1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * Landlock LSM - Filesystem management and hooks 4 * 5 * Copyright © 2016-2020 Mickaël Salaün <mic@digikod.net> 6 * Copyright © 2018-2020 ANSSI 7 */ 8 9 #include <linux/atomic.h> 10 #include <linux/bitops.h> 11 #include <linux/bits.h> 12 #include <linux/compiler_types.h> 13 #include <linux/dcache.h> 14 #include <linux/err.h> 15 #include <linux/fs.h> 16 #include <linux/init.h> 17 #include <linux/kernel.h> 18 #include <linux/limits.h> 19 #include <linux/list.h> 20 #include <linux/lsm_hooks.h> 21 #include <linux/mount.h> 22 #include <linux/namei.h> 23 #include <linux/path.h> 24 #include <linux/rcupdate.h> 25 #include <linux/spinlock.h> 26 #include <linux/stat.h> 27 #include <linux/types.h> 28 #include <linux/wait_bit.h> 29 #include <linux/workqueue.h> 30 #include <uapi/linux/landlock.h> 31 32 #include "common.h" 33 #include "cred.h" 34 #include "fs.h" 35 #include "limits.h" 36 #include "object.h" 37 #include "ruleset.h" 38 #include "setup.h" 39 40 /* Underlying object management */ 41 42 static void release_inode(struct landlock_object *const object) 43 __releases(object->lock) 44 { 45 struct inode *const inode = object->underobj; 46 struct super_block *sb; 47 48 if (!inode) { 49 spin_unlock(&object->lock); 50 return; 51 } 52 53 /* 54 * Protects against concurrent use by hook_sb_delete() of the reference 55 * to the underlying inode. 56 */ 57 object->underobj = NULL; 58 /* 59 * Makes sure that if the filesystem is concurrently unmounted, 60 * hook_sb_delete() will wait for us to finish iput(). 61 */ 62 sb = inode->i_sb; 63 atomic_long_inc(&landlock_superblock(sb)->inode_refs); 64 spin_unlock(&object->lock); 65 /* 66 * Because object->underobj was not NULL, hook_sb_delete() and 67 * get_inode_object() guarantee that it is safe to reset 68 * landlock_inode(inode)->object while it is not NULL. It is therefore 69 * not necessary to lock inode->i_lock. 70 */ 71 rcu_assign_pointer(landlock_inode(inode)->object, NULL); 72 /* 73 * Now, new rules can safely be tied to @inode with get_inode_object(). 74 */ 75 76 iput(inode); 77 if (atomic_long_dec_and_test(&landlock_superblock(sb)->inode_refs)) 78 wake_up_var(&landlock_superblock(sb)->inode_refs); 79 } 80 81 static const struct landlock_object_underops landlock_fs_underops = { 82 .release = release_inode 83 }; 84 85 /* Ruleset management */ 86 87 static struct landlock_object *get_inode_object(struct inode *const inode) 88 { 89 struct landlock_object *object, *new_object; 90 struct landlock_inode_security *inode_sec = landlock_inode(inode); 91 92 rcu_read_lock(); 93 retry: 94 object = rcu_dereference(inode_sec->object); 95 if (object) { 96 if (likely(refcount_inc_not_zero(&object->usage))) { 97 rcu_read_unlock(); 98 return object; 99 } 100 /* 101 * We are racing with release_inode(), the object is going 102 * away. Wait for release_inode(), then retry. 103 */ 104 spin_lock(&object->lock); 105 spin_unlock(&object->lock); 106 goto retry; 107 } 108 rcu_read_unlock(); 109 110 /* 111 * If there is no object tied to @inode, then create a new one (without 112 * holding any locks). 113 */ 114 new_object = landlock_create_object(&landlock_fs_underops, inode); 115 if (IS_ERR(new_object)) 116 return new_object; 117 118 /* 119 * Protects against concurrent calls to get_inode_object() or 120 * hook_sb_delete(). 121 */ 122 spin_lock(&inode->i_lock); 123 if (unlikely(rcu_access_pointer(inode_sec->object))) { 124 /* Someone else just created the object, bail out and retry. */ 125 spin_unlock(&inode->i_lock); 126 kfree(new_object); 127 128 rcu_read_lock(); 129 goto retry; 130 } 131 132 /* 133 * @inode will be released by hook_sb_delete() on its superblock 134 * shutdown, or by release_inode() when no more ruleset references the 135 * related object. 