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" | |
e1fef0b0 | 33 | #define DM_VERITY_OPT_PANIC "panic_on_corruption" |
0cc37c2d | 34 | #define DM_VERITY_OPT_IGN_ZEROES "ignore_zero_blocks" |
843f38d3 | 35 | #define DM_VERITY_OPT_AT_MOST_ONCE "check_at_most_once" |
a4ffc152 | 36 | |
160f99db | 37 | #define DM_VERITY_OPTS_MAX (3 + DM_VERITY_OPTS_FEC + \ |
88cd3e6c | 38 | DM_VERITY_ROOT_HASH_VERIFICATION_OPTS) |
753c1fd0 | 39 | |
a4ffc152 MP |
40 | static unsigned dm_verity_prefetch_cluster = DM_VERITY_DEFAULT_PREFETCH_SIZE; |
41 | ||
42 | module_param_named(prefetch_cluster, dm_verity_prefetch_cluster, uint, S_IRUGO | S_IWUSR); | |
43 | ||
3b6b7813 MP |
44 | struct dm_verity_prefetch_work { |
45 | struct work_struct work; | |
46 | struct dm_verity *v; | |
47 | sector_t block; | |
48 | unsigned n_blocks; | |
49 | }; | |
50 | ||
a4ffc152 MP |
51 | /* |
52 | * Auxiliary structure appended to each dm-bufio buffer. If the value | |
53 | * hash_verified is nonzero, hash of the block has been verified. | |
54 | * | |
55 | * The variable hash_verified is set to 0 when allocating the buffer, then | |
56 | * it can be changed to 1 and it is never reset to 0 again. | |
57 | * | |
58 | * There is no lock around this value, a race condition can at worst cause | |
59 | * that multiple processes verify the hash of the same buffer simultaneously | |
60 | * and write 1 to hash_verified simultaneously. | |
61 | * This condition is harmless, so we don't need locking. | |
62 | */ | |
63 | struct buffer_aux { | |
64 | int hash_verified; | |
65 | }; | |
66 | ||
67 | /* | |
68 | * Initialize struct buffer_aux for a freshly created buffer. | |
69 | */ | |
70 | static void dm_bufio_alloc_callback(struct dm_buffer *buf) | |
71 | { | |
72 | struct buffer_aux *aux = dm_bufio_get_aux_data(buf); | |
73 | ||
74 | aux->hash_verified = 0; | |
75 | } | |
76 | ||
77 | /* | |
78 | * Translate input sector number to the sector number on the target device. | |
79 | */ | |
80 | static sector_t verity_map_sector(struct dm_verity *v, sector_t bi_sector) | |
81 | { | |
82 | return v->data_start + dm_target_offset(v->ti, bi_sector); | |
83 | } | |
84 | ||
85 | /* | |
86 | * Return hash position of a specified block at a specified tree level | |
87 | * (0 is the lowest level). | |
88 | * The lowest "hash_per_block_bits"-bits of the result denote hash position | |
89 | * inside a hash block. The remaining bits denote location of the hash block. | |
90 | */ | |
91 | static sector_t verity_position_at_level(struct dm_verity *v, sector_t block, | |
92 | int level) | |
93 | { | |
94 | return block >> (level * v->hash_per_block_bits); | |
95 | } | |
96 | ||
d1ac3ff0 GBY |
97 | static int verity_hash_update(struct dm_verity *v, struct ahash_request *req, |
98 | const u8 *data, size_t len, | |
12f1ffc4 | 99 | struct crypto_wait *wait) |
6dbeda34 | 100 | { |
d1ac3ff0 | 101 | struct scatterlist sg; |
6dbeda34 | 102 | |
e4b069e0 MP |
103 | if (likely(!is_vmalloc_addr(data))) { |
