Commit | Line | Data |
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55716d26 | 1 | // SPDX-License-Identifier: GPL-2.0-only |
a4ffc152 MP |
2 | /* |
3 | * Copyright (C) 2012 Red Hat, Inc. | |
4 | * | |
5 | * Author: Mikulas Patocka <mpatocka@redhat.com> | |
6 | * | |
7 | * Based on Chromium dm-verity driver (C) 2011 The Chromium OS Authors | |
8 | * | |
a4ffc152 MP |
9 | * In the file "/sys/module/dm_verity/parameters/prefetch_cluster" you can set |
10 | * default prefetch value. Data are read in "prefetch_cluster" chunks from the | |
11 | * hash device. Setting this greatly improves performance when data and hash | |
12 | * are on the same disk on different partitions on devices with poor random | |
13 | * access behavior. | |
14 | */ | |
15 | ||
ffa39380 | 16 | #include "dm-verity.h" |
a739ff3f | 17 | #include "dm-verity-fec.h" |
88cd3e6c | 18 | #include "dm-verity-verify-sig.h" |
a4ffc152 | 19 | #include <linux/module.h> |
65ff5b7d | 20 | #include <linux/reboot.h> |
a4ffc152 MP |
21 | |
22 | #define DM_MSG_PREFIX "verity" | |
23 | ||
65ff5b7d ST |
24 | #define DM_VERITY_ENV_LENGTH 42 |
25 | #define DM_VERITY_ENV_VAR_NAME "DM_VERITY_ERR_BLOCK_NR" | |
26 | ||
a4ffc152 MP |
27 | #define DM_VERITY_DEFAULT_PREFETCH_SIZE 262144 |
28 | ||
65ff5b7d ST |
29 | #define DM_VERITY_MAX_CORRUPTED_ERRS 100 |
30 | ||
31 | #define DM_VERITY_OPT_LOGGING "ignore_corruption" | |
32 | #define DM_VERITY_OPT_RESTART "restart_on_corruption" | |
0cc37c2d | 33 | #define DM_VERITY_OPT_IGN_ZEROES "ignore_zero_blocks" |
843f38d3 | 34 | #define DM_VERITY_OPT_AT_MOST_ONCE "check_at_most_once" |
a4ffc152 | 35 | |
88cd3e6c JK |
36 | #define DM_VERITY_OPTS_MAX (2 + DM_VERITY_OPTS_FEC + \ |
37 | DM_VERITY_ROOT_HASH_VERIFICATION_OPTS) | |
753c1fd0 | 38 | |
a4ffc152 MP |
39 | static unsigned dm_verity_prefetch_cluster = DM_VERITY_DEFAULT_PREFETCH_SIZE; |
40 | ||
41 | module_param_named(prefetch_cluster, dm_verity_prefetch_cluster, uint, S_IRUGO | S_IWUSR); | |
42 | ||
3b6b7813 MP |
43 | struct dm_verity_prefetch_work { |
44 | struct work_struct work; | |
45 | struct dm_verity *v; | |
46 | sector_t block; | |
47 | unsigned n_blocks; | |
48 | }; | |
49 | ||
a4ffc152 MP |
50 | /* |
51 | * Auxiliary structure appended to each dm-bufio buffer. If the value | |
52 | * hash_verified is nonzero, hash of the block has been verified. | |
53 | * | |
54 | * The variable hash_verified is set to 0 when allocating the buffer, then | |
55 | * it can be changed to 1 and it is never reset to 0 again. | |
56 | * | |
57 | * There is no lock around this value, a race condition can at worst cause | |
58 | * that multiple processes verify the hash of the same buffer simultaneously | |
59 | * and write 1 to hash_verified simultaneously. | |
60 | * This condition is harmless, so we don't need locking. | |
61 | */ | |
62 | struct buffer_aux { | |
63 | int hash_verified; | |
64 | }; | |
65 | ||
66 | /* | |
67 | * Initialize struct buffer_aux for a freshly created buffer. | |
68 | */ | |
69 | static void dm_bufio_alloc_callback(struct dm_buffer *buf) | |
70 | { | |
71 | struct buffer_aux *aux = dm_bufio_get_aux_data(buf); | |
72 | ||
73 | aux->hash_verified = 0; | |
74 | } | |
75 | ||
76 | /* | |
77 | * Translate input sector number to the sector number on the target device. | |
78 | */ | |
79 | static sector_t verity_map_sector(struct dm_verity *v, sector_t bi_sector) | |
80 | { | |
81 | return v->data_start + dm_target_offset(v->ti, bi_sector); | |
82 | } | |
83 | ||
84 | /* | |
85 | * Return hash position of a specified block at a specified tree level | |
86 | * (0 is the lowest level). | |
87 | * The lowest "hash_per_block_bits"-bits of the result denote hash position | |
88 | * inside a hash block. The remaining bits denote location of the hash block. | |
89 | */ | |
90 | static sector_t verity_position_at_level(struct dm_verity *v, sector_t block, | |
91 | int level) | |
92 | { | |
93 | return block >> (level * v->hash_per_block_bits); | |
94 | } | |
95 | ||
d1ac3ff0 GBY |
96 | static int verity_hash_update(struct dm_verity *v, struct ahash_request *req, |
97 | const u8 *data, size_t len, | |
12f1ffc4 | 98 | struct crypto_wait *wait) |
6dbeda34 | 99 | { |
d1ac3ff0 | 100 | struct scatterlist sg; |
6dbeda34 | 101 | |
e4b069e0 MP |
102 | if (likely(!is_vmalloc_addr(data))) { |
103 | sg_init_one(&sg, data, len); | |
104 | ahash_request_set_crypt(req, &sg, NULL, len); | |
105 | return crypto_wait_req(crypto_ahash_update(req), wait); | |
106 | } else { | |
107 | do { | |
108 | int r; | |
109 | size_t this_step = min_t(size_t, len, PAGE_SIZE - offset_in_page(data)); | |
110 | flush_kernel_vmap_range((void *)data, this_step); | |
111 | sg_init_table(&sg, 1); | |
112 | sg_set_page(&sg, vmalloc_to_page(data), this_step, offset_in_page(data)); | |
113 | ahash_request_set_crypt(req, &sg, NULL, this_step); | |
114 | r = crypto_wait_req(crypto_ahash_update(req), wait); | |
115 | if (unlikely(r)) | |
116 | return r; | |
117 | data += this_step; | |
118 | len -= this_step; | |
119 | } while (len); | |
120 | return 0; | |
121 | } | |
d1ac3ff0 GBY |
122 | } |
123 | ||
124 | /* | |
125 | * Wrapper for crypto_ahash_init, which handles verity salting. | |
126 | */ | |
127 | static int verity_hash_init(struct dm_verity *v, struct ahash_request *req, | |
12f1ffc4 | 128 | struct crypto_wait *wait) |
d1ac3ff0 GBY |
129 | { |
130 | int r; | |
131 | ||
132 | ahash_request_set_tfm(req, v->tfm); | |
133 | ahash_request_set_callback(req, CRYPTO_TFM_REQ_MAY_SLEEP | | |
134 | CRYPTO_TFM_REQ_MAY_BACKLOG, | |
12f1ffc4 GBY |
