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
__ecryptfs_printk(const char * fmt,...)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 */
ecryptfs_init_lower_file(struct dentry * dentry,struct file ** lower_file)104 static int ecryptfs_init_lower_file(struct dentry *dentry,
105 struct file **lower_file)
106 {
107 const struct cred *cred = current_cred();
108 const 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
ecryptfs_get_lower_file(struct dentry * dentry,struct inode * inode)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
ecryptfs_put_lower_file(struct inode * inode)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
ecryptfs_init_global_auth_toks(struct ecryptfs_mount_crypt_stat * mount_crypt_stat)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
ecryptfs_init_mount_crypt_stat(struct ecryptfs_mount_crypt_stat * mount_crypt_stat)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 */
ecryptfs_parse_options(struct ecryptfs_sb_info * sbi,char * options,uid_t * check_ruid)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_src;
260 char *fn_cipher_name_src;
261 char *fnek_src;
262 char *cipher_key_bytes_src;
263 char *fn_cipher_key_bytes_src;
264 u8 cipher_code;
265
266 *check_ruid = 0;
267
268 if (!options) {
269 rc = -EINVAL;
270 goto out;
271 }
272 ecryptfs_init_mount_crypt_stat(mount_crypt_stat);
273 while ((p = strsep(&options, ",")) != NULL) {
274 if (!*p)
275 continue;
276 token = match_token(p, tokens, args);
277 switch (token) {
278 case ecryptfs_opt_sig:
279 case ecryptfs_opt_ecryptfs_sig:
280 sig_src = args[0].from;
281 rc = ecryptfs_add_global_auth_tok(mount_crypt_stat,
282 sig_src, 0);
283 if (rc) {
284 printk(KERN_ERR "Error attempting to register "
285 "global sig; rc = [%d]\n", rc);
286 goto out;
287 }
288 sig_set = 1;
289 break;
290 case ecryptfs_opt_cipher:
291 case ecryptfs_opt_ecryptfs_cipher:
292 cipher_name_src = args[0].from;
293 strscpy(mount_crypt_stat->global_default_cipher_name,
294 cipher_name_src);
295 cipher_name_set = 1;
296 break;
297 case ecryptfs_opt_ecryptfs_key_bytes:
298 cipher_key_bytes_src = args[0].from;
299 cipher_key_bytes =
300 (int)simple_strtol(cipher_key_bytes_src,
301 &cipher_key_bytes_src, 0);
302 mount_crypt_stat->global_default_cipher_key_size =
303 cipher_key_bytes;
304 cipher_key_bytes_set = 1;
305 break;
306 case ecryptfs_opt_passthrough:
307 mount_crypt_stat->flags |=
308 ECRYPTFS_PLAINTEXT_PASSTHROUGH_ENABLED;
309 break;
310 case ecryptfs_opt_xattr_metadata:
311 mount_crypt_stat->flags |=
312 ECRYPTFS_XATTR_METADATA_ENABLED;
313 break;
314 case ecryptfs_opt_encrypted_view:
315 mount_crypt_stat->flags |=
316 ECRYPTFS_XATTR_METADATA_ENABLED;
317 mount_crypt_stat->flags |=
318 ECRYPTFS_ENCRYPTED_VIEW_ENABLED;
319 break;
320 case ecryptfs_opt_fnek_sig:
321 fnek_src = args[0].from;
322 strscpy(mount_crypt_stat->global_default_fnek_sig,
323 fnek_src);
324 rc = ecryptfs_add_global_auth_tok(
325 mount_crypt_stat,
326 mount_crypt_stat->global_default_fnek_sig,
327 ECRYPTFS_AUTH_TOK_FNEK);
328 if (rc) {
329 printk(KERN_ERR "Error attempting to register "
330 "global fnek sig [%s]; rc = [%d]\n",
331 mount_crypt_stat->global_default_fnek_sig,
332 rc);
333 goto out;
334 }
335 mount_crypt_stat->flags |=
336 (ECRYPTFS_GLOBAL_ENCRYPT_FILENAMES