104 | sg_init_one(&sg, data, len); | |
105 | ahash_request_set_crypt(req, &sg, NULL, len); | |
106 | return crypto_wait_req(crypto_ahash_update(req), wait); | |
107 | } else { | |
108 | do { | |
109 | int r; | |
110 | size_t this_step = min_t(size_t, len, PAGE_SIZE - offset_in_page(data)); | |
111 | flush_kernel_vmap_range((void *)data, this_step); | |
112 | sg_init_table(&sg, 1); | |
113 | sg_set_page(&sg, vmalloc_to_page(data), this_step, offset_in_page(data)); | |
114 | ahash_request_set_crypt(req, &sg, NULL, this_step); | |
115 | r = crypto_wait_req(crypto_ahash_update(req), wait); | |
116 | if (unlikely(r)) | |
117 | return r; | |
118 | data += this_step; | |
119 | len -= this_step; | |
120 | } while (len); | |
121 | return 0; | |
122 | } | |
d1ac3ff0 GBY |
123 | } |
124 | ||
125 | /* | |
126 | * Wrapper for crypto_ahash_init, which handles verity salting. | |
127 | */ | |
128 | static int verity_hash_init(struct dm_verity *v, struct ahash_request *req, | |
12f1ffc4 | 129 | struct crypto_wait *wait) |
d1ac3ff0 GBY |
130 | { |
131 | int r; | |
132 | ||
133 | ahash_request_set_tfm(req, v->tfm); | |
134 | ahash_request_set_callback(req, CRYPTO_TFM_REQ_MAY_SLEEP | | |
135 | CRYPTO_TFM_REQ_MAY_BACKLOG, | |
12f1ffc4 GBY |
136 | crypto_req_done, (void *)wait); |
137 | crypto_init_wait(wait); | |
d1ac3ff0 | 138 | |
12f1ffc4 | 139 | r = crypto_wait_req(crypto_ahash_init(req), wait); |
d1ac3ff0 GBY |
140 | |
141 | if (unlikely(r < 0)) { | |
142 | DMERR("crypto_ahash_init failed: %d", r); | |
143 | return r; | |
144 | } | |
145 | ||
f52236e0 | 146 | if (likely(v->salt_size && (v->version >= 1))) |
12f1ffc4 | 147 | r = verity_hash_update(v, req, v->salt, v->salt_size, wait); |
6dbeda34 ST |
148 | |
149 | return r; | |
150 | } | |
151 | ||
d1ac3ff0 | 152 | static int verity_hash_final(struct dm_verity *v, struct ahash_request *req, |
12f1ffc4 | 153 | u8 *digest, struct crypto_wait *wait) |
6dbeda34 ST |
154 | { |
155 | int r; | |
156 | ||
f52236e0 | 157 | if (unlikely(v->salt_size && (!v->version))) { |
12f1ffc4 | 158 | r = verity_hash_update(v, req, v->salt, v->salt_size, wait); |
6dbeda34 ST |
159 | |
160 | if (r < 0) { | |
d1ac3ff0 GBY |
161 | DMERR("verity_hash_final failed updating salt: %d", r); |
162 | goto out; | |
6dbeda34 ST |
163 | } |
164 | } | |
165 | ||
d1ac3ff0 | 166 | ahash_request_set_crypt(req, NULL, digest, 0); |
12f1ffc4 | 167 | r = crypto_wait_req(crypto_ahash_final(req), wait); |
d1ac3ff0 | 168 | out: |
6dbeda34 ST |
169 | return r; |
170 | } | |
171 | ||
d1ac3ff0 | 172 | int verity_hash(struct dm_verity *v, struct ahash_request *req, |
ffa39380 | 173 | const u8 *data, size_t len, u8 *digest) |
6dbeda34 ST |
174 | { |
175 | int r; | |
12f1ffc4 | 176 | struct crypto_wait wait; |
6dbeda34 | 177 | |
12f1ffc4 | 178 | r = verity_hash_init(v, req, &wait); |
6dbeda34 | 179 | if (unlikely(r < 0)) |
d1ac3ff0 | 180 | goto out; |
6dbeda34 | 181 | |
12f1ffc4 | 182 | r = verity_hash_update(v, req, data, len, &wait); |