135 | crypto_req_done, (void *)wait); |
136 | crypto_init_wait(wait); | |
d1ac3ff0 | 137 | |
12f1ffc4 | 138 | r = crypto_wait_req(crypto_ahash_init(req), wait); |
d1ac3ff0 GBY |
139 | |
140 | if (unlikely(r < 0)) { | |
141 | DMERR("crypto_ahash_init failed: %d", r); | |
142 | return r; | |
143 | } | |
144 | ||
f52236e0 | 145 | if (likely(v->salt_size && (v->version >= 1))) |
12f1ffc4 | 146 | r = verity_hash_update(v, req, v->salt, v->salt_size, wait); |
6dbeda34 ST |
147 | |
148 | return r; | |
149 | } | |
150 | ||
d1ac3ff0 | 151 | static int verity_hash_final(struct dm_verity *v, struct ahash_request *req, |
12f1ffc4 | 152 | u8 *digest, struct crypto_wait *wait) |
6dbeda34 ST |
153 | { |
154 | int r; | |
155 | ||
f52236e0 | 156 | if (unlikely(v->salt_size && (!v->version))) { |
12f1ffc4 | 157 | r = verity_hash_update(v, req, v->salt, v->salt_size, wait); |
6dbeda34 ST |
158 | |
159 | if (r < 0) { | |
d1ac3ff0 GBY |
160 | DMERR("verity_hash_final failed updating salt: %d", r); |
161 | goto out; | |
6dbeda34 ST |
162 | } |
163 | } | |
164 | ||
d1ac3ff0 | 165 | ahash_request_set_crypt(req, NULL, digest, 0); |
12f1ffc4 | 166 | r = crypto_wait_req(crypto_ahash_final(req), wait); |
d1ac3ff0 | 167 | out: |
6dbeda34 ST |
168 | return r; |
169 | } | |
170 | ||
d1ac3ff0 | 171 | int verity_hash(struct dm_verity *v, struct ahash_request *req, |
ffa39380 | 172 | const u8 *data, size_t len, u8 *digest) |
6dbeda34 ST |
173 | { |
174 | int r; | |
12f1ffc4 | 175 | struct crypto_wait wait; |
6dbeda34 | 176 | |
12f1ffc4 | 177 | r = verity_hash_init(v, req, &wait); |
6dbeda34 | 178 | if (unlikely(r < 0)) |
d1ac3ff0 | 179 | goto out; |
6dbeda34 | 180 | |
12f1ffc4 | 181 | r = verity_hash_update(v, req, data, len, &wait); |
6dbeda34 | 182 | if (unlikely(r < 0)) |
d1ac3ff0 GBY |
183 | goto out; |
184 | ||
12f1ffc4 | 185 | r = verity_hash_final(v, req, digest, &wait); |
6dbeda34 | 186 | |
d1ac3ff0 GBY |
187 | out: |
188 | return r; | |
6dbeda34 ST |
189 | } |
190 | ||
a4ffc152 MP |
191 | static void verity_hash_at_level(struct dm_verity *v, sector_t block, int level, |
192 | sector_t *hash_block, unsigned *offset) | |
193 | { | |
194 | sector_t position = verity_position_at_level(v, block, level); | |
195 | unsigned idx; | |
196 | ||
197 | *hash_block = v->hash_level_block[level] + (position >> v->hash_per_block_bits); | |
198 | ||
199 | if (!offset) | |
200 | return; | |
201 | ||
202 | idx = position & ((1 << v->hash_per_block_bits) - 1); | |
203 | if (!v->version) | |
204 | *offset = idx * v->digest_size; | |
205 | else | |
206 | *offset = idx << (v->hash_dev_block_bits - v->hash_per_block_bits); | |
207 | } | |
208 | ||
65ff5b7d ST |
209 | /* |
210 | * Handle verification errors. | |
211 | */ | |
212 | static int verity_handle_err(struct dm_verity *v, enum verity_block_type type, | |
213 | unsigned long long block) | |
214 | { | |
215 | char verity_env[DM_VERITY_ENV_LENGTH]; | |
216 | char *envp[] = { verity_env, NULL }; | |
217 | const char *type_str = ""; | |
218 | struct mapped_device *md = dm_table_get_md(v->ti->table); | |
219 | ||
220 | /* Corruption should be visible in device status in all modes */ | |
221 | v->hash_failed = 1; | |
222 | ||
223 | if (v->corrupted_errs >= DM_VERITY_MAX_CORRUPTED_ERRS) | |
224 | goto out; | |
225 | ||
226 | v->corrupted_errs++; | |
227 | ||
228 | switch (type) { | |
229 | case DM_VERITY_BLOCK_TYPE_DATA: | |
230 | type_str = "data"; | |
231 | break; | |
232 | case DM_VERITY_BLOCK_TYPE_METADATA: | |
233 | type_str = "metadata"; | |
234 | break; | |
235 | default: | |
236 | BUG(); | |
237 | } | |
238 | ||
2eba4e64 MB |
239 | DMERR_LIMIT("%s: %s block %llu is corrupted", v->data_dev->name, |
240 | type_str, block); | |
65ff5b7d ST |
241 | |
242 | if (v->corrupted_errs == DM_VERITY_MAX_CORRUPTED_ERRS) | |
243 | DMERR("%s: reached maximum errors", v->data_dev->name); | |
244 | ||
245 | snprintf(verity_env, DM_VERITY_ENV_LENGTH, "%s=%d,%llu", | |
246 | DM_VERITY_ENV_VAR_NAME, type, block); | |
247 | ||
248 | kobject_uevent_env(&disk_to_dev(dm_disk(md))->kobj, KOBJ_CHANGE, envp); | |
249 | ||
250 | out: | |
251 | if (v->mode == DM_VERITY_MODE_LOGGING) | |
252 | return 0; | |
253 | ||
254 | if (v->mode == DM_VERITY_MODE_RESTART) | |
255 | kernel_restart("dm-verity device corrupted"); | |
256 | ||
257 | return 1; | |
258 | } | |
259 | ||
a4ffc152 MP |
260 | /* |
261 | * Verify hash of a metadata block pertaining to the specified data block | |
262 | * ("block" argument) at a specified level ("level" argument). | |
263 | * | |
ffa39380 ST |
264 | * On successful return, verity_io_want_digest(v, io) contains the hash value |
265 | * for a lower tree level or for the data block (if we're at the lowest level). | |
a4ffc152 MP |
266 | * |
267 | * If "skip_unverified" is true, unverified buffer is skipped and 1 is returned. | |
268 | * If "skip_unverified" is false, unverified buffer is hashed and verified | |
ffa39380 | 269 | * against current value of verity_io_want_digest(v, io). |
a4ffc152 | 270 | */ |
6dbeda34 ST |
271 | static int verity_verify_level(struct dm_verity *v, struct dm_verity_io *io, |
272 | sector_t block, int level, bool skip_unverified, | |
273 | u8 *want_digest) | |
a4ffc152 | 274 | { |
a4ffc152 MP |
275 | struct dm_buffer *buf; |
276 | struct buffer_aux *aux; | |
277 | u8 *data; | |
278 | int r; | |
279 | sector_t hash_block; | |
280 | unsigned offset; | |
281 | ||
282 | verity_hash_at_level(v, block, level, &hash_block, &offset); | |
283 | ||
284 | data = dm_bufio_read(v->bufio, hash_block, &buf); | |
fc0a4461 | 285 | if (IS_ERR(data)) |
