |
|
| 238 | |
| 239 | * inode_newsize_ok - may this inode be truncated to a given size
|
| 240 | * @inode: the inode to be truncated
|
| 241 | * @offset: the new size to assign to the inode
|
| 242 | *
|
| 243 | * inode_newsize_ok must be called with i_rwsem held exclusively.
|
| 244 | *
|
| 245 | * inode_newsize_ok will check filesystem limits and ulimits to check that the
|
| 246 | * new inode size is within limits. inode_newsize_ok will also send SIGXFSZ
|
| 247 | * when necessary. Caller must not proceed with inode size change if failure is
|
| 248 | * returned. @inode must be a file (not directory), with appropriate
|
| 249 | * permissions to allow truncate (inode_newsize_ok does NOT check these
|
| 250 | * conditions).
|
| 251 | *
|
| 252 | * Return: 0 on success, -ve errno on failure
|
| 253 |
|
| 254 | int inode_newsize_ok(const struct inode *inode, loff_t offset)
|
| 255 | {
|
| 256 | if (offset < 0)
|
| 257 | return -EINVAL;
|
| 258 | if (inode->i_size < offset) {
|
| 259 | unsigned long limit;
|
| 260 |
|
| 261 | limit = rlimit(RLIMIT_FSIZE);
|
| 262 | if (limit != RLIM_INFINITY && offset > limit)
|
| 263 | goto out_sig;
|
| 264 | if (offset > inode->i_sb->s_maxbytes)
|
| 265 | goto out_big;
|
| 266 | } else {
|
| 267 | |
| 268 | * truncation of in-use swapfiles is disallowed - it would
|
| 269 | * cause subsequent swapout to scribble on the now-freed
|
| 270 | * blocks.
|
| 271 |
|
| 272 | if (IS_SWAPFILE(inode))
|
| 273 | return -ETXTBSY;
|
| 274 | }
|
| 275 |
|
| 276 | return 0;
|
| 277 | out_sig:
|
| 278 | send_sig(SIGXFSZ, current, 0);
|
| 279 | out_big:
|
| 280 | return -EFBIG;
|
| 281 | }
|
| 282 | EXPORT_SYMBOL(inode_newsize_ok);
|
| 283 |
|
| 284 | |
| 285 | * setattr_copy_mgtime - update timestamps for mgtime inodes
|
| 286 | * @inode: inode timestamps to be updated
|
| 287 | * @attr: attrs for the update
|
| 288 | *
|
| 289 | * With multigrain timestamps, take more care to prevent races when
|
| 290 | * updating the ctime. Always update the ctime to the very latest using
|
| 291 | * the standard mechanism, and use that to populate the atime and mtime
|
| 292 | * appropriately (unless those are being set to specific values).
|
| 293 |
|
| 294 | static void setattr_copy_mgtime(struct inode *inode, const struct iattr *attr)
|
| 295 | {
|
| 296 | unsigned int ia_valid = attr->ia_valid;
|
| 297 | struct timespec64 now;
|
| 298 |
|
| 299 | if (ia_valid & ATTR_CTIME_SET)
|
| 300 | now = inode_set_ctime_deleg(inode, attr->ia_ctime);
|
| 301 | else if (ia_valid & ATTR_CTIME)
|
| 302 | now = inode_set_ctime_current(inode);
|
| 303 | else
|
| 304 | now = current_time(inode);
|
| 305 |
|
| 306 | if (ia_valid & ATTR_ATIME_SET)
|
| 307 | inode_set_atime_to_ts(inode, attr->ia_atime);
|
| 308 | else if (ia_valid & ATTR_ATIME)
|
| 309 | inode_set_atime_to_ts(inode, now);
|
| 310 |
|
| 311 | if (ia_valid & ATTR_MTIME_SET)
|
| 312 | inode_set_mtime_to_ts(inode, attr->ia_mtime);
|
| 313 | else if (ia_valid & ATTR_MTIME)
|
| 314 | inode_set_mtime_to_ts(inode, now);
|
| 315 | }
|
| 316 |
|
| 317 | |
| 318 | * setattr_copy - copy simple metadata updates into the generic inode
|
| 319 | * @idmap: idmap of the mount the inode was found from
|
| 320 | * @inode: the inode to be updated
|
| 321 | * @attr: the new attributes
|
| 322 | *
|
| 323 | * setattr_copy must be called with i_rwsem held exclusively.