6dbeda34 | 183 | if (unlikely(r < 0)) |
d1ac3ff0 GBY |
184 | goto out; |
185 | ||
12f1ffc4 | 186 | r = verity_hash_final(v, req, digest, &wait); |
6dbeda34 | 187 | |
d1ac3ff0 GBY |
188 | out: |
189 | return r; | |
6dbeda34 ST |
190 | } |
191 | ||
a4ffc152 MP |
192 | static void verity_hash_at_level(struct dm_verity *v, sector_t block, int level, |
193 | sector_t *hash_block, unsigned *offset) | |
194 | { | |
195 | sector_t position = verity_position_at_level(v, block, level); | |
196 | unsigned idx; | |
197 | ||
198 | *hash_block = v->hash_level_block[level] + (position >> v->hash_per_block_bits); | |
199 | ||
200 | if (!offset) | |
201 | return; | |
202 | ||
203 | idx = position & ((1 << v->hash_per_block_bits) - 1); | |
204 | if (!v->version) | |
205 | *offset = idx * v->digest_size; | |
206 | else | |
207 | *offset = idx << (v->hash_dev_block_bits - v->hash_per_block_bits); | |
208 | } | |
209 | ||
65ff5b7d ST |
210 | /* |
211 | * Handle verification errors. | |
212 | */ | |
213 | static int verity_handle_err(struct dm_verity *v, enum verity_block_type type, | |
214 | unsigned long long block) | |
215 | { | |
216 | char verity_env[DM_VERITY_ENV_LENGTH]; | |
217 | char *envp[] = { verity_env, NULL }; | |
218 | const char *type_str = ""; | |
219 | struct mapped_device *md = dm_table_get_md(v->ti->table); | |
220 | ||
221 | /* Corruption should be visible in device status in all modes */ | |
222 | v->hash_failed = 1; | |
223 | ||
224 | if (v->corrupted_errs >= DM_VERITY_MAX_CORRUPTED_ERRS) | |
225 | goto out; | |
226 | ||
227 | v->corrupted_errs++; | |
228 | ||
229 | switch (type) { | |
230 | case DM_VERITY_BLOCK_TYPE_DATA: | |
231 | type_str = "data"; | |
232 | break; | |
233 | case DM_VERITY_BLOCK_TYPE_METADATA: | |
234 | type_str = "metadata"; | |
235 | break; | |
236 | default: | |
237 | BUG(); | |
238 | } | |
239 | ||
2eba4e64 MB |
240 | DMERR_LIMIT("%s: %s block %llu is corrupted", v->data_dev->name, |
241 | type_str, block); | |
65ff5b7d ST |
242 | |
243 | if (v->corrupted_errs == DM_VERITY_MAX_CORRUPTED_ERRS) | |
244 | DMERR("%s: reached maximum errors", v->data_dev->name); | |
245 | ||
246 | snprintf(verity_env, DM_VERITY_ENV_LENGTH, "%s=%d,%llu", | |
247 | DM_VERITY_ENV_VAR_NAME, type, block); | |
248 | ||
249 | kobject_uevent_env(&disk_to_dev(dm_disk(md))->kobj, KOBJ_CHANGE, envp); | |
250 | ||
251 | out: | |
252 | if (v->mode == DM_VERITY_MODE_LOGGING) | |
253 | return 0; | |
254 | ||
255 | if (v->mode == DM_VERITY_MODE_RESTART) | |
256 | kernel_restart("dm-verity device corrupted"); | |
257 | ||
e1fef0b0 JL |
258 | if (v->mode == DM_VERITY_MODE_PANIC) |
259 | panic("dm-verity device corrupted"); | |
260 | ||
65ff5b7d ST |
261 | return 1; |
262 | } | |
263 | ||
a4ffc152 MP |
264 | /* |
265 | * Verify hash of a metadata block pertaining to the specified data block | |
266 | * ("block" argument) at a specified level ("level" argument). | |
267 | * | |
ffa39380 ST |