a4ffc152 MP |
286 | return PTR_ERR(data); |
287 | ||
288 | aux = dm_bufio_get_aux_data(buf); | |
289 | ||
290 | if (!aux->hash_verified) { | |
a4ffc152 MP |
291 | if (skip_unverified) { |
292 | r = 1; | |
293 | goto release_ret_r; | |
294 | } | |
295 | ||
d1ac3ff0 | 296 | r = verity_hash(v, verity_io_hash_req(v, io), |
6dbeda34 | 297 | data, 1 << v->hash_dev_block_bits, |
ffa39380 | 298 | verity_io_real_digest(v, io)); |
6dbeda34 | 299 | if (unlikely(r < 0)) |
a4ffc152 | 300 | goto release_ret_r; |
a4ffc152 | 301 | |
ffa39380 | 302 | if (likely(memcmp(verity_io_real_digest(v, io), want_digest, |
6dbeda34 ST |
303 | v->digest_size) == 0)) |
304 | aux->hash_verified = 1; | |
a739ff3f ST |
305 | else if (verity_fec_decode(v, io, |
306 | DM_VERITY_BLOCK_TYPE_METADATA, | |
307 | hash_block, data, NULL) == 0) | |
308 | aux->hash_verified = 1; | |
6dbeda34 ST |
309 | else if (verity_handle_err(v, |
310 | DM_VERITY_BLOCK_TYPE_METADATA, | |
311 | hash_block)) { | |
312 | r = -EIO; | |
a4ffc152 MP |
313 | goto release_ret_r; |
314 | } | |
a4ffc152 MP |
315 | } |
316 | ||
317 | data += offset; | |
6dbeda34 ST |
318 | memcpy(want_digest, data, v->digest_size); |
319 | r = 0; | |
a4ffc152 MP |
320 | |
321 | release_ret_r: | |
322 | dm_bufio_release(buf); | |
a4ffc152 MP |
323 | return r; |
324 | } | |
325 | ||
6dbeda34 ST |
326 | /* |
327 | * Find a hash for a given block, write it to digest and verify the integrity | |
328 | * of the hash tree if necessary. | |
329 | */ | |
ffa39380 | 330 | int verity_hash_for_block(struct dm_verity *v, struct dm_verity_io *io, |
0cc37c2d | 331 | sector_t block, u8 *digest, bool *is_zero) |
6dbeda34 | 332 | { |
0cc37c2d | 333 | int r = 0, i; |
6dbeda34 ST |
334 | |
335 | if (likely(v->levels)) { | |
336 | /* | |
337 | * First, we try to get the requested hash for | |
338 | * the current block. If the hash block itself is | |
339 | * verified, zero is returned. If it isn't, this | |
340 | * function returns 1 and we fall back to whole | |
341 | * chain verification. | |
342 | */ | |
343 | r = verity_verify_level(v, io, block, 0, true, digest); | |
344 | if (likely(r <= 0)) | |
0cc37c2d | 345 | goto out; |
6dbeda34 ST |
346 | } |
347 | ||
348 | memcpy(digest, v->root_digest, v->digest_size); | |
349 | ||
350 | for (i = v->levels - 1; i >= 0; i--) { | |
351 | r = verity_verify_level(v, io, block, i, false, digest); | |
352 | if (unlikely(r)) | |
0cc37c2d | 353 | goto out; |
6dbeda34 | 354 | } |
0cc37c2d ST |
355 | out: |
356 | if (!r && v->zero_digest) | |
357 | *is_zero = !memcmp(v->zero_digest, digest, v->digest_size); | |
358 | else | |
359 | *is_zero = false; | |
6dbeda34 | 360 | |
0cc37c2d | 361 | return r; |
6dbeda34 ST |
362 | } |
363 | ||
d1ac3ff0 GBY |
364 | /* |
365 | * Calculates the digest for the given bio | |
366 | */ | |
d4b1aaf5 | 367 | static int verity_for_io_block(struct dm_verity *v, struct dm_verity_io *io, |
368 | struct bvec_iter *iter, struct crypto_wait *wait) | |
d1ac3ff0 GBY |
369 | { |
370 | unsigned int todo = 1 << v->data_dev_block_bits; | |
371 | struct bio *bio = dm_bio_from_per_bio_data(io, v->ti->per_io_data_size); | |
372 | struct scatterlist sg; | |
373 | struct ahash_request *req = verity_io_hash_req(v, io); | |
374 | ||
375 | do { | |
376 | int r; | |
377 | unsigned int len; | |
378 | struct bio_vec bv = bio_iter_iovec(bio, *iter); | |
379 | ||
380 | sg_init_table(&sg, 1); | |
381 | ||
382 | len = bv.bv_len; | |
383 | ||
384 | if (likely(len >= todo)) | |
385 | len = todo; | |
386 | /* | |
387 | * Operating on a single page at a time looks suboptimal | |
388 | * until you consider the typical block size is 4,096B. | |
389 | * Going through this loops twice should be very rare. | |
390 | */ | |
391 | sg_set_page(&sg, bv.bv_page, len, bv.bv_offset); | |
392 | ahash_request_set_crypt(req, &sg, NULL, len); | |
12f1ffc4 | 393 | r = crypto_wait_req(crypto_ahash_update(req), wait); |
d1ac3ff0 GBY |
394 | |
395 | if (unlikely(r < 0)) { | |
396 | DMERR("verity_for_io_block crypto op failed: %d", r); | |
397 | return r; | |
398 | } | |
399 | ||
400 | bio_advance_iter(bio, iter, len); | |
401 | todo -= len; | |
402 | } while (todo); | |
403 | ||
404 | return 0; | |
405 | } | |
406 | ||
bb4d73ac ST |
407 | /* |
408 | * Calls function process for 1 << v->data_dev_block_bits bytes in the bio_vec | |
409 | * starting from iter. | |
410 | */ | |
411 | int verity_for_bv_block(struct dm_verity *v, struct dm_verity_io *io, | |
412 | struct bvec_iter *iter, | |
413 | int (*process)(struct dm_verity *v, | |
414 | struct dm_verity_io *io, u8 *data, | |
415 | size_t len)) | |
416 | { | |
417 | unsigned todo = 1 << v->data_dev_block_bits; | |
30187e1d | 418 | struct bio *bio = dm_bio_from_per_bio_data(io, v->ti->per_io_data_size); |
bb4d73ac ST |
419 | |
420 | do { | |
421 | int r; | |
422 | u8 *page; | |
423 | unsigned len; | |
424 | struct bio_vec bv = bio_iter_iovec(bio, *iter); | |
425 | ||
426 | page = kmap_atomic(bv.bv_page); | |
427 | len = bv.bv_len; | |
428 | ||
429 | if (likely(len >= todo)) | |
430 | len = todo; | |
431 | ||
432 | r = process(v, io, page + bv.bv_offset, len); | |
433 | kunmap_atomic(page); | |
434 | ||
435 | if (r < 0) | |
436 | return r; | |
437 | ||
438 | bio_advance_iter(bio, iter, len); | |
439 | todo -= len; | |
440 | } while (todo); | |
441 | ||
442 | return 0; | |
443 | } | |
444 | ||
0cc37c2d ST |
445 | static int verity_bv_zero(struct dm_verity *v, struct dm_verity_io *io, |
446 | u8 *data, size_t len) | |
447 | { | |
448 | memset(data, 0, len); | |
449 | return 0; | |
450 | } | |