|
| 324 | *
|
| 325 | * setattr_copy updates the inode's metadata with that specified
|
| 326 | * in attr on idmapped mounts. Necessary permission checks to determine
|
| 327 | * whether or not the S_ISGID property needs to be removed are performed with
|
| 328 | * the correct idmapped mount permission helpers.
|
| 329 | * Noticeably missing is inode size update, which is more complex
|
| 330 | * as it requires pagecache updates.
|
| 331 | *
|
| 332 | * If the inode has been found through an idmapped mount the idmap of
|
| 333 | * the vfsmount must be passed through @idmap. This function will then
|
| 334 | * take care to map the inode according to @idmap before checking
|
| 335 | * permissions. On non-idmapped mounts or if permission checking is to be
|
| 336 | * performed on the raw inode simply pass @nop_mnt_idmap.
|
| 337 | *
|
| 338 | * The inode is not marked as dirty after this operation. The rationale is
|
| 339 | * that for "simple" filesystems, the struct inode is the inode storage.
|
| 340 | * The caller is free to mark the inode dirty afterwards if needed.
|
| 341 |
|
| 342 | void setattr_copy(struct mnt_idmap *idmap, struct inode *inode,
|
| 343 | const struct iattr *attr)
|
| 344 | {
|
| 345 | unsigned int ia_valid = attr->ia_valid;
|
| 346 |
|
| 347 | i_uid_update(idmap, attr, inode);
|
| 348 | i_gid_update(idmap, attr, inode);
|
| 349 | if (ia_valid & ATTR_MODE) {
|
| 350 | umode_t mode = attr->ia_mode;
|
| 351 | if (!in_group_or_capable(idmap, inode,
|
| 352 | i_gid_into_vfsgid(idmap, inode)))
|
| 353 | mode &= ~S_ISGID;
|
| 354 | inode->i_mode = mode;
|
| 355 | }
|
| 356 |
|
| 357 | if (is_mgtime(inode))
|
| 358 | return setattr_copy_mgtime(inode, attr);
|
| 359 |
|
| 360 | if (ia_valid & ATTR_ATIME)
|
| 361 | inode_set_atime_to_ts(inode, attr->ia_atime);
|
| 362 | if (ia_valid & ATTR_MTIME)
|
| 363 | inode_set_mtime_to_ts(inode, attr->ia_mtime);
|
| 364 |
|
| 365 | if (ia_valid & ATTR_CTIME_SET)
|
| 366 | inode_set_ctime_deleg(inode, attr->ia_ctime);
|
| 367 | else if (ia_valid & ATTR_CTIME)
|
| 368 | inode_set_ctime_to_ts(inode, attr->ia_ctime);
|
| 369 | }
|
| 370 | EXPORT_SYMBOL(setattr_copy);
|
| 371 |
|
| 372 | int may_setattr(struct mnt_idmap *idmap, struct inode *inode,
|
| 373 | unsigned int ia_valid)
|
| 374 | {
|
| 375 | int error;
|
| 376 |
|
| 377 | if (ia_valid & (ATTR_MODE | ATTR_UID | ATTR_GID | ATTR_TIMES_SET)) {
|
| 378 | if (IS_IMMUTABLE(inode) || IS_APPEND(inode))
|
| 379 | return -EPERM;
|
| 380 | }
|
| 381 |
|
| 382 | |
| 383 | * If utimes(2) and friends are called with times == NULL (or both
|
| 384 | * times are UTIME_NOW), then we need to check for write permission
|
| 385 |
|
| 386 | if (ia_valid & ATTR_TOUCH) {
|
| 387 | if (IS_IMMUTABLE(inode))
|
| 388 | return -EPERM;
|
| 389 |
|
| 390 | if (!inode_owner_or_capable(idmap, inode)) {
|
| 391 | error = inode_permission(idmap, inode, MAY_WRITE);
|
| 392 | if (error)
|
| 393 | return error;
|
| 394 | }
|
| 395 | }
|
| 396 | return 0;
|
| 397 | }
|
| 398 | EXPORT_SYMBOL(may_setattr);
|
| 399 |
|
| 400 | |
| 401 | * notify_change - modify attributes of a filesystem object
|
| 402 | * @idmap: idmap of the mount the inode was found from
|
| 403 | * @dentry: object affected
|
| 404 | * @attr: new attributes
|
| 405 | * @delegated_inode: returns inode, if the inode is delegated
|
| 406 | *
|
| 407 | * The caller must hold the i_rwsem exclusively on the affected object.