268 | * On successful return, verity_io_want_digest(v, io) contains the hash value |
269 | * for a lower tree level or for the data block (if we're at the lowest level). | |
a4ffc152 MP |
270 | * |
271 | * If "skip_unverified" is true, unverified buffer is skipped and 1 is returned. | |
272 | * If "skip_unverified" is false, unverified buffer is hashed and verified | |
ffa39380 | 273 | * against current value of verity_io_want_digest(v, io). |
a4ffc152 | 274 | */ |
6dbeda34 ST |
275 | static int verity_verify_level(struct dm_verity *v, struct dm_verity_io *io, |
276 | sector_t block, int level, bool skip_unverified, | |
277 | u8 *want_digest) | |
a4ffc152 | 278 | { |
a4ffc152 MP |
279 | struct dm_buffer *buf; |
280 | struct buffer_aux *aux; | |
281 | u8 *data; | |
282 | int r; | |
283 | sector_t hash_block; | |
284 | unsigned offset; | |
285 | ||
286 | verity_hash_at_level(v, block, level, &hash_block, &offset); | |
287 | ||
288 | data = dm_bufio_read(v->bufio, hash_block, &buf); | |
fc0a4461 | 289 | if (IS_ERR(data)) |
a4ffc152 MP |
290 | return PTR_ERR(data); |
291 | ||
292 | aux = dm_bufio_get_aux_data(buf); | |
293 | ||
294 | if (!aux->hash_verified) { | |
a4ffc152 MP |
295 | if (skip_unverified) { |
296 | r = 1; | |
297 | goto release_ret_r; | |
298 | } | |
299 | ||
d1ac3ff0 | 300 | r = verity_hash(v, verity_io_hash_req(v, io), |
6dbeda34 | 301 | data, 1 << v->hash_dev_block_bits, |
ffa39380 | 302 | verity_io_real_digest(v, io)); |
6dbeda34 | 303 | if (unlikely(r < 0)) |
a4ffc152 | 304 | goto release_ret_r; |
a4ffc152 | 305 | |
ffa39380 | 306 | if (likely(memcmp(verity_io_real_digest(v, io), want_digest, |
6dbeda34 ST |
307 | v->digest_size) == 0)) |
308 | aux->hash_verified = 1; | |
a739ff3f ST |
309 | else if (verity_fec_decode(v, io, |
310 | DM_VERITY_BLOCK_TYPE_METADATA, | |
311 | hash_block, data, NULL) == 0) | |
312 | aux->hash_verified = 1; | |
6dbeda34 ST |
313 | else if (verity_handle_err(v, |
314 | DM_VERITY_BLOCK_TYPE_METADATA, | |
315 | hash_block)) { | |
316 | r = -EIO; | |
a4ffc152 MP |
317 | goto release_ret_r; |
318 | } | |
a4ffc152 MP |
319 | } |
320 | ||
321 | data += offset; | |
6dbeda34 ST |
322 | memcpy(want_digest, data, v->digest_size); |
323 | r = 0; | |
a4ffc152 MP |
324 | |
325 | release_ret_r: | |
326 | dm_bufio_release(buf); | |
a4ffc152 MP |
327 | return r; |
328 | } | |
329 | ||
6dbeda34 ST |
330 | /* |
331 | * Find a hash for a given block, write it to digest and verify the integrity | |
332 | * of the hash tree if necessary. | |
333 | */ | |
ffa39380 | 334 | int verity_hash_for_block(struct dm_verity *v, struct dm_verity_io *io, |
0cc37c2d | 335 | sector_t block, u8 *digest, bool *is_zero) |
6dbeda34 | 336 | { |
0cc37c2d | 337 | int r = 0, i; |
6dbeda34 ST |
338 | |
339 | if (likely(v->levels)) { | |
340 | /* | |
341 | * First, we try to get the requested hash for | |
342 | * the current block. If the hash block itself is | |
343 | * verified, zero is returned. If it isn't, this | |
