1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* 3 * eCryptfs: Linux filesystem encryption layer 4 * 5 * Copyright (C) 1997-2003 Erez Zadok 6 * Copyright (C) 2001-2003 Stony Brook University 7 * Copyright (C) 2004-2007 International Business Machines Corp. 8 * Author(s): Michael A. Halcrow <mahalcro@us.ibm.com> 9 * Michael C. Thompson <mcthomps@us.ibm.com> 10 * Tyler Hicks <code@tyhicks.com> 11 */ 12 13 #include <linux/dcache.h> 14 #include <linux/file.h> 15 #include <linux/module.h> 16 #include <linux/namei.h> 17 #include <linux/skbuff.h> 18 #include <linux/mount.h> 19 #include <linux/pagemap.h> 20 #include <linux/key.h> 21 #include <linux/parser.h> 22 #include <linux/fs_stack.h> 23 #include <linux/slab.h> 24 #include <linux/magic.h> 25 #include "ecryptfs_kernel.h" 26 27 /* 28 * Module parameter that defines the ecryptfs_verbosity level. 29 */ 30 int ecryptfs_verbosity = 0; 31 32 module_param(ecryptfs_verbosity, int, 0); 33 MODULE_PARM_DESC(ecryptfs_verbosity, 34 "Initial verbosity level (0 or 1; defaults to " 35 "0, which is Quiet)"); 36 37 /* 38 * Module parameter that defines the number of message buffer elements 39 */ 40 unsigned int ecryptfs_message_buf_len = ECRYPTFS_DEFAULT_MSG_CTX_ELEMS; 41 42 module_param(ecryptfs_message_buf_len, uint, 0); 43 MODULE_PARM_DESC(ecryptfs_message_buf_len, 44 "Number of message buffer elements"); 45 46 /* 47 * Module parameter that defines the maximum guaranteed amount of time to wait 48 * for a response from ecryptfsd. The actual sleep time will be, more than 49 * likely, a small amount greater than this specified value, but only less if 50 * the message successfully arrives. 51 */ 52 signed long ecryptfs_message_wait_timeout = ECRYPTFS_MAX_MSG_CTX_TTL / HZ; 53 54 module_param(ecryptfs_message_wait_timeout, long, 0); 55 MODULE_PARM_DESC(ecryptfs_message_wait_timeout, 56 "Maximum number of seconds that an operation will " 57 "sleep while waiting for a message response from " 58 "userspace"); 59 60 /* 61 * Module parameter that is an estimate of the maximum number of users 62 * that will be concurrently using eCryptfs. Set this to the right 63 * value to balance performance and memory use. 64 */ 65 unsigned int ecryptfs_number_of_users = ECRYPTFS_DEFAULT_NUM_USERS; 66 67 module_param(ecryptfs_number_of_users, uint, 0); 68 MODULE_PARM_DESC(ecryptfs_number_of_users, "An estimate of the number of " 69 "concurrent users of eCryptfs"); 70 71 void __ecryptfs_printk(const char *fmt, ...) 72 { 73 va_list args; 74 va_start(args, fmt); 75 if (fmt[1] == '7') { /* KERN_DEBUG */ 76 if (ecryptfs_verbosity >= 1) 77 vprintk(fmt, args); 78 } else 79 vprintk(fmt, args); 80 va_end(args); 81 } 82 83 /* 84 * ecryptfs_init_lower_file 85 * @ecryptfs_dentry: Fully initialized eCryptfs dentry object, with 86 * the lower dentry and the lower mount set 87 * 88 * eCryptfs only ever keeps a single open file for every lower 89 * inode. All I/O operations to the lower inode occur through that 90 * file. When the first eCryptfs dentry that interposes with the first 91 * lower dentry for that inode is created, this function creates the 92 * lower file struct and associates it with the eCryptfs 93 * inode. When all eCryptfs files associated with the inode are released, the 94 * file is closed. 95 * 96 * The lower file will be opened with read/write permissions, if 97 * possible. Otherwise, it is opened read-only. 98 * 99 * This function does nothing if a lower file is already 100 * associated with the eCryptfs inode. 