|
| 408 | *
|
| 409 | * If notify_change discovers a delegation in need of breaking,
|
| 410 | * it will return -EWOULDBLOCK and return a reference to the inode in
|
| 411 | * delegated_inode. The caller should then break the delegation and
|
| 412 | * retry. Because breaking a delegation may take a long time, the
|
| 413 | * caller should drop the i_rwsem before doing so.
|
| 414 | *
|
| 415 | * Alternatively, a caller may pass NULL for delegated_inode. This may
|
| 416 | * be appropriate for callers that expect the underlying filesystem not
|
| 417 | * to be NFS exported. Also, passing NULL is fine for callers holding
|
| 418 | * the file open for write, as there can be no conflicting delegation in
|
| 419 | * that case.
|
| 420 | *
|
| 421 | * If the inode has been found through an idmapped mount the idmap of
|
| 422 | * the vfsmount must be passed through @idmap. This function will then
|
| 423 | * take care to map the inode according to @idmap before checking
|
| 424 | * permissions. On non-idmapped mounts or if permission checking is to be
|
| 425 | * performed on the raw inode simply pass @nop_mnt_idmap.
|
| 426 |
|
| 427 | int notify_change(struct mnt_idmap *idmap, struct dentry *dentry,
|
| 428 | struct iattr *attr, struct delegated_inode *delegated_inode)
|
| 429 | {
|
| 430 | struct inode *inode = dentry->d_inode;
|
| 431 | umode_t mode = inode->i_mode;
|
| 432 | int error;
|
| 433 | struct timespec64 now;
|
| 434 | unsigned int ia_valid = attr->ia_valid;
|
| 435 |
|
| 436 | WARN_ON_ONCE(!inode_is_locked(inode));
|
| 437 |
|
| 438 | error = may_setattr(idmap, inode, ia_valid);
|
| 439 | if (error)
|
| 440 | return error;
|
| 441 |
|
| 442 | if ((ia_valid & ATTR_MODE)) {
|
| 443 | |
| 444 | * Don't allow changing the mode of symlinks:
|
| 445 | *
|
| 446 | * (1) The vfs doesn't take the mode of symlinks into account
|
| 447 | * during permission checking.
|
| 448 | * (2) This has never worked correctly. Most major filesystems
|
| 449 | * did return EOPNOTSUPP due to interactions with POSIX ACLs
|
| 450 | * but did still updated the mode of the symlink.
|
| 451 | * This inconsistency led system call wrapper providers such
|
| 452 | * as libc to block changing the mode of symlinks with
|
| 453 | * EOPNOTSUPP already.
|
| 454 | * (3) To even do this in the first place one would have to use
|
| 455 | * specific file descriptors and quite some effort.
|
| 456 |
|
| 457 | if (S_ISLNK(inode->i_mode))
|
| 458 | return -EOPNOTSUPP;
|
| 459 |
|
| 460 |
|
| 461 | if (is_sxid(attr->ia_mode))
|
| 462 | inode->i_flags &= ~S_NOSEC;
|
| 463 | }
|
| 464 |
|
| 465 | now = current_time(inode);
|
| 466 |
|
| 467 | if (ia_valid & ATTR_ATIME_SET)
|
| 468 | attr->ia_atime = timestamp_truncate(attr->ia_atime, inode);
|
| 469 | else
|
| 470 | attr->ia_atime = now;
|
| 471 | if (ia_valid & ATTR_CTIME_SET)
|
| 472 | attr->ia_ctime = timestamp_truncate(attr->ia_ctime, inode);
|
| 473 | else
|
| 474 | attr->ia_ctime = now;
|
| 475 | if (ia_valid & ATTR_MTIME_SET)
|
| 476 | attr->ia_mtime = timestamp_truncate(attr->ia_mtime, inode);
|
| 477 | else
|
| 478 | attr->ia_mtime = now;
|
| 479 |
|
| 480 | if (ia_valid & ATTR_KILL_PRIV) {
|
| 481 | error = security_inode_need_killpriv(dentry);
|
| 482 | if (error < 0)
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| 483 | return error;
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| 484 | if (error == 0)
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| 485 | ia_valid = attr->ia_valid &= ~ATTR_KILL_PRIV;
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| 486 | }
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| 487 |
|
| 488 | |
| 489 | * We now pass ATTR_KILL_S*ID to the lower level setattr function so
|
| 490 | * that the function has the ability to reinterpret a mode change
|
| 491 | * that's due to these bits. This adds an implicit restriction that
|
| 492 | * no function will ever call notify_change with both ATTR_MODE and
|
| 493 | * ATTR_KILL_S*ID set.