344 | * function returns 1 and we fall back to whole | |
345 | * chain verification. | |
346 | */ | |
347 | r = verity_verify_level(v, io, block, 0, true, digest); | |
348 | if (likely(r <= 0)) | |
0cc37c2d | 349 | goto out; |
6dbeda34 ST |
350 | } |
351 | ||
352 | memcpy(digest, v->root_digest, v->digest_size); | |
353 | ||
354 | for (i = v->levels - 1; i >= 0; i--) { | |
355 | r = verity_verify_level(v, io, block, i, false, digest); | |
356 | if (unlikely(r)) | |
0cc37c2d | 357 | goto out; |
6dbeda34 | 358 | } |
0cc37c2d ST |
359 | out: |
360 | if (!r && v->zero_digest) | |
361 | *is_zero = !memcmp(v->zero_digest, digest, v->digest_size); | |
362 | else | |
363 | *is_zero = false; | |
6dbeda34 | 364 | |
0cc37c2d | 365 | return r; |
6dbeda34 ST |
366 | } |
367 | ||
d1ac3ff0 GBY |
368 | /* |
369 | * Calculates the digest for the given bio | |
370 | */ | |
d4b1aaf5 | 371 | static int verity_for_io_block(struct dm_verity *v, struct dm_verity_io *io, |
372 | struct bvec_iter *iter, struct crypto_wait *wait) | |
d1ac3ff0 GBY |
373 | { |
374 | unsigned int todo = 1 << v->data_dev_block_bits; | |
375 | struct bio *bio = dm_bio_from_per_bio_data(io, v->ti->per_io_data_size); | |
376 | struct scatterlist sg; | |
377 | struct ahash_request *req = verity_io_hash_req(v, io); | |
378 | ||
379 | do { | |
380 | int r; | |
381 | unsigned int len; | |
382 | struct bio_vec bv = bio_iter_iovec(bio, *iter); | |
383 | ||
384 | sg_init_table(&sg, 1); | |
385 | ||
386 | len = bv.bv_len; | |
387 | ||
388 | if (likely(len >= todo)) | |
389 | len = todo; | |
390 | /* | |
391 | * Operating on a single page at a time looks suboptimal | |
392 | * until you consider the typical block size is 4,096B. | |
393 | * Going through this loops twice should be very rare. | |
394 | */ | |
395 | sg_set_page(&sg, bv.bv_page, len, bv.bv_offset); | |
396 | ahash_request_set_crypt(req, &sg, NULL, len); | |
12f1ffc4 | 397 | r = crypto_wait_req(crypto_ahash_update(req), wait); |
d1ac3ff0 GBY |
398 | |
399 | if (unlikely(r < 0)) { | |
400 | DMERR("verity_for_io_block crypto op failed: %d", r); | |
401 | return r; | |
402 | } | |
403 | ||
404 | bio_advance_iter(bio, iter, len); | |
405 | todo -= len; | |
406 | } while (todo); | |
407 | ||
408 | return 0; | |
409 | } | |
410 | ||
bb4d73ac ST |
411 | /* |
412 | * Calls function process for 1 << v->data_dev_block_bits bytes in the bio_vec | |
413 | * starting from iter. | |
414 | */ | |
415 | int verity_for_bv_block(struct dm_verity *v, struct dm_verity_io *io, | |
416 | struct bvec_iter *iter, | |
417 | int (*process)(struct dm_verity *v, | |
418 | struct dm_verity_io *io, u8 *data, | |
419 | size_t len)) | |
420 | { | |
421 | unsigned todo = 1 << v->data_dev_block_bits; | |
30187e1d | 422 | struct bio *bio = dm_bio_from_per_bio_data(io, v->ti->per_io_data_size); |
bb4d73ac ST |
423 | |
424 | do { | |
425 | int r; | |
426 | u8 *page; | |
427 | unsigned len; | |
428 | struct bio_vec bv = bio_iter_iovec(bio, *iter); | |