451 | ||
843f38d3 PT |
452 | /* |
453 | * Moves the bio iter one data block forward. | |
454 | */ | |
455 | static inline void verity_bv_skip_block(struct dm_verity *v, | |
456 | struct dm_verity_io *io, | |
457 | struct bvec_iter *iter) | |
458 | { | |
459 | struct bio *bio = dm_bio_from_per_bio_data(io, v->ti->per_io_data_size); | |
460 | ||
461 | bio_advance_iter(bio, iter, 1 << v->data_dev_block_bits); | |
462 | } | |
463 | ||
a4ffc152 MP |
464 | /* |
465 | * Verify one "dm_verity_io" structure. | |
466 | */ | |
467 | static int verity_verify_io(struct dm_verity_io *io) | |
468 | { | |
0cc37c2d | 469 | bool is_zero; |
a4ffc152 | 470 | struct dm_verity *v = io->v; |
bb4d73ac | 471 | struct bvec_iter start; |
a4ffc152 | 472 | unsigned b; |
12f1ffc4 | 473 | struct crypto_wait wait; |
a4ffc152 MP |
474 | |
475 | for (b = 0; b < io->n_blocks; b++) { | |
a4ffc152 | 476 | int r; |
843f38d3 | 477 | sector_t cur_block = io->block + b; |
d1ac3ff0 | 478 | struct ahash_request *req = verity_io_hash_req(v, io); |
a4ffc152 | 479 | |
843f38d3 PT |
480 | if (v->validated_blocks && |
481 | likely(test_bit(cur_block, v->validated_blocks))) { | |
482 | verity_bv_skip_block(v, io, &io->iter); | |
483 | continue; | |
484 | } | |
485 | ||
486 | r = verity_hash_for_block(v, io, cur_block, | |
0cc37c2d ST |
487 | verity_io_want_digest(v, io), |
488 | &is_zero); | |
6dbeda34 ST |
489 | if (unlikely(r < 0)) |
490 | return r; | |
a4ffc152 | 491 | |
0cc37c2d ST |
492 | if (is_zero) { |
493 | /* | |
494 | * If we expect a zero block, don't validate, just | |
495 | * return zeros. | |
496 | */ | |
497 | r = verity_for_bv_block(v, io, &io->iter, | |
498 | verity_bv_zero); | |
499 | if (unlikely(r < 0)) | |
500 | return r; | |
501 | ||
502 | continue; | |
503 | } | |
504 | ||
12f1ffc4 | 505 | r = verity_hash_init(v, req, &wait); |
6dbeda34 | 506 | if (unlikely(r < 0)) |
a4ffc152 | 507 | return r; |
a4ffc152 | 508 | |
bb4d73ac | 509 | start = io->iter; |
12f1ffc4 | 510 | r = verity_for_io_block(v, io, &io->iter, &wait); |
bb4d73ac ST |
511 | if (unlikely(r < 0)) |
512 | return r; | |
a4ffc152 | 513 | |
d1ac3ff0 | 514 | r = verity_hash_final(v, req, verity_io_real_digest(v, io), |
12f1ffc4 | 515 | &wait); |
6dbeda34 | 516 | if (unlikely(r < 0)) |
a4ffc152 | 517 | return r; |
6dbeda34 | 518 | |
ffa39380 | 519 | if (likely(memcmp(verity_io_real_digest(v, io), |
843f38d3 PT |
520 | verity_io_want_digest(v, io), v->digest_size) == 0)) { |
521 | if (v->validated_blocks) | |
522 | set_bit(cur_block, v->validated_blocks); | |
6dbeda34 | 523 | continue; |
843f38d3 | 524 | } |
a739ff3f | 525 | else if (verity_fec_decode(v, io, DM_VERITY_BLOCK_TYPE_DATA, |
843f38d3 | 526 | cur_block, NULL, &start) == 0) |
a739ff3f | 527 | continue; |
6dbeda34 | 528 | else if (verity_handle_err(v, DM_VERITY_BLOCK_TYPE_DATA, |
843f38d3 | 529 | cur_block)) |
6dbeda34 | 530 | return -EIO; |
a4ffc152 | 531 | } |
a4ffc152 MP |
532 | |
533 | return 0; | |
534 | } | |
535 | ||
536 | /* | |
537 | * End one "io" structure with a given error. | |
538 | */ | |
4e4cbee9 | 539 | static void verity_finish_io(struct dm_verity_io *io, blk_status_t status) |
a4ffc152 | 540 | { |
a4ffc152 | 541 | struct dm_verity *v = io->v; |
30187e1d | 542 | struct bio *bio = dm_bio_from_per_bio_data(io, v->ti->per_io_data_size); |
a4ffc152 MP |
543 | |
544 | bio->bi_end_io = io->orig_bi_end_io; | |
4e4cbee9 | 545 | bio->bi_status = status; |
a4ffc152 | 546 | |
a739ff3f ST |
547 | verity_fec_finish_io(io); |
548 | ||
4246a0b6 | 549 | bio_endio(bio); |
a4ffc152 MP |
550 | } |
551 | ||
552 | static void verity_work(struct work_struct *w) | |
553 | { | |
554 | struct dm_verity_io *io = container_of(w, struct dm_verity_io, work); | |
555 | ||
4e4cbee9 | 556 | verity_finish_io(io, errno_to_blk_status(verity_verify_io(io))); |
a4ffc152 MP |
557 | } |
558 | ||
4246a0b6 | 559 | static void verity_end_io(struct bio *bio) |
a4ffc152 MP |
560 | { |
561 | struct dm_verity_io *io = bio->bi_private; | |
562 | ||
4e4cbee9 CH |
563 | if (bio->bi_status && !verity_fec_is_enabled(io->v)) { |
564 | verity_finish_io(io, bio->bi_status); | |
a4ffc152 MP |
565 | return; |
566 | } | |
567 | ||
568 | INIT_WORK(&io->work, verity_work); | |
569 | queue_work(io->v->verify_wq, &io->work); | |
570 | } | |
571 | ||
572 | /* | |
573 | * Prefetch buffers for the specified io. | |
574 | * The root buffer is not prefetched, it is assumed that it will be cached | |
575 | * all the time. | |
576 | */ | |
3b6b7813 | 577 | static void verity_prefetch_io(struct work_struct *work) |
a4ffc152 | 578 | { |
3b6b7813 MP |
579 | struct dm_verity_prefetch_work *pw = |
580 | container_of(work, struct dm_verity_prefetch_work, work); | |
581 | struct dm_verity *v = pw->v; | |
a4ffc152 MP |
582 | int i; |
583 | ||
584 | for (i = v->levels - 2; i >= 0; i--) { | |
585 | sector_t hash_block_start; | |
586 | sector_t hash_block_end; | |
3b6b7813 MP |
587 | verity_hash_at_level(v, pw->block, i, &hash_block_start, NULL); |
588 | verity_hash_at_level(v, pw->block + pw->n_blocks - 1, i, &hash_block_end, NULL); | |
a4ffc152 | 589 | if (!i) { |
6aa7de05 | 590 | unsigned cluster = READ_ONCE(dm_verity_prefetch_cluster); |
a4ffc152 MP |
591 | |
592 | cluster >>= v->data_dev_block_bits; | |
593 | if (unlikely(!cluster)) | |
594 | goto no_prefetch_cluster; | |
595 | ||
596 | if (unlikely(cluster & (cluster - 1))) | |
553d8fe0 | 597 | cluster = 1 << __fls(cluster); |
a4ffc152 MP |
598 | |
599 | hash_block_start &= ~(sector_t)(cluster - 1); | |
600 | hash_block_end |= cluster - 1; | |