136 */ 137 ihold(inode); 138 rcu_assign_pointer(inode_sec->object, new_object); 139 spin_unlock(&inode->i_lock); 140 return new_object; 141 } 142 143 /* All access rights that can be tied to files. */ 144 /* clang-format off */ 145 #define ACCESS_FILE ( \ 146 LANDLOCK_ACCESS_FS_EXECUTE | \ 147 LANDLOCK_ACCESS_FS_WRITE_FILE | \ 148 LANDLOCK_ACCESS_FS_READ_FILE) 149 /* clang-format on */ 150 151 /* 152 * @path: Should have been checked by get_path_from_fd(). 153 */ 154 int landlock_append_fs_rule(struct landlock_ruleset *const ruleset, 155 const struct path *const path, 156 access_mask_t access_rights) 157 { 158 int err; 159 struct landlock_object *object; 160 161 /* Files only get access rights that make sense. */ 162 if (!d_is_dir(path->dentry) && 163 (access_rights | ACCESS_FILE) != ACCESS_FILE) 164 return -EINVAL; 165 if (WARN_ON_ONCE(ruleset->num_layers != 1)) 166 return -EINVAL; 167 168 /* Transforms relative access rights to absolute ones. */ 169 access_rights |= LANDLOCK_MASK_ACCESS_FS & ~ruleset->fs_access_masks[0]; 170 object = get_inode_object(d_backing_inode(path->dentry)); 171 if (IS_ERR(object)) 172 return PTR_ERR(object); 173 mutex_lock(&ruleset->lock); 174 err = landlock_insert_rule(ruleset, object, access_rights); 175 mutex_unlock(&ruleset->lock); 176 /* 177 * No need to check for an error because landlock_insert_rule() 178 * increments the refcount for the new object if needed. 179 */ 180 landlock_put_object(object); 181 return err; 182 } 183 184 /* Access-control management */ 185 186 /* 187 * The lifetime of the returned rule is tied to @domain. 188 * 189 * Returns NULL if no rule is found or if @dentry is negative. 190 */ 191 static inline const struct landlock_rule * 192 find_rule(const struct landlock_ruleset *const domain, 193 const struct dentry *const dentry) 194 { 195 const struct landlock_rule *rule; 196 const struct inode *inode; 197 198 /* Ignores nonexistent leafs. */ 199 if (d_is_negative(dentry)) 200 return NULL; 201 202 inode = d_backing_inode(dentry); 203 rcu_read_lock(); 204 rule = landlock_find_rule( 205 domain, rcu_dereference(landlock_inode(inode)->object)); 206 rcu_read_unlock(); 207 return rule; 208 } 209 210 /* 211 * @layer_masks is read and may be updated according to the access request and 212 * the matching rule. 213 * 214 * Returns true if the request is allowed (i.e. relevant layer masks for the 215 * request are empty). 216 */ 217 static inline bool 218 unmask_layers(const struct landlock_rule *const rule, 219 const access_mask_t access_request, 220 layer_mask_t (*const layer_masks)[LANDLOCK_NUM_ACCESS_FS]) 221 { 222 size_t layer_level; 223 224 if (!access_request || !layer_masks) 225 return true; 226 if (!rule) 227 return false; 228 229 /* 230 * An access is granted if, for each policy layer, at least one rule 231 * encountered on the pathwalk grants the requested access, 232 * regardless of its position in the layer stack. We must then check 233 * the remaining layers for each inode, from the first added layer to 234 * the last one. When there is multiple requested accesses, for each 235 * policy layer, the full set of requested accesses may not be granted 236 * by only one rule, but by the union (binary OR) of multiple rules. 237 * E.g. /a/b <execute> + /a <read> => /a/b <execute + read> 238 */ 239 for (layer_level = 0; layer_level < rule->num_layers; layer_level++) { 240 const struct landlock_layer *const layer = 241 &rule->layers[layer_level]; 242 const layer_mask_t layer_bit = BIT_ULL(layer->level - 1); 243 const unsigned long access_req = access_request; 244 unsigned long access_bit; 245 bool is_empty; 246 247 /* 248 * Records in @layer_masks which layer grants access to each 249 * requested access. 250 */ 251 is_empty = true; 252 for_each_set_bit(access_bit, &access_req, 253 ARRAY_SIZE(*layer_masks)) { 254 if (layer->access & BIT_ULL(access_bit)) 255 (*layer_masks)[access_bit] &= ~layer_bit; 256 is_empty = is_empty && !