429 | ||
430 | page = kmap_atomic(bv.bv_page); | |
431 | len = bv.bv_len; | |
432 | ||
433 | if (likely(len >= todo)) | |
434 | len = todo; | |
435 | ||
436 | r = process(v, io, page + bv.bv_offset, len); | |
437 | kunmap_atomic(page); | |
438 | ||
439 | if (r < 0) | |
440 | return r; | |
441 | ||
442 | bio_advance_iter(bio, iter, len); | |
443 | todo -= len; | |
444 | } while (todo); | |
445 | ||
446 | return 0; | |
447 | } | |
448 | ||
0cc37c2d ST |
449 | static int verity_bv_zero(struct dm_verity *v, struct dm_verity_io *io, |
450 | u8 *data, size_t len) | |
451 | { | |
452 | memset(data, 0, len); | |
453 | return 0; | |
454 | } | |
455 | ||
843f38d3 PT |
456 | /* |
457 | * Moves the bio iter one data block forward. | |
458 | */ | |
459 | static inline void verity_bv_skip_block(struct dm_verity *v, | |
460 | struct dm_verity_io *io, | |
461 | struct bvec_iter *iter) | |
462 | { | |
463 | struct bio *bio = dm_bio_from_per_bio_data(io, v->ti->per_io_data_size); | |
464 | ||
465 | bio_advance_iter(bio, iter, 1 << v->data_dev_block_bits); | |
466 | } | |
467 | ||
a4ffc152 MP |
468 | /* |
469 | * Verify one "dm_verity_io" structure. | |
470 | */ | |
471 | static int verity_verify_io(struct dm_verity_io *io) | |
472 | { | |
0cc37c2d | 473 | bool is_zero; |
a4ffc152 | 474 | struct dm_verity *v = io->v; |
bb4d73ac | 475 | struct bvec_iter start; |
a4ffc152 | 476 | unsigned b; |
12f1ffc4 | 477 | struct crypto_wait wait; |
a4ffc152 MP |
478 | |
479 | for (b = 0; b < io->n_blocks; b++) { | |
a4ffc152 | 480 | int r; |
843f38d3 | 481 | sector_t cur_block = io->block + b; |
d1ac3ff0 | 482 | struct ahash_request *req = verity_io_hash_req(v, io); |
a4ffc152 | 483 | |
843f38d3 PT |
484 | if (v->validated_blocks && |
485 | likely(test_bit(cur_block, v->validated_blocks))) { | |
486 | verity_bv_skip_block(v, io, &io->iter); | |
487 | continue; | |
488 | } | |
489 | ||
490 | r = verity_hash_for_block(v, io, cur_block, | |
0cc37c2d ST |
491 | verity_io_want_digest(v, io), |
492 | &is_zero); | |
6dbeda34 ST |
493 | if (unlikely(r < 0)) |
494 | return r; | |
a4ffc152 | 495 | |
0cc37c2d ST |
496 | if (is_zero) { |
497 | /* | |
498 | * If we expect a zero block, don't validate, just | |
499 | * return zeros. | |
500 | */ | |
501 | r = verity_for_bv_block(v, io, &io->iter, | |
502 | verity_bv_zero); | |
503 | if (unlikely(r < 0)) | |
504 | return r; | |
505 | ||
506 | continue; | |
507 | } | |
508 | ||
12f1ffc4 | 509 | r = verity_hash_init(v, req, &wait); |
6dbeda34 | 510 | if (unlikely(r < 0)) |
a4ffc152 | 511 | return r; |
a4ffc152 | 512 | |
bb4d73ac | 513 | start = io->iter; |
12f1ffc4 | 514 | r = verity_for_io_block(v, io, &io->iter, &wait); |
bb4d73ac ST |
515 | if (unlikely(r < 0)) |
516 | return r; | |
a4ffc152 | 517 | |
d1ac3ff0 | 518 | r = verity_hash_final(v, req, verity_io_real_digest(v, io), |
12f1ffc4 | 519 | &wait); |
6dbeda34 | 520 | if (unlikely(r < 0)) |
a4ffc152 | 521 | return r; |
6dbeda34 | 522 | |