101 * 102 * Returns zero on success; non-zero otherwise 103 */ 104 static int ecryptfs_init_lower_file(struct dentry *dentry, 105 struct file **lower_file) 106 { 107 const struct cred *cred = current_cred(); 108 struct path *path = ecryptfs_dentry_to_lower_path(dentry); 109 int rc; 110 111 rc = ecryptfs_privileged_open(lower_file, path->dentry, path->mnt, 112 cred); 113 if (rc) { 114 printk(KERN_ERR "Error opening lower file " 115 "for lower_dentry [0x%p] and lower_mnt [0x%p]; " 116 "rc = [%d]\n", path->dentry, path->mnt, rc); 117 (*lower_file) = NULL; 118 } 119 return rc; 120 } 121 122 int ecryptfs_get_lower_file(struct dentry *dentry, struct inode *inode) 123 { 124 struct ecryptfs_inode_info *inode_info; 125 int count, rc = 0; 126 127 inode_info = ecryptfs_inode_to_private(inode); 128 mutex_lock(&inode_info->lower_file_mutex); 129 count = atomic_inc_return(&inode_info->lower_file_count); 130 if (WARN_ON_ONCE(count < 1)) 131 rc = -EINVAL; 132 else if (count == 1) { 133 rc = ecryptfs_init_lower_file(dentry, 134 &inode_info->lower_file); 135 if (rc) 136 atomic_set(&inode_info->lower_file_count, 0); 137 } 138 mutex_unlock(&inode_info->lower_file_mutex); 139 return rc; 140 } 141 142 void ecryptfs_put_lower_file(struct inode *inode) 143 { 144 struct ecryptfs_inode_info *inode_info; 145 146 inode_info = ecryptfs_inode_to_private(inode); 147 if (atomic_dec_and_mutex_lock(&inode_info->lower_file_count, 148 &inode_info->lower_file_mutex)) { 149 filemap_write_and_wait(inode->i_mapping); 150 fput(inode_info->lower_file); 151 inode_info->lower_file = NULL; 152 mutex_unlock(&inode_info->lower_file_mutex); 153 } 154 } 155 156 enum { ecryptfs_opt_sig, ecryptfs_opt_ecryptfs_sig, 157 ecryptfs_opt_cipher, ecryptfs_opt_ecryptfs_cipher, 158 ecryptfs_opt_ecryptfs_key_bytes, 159 ecryptfs_opt_passthrough, ecryptfs_opt_xattr_metadata, 160 ecryptfs_opt_encrypted_view, ecryptfs_opt_fnek_sig, 161 ecryptfs_opt_fn_cipher, ecryptfs_opt_fn_cipher_key_bytes, 162 ecryptfs_opt_unlink_sigs, ecryptfs_opt_mount_auth_tok_only, 163 ecryptfs_opt_check_dev_ruid, 164 ecryptfs_opt_err }; 165 166 static const match_table_t tokens = { 167 {ecryptfs_opt_sig, "sig=%s"}, 168 {ecryptfs_opt_ecryptfs_sig, "ecryptfs_sig=%s"}, 169 {ecryptfs_opt_cipher, "cipher=%s"}, 170 {ecryptfs_opt_ecryptfs_cipher, "ecryptfs_cipher=%s"}, 171 {ecryptfs_opt_ecryptfs_key_bytes, "ecryptfs_key_bytes=%u"}, 172 {ecryptfs_opt_passthrough, "ecryptfs_passthrough"}, 173 {ecryptfs_opt_xattr_metadata, "ecryptfs_xattr_metadata"}, 174 {ecryptfs_opt_encrypted_view, "ecryptfs_encrypted_view"}, 175 {ecryptfs_opt_fnek_sig, "ecryptfs_fnek_sig=%s"}, 176 {ecryptfs_opt_fn_cipher, "ecryptfs_fn_cipher=%s"}, 177 {ecryptfs_opt_fn_cipher_key_bytes, "ecryptfs_fn_key_bytes=%u"}, 178 {ecryptfs_opt_unlink_sigs, "ecryptfs_unlink_sigs"}, 179 {ecryptfs_opt_mount_auth_tok_only, "ecryptfs_mount_auth_tok_only"}, 180 {ecryptfs_opt_check_dev_ruid, "ecryptfs_check_dev_ruid"}, 181 {ecryptfs_opt_err, NULL} 182 }; 183 184 static int ecryptfs_init_global_auth_toks( 185 struct ecryptfs_mount_crypt_stat *mount_crypt_stat) 186 { 187 struct ecryptfs_global_auth_tok *global_auth_tok; 188 struct ecryptfs_auth_tok *auth_tok; 189 int rc = 0; 190 191 list_for_each_entry(global_auth_tok, 192 &mount_crypt_stat->global_auth_tok_list, 193 mount_crypt_stat_list) { 194 rc = ecryptfs_keyring_auth_tok_for_sig( 195 &global_auth_tok->global_auth_tok_key, &auth_tok, 196 global_auth_tok->sig); 197 if (rc) { 198 printk(KERN_ERR "Could not find valid key in user " 199 "session keyring for sig specified in mount " 200 "option: [%s]\n", global_auth_tok->sig); 201 global_auth_tok->flags |= ECRYPTFS_AUTH_TOK_INVALID; 202 goto out; 203 } else { 204 global_auth_tok->flags &= ~ECRYPTFS_AUTH_TOK_INVALID; 205 up_write(&(global_auth_tok->global_auth_tok_key)->sem); 206 } 207 } 208 out: 209 return rc; 210 } 211 212 static void ecryptfs_init_mount_crypt_stat( 213 struct ecryptfs_mount_crypt_stat *mount_crypt_stat) 214 { 215 memset((void *)mount_crypt_stat, 0, 216 sizeof(struct ecryptfs_mount_crypt_stat)); 217 INIT_LIST_HEAD(&mount_crypt_stat->global_auth_tok_list); 218 mutex_init(&mount_crypt_stat->global_auth_tok_list_mutex); 219 mount_crypt_stat->flags |= ECRYPTFS_MOUNT_CRYPT_STAT_INITIALIZED; 220 } 221 222 /** 223 * ecryptfs_parse_options 224 * @sbi: The ecryptfs super block 225 * @options: The options passed to the kernel 226 * @check_ruid: set to 1 if device uid should be checked against the ruid 227 * 228 * Parse mount options: 229 * debug=N - ecryptfs_verbosity level for debug output 230 * sig=XXX - description(signature) of the key to use 231 * 232 * Returns the dentry object of the lower-level (lower/interposed) 233 * directory; We want to mount our stackable file system on top of 234 * that lower directory. 235 * 236 * The signature of the key to use must be the description of a key 237 * already in the keyring. Mounting will fail if the key can not be 238 * found. 239 * 240 * Returns zero on success; non-zero on error 241 */ 242 static int ecryptfs_parse_options(struct ecryptfs_sb_info *sbi, char *options, 243 uid_t *check_ruid) 244 { 245 char *p; 246 int rc = 0; 247 int sig_set = 0; 248 int cipher_name_set = 0; 249 int fn_cipher_name_set = 0; 250 int cipher_key_bytes; 251 int cipher_key_bytes_set = 0; 252 int fn_cipher_key_bytes; 253 int fn_cipher_key_bytes_set = 0; 254 struct ecryptfs_mount_crypt_stat *mount_crypt_stat = 255 &sbi->mount_crypt_stat; 256 substring_t args[MAX_OPT_ARGS]; 257 int token; 258 char *sig_src; 259 char *cipher_name_dst; 260 char *cipher_name_src; 261 char *fn_cipher_name_dst; 262 char *fn_cipher_name_src; 263 char *fnek_dst; 264 char *fnek_src; 265 char *cipher_key_bytes_src; 266 char *fn_cipher_key_bytes_src; 267 u8 cipher_code; 268 269 *check_ruid = 0; 270 271 if (!options) { 272 rc = -EINVAL; 273 goto out; 274 } 275 ecryptfs_init_mount_crypt_stat(mount_crypt_stat); 276 while ((p = strsep(&options, ",")) != NULL) { 277 if (!*p) 278 continue; 279 token = match_token(p, tokens, args); 280 switch (token) { 281 case ecryptfs_opt_sig: 282 case ecryptfs_opt_ecryptfs_sig: 283 sig_src = args[0].from; 284 rc = ecryptfs_add_global_auth_tok(mount_crypt_stat, 285 sig_src, 0); 286 if (rc) { 287 printk(KERN_ERR "Error attempting to register " 288 "global sig; rc = [%d]\n", rc); 289 goto out; 290 } 291 sig_set = 1; 292 break; 293 case ecryptfs_opt_cipher: 294 case ecryptfs_opt_ecryptfs_cipher: 295 cipher_name_src = args[0].from; 296 cipher_name_dst = 297 mount_crypt_stat-> 298 global_default_cipher_name; 299 strncpy(cipher_name_dst, cipher_name_src, 300 ECRYPTFS_MAX_CIPHER_NAME_SIZE); 301 cipher_name_dst[ECRYPTFS_MAX_CIPHER_NAME_SIZE] = '\0'; 302 cipher_name_set = 1; 303 break; 304 case ecryptfs_opt_ecryptfs_key_bytes: 305 cipher_key_bytes_src = args[0].from; 306 