(*layer_masks)[access_bit]; 257 } 258 if (is_empty) 259 return true; 260 } 261 return false; 262 } 263 264 /* 265 * Allows access to pseudo filesystems that will never be mountable (e.g. 266 * sockfs, pipefs), but can still be reachable through 267 * /proc/<pid>/fd/<file-descriptor> 268 */ 269 static inline bool is_nouser_or_private(const struct dentry *dentry) 270 { 271 return (dentry->d_sb->s_flags & SB_NOUSER) || 272 (d_is_positive(dentry) && 273 unlikely(IS_PRIVATE(d_backing_inode(dentry)))); 274 } 275 276 static int check_access_path(const struct landlock_ruleset *const domain, 277 const struct path *const path, 278 const access_mask_t access_request) 279 { 280 layer_mask_t layer_masks[LANDLOCK_NUM_ACCESS_FS] = {}; 281 bool allowed = false, has_access = false; 282 struct path walker_path; 283 size_t i; 284 285 if (!access_request) 286 return 0; 287 if (WARN_ON_ONCE(!domain || !path)) 288 return 0; 289 if (is_nouser_or_private(path->dentry)) 290 return 0; 291 if (WARN_ON_ONCE(domain->num_layers < 1)) 292 return -EACCES; 293 294 /* Saves all layers handling a subset of requested accesses. */ 295 for (i = 0; i < domain->num_layers; i++) { 296 const unsigned long access_req = access_request; 297 unsigned long access_bit; 298 299 for_each_set_bit(access_bit, &access_req, 300 ARRAY_SIZE(layer_masks)) { 301 if (domain->fs_access_masks[i] & BIT_ULL(access_bit)) { 302 layer_masks[access_bit] |= BIT_ULL(i); 303 has_access = true; 304 } 305 } 306 } 307 /* An access request not handled by the domain is allowed. */ 308 if (!has_access) 309 return 0; 310 311 walker_path = *path; 312 path_get(&walker_path); 313 /* 314 * We need to walk through all the hierarchy to not miss any relevant 315 * restriction. 316 */ 317 while (true) { 318 struct dentry *parent_dentry; 319 320 allowed = unmask_layers(find_rule(domain, walker_path.dentry), 321 access_request, &layer_masks); 322 if (allowed) 323 /* Stops when a rule from each layer grants access. */ 324 break; 325 326 jump_up: 327 if (walker_path.dentry == walker_path.mnt->mnt_root) { 328 if (follow_up(&walker_path)) { 329 /* Ignores hidden mount points. */ 330 goto jump_up; 331 } else { 332 /* 333 * Stops at the real root. Denies access 334 * because not all layers have granted access. 335 */ 336 allowed = false; 337 break; 338 } 339 } 340 if (unlikely(IS_ROOT(walker_path.dentry))) { 341 /* 342 * Stops at disconnected root directories. Only allows 343 * access to internal filesystems (e.g. nsfs, which is 344 * reachable through /proc/<pid>/ns/<namespace>). 345 */ 346 allowed = !!(walker_path.mnt->mnt_flags & MNT_INTERNAL); 347 break; 348 } 349 parent_dentry = dget_parent(walker_path.dentry); 350 dput(walker_path.dentry); 351 walker_path.dentry = parent_dentry; 352 } 353 path_put(&walker_path); 354 return allowed ? 0 : -EACCES; 355 } 356 357 static inline int current_check_access_path(const struct path *const path, 358 const access_mask_t access_request) 359 { 360 const struct landlock_ruleset *const dom = 361 landlock_get_current_domain(); 362 363 if (!dom) 364 return 0; 365 return check_access_path(dom, path, access_request); 366 } 367 368 static inline access_mask_t get_mode_access(const umode_t mode) 369 { 370 switch (mode & S_IFMT) { 371 case S_IFLNK: 372 return LANDLOCK_ACCESS_FS_MAKE_SYM; 373 case 0: 374 /* A zero mode translates to S_IFREG. */ 375 case S_IFREG: 376 return LANDLOCK_ACCESS_FS_MAKE_REG; 377 case S_IFDIR: 378 return LANDLOCK_ACCESS_FS_MAKE_DIR; 379 case S_IFCHR: 380 return LANDLOCK_ACCESS_FS_MAKE_CHAR; 381 case S_IFBLK: 382 return LANDLOCK_ACCESS_FS_MAKE_BLOCK; 383 case S_IFIFO: 384 return LANDLOCK_ACCESS_FS_MAKE_FIFO; 385 case S_IFSOCK: 386 return LANDLOCK_ACCESS_FS_MAKE_SOCK; 387 default: 388 WARN_ON_ONCE(1); 389 return 0; 390 } 391 } 392 393 static inline access_mask_t maybe_remove(const struct dentry *const dentry) 394 { 395 if (d_is_negative(dentry)) 396 return 0; 397 return d_is_dir(dentry) ? LANDLOCK_ACCESS_FS_REMOVE_DIR : 398 LANDLOCK_ACCESS_FS_REMOVE_FILE; 399 } 400 401 /* Inode hooks */ 402 403 static void hook_inode_free_security(struct inode *const inode) 404 { 405 /* 406 * All inodes must already have been untied from their object by 407 * release_inode() or hook_sb_delete(). 