ffa39380 | 523 | if (likely(memcmp(verity_io_real_digest(v, io), |
843f38d3 PT |
524 | verity_io_want_digest(v, io), v->digest_size) == 0)) { |
525 | if (v->validated_blocks) | |
526 | set_bit(cur_block, v->validated_blocks); | |
6dbeda34 | 527 | continue; |
843f38d3 | 528 | } |
a739ff3f | 529 | else if (verity_fec_decode(v, io, DM_VERITY_BLOCK_TYPE_DATA, |
843f38d3 | 530 | cur_block, NULL, &start) == 0) |
a739ff3f | 531 | continue; |
6dbeda34 | 532 | else if (verity_handle_err(v, DM_VERITY_BLOCK_TYPE_DATA, |
843f38d3 | 533 | cur_block)) |
6dbeda34 | 534 | return -EIO; |
a4ffc152 | 535 | } |
a4ffc152 MP |
536 | |
537 | return 0; | |
538 | } | |
539 | ||
252bd125 HK |
540 | /* |
541 | * Skip verity work in response to I/O error when system is shutting down. | |
542 | */ | |
543 | static inline bool verity_is_system_shutting_down(void) | |
544 | { | |
545 | return system_state == SYSTEM_HALT || system_state == SYSTEM_POWER_OFF | |
546 | || system_state == SYSTEM_RESTART; | |
547 | } | |
548 | ||
a4ffc152 MP |
549 | /* |
550 | * End one "io" structure with a given error. | |
551 | */ | |
4e4cbee9 | 552 | static void verity_finish_io(struct dm_verity_io *io, blk_status_t status) |
a4ffc152 | 553 | { |
a4ffc152 | 554 | struct dm_verity *v = io->v; |
30187e1d | 555 | struct bio *bio = dm_bio_from_per_bio_data(io, v->ti->per_io_data_size); |
a4ffc152 MP |
556 | |
557 | bio->bi_end_io = io->orig_bi_end_io; | |
4e4cbee9 | 558 | bio->bi_status = status; |
a4ffc152 | 559 | |
a739ff3f ST |
560 | verity_fec_finish_io(io); |
561 | ||
4246a0b6 | 562 | bio_endio(bio); |
a4ffc152 MP |
563 | } |
564 | ||
565 | static void verity_work(struct work_struct *w) | |
566 | { | |
567 | struct dm_verity_io *io = container_of(w, struct dm_verity_io, work); | |
568 | ||
4e4cbee9 | 569 | verity_finish_io(io, errno_to_blk_status(verity_verify_io(io))); |
a4ffc152 MP |
570 | } |
571 | ||
4246a0b6 | 572 | static void verity_end_io(struct bio *bio) |
a4ffc152 MP |
573 | { |
574 | struct dm_verity_io *io = bio->bi_private; | |
575 | ||
252bd125 HK |
576 | if (bio->bi_status && |
577 | (!verity_fec_is_enabled(io->v) || verity_is_system_shutting_down())) { | |
4e4cbee9 | 578 | verity_finish_io(io, bio->bi_status); |
a4ffc152 MP |
579 | return; |
580 | } | |
581 | ||
582 | INIT_WORK(&io->work, verity_work); | |
583 | queue_work(io->v->verify_wq, &io->work); | |
584 | } | |
585 | ||
586 | /* | |
587 | * Prefetch buffers for the specified io. | |
588 | * The root buffer is not prefetched, it is assumed that it will be cached | |
589 | * all the time. | |
590 | */ | |
3b6b7813 | 591 | static void verity_prefetch_io(struct work_struct *work) |
a4ffc152 | 592 | { |
3b6b7813 MP |
593 | struct dm_verity_prefetch_work *pw = |
594 | container_of(work, struct dm_verity_prefetch_work, work); | |
595 | struct dm_verity *v = pw->v; | |
a4ffc152 MP |
596 | int i; |
597 | ||
598 | for (i = v->levels - 2; i >= 0; i--) { | |
599 | sector_t hash_block_start; | |
600 | sector_t hash_block_end; | |