601 | if (unlikely(hash_block_end >= v->hash_blocks)) | |
602 | hash_block_end = v->hash_blocks - 1; | |
603 | } | |
604 | no_prefetch_cluster: | |
605 | dm_bufio_prefetch(v->bufio, hash_block_start, | |
606 | hash_block_end - hash_block_start + 1); | |
607 | } | |
3b6b7813 MP |
608 | |
609 | kfree(pw); | |
610 | } | |
611 | ||
612 | static void verity_submit_prefetch(struct dm_verity *v, struct dm_verity_io *io) | |
613 | { | |
614 | struct dm_verity_prefetch_work *pw; | |
615 | ||
616 | pw = kmalloc(sizeof(struct dm_verity_prefetch_work), | |
617 | GFP_NOIO | __GFP_NORETRY | __GFP_NOMEMALLOC | __GFP_NOWARN); | |
618 | ||
619 | if (!pw) | |
620 | return; | |
621 | ||
622 | INIT_WORK(&pw->work, verity_prefetch_io); | |
623 | pw->v = v; | |
624 | pw->block = io->block; | |
625 | pw->n_blocks = io->n_blocks; | |
626 | queue_work(v->verify_wq, &pw->work); | |
a4ffc152 MP |
627 | } |
628 | ||
629 | /* | |
630 | * Bio map function. It allocates dm_verity_io structure and bio vector and | |
631 | * fills them. Then it issues prefetches and the I/O. | |
632 | */ | |
7de3ee57 | 633 | static int verity_map(struct dm_target *ti, struct bio *bio) |
a4ffc152 MP |
634 | { |
635 | struct dm_verity *v = ti->private; | |
636 | struct dm_verity_io *io; | |
637 | ||
74d46992 | 638 | bio_set_dev(bio, v->data_dev->bdev); |
4f024f37 | 639 | bio->bi_iter.bi_sector = verity_map_sector(v, bio->bi_iter.bi_sector); |
a4ffc152 | 640 | |
4f024f37 | 641 | if (((unsigned)bio->bi_iter.bi_sector | bio_sectors(bio)) & |
a4ffc152 MP |
642 | ((1 << (v->data_dev_block_bits - SECTOR_SHIFT)) - 1)) { |
643 | DMERR_LIMIT("unaligned io"); | |
846785e6 | 644 | return DM_MAPIO_KILL; |
a4ffc152 MP |
645 | } |
646 | ||
f73a1c7d | 647 | if (bio_end_sector(bio) >> |
a4ffc152 MP |
648 | (v->data_dev_block_bits - SECTOR_SHIFT) > v->data_blocks) { |
649 | DMERR_LIMIT("io out of range"); | |
846785e6 | 650 | return DM_MAPIO_KILL; |
a4ffc152 MP |
651 | } |
652 | ||
653 | if (bio_data_dir(bio) == WRITE) | |
846785e6 | 654 | return DM_MAPIO_KILL; |
a4ffc152 | 655 | |
30187e1d | 656 | io = dm_per_bio_data(bio, ti->per_io_data_size); |
a4ffc152 | 657 | io->v = v; |
a4ffc152 | 658 | io->orig_bi_end_io = bio->bi_end_io; |
4f024f37 KO |
659 | io->block = bio->bi_iter.bi_sector >> (v->data_dev_block_bits - SECTOR_SHIFT); |
660 | io->n_blocks = bio->bi_iter.bi_size >> v->data_dev_block_bits; | |
a4ffc152 MP |
661 | |
662 | bio->bi_end_io = verity_end_io; | |
663 | bio->bi_private = io; | |
003b5c57 | 664 | io->iter = bio->bi_iter; |
a4ffc152 | 665 | |
a739ff3f ST |
666 | verity_fec_init_io(io); |
667 | ||
3b6b7813 | 668 | verity_submit_prefetch(v, io); |
a4ffc152 MP |
669 | |
670 | generic_make_request(bio); | |
671 | ||
672 | return DM_MAPIO_SUBMITTED; | |
673 | } | |
674 | ||
675 | /* | |
676 | * Status: V (valid) or C (corruption found) | |
677 | */ | |
fd7c092e MP |
678 | static void verity_status(struct dm_target *ti, status_type_t type, |
679 | unsigned status_flags, char *result, unsigned maxlen) | |
a4ffc152 MP |
680 | { |
681 | struct dm_verity *v = ti->private; | |
a739ff3f | 682 | unsigned args = 0; |
a4ffc152 MP |
683 | unsigned sz = 0; |
684 | unsigned x; | |
685 | ||
686 | switch (type) { | |
687 | case STATUSTYPE_INFO: | |
688 | DMEMIT("%c", v->hash_failed ? 'C' : 'V'); | |
689 | break; | |
690 | case STATUSTYPE_TABLE: | |
691 | DMEMIT("%u %s %s %u %u %llu %llu %s ", | |
692 | v->version, | |
693 | v->data_dev->name, | |
694 | v->hash_dev->name, | |
695 | 1 << v->data_dev_block_bits, | |
696 | 1 << v->hash_dev_block_bits, | |
697 | (unsigned long long)v->data_blocks, | |
698 | (unsigned long long)v->hash_start, | |
699 | v->alg_name | |
700 | ); | |
701 | for (x = 0; x < v->digest_size; x++) | |
702 | DMEMIT("%02x", v->root_digest[x]); | |
703 | DMEMIT(" "); | |
704 | if (!v->salt_size) | |
705 | DMEMIT("-"); | |
706 | else | |
707 | for (x = 0; x < v->salt_size; x++) | |
708 | DMEMIT("%02x", v->salt[x]); | |
a739ff3f ST |
709 | if (v->mode != DM_VERITY_MODE_EIO) |
710 | args++; | |
711 | if (verity_fec_is_enabled(v)) | |
712 | args += DM_VERITY_OPTS_FEC; | |
0cc37c2d ST |
713 | if (v->zero_digest) |
714 | args++; | |
843f38d3 PT |
715 | if (v->validated_blocks) |
716 | args++; | |
88cd3e6c JK |
717 | if (v->signature_key_desc) |
718 | args += DM_VERITY_ROOT_HASH_VERIFICATION_OPTS; | |
a739ff3f ST |
719 | if (!args) |
720 | return; | |
721 | DMEMIT(" %u", args); | |
65ff5b7d | 722 | if (v->mode != DM_VERITY_MODE_EIO) { |
a739ff3f | 723 | DMEMIT(" "); |
65ff5b7d ST |
724 | switch (v->mode) { |
725 | case DM_VERITY_MODE_LOGGING: | |
726 | DMEMIT(DM_VERITY_OPT_LOGGING); | |
727 | break; | |
728 | case DM_VERITY_MODE_RESTART: | |
729 | DMEMIT(DM_VERITY_OPT_RESTART); | |
730 | break; | |
731 | default: | |
732 | BUG(); | |
733 | } | |
734 | } | |
0cc37c2d ST |
735 | if (v->zero_digest) |
736 | DMEMIT(" " DM_VERITY_OPT_IGN_ZEROES); | |
843f38d3 PT |
737 | if (v->validated_blocks) |
738 | DMEMIT(" " DM_VERITY_OPT_AT_MOST_ONCE); | |
a739ff3f | 739 | sz = verity_fec_status_table(v, sz, result, maxlen); |
88cd3e6c JK |
740 | if (v->signature_key_desc) |
741 | DMEMIT(" " DM_VERITY_ROOT_HASH_VERIFICATION_OPT_SIG_KEY | |
742 | " %s", v->signature_key_desc); | |
a4ffc152 MP |
743 | break; |
744 | } | |
a4ffc152 MP |
745 | } |
746 | ||
5bd5e8d8 | 747 | static int verity_prepare_ioctl(struct dm_target *ti, struct block_device **bdev) |
a4ffc152 MP |
748 | { |
749 | struct dm_verity *v = ti->private; | |
e56f81e0 CH |
750 | |
751 | *bdev = v->data_dev->bdev; | |
a4ffc152 MP |
752 | |
753 | if (v->data_start || | |