337 | ECRYPTFS_GLOBAL_ENCFN_USE_MOUNT_FNEK);
338 break;
339 case ecryptfs_opt_fn_cipher:
340 fn_cipher_name_src = args[0].from;
341 strscpy(mount_crypt_stat->global_default_fn_cipher_name,
342 fn_cipher_name_src);
343 fn_cipher_name_set = 1;
344 break;
345 case ecryptfs_opt_fn_cipher_key_bytes:
346 fn_cipher_key_bytes_src = args[0].from;
347 fn_cipher_key_bytes =
348 (int)simple_strtol(fn_cipher_key_bytes_src,
349 &fn_cipher_key_bytes_src, 0);
350 mount_crypt_stat->global_default_fn_cipher_key_bytes =
351 fn_cipher_key_bytes;
352 fn_cipher_key_bytes_set = 1;
353 break;
354 case ecryptfs_opt_unlink_sigs:
355 mount_crypt_stat->flags |= ECRYPTFS_UNLINK_SIGS;
356 break;
357 case ecryptfs_opt_mount_auth_tok_only:
358 mount_crypt_stat->flags |=
359 ECRYPTFS_GLOBAL_MOUNT_AUTH_TOK_ONLY;
360 break;
361 case ecryptfs_opt_check_dev_ruid:
362 *check_ruid = 1;
363 break;
364 case ecryptfs_opt_err:
365 default:
366 printk(KERN_WARNING
367 "%s: eCryptfs: unrecognized option [%s]\n",
368 __func__, p);
369 }
370 }
371 if (!sig_set) {
372 rc = -EINVAL;
373 ecryptfs_printk(KERN_ERR, "You must supply at least one valid "
374 "auth tok signature as a mount "
375 "parameter; see the eCryptfs README\n");
376 goto out;
377 }
378 if (!cipher_name_set) {
379 int cipher_name_len = strlen(ECRYPTFS_DEFAULT_CIPHER);
380
381 BUG_ON(cipher_name_len > ECRYPTFS_MAX_CIPHER_NAME_SIZE);
382 strcpy(mount_crypt_stat->global_default_cipher_name,
383 ECRYPTFS_DEFAULT_CIPHER);
384 }
385 if ((mount_crypt_stat->flags & ECRYPTFS_GLOBAL_ENCRYPT_FILENAMES)
386 && !fn_cipher_name_set)
387 strcpy(mount_crypt_stat->global_default_fn_cipher_name,
388 mount_crypt_stat->global_default_cipher_name);
389 if (!cipher_key_bytes_set)
390 mount_crypt_stat->global_default_cipher_key_size = 0;
391 if ((mount_crypt_stat->flags & ECRYPTFS_GLOBAL_ENCRYPT_FILENAMES)
392 && !fn_cipher_key_bytes_set)
393 mount_crypt_stat->global_default_fn_cipher_key_bytes =
394 mount_crypt_stat->global_default_cipher_key_size;
395
396 cipher_code = ecryptfs_code_for_cipher_string(
397 mount_crypt_stat->global_default_cipher_name,
398 mount_crypt_stat->global_default_cipher_key_size);
399 if (!cipher_code) {
400 ecryptfs_printk(KERN_ERR,
401 "eCryptfs doesn't support cipher: %s\n",
402 mount_crypt_stat->global_default_cipher_name);
403 rc = -EINVAL;
404 goto out;
405 }
406
407 mutex_lock(&key_tfm_list_mutex);
408 if (!ecryptfs_tfm_exists(mount_crypt_stat->global_default_cipher_name,
409 NULL)) {
410 rc = ecryptfs_add_new_key_tfm(
411 NULL, mount_crypt_stat->global_default_cipher_name,
412 mount_crypt_stat->global_default_cipher_key_size);
413 if (rc) {
414 printk(KERN_ERR "Error attempting to initialize "
415 "cipher with name = [%s] and key size = [%td]; "
416 "rc = [%d]\n",
417 mount_crypt_stat->global_default_cipher_name,
418 mount_crypt_stat->global_default_cipher_key_size,
419 rc);
420 rc = -EINVAL;
421 mutex_unlock(&key_tfm_list_mutex);
422 goto out;
423 }
424 }
425 if ((mount_crypt_stat->flags & ECRYPTFS_GLOBAL_ENCRYPT_FILENAMES)
426 && !ecryptfs_tfm_exists(
427 mount_crypt_stat->global_default_fn_cipher_name, NULL)) {
428 rc = ecryptfs_add_new_key_tfm(
429 NULL, mount_crypt_stat->global_default_fn_cipher_name,
430 mount_crypt_stat->global_default_fn_cipher_key_bytes);
431 if (rc) {
432 printk(KERN_ERR "Error attempting to initialize "