408 */ 409 WARN_ON_ONCE(landlock_inode(inode)->object); 410 } 411 412 /* Super-block hooks */ 413 414 /* 415 * Release the inodes used in a security policy. 416 * 417 * Cf. fsnotify_unmount_inodes() and invalidate_inodes() 418 */ 419 static void hook_sb_delete(struct super_block *const sb) 420 { 421 struct inode *inode, *prev_inode = NULL; 422 423 if (!landlock_initialized) 424 return; 425 426 spin_lock(&sb->s_inode_list_lock); 427 list_for_each_entry(inode, &sb->s_inodes, i_sb_list) { 428 struct landlock_object *object; 429 430 /* Only handles referenced inodes. */ 431 if (!atomic_read(&inode->i_count)) 432 continue; 433 434 /* 435 * Protects against concurrent modification of inode (e.g. 436 * from get_inode_object()). 437 */ 438 spin_lock(&inode->i_lock); 439 /* 440 * Checks I_FREEING and I_WILL_FREE to protect against a race 441 * condition when release_inode() just called iput(), which 442 * could lead to a NULL dereference of inode->security or a 443 * second call to iput() for the same Landlock object. Also 444 * checks I_NEW because such inode cannot be tied to an object. 445 */ 446 if (inode->i_state & (I_FREEING | I_WILL_FREE | I_NEW)) { 447 spin_unlock(&inode->i_lock); 448 continue; 449 } 450 451 rcu_read_lock(); 452 object = rcu_dereference(landlock_inode(inode)->object); 453 if (!object) { 454 rcu_read_unlock(); 455 spin_unlock(&inode->i_lock); 456 continue; 457 } 458 /* Keeps a reference to this inode until the next loop walk. */ 459 __iget(inode); 460 spin_unlock(&inode->i_lock); 461 462 /* 463 * If there is no concurrent release_inode() ongoing, then we 464 * are in charge of calling iput() on this inode, otherwise we 465 * will just wait for it to finish. 466 */ 467 spin_lock(&object->lock); 468 if (object->underobj == inode) { 469 object->underobj = NULL; 470 spin_unlock(&object->lock); 471 rcu_read_unlock(); 472 473 /* 474 * Because object->underobj was not NULL, 475 * release_inode() and get_inode_object() guarantee 476 * that it is safe to reset 477 * landlock_inode(inode)->object while it is not NULL. 478 * It is therefore not necessary to lock inode->i_lock. 479 */ 480 rcu_assign_pointer(landlock_inode(inode)->object, NULL); 481 /* 482 * At this point, we own the ihold() reference that was 483 * originally set up by get_inode_object() and the 484 * __iget() reference that we just set in this loop 485 * walk. Therefore the following call to iput() will 486 * not sleep nor drop the inode because there is now at 487 * least two references to it. 488 */ 489 iput(inode); 490 } else { 491 spin_unlock(&object->lock); 492 rcu_read_unlock(); 493 } 494 495 if (prev_inode) { 496 /* 497 * At this point, we still own the __iget() reference 498 * that we just set in this loop walk. Therefore we 499 * can drop the list lock and know that the inode won't 500 * disappear from under us until the next loop walk. 501 */ 502 spin_unlock(&sb->s_inode_list_lock); 503 /* 504 * We can now actually put the inode reference from the 505 * previous loop walk, which is not needed anymore. 506 */ 507 iput(prev_inode); 508 cond_resched(); 509 spin_lock(&sb->s_inode_list_lock); 510 } 511 prev_inode = inode; 512 } 513 spin_unlock(&sb->s_inode_list_lock); 514 515 /* Puts the inode reference from the last loop walk, if any. */ 516 if (prev_inode) 517 iput(prev_inode); 518 /* Waits for pending iput() in release_inode(). */ 519 wait_var_event(&landlock_superblock(sb)->inode_refs, 520 !atomic_long_read(&landlock_superblock(sb)->inode_refs)); 521 } 522 523 /* 524 * Because a Landlock security policy is defined according to the filesystem 525 * topology (i.e. the mount namespace), changing it may grant access to files 526 * not previously allowed. 