754 | ti->len != i_size_read(v->data_dev->bdev->bd_inode) >> SECTOR_SHIFT) | |
e56f81e0 CH |
755 | return 1; |
756 | return 0; | |
a4ffc152 MP |
757 | } |
758 | ||
a4ffc152 MP |
759 | static int verity_iterate_devices(struct dm_target *ti, |
760 | iterate_devices_callout_fn fn, void *data) | |
761 | { | |
762 | struct dm_verity *v = ti->private; | |
763 | ||
764 | return fn(ti, v->data_dev, v->data_start, ti->len, data); | |
765 | } | |
766 | ||
767 | static void verity_io_hints(struct dm_target *ti, struct queue_limits *limits) | |
768 | { | |
769 | struct dm_verity *v = ti->private; | |
770 | ||
771 | if (limits->logical_block_size < 1 << v->data_dev_block_bits) | |
772 | limits->logical_block_size = 1 << v->data_dev_block_bits; | |
773 | ||
774 | if (limits->physical_block_size < 1 << v->data_dev_block_bits) | |
775 | limits->physical_block_size = 1 << v->data_dev_block_bits; | |
776 | ||
777 | blk_limits_io_min(limits, limits->logical_block_size); | |
778 | } | |
779 | ||
780 | static void verity_dtr(struct dm_target *ti) | |
781 | { | |
782 | struct dm_verity *v = ti->private; | |
783 | ||
784 | if (v->verify_wq) | |
785 | destroy_workqueue(v->verify_wq); | |
786 | ||
a4ffc152 MP |
787 | if (v->bufio) |
788 | dm_bufio_client_destroy(v->bufio); | |
789 | ||
843f38d3 | 790 | kvfree(v->validated_blocks); |
a4ffc152 MP |
791 | kfree(v->salt); |
792 | kfree(v->root_digest); | |
0cc37c2d | 793 | kfree(v->zero_digest); |
a4ffc152 MP |
794 | |
795 | if (v->tfm) | |
d1ac3ff0 | 796 | crypto_free_ahash(v->tfm); |
a4ffc152 MP |
797 | |
798 | kfree(v->alg_name); | |
799 | ||
800 | if (v->hash_dev) | |
801 | dm_put_device(ti, v->hash_dev); | |
802 | ||
803 | if (v->data_dev) | |
804 | dm_put_device(ti, v->data_dev); | |
805 | ||
a739ff3f ST |
806 | verity_fec_dtr(v); |
807 | ||
88cd3e6c JK |
808 | kfree(v->signature_key_desc); |
809 | ||
a4ffc152 MP |
810 | kfree(v); |
811 | } | |
812 | ||
843f38d3 PT |
813 | static int verity_alloc_most_once(struct dm_verity *v) |
814 | { | |
815 | struct dm_target *ti = v->ti; | |
816 | ||
817 | /* the bitset can only handle INT_MAX blocks */ | |
818 | if (v->data_blocks > INT_MAX) { | |
819 | ti->error = "device too large to use check_at_most_once"; | |
820 | return -E2BIG; | |
821 | } | |
822 | ||
778e1cdd KC |
823 | v->validated_blocks = kvcalloc(BITS_TO_LONGS(v->data_blocks), |
824 | sizeof(unsigned long), | |
825 | GFP_KERNEL); | |
843f38d3 PT |
826 | if (!v->validated_blocks) { |
827 | ti->error = "failed to allocate bitset for check_at_most_once"; | |
828 | return -ENOMEM; | |
829 | } | |
830 | ||
831 | return 0; | |
832 | } | |
833 | ||
0cc37c2d ST |
834 | static int verity_alloc_zero_digest(struct dm_verity *v) |
835 | { | |
836 | int r = -ENOMEM; | |
d1ac3ff0 | 837 | struct ahash_request *req; |
0cc37c2d ST |
838 | u8 *zero_data; |
839 | ||
840 | v->zero_digest = kmalloc(v->digest_size, GFP_KERNEL); | |
841 | ||
842 | if (!v->zero_digest) | |
843 | return r; | |
844 | ||
d1ac3ff0 | 845 | req = kmalloc(v->ahash_reqsize, GFP_KERNEL); |
0cc37c2d | 846 | |
d1ac3ff0 | 847 | if (!req) |
0cc37c2d ST |
848 | return r; /* verity_dtr will free zero_digest */ |
849 | ||
850 | zero_data = kzalloc(1 << v->data_dev_block_bits, GFP_KERNEL); | |
851 | ||
852 | if (!zero_data) | |
853 | goto out; | |
854 | ||
d1ac3ff0 | 855 | r = verity_hash(v, req, zero_data, 1 << v->data_dev_block_bits, |
0cc37c2d ST |
856 | v->zero_digest); |
857 | ||
858 | out: | |
d1ac3ff0 | 859 | kfree(req); |
0cc37c2d ST |
860 | kfree(zero_data); |
861 | ||
862 | return r; | |
863 | } | |
864 | ||
88cd3e6c JK |
865 | static int verity_parse_opt_args(struct dm_arg_set *as, struct dm_verity *v, |
866 | struct dm_verity_sig_opts *verify_args) | |
753c1fd0 ST |
867 | { |
868 | int r; | |
869 | unsigned argc; | |
870 | struct dm_target *ti = v->ti; | |
871 | const char *arg_name; | |
872 | ||
5916a22b | 873 | static const struct dm_arg _args[] = { |
753c1fd0 ST |
874 | {0, DM_VERITY_OPTS_MAX, "Invalid number of feature args"}, |
875 | }; | |
876 | ||
877 | r = dm_read_arg_group(_args, as, &argc, &ti->error); | |
878 | if (r) | |
879 | return -EINVAL; | |
880 | ||
881 | if (!argc) | |
882 | return 0; | |
883 | ||
884 | do { | |
885 | arg_name = dm_shift_arg(as); | |
886 | argc--; | |
887 | ||
888 | if (!strcasecmp(arg_name, DM_VERITY_OPT_LOGGING)) { | |
889 | v->mode = DM_VERITY_MODE_LOGGING; | |
890 | continue; | |
891 | ||
892 | } else if (!strcasecmp(arg_name, DM_VERITY_OPT_RESTART)) { | |
893 | v->mode = DM_VERITY_MODE_RESTART; | |
894 | continue; | |
a739ff3f | 895 | |
0cc37c2d ST |
896 | } else if (!strcasecmp(arg_name, DM_VERITY_OPT_IGN_ZEROES)) { |
897 | r = verity_alloc_zero_digest(v); | |
898 | if (r) { | |
899 | ti->error = "Cannot allocate zero digest"; | |
900 | return r; | |
901 | } | |
902 | continue; | |
903 | ||
843f38d3 PT |
904 | } else if (!strcasecmp(arg_name, DM_VERITY_OPT_AT_MOST_ONCE)) { |
905 | r = verity_alloc_most_once(v); | |
906 | if (r) | |
907 | return r; | |
908 | continue; | |
909 | ||
a739ff3f ST |
910 | } else if (verity_is_fec_opt_arg(arg_name)) { |
911 | r = verity_fec_parse_opt_args(as, v, &argc, arg_name); | |
912 | if (r) | |
913 | return r; | |
914 | continue; | |
88cd3e6c JK |
915 | } else if (verity_verify_is_sig_opt_arg(arg_name)) { |
916 | r = verity_verify_sig_parse_opt_args(as, v, | |
917 | verify_args, | |
918 | &argc, arg_name); | |
919 | if (r) | |
920 | return r; | |
921 | continue; | |
922 | ||
753c1fd0 ST |
923 | } |
924 | ||
925 | ti->error = "Unrecognized verity feature request"; | |
926 | return -EINVAL; | |
927 | } while (argc && !r); | |