433 "cipher with name = [%s] and key size = [%td]; "
434 "rc = [%d]\n",
435 mount_crypt_stat->global_default_fn_cipher_name,
436 mount_crypt_stat->global_default_fn_cipher_key_bytes,
437 rc);
438 rc = -EINVAL;
439 mutex_unlock(&key_tfm_list_mutex);
440 goto out;
441 }
442 }
443 mutex_unlock(&key_tfm_list_mutex);
444 rc = ecryptfs_init_global_auth_toks(mount_crypt_stat);
445 if (rc)
446 printk(KERN_WARNING "One or more global auth toks could not "
447 "properly register; rc = [%d]\n", rc);
448 out:
449 return rc;
450 }
451
452 struct kmem_cache *ecryptfs_sb_info_cache;
453 static struct file_system_type ecryptfs_fs_type;
454
455 /*
456 * ecryptfs_mount
457 * @fs_type: The filesystem type that the superblock should belong to
458 * @flags: The flags associated with the mount
459 * @dev_name: The path to mount over
460 * @raw_data: The options passed into the kernel
461 */
ecryptfs_mount(struct file_system_type * fs_type,int flags,const char * dev_name,void * raw_data)462 static struct dentry *ecryptfs_mount(struct file_system_type *fs_type, int flags,
463 const char *dev_name, void *raw_data)
464 {
465 struct super_block *s;
466 struct ecryptfs_sb_info *sbi;
467 struct ecryptfs_mount_crypt_stat *mount_crypt_stat;
468 struct ecryptfs_dentry_info *root_info;
469 const char *err = "Getting sb failed";
470 struct inode *inode;
471 struct path path;
472 uid_t check_ruid;
473 int rc;
474
475 sbi = kmem_cache_zalloc(ecryptfs_sb_info_cache, GFP_KERNEL);
476 if (!sbi) {
477 rc = -ENOMEM;
478 goto out;
479 }
480
481 if (!dev_name) {
482 rc = -EINVAL;
483 err = "Device name cannot be null";
484 goto out;
485 }
486
487 rc = ecryptfs_parse_options(sbi, raw_data, &check_ruid);
488 if (rc) {
489 err = "Error parsing options";
490 goto out;
491 }
492 mount_crypt_stat = &sbi->mount_crypt_stat;
493
494 s = sget(fs_type, NULL, set_anon_super, flags, NULL);
495 if (IS_ERR(s)) {
496 rc = PTR_ERR(s);
497 goto out;
498 }
499
500 rc = super_setup_bdi(s);
501 if (rc)
502 goto out1;
503
504 ecryptfs_set_superblock_private(s, sbi);
505
506 /* ->kill_sb() will take care of sbi after that point */
507 sbi = NULL;
508 s->s_op = &ecryptfs_sops;
509 s->s_xattr = ecryptfs_xattr_handlers;
510 s->s_d_op = &ecryptfs_dops;
511
512 err = "Reading sb failed";
513 rc = kern_path(dev_name, LOOKUP_FOLLOW | LOOKUP_DIRECTORY, &path);
514 if (rc) {
515 ecryptfs_printk(KERN_WARNING, "kern_path() failed\n");
516 goto out1;
517 }
518 if (path.dentry->d_sb->s_type == &ecryptfs_fs_type) {
519 rc = -EINVAL;
520 printk(KERN_ERR "Mount on filesystem of type "
521 "eCryptfs explicitly disallowed due to "
522 "known incompatibilities\n");
523 goto out_free;
524 }
525
526 if (is_idmapped_mnt(path.mnt)) {
527 rc = -EINVAL;
528 printk(KERN_ERR "Mounting on idmapped mounts currently disallowed\n");
529 goto out_free;
530 }
531
532 if (check_ruid && !uid_eq(d_inode(path.dentry)->i_uid, current_uid())) {
533 rc = -EPERM;
534 printk(KERN_ERR "Mount of device (uid: %d) not owned by "
535 "requested user (uid: %d)\n",
536 i_uid_read(d_inode(path.dentry)),
537 from_kuid(&init_user_ns, current_uid()));
538 goto out_free;
539 }
540
541 ecryptfs_set_superblock_lower(s, path.dentry->d_sb);
542
543 /**
544 * Set the POSIX ACL flag based on whether they're enabled in the lower
545 * mount.