cipher_key_bytes = 307 (int)simple_strtol(cipher_key_bytes_src, 308 &cipher_key_bytes_src, 0); 309 mount_crypt_stat->global_default_cipher_key_size = 310 cipher_key_bytes; 311 cipher_key_bytes_set = 1; 312 break; 313 case ecryptfs_opt_passthrough: 314 mount_crypt_stat->flags |= 315 ECRYPTFS_PLAINTEXT_PASSTHROUGH_ENABLED; 316 break; 317 case ecryptfs_opt_xattr_metadata: 318 mount_crypt_stat->flags |= 319 ECRYPTFS_XATTR_METADATA_ENABLED; 320 break; 321 case ecryptfs_opt_encrypted_view: 322 mount_crypt_stat->flags |= 323 ECRYPTFS_XATTR_METADATA_ENABLED; 324 mount_crypt_stat->flags |= 325 ECRYPTFS_ENCRYPTED_VIEW_ENABLED; 326 break; 327 case ecryptfs_opt_fnek_sig: 328 fnek_src = args[0].from; 329 fnek_dst = 330 mount_crypt_stat->global_default_fnek_sig; 331 strncpy(fnek_dst, fnek_src, ECRYPTFS_SIG_SIZE_HEX); 332 mount_crypt_stat->global_default_fnek_sig[ 333 ECRYPTFS_SIG_SIZE_HEX] = '\0'; 334 rc = ecryptfs_add_global_auth_tok( 335 mount_crypt_stat, 336 mount_crypt_stat->global_default_fnek_sig, 337 ECRYPTFS_AUTH_TOK_FNEK); 338 if (rc) { 339 printk(KERN_ERR "Error attempting to register " 340 "global fnek sig [%s]; rc = [%d]\n", 341 mount_crypt_stat->global_default_fnek_sig, 342 rc); 343 goto out; 344 } 345 mount_crypt_stat->flags |= 346 (ECRYPTFS_GLOBAL_ENCRYPT_FILENAMES 347 | ECRYPTFS_GLOBAL_ENCFN_USE_MOUNT_FNEK); 348 break; 349 case ecryptfs_opt_fn_cipher: 350 fn_cipher_name_src = args[0].from; 351 fn_cipher_name_dst = 352 mount_crypt_stat->global_default_fn_cipher_name; 353 strncpy(fn_cipher_name_dst, fn_cipher_name_src, 354 ECRYPTFS_MAX_CIPHER_NAME_SIZE); 355 mount_crypt_stat->global_default_fn_cipher_name[ 356 ECRYPTFS_MAX_CIPHER_NAME_SIZE] = '\0'; 357 fn_cipher_name_set = 1; 358 break; 359 case ecryptfs_opt_fn_cipher_key_bytes: 360 fn_cipher_key_bytes_src = args[0].from; 361 fn_cipher_key_bytes = 362 (int)simple_strtol(fn_cipher_key_bytes_src, 363 &fn_cipher_key_bytes_src, 0); 364 mount_crypt_stat->global_default_fn_cipher_key_bytes = 365 fn_cipher_key_bytes; 366 fn_cipher_key_bytes_set = 1; 367 break; 368 case ecryptfs_opt_unlink_sigs: 369 mount_crypt_stat->flags |= ECRYPTFS_UNLINK_SIGS; 370 break; 371 case ecryptfs_opt_mount_auth_tok_only: 372 mount_crypt_stat->flags |= 373 ECRYPTFS_GLOBAL_MOUNT_AUTH_TOK_ONLY; 374 break; 375 case ecryptfs_opt_check_dev_ruid: 376 *check_ruid = 1; 377 break; 378 case ecryptfs_opt_err: 379 default: 380 printk(KERN_WARNING 381 "%s: eCryptfs: unrecognized option [%s]\n", 382 __func__, p); 383 } 384 } 385 if (!sig_set) { 386 rc = -EINVAL; 387 ecryptfs_printk(KERN_ERR, "You must supply at least one valid " 388 "auth tok signature as a mount " 389 "parameter; see the eCryptfs README\n"); 390 goto out; 391 } 392 if (!cipher_name_set) { 393 int cipher_name_len = strlen(ECRYPTFS_DEFAULT_CIPHER); 394 395 BUG_ON(cipher_name_len > ECRYPTFS_MAX_CIPHER_NAME_SIZE); 396 strcpy(mount_crypt_stat->global_default_cipher_name, 397 ECRYPTFS_DEFAULT_CIPHER); 398 } 399 if ((mount_crypt_stat->flags & ECRYPTFS_GLOBAL_ENCRYPT_FILENAMES) 400 && !fn_cipher_name_set) 401 strcpy(mount_crypt_stat->global_default_fn_cipher_name, 402 mount_crypt_stat->global_default_cipher_name); 403 if (!cipher_key_bytes_set) 404 mount_crypt_stat->global_default_cipher_key_size = 0; 405 if ((mount_crypt_stat->flags & ECRYPTFS_GLOBAL_ENCRYPT_FILENAMES) 406 && !fn_cipher_key_bytes_set) 407 mount_crypt_stat->global_default_fn_cipher_key_bytes = 408 mount_crypt_stat->global_default_cipher_key_size; 