928 | ||
929 | return r; | |
930 | } | |
931 | ||
a4ffc152 MP |
932 | /* |
933 | * Target parameters: | |
934 | * <version> The current format is version 1. | |
935 | * Vsn 0 is compatible with original Chromium OS releases. | |
936 | * <data device> | |
937 | * <hash device> | |
938 | * <data block size> | |
939 | * <hash block size> | |
940 | * <the number of data blocks> | |
941 | * <hash start block> | |
942 | * <algorithm> | |
943 | * <digest> | |
944 | * <salt> Hex string or "-" if no salt. | |
945 | */ | |
946 | static int verity_ctr(struct dm_target *ti, unsigned argc, char **argv) | |
947 | { | |
948 | struct dm_verity *v; | |
88cd3e6c | 949 | struct dm_verity_sig_opts verify_args = {0}; |
65ff5b7d | 950 | struct dm_arg_set as; |
753c1fd0 | 951 | unsigned int num; |
a4ffc152 MP |
952 | unsigned long long num_ll; |
953 | int r; | |
954 | int i; | |
955 | sector_t hash_position; | |
956 | char dummy; | |
88cd3e6c | 957 | char *root_hash_digest_to_validate; |
a4ffc152 MP |
958 | |
959 | v = kzalloc(sizeof(struct dm_verity), GFP_KERNEL); | |
960 | if (!v) { | |
961 | ti->error = "Cannot allocate verity structure"; | |
962 | return -ENOMEM; | |
963 | } | |
964 | ti->private = v; | |
965 | v->ti = ti; | |
966 | ||
a739ff3f ST |
967 | r = verity_fec_ctr_alloc(v); |
968 | if (r) | |
969 | goto bad; | |
970 | ||
a4ffc152 MP |
971 | if ((dm_table_get_mode(ti->table) & ~FMODE_READ)) { |
972 | ti->error = "Device must be readonly"; | |
973 | r = -EINVAL; | |
974 | goto bad; | |
975 | } | |
976 | ||
65ff5b7d ST |
977 | if (argc < 10) { |
978 | ti->error = "Not enough arguments"; | |
a4ffc152 MP |
979 | r = -EINVAL; |
980 | goto bad; | |
981 | } | |
982 | ||
5d8be843 MP |
983 | if (sscanf(argv[0], "%u%c", &num, &dummy) != 1 || |
984 | num > 1) { | |
a4ffc152 MP |
985 | ti->error = "Invalid version"; |
986 | r = -EINVAL; | |
987 | goto bad; | |
988 | } | |
989 | v->version = num; | |
990 | ||
991 | r = dm_get_device(ti, argv[1], FMODE_READ, &v->data_dev); | |
992 | if (r) { | |
993 | ti->error = "Data device lookup failed"; | |
994 | goto bad; | |
995 | } | |
996 | ||
997 | r = dm_get_device(ti, argv[2], FMODE_READ, &v->hash_dev); | |
998 | if (r) { | |
21ffe552 | 999 | ti->error = "Hash device lookup failed"; |
a4ffc152 MP |
1000 | goto bad; |
1001 | } | |
1002 | ||
1003 | if (sscanf(argv[3], "%u%c", &num, &dummy) != 1 || | |
1004 | !num || (num & (num - 1)) || | |
1005 | num < bdev_logical_block_size(v->data_dev->bdev) || | |
1006 | num > PAGE_SIZE) { | |
1007 | ti->error = "Invalid data device block size"; | |
1008 | r = -EINVAL; | |
1009 | goto bad; | |
1010 | } | |
553d8fe0 | 1011 | v->data_dev_block_bits = __ffs(num); |
a4ffc152 MP |
1012 | |
1013 | if (sscanf(argv[4], "%u%c", &num, &dummy) != 1 || | |
1014 | !num || (num & (num - 1)) || | |
1015 | num < bdev_logical_block_size(v->hash_dev->bdev) || | |
1016 | num > INT_MAX) { | |
1017 | ti->error = "Invalid hash device block size"; | |
1018 | r = -EINVAL; | |
1019 | goto bad; | |
1020 | } | |
553d8fe0 | 1021 | v->hash_dev_block_bits = __ffs(num); |
a4ffc152 MP |
1022 | |
1023 | if (sscanf(argv[5], "%llu%c", &num_ll, &dummy) != 1 || | |
1d55f6bc MP |
1024 | (sector_t)(num_ll << (v->data_dev_block_bits - SECTOR_SHIFT)) |
1025 | >> (v->data_dev_block_bits - SECTOR_SHIFT) != num_ll) { | |
a4ffc152 MP |
1026 | ti->error = "Invalid data blocks"; |
1027 | r = -EINVAL; | |
1028 | goto bad; | |
1029 | } | |
1030 | v->data_blocks = num_ll; | |
1031 | ||
1032 | if (ti->len > (v->data_blocks << (v->data_dev_block_bits - SECTOR_SHIFT))) { | |
1033 | ti->error = "Data device is too small"; | |
1034 | r = -EINVAL; | |
1035 | goto bad; | |
1036 | } | |
1037 | ||
1038 | if (sscanf(argv[6], "%llu%c", &num_ll, &dummy) != 1 || | |
1d55f6bc MP |
1039 | (sector_t)(num_ll << (v->hash_dev_block_bits - SECTOR_SHIFT)) |
1040 | >> (v->hash_dev_block_bits - SECTOR_SHIFT) != num_ll) { | |
a4ffc152 MP |
1041 | ti->error = "Invalid hash start"; |
1042 | r = -EINVAL; | |
1043 | goto bad; | |
1044 | } | |
1045 | v->hash_start = num_ll; | |
1046 | ||
1047 | v->alg_name = kstrdup(argv[7], GFP_KERNEL); | |
1048 | if (!v->alg_name) { | |
1049 | ti->error = "Cannot allocate algorithm name"; | |
1050 | r = -ENOMEM; | |
1051 | goto bad; | |
1052 | } | |
1053 | ||
d1ac3ff0 | 1054 | v->tfm = crypto_alloc_ahash(v->alg_name, 0, 0); |
a4ffc152 MP |
1055 | if (IS_ERR(v->tfm)) { |
1056 | ti->error = "Cannot initialize hash function"; | |
1057 | r = PTR_ERR(v->tfm); | |
1058 | v->tfm = NULL; | |
1059 | goto bad; | |
1060 | } | |
bbf6a566 EB |
1061 | |
1062 | /* | |
1063 | * dm-verity performance can vary greatly depending on which hash | |
1064 | * algorithm implementation is used. Help people debug performance | |
1065 | * problems by logging the ->cra_driver_name. | |
1066 | */ | |
1067 | DMINFO("%s using implementation \"%s\"", v->alg_name, | |
1068 | crypto_hash_alg_common(v->tfm)->base.cra_driver_name); | |
1069 | ||
d1ac3ff0 | 1070 | v->digest_size = crypto_ahash_digestsize(v->tfm); |
a4ffc152 MP |
1071 | if ((1 << v->hash_dev_block_bits) < v->digest_size * 2) { |
1072 | ti->error = "Digest size too big"; | |
1073 | r = -EINVAL; | |
1074 | goto bad; | |
1075 | } | |
d1ac3ff0 GBY |
1076 | v->ahash_reqsize = sizeof(struct ahash_request) + |
1077 | crypto_ahash_reqsize(v->tfm); | |
a4ffc152 MP |
1078 | |
1079 | v->root_digest = kmalloc(v->digest_size, GFP_KERNEL); | |
1080 | if (!v->root_digest) { | |
1081 | ti->error = "Cannot allocate root digest"; | |
1082 | r = -ENOMEM; | |
1083 | goto bad; | |
1084 | } | |
1085 | if (strlen(argv[8]) != v->digest_size * 2 || | |