546 */
547 s->s_flags = flags & ~SB_POSIXACL;
548 s->s_flags |= path.dentry->d_sb->s_flags & SB_POSIXACL;
549
550 /**
551 * Force a read-only eCryptfs mount when:
552 * 1) The lower mount is ro
553 * 2) The ecryptfs_encrypted_view mount option is specified
554 */
555 if (sb_rdonly(path.dentry->d_sb) || mount_crypt_stat->flags & ECRYPTFS_ENCRYPTED_VIEW_ENABLED)
556 s->s_flags |= SB_RDONLY;
557
558 s->s_maxbytes = path.dentry->d_sb->s_maxbytes;
559 s->s_blocksize = path.dentry->d_sb->s_blocksize;
560 s->s_magic = ECRYPTFS_SUPER_MAGIC;
561 s->s_stack_depth = path.dentry->d_sb->s_stack_depth + 1;
562
563 rc = -EINVAL;
564 if (s->s_stack_depth > FILESYSTEM_MAX_STACK_DEPTH) {
565 pr_err("eCryptfs: maximum fs stacking depth exceeded\n");
566 goto out_free;
567 }
568
569 inode = ecryptfs_get_inode(d_inode(path.dentry), s);
570 rc = PTR_ERR(inode);
571 if (IS_ERR(inode))
572 goto out_free;
573
574 s->s_root = d_make_root(inode);
575 if (!s->s_root) {
576 rc = -ENOMEM;
577 goto out_free;
578 }
579
580 rc = -ENOMEM;
581 root_info = kmem_cache_zalloc(ecryptfs_dentry_info_cache, GFP_KERNEL);
582 if (!root_info)
583 goto out_free;
584
585 /* ->kill_sb() will take care of root_info */
586 ecryptfs_set_dentry_private(s->s_root, root_info);
587 root_info->lower_path = path;
588
589 s->s_flags |= SB_ACTIVE;
590 return dget(s->s_root);
591
592 out_free:
593 path_put(&path);
594 out1:
595 deactivate_locked_super(s);
596 out:
597 if (sbi) {
598 ecryptfs_destroy_mount_crypt_stat(&sbi->mount_crypt_stat);
599 kmem_cache_free(ecryptfs_sb_info_cache, sbi);
600 }
601 printk(KERN_ERR "%s; rc = [%d]\n", err, rc);
602 return ERR_PTR(rc);
603 }
604
605 /**
606 * ecryptfs_kill_block_super
607 * @sb: The ecryptfs super block
608 *
609 * Used to bring the superblock down and free the private data.
610 */
ecryptfs_kill_block_super(struct super_block * sb)611 static void ecryptfs_kill_block_super(struct super_block *sb)
612 {
613 struct ecryptfs_sb_info *sb_info = ecryptfs_superblock_to_private(sb);
614 kill_anon_super(sb);
615 if (!sb_info)
616 return;
617 ecryptfs_destroy_mount_crypt_stat(&sb_info->mount_crypt_stat);
618 kmem_cache_free(ecryptfs_sb_info_cache, sb_info);
619 }
620
621 static struct file_system_type ecryptfs_fs_type = {
622 .owner = THIS_MODULE,
623 .name = "ecryptfs",
624 .mount = ecryptfs_mount,
625 .kill_sb = ecryptfs_kill_block_super,
626 .fs_flags = 0
627 };
628 MODULE_ALIAS_FS("ecryptfs");
629
630 /*
631 * inode_info_init_once
632 *
633 * Initializes the ecryptfs_inode_info_cache when it is created
634 */
635 static void
inode_info_init_once(void * vptr)636 inode_info_init_once(void *vptr)
637 {
638 struct ecryptfs_inode_info *ei = (struct ecryptfs_inode_info *)vptr;
639
640 inode_init_once(&ei->vfs_inode);
641 }
642
643 static struct ecryptfs_cache_info {
644 struct kmem_cache **cache;
645 const char *name;
646 size_t size;
647 slab_flags_t flags;
648 void (*ctor)(void *obj);
649 } ecryptfs_cache_infos[] = {
650 {
651 .cache = &ecryptfs_auth_tok_list_item_cache,
652 .name = "ecryptfs_auth_tok_list_item",
653 .size = sizeof(struct ecryptfs_auth_tok_list_item),
654 },
655 {
656 .cache = &ecryptfs_file_info_cache,