409 410 cipher_code = ecryptfs_code_for_cipher_string( 411 mount_crypt_stat->global_default_cipher_name, 412 mount_crypt_stat->global_default_cipher_key_size); 413 if (!cipher_code) { 414 ecryptfs_printk(KERN_ERR, 415 "eCryptfs doesn't support cipher: %s\n", 416 mount_crypt_stat->global_default_cipher_name); 417 rc = -EINVAL; 418 goto out; 419 } 420 421 mutex_lock(&key_tfm_list_mutex); 422 if (!ecryptfs_tfm_exists(mount_crypt_stat->global_default_cipher_name, 423 NULL)) { 424 rc = ecryptfs_add_new_key_tfm( 425 NULL, mount_crypt_stat->global_default_cipher_name, 426 mount_crypt_stat->global_default_cipher_key_size); 427 if (rc) { 428 printk(KERN_ERR "Error attempting to initialize " 429 "cipher with name = [%s] and key size = [%td]; " 430 "rc = [%d]\n", 431 mount_crypt_stat->global_default_cipher_name, 432 mount_crypt_stat->global_default_cipher_key_size, 433 rc); 434 rc = -EINVAL; 435 mutex_unlock(&key_tfm_list_mutex); 436 goto out; 437 } 438 } 439 if ((mount_crypt_stat->flags & ECRYPTFS_GLOBAL_ENCRYPT_FILENAMES) 440 && !ecryptfs_tfm_exists( 441 mount_crypt_stat->global_default_fn_cipher_name, NULL)) { 442 rc = ecryptfs_add_new_key_tfm( 443 NULL, mount_crypt_stat->global_default_fn_cipher_name, 444 mount_crypt_stat->global_default_fn_cipher_key_bytes); 445 if (rc) { 446 printk(KERN_ERR "Error attempting to initialize " 447 "cipher with name = [%s] and key size = [%td]; " 448 "rc = [%d]\n", 449 mount_crypt_stat->global_default_fn_cipher_name, 450 mount_crypt_stat->global_default_fn_cipher_key_bytes, 451 rc); 452 rc = -EINVAL; 453 mutex_unlock(&key_tfm_list_mutex); 454 goto out; 455 } 456 } 457 mutex_unlock(&key_tfm_list_mutex); 458 rc = ecryptfs_init_global_auth_toks(mount_crypt_stat); 459 if (rc) 460 printk(KERN_WARNING "One or more global auth toks could not " 461 "properly register; rc = [%d]\n", rc); 462 out: 463 return rc; 464 } 465 466 struct kmem_cache *ecryptfs_sb_info_cache; 467 static struct file_system_type ecryptfs_fs_type; 468 469 /* 470 * ecryptfs_mount 471 * @fs_type: The filesystem type that the superblock should belong to 472 * @flags: The flags associated with the mount 473 * @dev_name: The path to mount over 474 * @raw_data: The options passed into the kernel 475 */ 476 static struct dentry *ecryptfs_mount(struct file_system_type *fs_type, int flags, 477 const char *dev_name, void *raw_data) 478 { 479 struct super_block *s; 480 struct ecryptfs_sb_info *sbi; 481 struct ecryptfs_mount_crypt_stat *mount_crypt_stat; 482 struct ecryptfs_dentry_info *root_info; 483 const char *err = "Getting sb failed"; 484 struct inode *inode; 485 struct path path; 486 uid_t check_ruid; 487 int rc; 488 489 sbi = kmem_cache_zalloc(ecryptfs_sb_info_cache, GFP_KERNEL); 490 if (!sbi) { 491 rc = -ENOMEM; 492 goto out; 493 } 494 495 if (!dev_name) { 496 rc = -EINVAL; 497 err = "Device name cannot be null"; 498 goto out; 499 } 500 501 rc = ecryptfs_parse_options(sbi, raw_data, &check_ruid); 502 if (rc) { 503 err = "Error parsing options"; 504 goto out; 505 } 506 mount_crypt_stat = &sbi->mount_crypt_stat; 507 508 s = sget(fs_type, NULL, set_anon_super, flags, NULL); 509 if (IS_ERR(s)) { 510 rc = PTR_ERR(s); 511 goto out; 512 } 513 514 rc = super_setup_bdi(s); 515 if (rc) 516 goto out1; 517 518 ecryptfs_set_superblock_private(s, sbi); 519 520 /* ->kill_sb() will take care of sbi after that point */ 521 sbi = NULL; 522 s->s_op = &ecryptfs_sops; 523 s->s_xattr = ecryptfs_xattr_handlers; 524 s->s_d_op = &ecryptfs_dops; 525 526 err = "Reading sb failed"; 527 rc = kern_path(dev_name, LOOKUP_FOLLOW | LOOKUP_DIRECTORY, &path); 528 if (rc) { 529 ecryptfs_printk(KERN_WARNING, "kern_path() failed\n"); 530 goto out1; 531 } 532 if (path.dentry->d_sb->s_type == &ecryptfs_fs_type) { 533 rc = -EINVAL; 534 printk(KERN_ERR "Mount on filesystem of type " 535 "eCryptfs explicitly disallowed due to " 536 "known incompatibilities\n"); 537 goto out_free; 538 } 539 540 if (mnt_user_ns(path.mnt) != &init_user_ns) { 541 rc = -EINVAL; 542 printk(KERN_ERR "Mounting on idmapped mounts currently disallowed\n"); 543 goto out_free; 544 } 545 546 if (check_ruid && !uid_eq(d_inode(path.dentry)->i_uid, current_uid())) { 547 rc = -EPERM; 548 printk(KERN_ERR "Mount of device (uid: %d) not owned by " 549 "requested user (uid: %d)\n", 550 i_uid_read(d_inode(path.dentry)), 551 from_kuid(&init_user_ns, current_uid())); 552 goto out_free; 553 } 554 555 ecryptfs_set_superblock_lower(s, path.dentry->d_sb); 556 557 /** 558 * Set the POSIX ACL flag based on whether they're enabled in the lower 559 * mount. 560 */ 561 s->s_flags = flags & ~SB_POSIXACL; 562 s->s_flags |= path.dentry->d_sb->s_flags & SB_POSIXACL; 563 564 /** 565 * Force a read-only eCryptfs mount when: 566 * 1) The lower mount is ro 567 * 2) The ecryptfs_encrypted_view mount option is specified 568 */ 569 if (sb_rdonly(path.dentry->d_sb) || mount_crypt_stat->flags & ECRYPTFS_ENCRYPTED_VIEW_ENABLED) 570 s->s_flags |= SB_RDONLY; 571 572 s->s_maxbytes = path.dentry->d_sb->s_maxbytes; 573 s->s_blocksize = path.dentry->d_sb->s_blocksize; 574 s->s_magic = ECRYPTFS_SUPER_MAGIC; 575 s->s_stack_depth = path.dentry->d_sb->s_stack_depth + 1; 576 577 rc = -EINVAL; 578 if (s->s_stack_depth > FILESYSTEM_MAX_STACK_DEPTH) { 579 pr_err("eCryptfs: maximum fs stacking depth exceeded\n"); 580 goto out_free; 581 } 582 583 inode = ecryptfs_get_inode(d_inode(path.dentry), s); 584 rc = PTR_ERR(inode); 585 if (IS_ERR(inode)) 586 goto out_free; 587 588 s->s_root = d_make_root(inode); 589 if (!s->s_root) { 590 rc = -ENOMEM; 591 goto out_free; 592 } 593 594 rc = -ENOMEM; 595 root_info = kmem_cache_zalloc(ecryptfs_dentry_info_cache, GFP_KERNEL); 596 if (!root_info) 597 goto out_free; 598 599 /* ->kill_sb() will take care of root_info */ 600 ecryptfs_set_dentry_private(s->s_root, root_info); 601 root_info->lower_path = path; 602 603 s->s_flags |= SB_ACTIVE; 604 return dget(s->s_root); 605 606 out_free: 607 path_put(&path); 608 out1: 609 deactivate_locked_super(s); 610 out: 611 if (sbi) { 612 ecryptfs_destroy_mount_crypt_stat(&sbi->mount_crypt_stat); 613 kmem_cache_free(ecryptfs_sb_info_cache, sbi); 614 } 615 printk(KERN_ERR "%s; rc = [%d]\n", err, rc); 616 return ERR_PTR(rc); 617 } 618 619 /** 620 * ecryptfs_kill_block_super 621 * @sb: The ecryptfs super block 622 * 623 * Used to bring the superblock down and free the private data. 624 */ 625 static void ecryptfs_kill_block_super(struct super_block *sb) 626 { 627 struct ecryptfs_sb_info *sb_info = ecryptfs_superblock_to_private(sb); 628 kill_anon_super(sb); 629 if (!sb_info) 630 return; 631 ecryptfs_destroy_mount_crypt_stat(&sb_info->mount_crypt_stat); 632 kmem_cache_free(ecryptfs_sb_info_cache, sb_info); 633 } 634 635 static struct file_system_type ecryptfs_fs_type = { 636 .owner = THIS_MODULE, 637 .name = "ecryptfs", 638 .mount = ecryptfs_mount, 639 .kill_sb = ecryptfs_kill_block_super, 640 .fs_flags = 0 641 }; 642 MODULE_ALIAS_FS("ecryptfs"); 643 644 /* 645 * inode_info_init_once 646 * 647 * Initializes the ecryptfs_inode_info_cache when it is created 648 */ 649 static void 650 inode_info_init_once(void *vptr) 651 { 652 struct ecryptfs_inode_info *ei = (struct ecryptfs_inode_info *)vptr; 653 654 inode_init_once(&ei->vfs_inode); 655 } 656 657 static struct ecryptfs_cache_info { 658 struct kmem_cache **cache; 659 const char *name; 660 size_t size; 661 slab_flags_t flags; 662 void (*ctor)(void *obj); 663 } ecryptfs_cache_infos[] = { 664 { 665 .cache = &ecryptfs_auth_tok_list_item_cache, 666 .name = "ecryptfs_auth_tok_list_item", 667 .size = sizeof(struct ecryptfs_auth_tok_list_item), 668 }, 669 { 670 .cache = &ecryptfs_file_info_cache, 671 .name = "ecryptfs_file_cache", 672 .size = sizeof(struct ecryptfs_file_info), 673 }, 674 { 675 .cache = &ecryptfs_dentry_info_cache, 676 .name = "ecryptfs_dentry_info_cache", 677 .size = sizeof(struct ecryptfs_dentry_info), 678 }, 679 { 680 .cache = &ecryptfs_inode_info_cache, 681 .name = "ecryptfs_inode_cache", 682 .size = sizeof(struct ecryptfs_inode_info), 683 .flags = SLAB_ACCOUNT, 684 .ctor = inode_info_init_once, 685 }, 686 { 687 .cache = &ecryptfs_sb_info_cache, 688 .name = "ecryptfs_sb_cache", 689 .size = sizeof(struct ecryptfs_sb_info), 690 }, 691 { 692 .cache = &ecryptfs_header_cache, 693 .name = "ecryptfs_headers", 694 .size = PAGE_SIZE, 695 }, 696 { 697 .cache = &ecryptfs_xattr_cache, 698 .name = "ecryptfs_xattr_cache", 699 .size = PAGE_SIZE, 700 }, 701 { 702 .cache = &ecryptfs_key_record_cache, 703 .name = "ecryptfs_key_record_cache", 704 .size = sizeof(struct ecryptfs_key_record), 705 }, 706 { 707 .cache = &ecryptfs_key_sig_cache, 708 .name = "ecryptfs_key_sig_cache", 709 .size = sizeof(struct ecryptfs_key_sig), 710 }, 711 { 712 .cache = &ecryptfs_global_auth_tok_cache, 713 .name = "ecryptfs_global_auth_tok_cache", 714 .size = sizeof(struct ecryptfs_global_auth_tok), 715 }, 716 { 717 .cache = &ecryptfs_key_tfm_cache, 718 .name = "ecryptfs_key_tfm_cache", 719 .size = sizeof(struct ecryptfs_key_tfm), 720 }, 721 }; 722 723 static void ecryptfs_free_kmem_caches(void) 724 { 725 int i; 726 727 /* 728 * Make sure all delayed rcu free inodes are flushed before we 729 * destroy cache. 730 */ 731 rcu_barrier(); 732 733 for (i = 0; i < ARRAY_SIZE(ecryptfs_cache_infos); i++) { 734 struct ecryptfs_cache_info *info; 735 736 info = &ecryptfs_cache_infos[i]; 737 kmem_cache_destroy(*(info->cache)); 738 } 739 } 740 741 /** 742 * ecryptfs_init_kmem_caches 743 * 744 * Returns zero on success; non-zero otherwise 745 */ 746 static int ecryptfs_init_kmem_caches(void) 747 { 748 int i; 749 750 for (i = 0; i < ARRAY_SIZE(ecryptfs_cache_infos); i++) { 751 struct ecryptfs_cache_info *info; 752 753 info = &ecryptfs_cache_infos[i]; 754 *(info->cache) = kmem_cache_create(info->name, info->size, 0, 755 SLAB_HWCACHE_ALIGN | info->flags, info->ctor); 756 if (!