1086 | hex2bin(v->root_digest, argv[8], v->digest_size)) { | |
1087 | ti->error = "Invalid root digest"; | |
1088 | r = -EINVAL; | |
1089 | goto bad; | |
1090 | } | |
88cd3e6c | 1091 | root_hash_digest_to_validate = argv[8]; |
a4ffc152 MP |
1092 | |
1093 | if (strcmp(argv[9], "-")) { | |
1094 | v->salt_size = strlen(argv[9]) / 2; | |
1095 | v->salt = kmalloc(v->salt_size, GFP_KERNEL); | |
1096 | if (!v->salt) { | |
1097 | ti->error = "Cannot allocate salt"; | |
1098 | r = -ENOMEM; | |
1099 | goto bad; | |
1100 | } | |
1101 | if (strlen(argv[9]) != v->salt_size * 2 || | |
1102 | hex2bin(v->salt, argv[9], v->salt_size)) { | |
1103 | ti->error = "Invalid salt"; | |
1104 | r = -EINVAL; | |
1105 | goto bad; | |
1106 | } | |
1107 | } | |
1108 | ||
65ff5b7d ST |
1109 | argv += 10; |
1110 | argc -= 10; | |
1111 | ||
1112 | /* Optional parameters */ | |
1113 | if (argc) { | |
1114 | as.argc = argc; | |
1115 | as.argv = argv; | |
1116 | ||
88cd3e6c | 1117 | r = verity_parse_opt_args(&as, v, &verify_args); |
753c1fd0 | 1118 | if (r < 0) |
65ff5b7d | 1119 | goto bad; |
65ff5b7d ST |
1120 | } |
1121 | ||
88cd3e6c JK |
1122 | /* Root hash signature is a optional parameter*/ |
1123 | r = verity_verify_root_hash(root_hash_digest_to_validate, | |
1124 | strlen(root_hash_digest_to_validate), | |
1125 | verify_args.sig, | |
1126 | verify_args.sig_size); | |
1127 | if (r < 0) { | |
1128 | ti->error = "Root hash verification failed"; | |
1129 | goto bad; | |
1130 | } | |
a4ffc152 | 1131 | v->hash_per_block_bits = |
553d8fe0 | 1132 | __fls((1 << v->hash_dev_block_bits) / v->digest_size); |
a4ffc152 MP |
1133 | |
1134 | v->levels = 0; | |
1135 | if (v->data_blocks) | |
1136 | while (v->hash_per_block_bits * v->levels < 64 && | |
1137 | (unsigned long long)(v->data_blocks - 1) >> | |
1138 | (v->hash_per_block_bits * v->levels)) | |
1139 | v->levels++; | |
1140 | ||
1141 | if (v->levels > DM_VERITY_MAX_LEVELS) { | |
1142 | ti->error = "Too many tree levels"; | |
1143 | r = -E2BIG; | |
1144 | goto bad; | |
1145 | } | |
1146 | ||
1147 | hash_position = v->hash_start; | |
1148 | for (i = v->levels - 1; i >= 0; i--) { | |
1149 | sector_t s; | |
1150 | v->hash_level_block[i] = hash_position; | |
b1bf2de0 MP |
1151 | s = (v->data_blocks + ((sector_t)1 << ((i + 1) * v->hash_per_block_bits)) - 1) |
1152 | >> ((i + 1) * v->hash_per_block_bits); | |
a4ffc152 MP |
1153 | if (hash_position + s < hash_position) { |
1154 | ti->error = "Hash device offset overflow"; | |
1155 | r = -E2BIG; | |
1156 | goto bad; | |
1157 | } | |
1158 | hash_position += s; | |
1159 | } | |
1160 | v->hash_blocks = hash_position; | |
1161 | ||
1162 | v->bufio = dm_bufio_client_create(v->hash_dev->bdev, | |
1163 | 1 << v->hash_dev_block_bits, 1, sizeof(struct buffer_aux), | |
1164 | dm_bufio_alloc_callback, NULL); | |
1165 | if (IS_ERR(v->bufio)) { | |
1166 | ti->error = "Cannot initialize dm-bufio"; | |
1167 | r = PTR_ERR(v->bufio); | |
1168 | v->bufio = NULL; | |
1169 | goto bad; | |
1170 | } | |
1171 | ||
1172 | if (dm_bufio_get_device_size(v->bufio) < v->hash_blocks) { | |
1173 | ti->error = "Hash device is too small"; | |
1174 | r = -E2BIG; | |
1175 | goto bad; | |
1176 | } | |
1177 | ||
a4ffc152 MP |
1178 | /* WQ_UNBOUND greatly improves performance when running on ramdisk */ |
1179 | v->verify_wq = alloc_workqueue("kverityd", WQ_CPU_INTENSIVE | WQ_MEM_RECLAIM | WQ_UNBOUND, num_online_cpus()); | |
1180 | if (!v->verify_wq) { | |
1181 | ti->error = "Cannot allocate workqueue"; | |
1182 | r = -ENOMEM; | |
1183 | goto bad; | |
1184 | } | |
1185 | ||
30187e1d | 1186 | ti->per_io_data_size = sizeof(struct dm_verity_io) + |
d1ac3ff0 | 1187 | v->ahash_reqsize + v->digest_size * 2; |
a739ff3f ST |
1188 | |
1189 | r = verity_fec_ctr(v); | |
1190 | if (r) | |
1191 | goto bad; | |
1192 | ||
30187e1d MS |
1193 | ti->per_io_data_size = roundup(ti->per_io_data_size, |
1194 | __alignof__(struct dm_verity_io)); | |
a739ff3f | 1195 | |
88cd3e6c JK |
1196 | verity_verify_sig_opts_cleanup(&verify_args); |
1197 | ||
a4ffc152 MP |
1198 | return 0; |
1199 | ||
1200 | bad: | |
88cd3e6c JK |
1201 | |
1202 | verity_verify_sig_opts_cleanup(&verify_args); | |
a4ffc152 MP |
1203 | verity_dtr(ti); |
1204 | ||
1205 | return r; | |
1206 | } | |
1207 | ||
1208 | static struct target_type verity_target = { | |
1209 | .name = "verity", | |
88cd3e6c | 1210 | .version = {1, 5, 0}, |
a4ffc152 MP |
1211 | .module = THIS_MODULE, |
1212 | .ctr = verity_ctr, | |
1213 | .dtr = verity_dtr, | |
1214 | .map = verity_map, | |
1215 | .status = verity_status, | |
e56f81e0 | 1216 | .prepare_ioctl = verity_prepare_ioctl, |
a4ffc152 MP |
1217 | .iterate_devices = verity_iterate_devices, |
1218 | .io_hints = verity_io_hints, | |
1219 | }; | |
1220 | ||
1221 | static int __init dm_verity_init(void) | |
1222 | { | |
1223 | int r; | |
1224 | ||
1225 | r = dm_register_target(&verity_target); | |
1226 | if (r < 0) | |
1227 | DMERR("register failed %d", r); | |
1228 | ||
1229 | return r; | |
1230 | } | |
1231 | ||
1232 | static void __exit dm_verity_exit(void) | |
1233 | { | |
1234 | dm_unregister_target(&verity_target); | |
1235 | } | |
1236 | ||
1237 | module_init(dm_verity_init); | |
1238 | module_exit(dm_verity_exit); | |
1239 | ||
1240 | MODULE_AUTHOR("Mikulas Patocka <mpatocka@redhat.com>"); | |
1241 | MODULE_AUTHOR("Mandeep Baines <msb@chromium.org>"); | |
1242 | MODULE_AUTHOR("Will Drewry <wad@chromium.org>"); | |
1243 | MODULE_DESCRIPTION(DM_NAME " target for transparent disk integrity checking"); | |
1244 | MODULE_LICENSE("GPL"); |