527 * 528 * To make it simple, deny any filesystem topology modification by landlocked 529 * processes. Non-landlocked processes may still change the namespace of a 530 * landlocked process, but this kind of threat must be handled by a system-wide 531 * access-control security policy. 532 * 533 * This could be lifted in the future if Landlock can safely handle mount 534 * namespace updates requested by a landlocked process. Indeed, we could 535 * update the current domain (which is currently read-only) by taking into 536 * account the accesses of the source and the destination of a new mount point. 537 * However, it would also require to make all the child domains dynamically 538 * inherit these new constraints. Anyway, for backward compatibility reasons, 539 * a dedicated user space option would be required (e.g. as a ruleset flag). 540 */ 541 static int hook_sb_mount(const char *const dev_name, 542 const struct path *const path, const char *const type, 543 const unsigned long flags, void *const data) 544 { 545 if (!landlock_get_current_domain()) 546 return 0; 547 return -EPERM; 548 } 549 550 static int hook_move_mount(const struct path *const from_path, 551 const struct path *const to_path) 552 { 553 if (!landlock_get_current_domain()) 554 return 0; 555 return -EPERM; 556 } 557 558 /* 559 * Removing a mount point may reveal a previously hidden file hierarchy, which 560 * may then grant access to files, which may have previously been forbidden. 561 */ 562 static int hook_sb_umount(struct vfsmount *const mnt, const int flags) 563 { 564 if (!landlock_get_current_domain()) 565 return 0; 566 return -EPERM; 567 } 568 569 static int hook_sb_remount(struct super_block *const sb, void *const mnt_opts) 570 { 571 if (!landlock_get_current_domain()) 572 return 0; 573 return -EPERM; 574 } 575 576 /* 577 * pivot_root(2), like mount(2), changes the current mount namespace. It must 578 * then be forbidden for a landlocked process. 579 * 580 * However, chroot(2) may be allowed because it only changes the relative root 581 * directory of the current process. Moreover, it can be used to restrict the 582 * view of the filesystem. 583 */ 584 static int hook_sb_pivotroot(const struct path *const old_path, 585 const struct path *const new_path) 586 { 587 if (!landlock_get_current_domain()) 588 return 0; 589 return -EPERM; 590 } 591 592 /* Path hooks */ 593 594 /* 595 * Creating multiple links or renaming may lead to privilege escalations if not 596 * handled properly. Indeed, we must be sure that the source doesn't gain more 597 * privileges by being accessible from the destination. This is getting more 598 * complex when dealing with multiple layers. The whole picture can be seen as 599 * a multilayer partial ordering problem. A future version of Landlock will 600 * deal with that. 601 */ 602 static int hook_path_link(struct dentry *const old_dentry, 603 const struct path *const new_dir, 604 struct dentry *const new_dentry) 605 { 606 const struct landlock_ruleset *const dom = 607 landlock_get_current_domain(); 608 609 if (!dom) 610 return 0; 611 /* The mount points are the same for old and new paths, cf. EXDEV. */ 612 if (old_dentry->d_parent != new_dir->dentry) 613 /* Gracefully forbids reparenting. */ 614 return -EXDEV; 615 if (unlikely(d_is_negative(old_dentry))) 616 return -ENOENT; 617 return check_access_path( 618 dom, new_dir, 619 get_mode_access(d_backing_inode(old_dentry)->i_mode)); 620 } 621 622 static int hook_path_rename(const struct path *const old_dir, 623 struct dentry *const old_dentry, 