657 .name = "ecryptfs_file_cache",
658 .size = sizeof(struct ecryptfs_file_info),
659 },
660 {
661 .cache = &ecryptfs_dentry_info_cache,
662 .name = "ecryptfs_dentry_info_cache",
663 .size = sizeof(struct ecryptfs_dentry_info),
664 },
665 {
666 .cache = &ecryptfs_inode_info_cache,
667 .name = "ecryptfs_inode_cache",
668 .size = sizeof(struct ecryptfs_inode_info),
669 .flags = SLAB_ACCOUNT,
670 .ctor = inode_info_init_once,
671 },
672 {
673 .cache = &ecryptfs_sb_info_cache,
674 .name = "ecryptfs_sb_cache",
675 .size = sizeof(struct ecryptfs_sb_info),
676 },
677 {
678 .cache = &ecryptfs_header_cache,
679 .name = "ecryptfs_headers",
680 .size = PAGE_SIZE,
681 },
682 {
683 .cache = &ecryptfs_xattr_cache,
684 .name = "ecryptfs_xattr_cache",
685 .size = PAGE_SIZE,
686 },
687 {
688 .cache = &ecryptfs_key_record_cache,
689 .name = "ecryptfs_key_record_cache",
690 .size = sizeof(struct ecryptfs_key_record),
691 },
692 {
693 .cache = &ecryptfs_key_sig_cache,
694 .name = "ecryptfs_key_sig_cache",
695 .size = sizeof(struct ecryptfs_key_sig),
696 },
697 {
698 .cache = &ecryptfs_global_auth_tok_cache,
699 .name = "ecryptfs_global_auth_tok_cache",
700 .size = sizeof(struct ecryptfs_global_auth_tok),
701 },
702 {
703 .cache = &ecryptfs_key_tfm_cache,
704 .name = "ecryptfs_key_tfm_cache",
705 .size = sizeof(struct ecryptfs_key_tfm),
706 },
707 };
708
ecryptfs_free_kmem_caches(void)709 static void ecryptfs_free_kmem_caches(void)
710 {
711 int i;
712
713 /*
714 * Make sure all delayed rcu free inodes are flushed before we
715 * destroy cache.
716 */
717 rcu_barrier();
718
719 for (i = 0; i < ARRAY_SIZE(ecryptfs_cache_infos); i++) {
720 struct ecryptfs_cache_info *info;
721
722 info = &ecryptfs_cache_infos[i];
723 kmem_cache_destroy(*(info->cache));
724 }
725 }
726
727 /**
728 * ecryptfs_init_kmem_caches
729 *
730 * Returns zero on success; non-zero otherwise
731 */
ecryptfs_init_kmem_caches(void)732 static int ecryptfs_init_kmem_caches(void)
733 {
734 int i;
735
736 for (i = 0; i < ARRAY_SIZE(ecryptfs_cache_infos); i++) {
737 struct ecryptfs_cache_info *info;
738
739 info = &ecryptfs_cache_infos[i];
740 *(info->cache) = kmem_cache_create(info->name, info->size, 0,
741 SLAB_HWCACHE_ALIGN | info->flags, info->ctor);
742 if (!*(info->cache)) {
743 ecryptfs_free_kmem_caches();
744 ecryptfs_printk(KERN_WARNING, "%s: "
745 "kmem_cache_create failed\n",
746 info->name);
747 return -ENOMEM;
748 }
749 }
750 return 0;
751 }
752
753 static struct kobject *ecryptfs_kobj;
754
version_show(struct kobject * kobj,struct kobj_attribute * attr,char * buff)755 static ssize_t version_show(struct kobject *kobj,
756 struct kobj_attribute *attr, char *buff)
757 {
758 return snprintf(buff, PAGE_SIZE, "%d\n", ECRYPTFS_VERSIONING_MASK);
759 }
760
761 static struct kobj_attribute version_attr = __ATTR_RO(version);
762
763 static struct attribute *attributes[] = {
764 &version_attr.attr,
765 NULL,
766 };
767
768 static const struct attribute_group attr_group = {
769 .attrs = attributes,
770 };
771
do_sysfs_registration(void)772 static int do_sysfs_registration(void)
773 {
774 int rc;
775
776 ecryptfs_kobj = kobject_create_and_add("ecryptfs", fs_kobj);