*(info->cache)) { 757 ecryptfs_free_kmem_caches(); 758 ecryptfs_printk(KERN_WARNING, "%s: " 759 "kmem_cache_create failed\n", 760 info->name); 761 return -ENOMEM; 762 } 763 } 764 return 0; 765 } 766 767 static struct kobject *ecryptfs_kobj; 768 769 static ssize_t version_show(struct kobject *kobj, 770 struct kobj_attribute *attr, char *buff) 771 { 772 return snprintf(buff, PAGE_SIZE, "%d\n", ECRYPTFS_VERSIONING_MASK); 773 } 774 775 static struct kobj_attribute version_attr = __ATTR_RO(version); 776 777 static struct attribute *attributes[] = { 778 &version_attr.attr, 779 NULL, 780 }; 781 782 static const struct attribute_group attr_group = { 783 .attrs = attributes, 784 }; 785 786 static int do_sysfs_registration(void) 787 { 788 int rc; 789 790 ecryptfs_kobj = kobject_create_and_add("ecryptfs", fs_kobj); 791 if (!ecryptfs_kobj) { 792 printk(KERN_ERR "Unable to create ecryptfs kset\n"); 793 rc = -ENOMEM; 794 goto out; 795 } 796 rc = sysfs_create_group(ecryptfs_kobj, &attr_group); 797 if (rc) { 798 printk(KERN_ERR 799 "Unable to create ecryptfs version attributes\n"); 800 kobject_put(ecryptfs_kobj); 801 } 802 out: 803 return rc; 804 } 805 806 static void do_sysfs_unregistration(void) 807 { 808 sysfs_remove_group(ecryptfs_kobj, &attr_group); 809 kobject_put(ecryptfs_kobj); 810 } 811 812 static int __init ecryptfs_init(void) 813 { 814 int rc; 815 816 if (ECRYPTFS_DEFAULT_EXTENT_SIZE > PAGE_SIZE) { 817 rc = -EINVAL; 818 ecryptfs_printk(KERN_ERR, "The eCryptfs extent size is " 819 "larger than the host's page size, and so " 820 "eCryptfs cannot run on this system. The " 821 "default eCryptfs extent size is [%u] bytes; " 822 "the page size is [%lu] bytes.\n", 823 ECRYPTFS_DEFAULT_EXTENT_SIZE, 824 (unsigned long)PAGE_SIZE); 825 goto out; 826 } 827 rc = ecryptfs_init_kmem_caches(); 828 if (rc) { 829 printk(KERN_ERR 830 "Failed to allocate one or more kmem_cache objects\n"); 831 goto out; 832 } 833 rc = do_sysfs_registration(); 834 if (rc) { 835 printk(KERN_ERR "sysfs registration failed\n"); 836 goto out_free_kmem_caches; 837 } 838 rc = ecryptfs_init_kthread(); 839 if (rc) { 840 printk(KERN_ERR "%s: kthread initialization failed; " 841 "rc = [%d]\n", __func__, rc); 842 goto out_do_sysfs_unregistration; 843 } 844 rc = ecryptfs_init_messaging(); 845 if (rc) { 846 printk(KERN_ERR "Failure occurred while attempting to " 847 "initialize the communications channel to " 848 "ecryptfsd\n"); 849 goto out_destroy_kthread; 850 } 851 rc = ecryptfs_init_crypto(); 852 if (rc) { 853 printk(KERN_ERR "Failure whilst attempting to init crypto; " 854 "rc = [%d]\n", rc); 855 goto out_release_messaging; 856 } 857 rc = register_filesystem(&ecryptfs_fs_type); 858 if (rc) { 859 printk(KERN_ERR "Failed to register filesystem\n"); 860 goto out_destroy_crypto; 861 } 862 if (ecryptfs_verbosity > 0) 863 printk(KERN_CRIT "eCryptfs verbosity set to %d. Secret values " 864 "will be written to the syslog!\n", ecryptfs_verbosity); 865 866 goto out; 867 out_destroy_crypto: 868 ecryptfs_destroy_crypto(); 869 out_release_messaging: 870 ecryptfs_release_messaging(); 871 out_destroy_kthread: 872 ecryptfs_destroy_kthread(); 873 out_do_sysfs_unregistration: 874 do_sysfs_unregistration(); 875 out_free_kmem_caches: 876 ecryptfs_free_kmem_caches(); 877 out: 878 return rc; 879 } 880 881 static void __exit ecryptfs_exit(void) 882 { 883 int rc; 884 885 rc = ecryptfs_destroy_crypto(); 886 if (rc) 887 printk(KERN_ERR "Failure whilst attempting to destroy crypto; " 888 "rc = [%d]\n", rc); 889 ecryptfs_release_messaging(); 890 ecryptfs_destroy_kthread(); 891 do_sysfs_unregistration(); 892 unregister_filesystem(&ecryptfs_fs_type); 893 ecryptfs_free_kmem_caches(); 894 } 895 896 MODULE_AUTHOR("Michael A. Halcrow <mhalcrow@us.ibm.com>"); 897 MODULE_DESCRIPTION("eCryptfs"); 898 899 MODULE_LICENSE("GPL"); 900 901 module_init(ecryptfs_init) 902 module_exit(ecryptfs_exit) 903