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| 494 |
|
| 495 | if ((ia_valid & (ATTR_KILL_SUID|ATTR_KILL_SGID)) &&
|
| 496 | (ia_valid & ATTR_MODE))
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| 497 | BUG();
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| 498 |
|
| 499 | if (ia_valid & ATTR_KILL_SUID) {
|
| 500 | if (mode & S_ISUID) {
|
| 501 | ia_valid = attr->ia_valid |= ATTR_MODE;
|
| 502 | attr->ia_mode = (inode->i_mode & ~S_ISUID);
|
| 503 | }
|
| 504 | }
|
| 505 | if (ia_valid & ATTR_KILL_SGID) {
|
| 506 | if (mode & S_ISGID) {
|
| 507 | if (!(ia_valid & ATTR_MODE)) {
|
| 508 | ia_valid = attr->ia_valid |= ATTR_MODE;
|
| 509 | attr->ia_mode = inode->i_mode;
|
| 510 | }
|
| 511 | attr->ia_mode &= ~S_ISGID;
|
| 512 | }
|
| 513 | }
|
| 514 | if (!(attr->ia_valid & ~(ATTR_KILL_SUID | ATTR_KILL_SGID)))
|
| 515 | return 0;
|
| 516 |
|
| 517 | |
| 518 | * Verify that uid/gid changes are valid in the target
|
| 519 | * namespace of the superblock.
|
| 520 |
|
| 521 | if (ia_valid & ATTR_UID &&
|
| 522 | !vfsuid_has_fsmapping(idmap, inode->i_sb->s_user_ns,
|
| 523 | attr->ia_vfsuid))
|
| 524 | return -EOVERFLOW;
|
| 525 | if (ia_valid & ATTR_GID &&
|
| 526 | !vfsgid_has_fsmapping(idmap, inode->i_sb->s_user_ns,
|
| 527 | attr->ia_vfsgid))
|
| 528 | return -EOVERFLOW;
|
| 529 |
|
| 530 | |
| 531 | * gids unless those uids & gids are being made valid.
|
| 532 |
|
| 533 | if (!(ia_valid & ATTR_UID) &&
|
| 534 | !vfsuid_valid(i_uid_into_vfsuid(idmap, inode)))
|
| 535 | return -EOVERFLOW;
|
| 536 | if (!(ia_valid & ATTR_GID) &&
|
| 537 | !vfsgid_valid(i_gid_into_vfsgid(idmap, inode)))
|
| 538 | return -EOVERFLOW;
|
| 539 |
|
| 540 | error = security_inode_setattr(idmap, dentry, attr);
|
| 541 | if (error)
|
| 542 | return error;
|
| 543 |
|
| 544 | |
| 545 | * If ATTR_DELEG is set, then these attributes are being set on
|
| 546 | * behalf of the holder of a write delegation. We want to avoid
|
| 547 | * breaking the delegation in this case.
|
| 548 |
|
| 549 | if (!(ia_valid & ATTR_DELEG)) {
|
| 550 | error = try_break_deleg(inode, 0, delegated_inode);
|
| 551 | if (error)
|
| 552 | return error;
|
| 553 | }
|
| 554 |
|
| 555 | if (inode->i_op->setattr)
|
| 556 | error = inode->i_op->setattr(idmap, dentry, attr);
|
| 557 | else
|
| 558 | error = simple_setattr(idmap, dentry, attr);
|
| 559 |
|
| 560 | if (!error) {
|
| 561 | fsnotify_change(dentry, ia_valid);
|
| 562 | security_inode_post_setattr(idmap, dentry, ia_valid);
|
| 563 | }
|
| 564 |
|
| 565 | return error;
|
| 566 | }
|
| 567 | EXPORT_SYMBOL(notify_change);
|