777 if (!ecryptfs_kobj) {
778 printk(KERN_ERR "Unable to create ecryptfs kset\n");
779 rc = -ENOMEM;
780 goto out;
781 }
782 rc = sysfs_create_group(ecryptfs_kobj, &attr_group);
783 if (rc) {
784 printk(KERN_ERR
785 "Unable to create ecryptfs version attributes\n");
786 kobject_put(ecryptfs_kobj);
787 }
788 out:
789 return rc;
790 }
791
do_sysfs_unregistration(void)792 static void do_sysfs_unregistration(void)
793 {
794 sysfs_remove_group(ecryptfs_kobj, &attr_group);
795 kobject_put(ecryptfs_kobj);
796 }
797
ecryptfs_init(void)798 static int __init ecryptfs_init(void)
799 {
800 int rc;
801
802 if (ECRYPTFS_DEFAULT_EXTENT_SIZE > PAGE_SIZE) {
803 rc = -EINVAL;
804 ecryptfs_printk(KERN_ERR, "The eCryptfs extent size is "
805 "larger than the host's page size, and so "
806 "eCryptfs cannot run on this system. The "
807 "default eCryptfs extent size is [%u] bytes; "
808 "the page size is [%lu] bytes.\n",
809 ECRYPTFS_DEFAULT_EXTENT_SIZE,
810 (unsigned long)PAGE_SIZE);
811 goto out;
812 }
813 rc = ecryptfs_init_kmem_caches();
814 if (rc) {
815 printk(KERN_ERR
816 "Failed to allocate one or more kmem_cache objects\n");
817 goto out;
818 }
819 rc = do_sysfs_registration();
820 if (rc) {
821 printk(KERN_ERR "sysfs registration failed\n");
822 goto out_free_kmem_caches;
823 }
824 rc = ecryptfs_init_kthread();
825 if (rc) {
826 printk(KERN_ERR "%s: kthread initialization failed; "
827 "rc = [%d]\n", __func__, rc);
828 goto out_do_sysfs_unregistration;
829 }
830 rc = ecryptfs_init_messaging();
831 if (rc) {
832 printk(KERN_ERR "Failure occurred while attempting to "
833 "initialize the communications channel to "
834 "ecryptfsd\n");
835 goto out_destroy_kthread;
836 }
837 rc = ecryptfs_init_crypto();
838 if (rc) {
839 printk(KERN_ERR "Failure whilst attempting to init crypto; "
840 "rc = [%d]\n", rc);
841 goto out_release_messaging;
842 }
843 rc = register_filesystem(&ecryptfs_fs_type);
844 if (rc) {
845 printk(KERN_ERR "Failed to register filesystem\n");
846 goto out_destroy_crypto;
847 }
848 if (ecryptfs_verbosity > 0)
849 printk(KERN_CRIT "eCryptfs verbosity set to %d. Secret values "
850 "will be written to the syslog!\n", ecryptfs_verbosity);
851
852 goto out;
853 out_destroy_crypto:
854 ecryptfs_destroy_crypto();
855 out_release_messaging:
856 ecryptfs_release_messaging();
857 out_destroy_kthread:
858 ecryptfs_destroy_kthread();
859 out_do_sysfs_unregistration:
860 do_sysfs_unregistration();
861 out_free_kmem_caches:
862 ecryptfs_free_kmem_caches();
863 out:
864 return rc;
865 }
866
ecryptfs_exit(void)867 static void __exit ecryptfs_exit(void)
868 {
869 int rc;
870
871 rc = ecryptfs_destroy_crypto();
872 if (rc)
873 printk(KERN_ERR "Failure whilst attempting to destroy crypto; "
874 "rc = [%d]\n", rc);
875 ecryptfs_release_messaging();
876 ecryptfs_destroy_kthread();
877 do_sysfs_unregistration();
878 unregister_filesystem(&ecryptfs_fs_type);
879 ecryptfs_free_kmem_caches();
880 }
881
882 MODULE_AUTHOR("Michael A. Halcrow <mhalcrow@us.ibm.com>");
883 MODULE_DESCRIPTION("eCryptfs");
884
885 MODULE_LICENSE("GPL");
886
887 module_init(ecryptfs_init)
888 module_exit(ecryptfs_exit)
889