624 const struct path *const new_dir, 625 struct dentry *const new_dentry) 626 { 627 const struct landlock_ruleset *const dom = 628 landlock_get_current_domain(); 629 630 if (!dom) 631 return 0; 632 /* The mount points are the same for old and new paths, cf. EXDEV. */ 633 if (old_dir->dentry != new_dir->dentry) 634 /* Gracefully forbids reparenting. */ 635 return -EXDEV; 636 if (unlikely(d_is_negative(old_dentry))) 637 return -ENOENT; 638 /* RENAME_EXCHANGE is handled because directories are the same. */ 639 return check_access_path( 640 dom, old_dir, 641 maybe_remove(old_dentry) | maybe_remove(new_dentry) | 642 get_mode_access(d_backing_inode(old_dentry)->i_mode)); 643 } 644 645 static int hook_path_mkdir(const struct path *const dir, 646 struct dentry *const dentry, const umode_t mode) 647 { 648 return current_check_access_path(dir, LANDLOCK_ACCESS_FS_MAKE_DIR); 649 } 650 651 static int hook_path_mknod(const struct path *const dir, 652 struct dentry *const dentry, const umode_t mode, 653 const unsigned int dev) 654 { 655 const struct landlock_ruleset *const dom = 656 landlock_get_current_domain(); 657 658 if (!dom) 659 return 0; 660 return check_access_path(dom, dir, get_mode_access(mode)); 661 } 662 663 static int hook_path_symlink(const struct path *const dir, 664 struct dentry *const dentry, 665 const char *const old_name) 666 { 667 return current_check_access_path(dir, LANDLOCK_ACCESS_FS_MAKE_SYM); 668 } 669 670 static int hook_path_unlink(const struct path *const dir, 671 struct dentry *const dentry) 672 { 673 return current_check_access_path(dir, LANDLOCK_ACCESS_FS_REMOVE_FILE); 674 } 675 676 static int hook_path_rmdir(const struct path *const dir, 677 struct dentry *const dentry) 678 { 679 return current_check_access_path(dir, LANDLOCK_ACCESS_FS_REMOVE_DIR); 680 } 681 682 /* File hooks */ 683 684 static inline access_mask_t get_file_access(const struct file *const file) 685 { 686 access_mask_t access = 0; 687 688 if (file->f_mode & FMODE_READ) { 689 /* A directory can only be opened in read mode. */ 690 if (S_ISDIR(file_inode(file)->i_mode)) 691 return LANDLOCK_ACCESS_FS_READ_DIR; 692 access = LANDLOCK_ACCESS_FS_READ_FILE; 693 } 694 if (file->f_mode & FMODE_WRITE) 695 access |= LANDLOCK_ACCESS_FS_WRITE_FILE; 696 /* __FMODE_EXEC is indeed part of f_flags, not f_mode. */ 697 if (file->f_flags & __FMODE_EXEC) 698 access |= LANDLOCK_ACCESS_FS_EXECUTE; 699 return access; 700 } 701 702 static int hook_file_open(struct file *const file) 703 { 704 const struct landlock_ruleset *const dom = 705 landlock_get_current_domain(); 706 707 if (!dom) 708 return 0; 709 /* 710 * Because a file may be opened with O_PATH, get_file_access() may 711 * return 0. This case will be handled with a future Landlock 712 * evolution. 713 */ 714 return check_access_path(dom, &file->f_path, get_file_access(file)); 715 } 716 717 static struct security_hook_list landlock_hooks[] __lsm_ro_after_init = { 718 LSM_HOOK_INIT(inode_free_security, hook_inode_free_security), 719 720 LSM_HOOK_INIT(sb_delete, hook_sb_delete), 721 LSM_HOOK_INIT(sb_mount, hook_sb_mount), 722 LSM_HOOK_INIT(move_mount, hook_move_mount), 723 LSM_HOOK_INIT(sb_umount, hook_sb_umount), 724 LSM_HOOK_INIT(sb_remount, hook_sb_remount), 725 LSM_HOOK_INIT(sb_pivotroot, hook_sb_pivotroot), 726 727 LSM_HOOK_INIT(path_link, hook_path_link), 728 LSM_HOOK_INIT(path_rename, hook_path_rename), 729 LSM_HOOK_INIT(path_mkdir, hook_path_mkdir), 730 LSM_HOOK_INIT(path_mknod, hook_path_mknod), 731 LSM_HOOK_INIT(path_symlink, hook_path_symlink), 732 LSM_HOOK_INIT(path_unlink, hook_path_unlink), 733 LSM_HOOK_INIT(path_rmdir, hook_path_rmdir), 734 735 LSM_HOOK_INIT(file_open, hook_file_open), 736 }; 737 738 __init void landlock_add_fs_hooks(void) 739 { 740 security_add_hooks(landlock_hooks, ARRAY_SIZE(landlock_hooks), 741 LANDLOCK_NAME); 742 } 743