3b6b7813 MP |
601 | verity_hash_at_level(v, pw->block, i, &hash_block_start, NULL); |
602 | verity_hash_at_level(v, pw->block + pw->n_blocks - 1, i, &hash_block_end, NULL); | |
a4ffc152 | 603 | if (!i) { |
6aa7de05 | 604 | unsigned cluster = READ_ONCE(dm_verity_prefetch_cluster); |
a4ffc152 MP |
605 | |
606 | cluster >>= v->data_dev_block_bits; | |
607 | if (unlikely(!cluster)) | |
608 | goto no_prefetch_cluster; | |
609 | ||
610 | if (unlikely(cluster & (cluster - 1))) | |
553d8fe0 | 611 | cluster = 1 << __fls(cluster); |
a4ffc152 MP |
612 | |
613 | hash_block_start &= ~(sector_t)(cluster - 1); | |
614 | hash_block_end |= cluster - 1; | |
615 | if (unlikely(hash_block_end >= v->hash_blocks)) | |
616 | hash_block_end = v->hash_blocks - 1; | |
617 | } | |
618 | no_prefetch_cluster: | |
619 | dm_bufio_prefetch(v->bufio, hash_block_start, | |
620 | hash_block_end - hash_block_start + 1); | |
621 | } | |
3b6b7813 MP |
622 | |
623 | kfree(pw); | |
624 | } | |
625 | ||
626 | static void verity_submit_prefetch(struct dm_verity *v, struct dm_verity_io *io) | |
627 | { | |
0a531c5a | 628 | sector_t block = io->block; |
629 | unsigned int n_blocks = io->n_blocks; | |
3b6b7813 MP |
630 | struct dm_verity_prefetch_work *pw; |
631 | ||
0a531c5a | 632 | if (v->validated_blocks) { |
633 | while (n_blocks && test_bit(block, v->validated_blocks)) { | |
634 | block++; | |
635 | n_blocks--; | |
636 | } | |
637 | while (n_blocks && test_bit(block + n_blocks - 1, | |
638 | v->validated_blocks)) | |
639 | n_blocks--; | |
640 | if (!n_blocks) | |
641 | return; | |
642 | } | |
643 | ||
3b6b7813 MP |
644 | pw = kmalloc(sizeof(struct dm_verity_prefetch_work), |
645 | GFP_NOIO | __GFP_NORETRY | __GFP_NOMEMALLOC | __GFP_NOWARN); | |
646 | ||
647 | if (!pw) | |
648 | return; | |
649 | ||
650 | INIT_WORK(&pw->work, verity_prefetch_io); | |
651 | pw->v = v; | |
0a531c5a | 652 | pw->block = block; |
653 | pw->n_blocks = n_blocks; | |
3b6b7813 | 654 | queue_work(v->verify_wq, &pw->work); |
a4ffc152 MP |
655 | } |
656 | ||
657 | /* | |
658 | * Bio map function. It allocates dm_verity_io structure and bio vector and | |
659 | * fills them. Then it issues prefetches and the I/O. | |
660 | */ | |
7de3ee57 | 661 | static int verity_map(struct dm_target *ti, struct bio *bio) |
a4ffc152 MP |
662 | { |
663 | struct dm_verity *v = ti->private; | |
664 | struct dm_verity_io *io; | |
665 | ||
74d46992 | 666 | bio_set_dev(bio, v->data_dev->bdev); |
4f024f37 | 667 | bio->bi_iter.bi_sector = verity_map_sector(v, bio->bi_iter.bi_sector); |
a4ffc152 | 668 | |
4f024f37 | 669 | if (((unsigned)bio->bi_iter.bi_sector | bio_sectors(bio)) & |
a4ffc152 MP |
670 | ((1 << (v->data_dev_block_bits - SECTOR_SHIFT)) - 1)) { |
671 | DMERR_LIMIT("unaligned io"); | |
846785e6 | 672 | return DM_MAPIO_KILL; |
a4ffc152 MP |
673 | } |
674 | ||
f73a1c7d | 675 | if (bio_end_sector(bio) >> |
a4ffc152 MP |
676 | (v->data_dev_block_bits - SECTOR_SHIFT) > v->data_blocks) { |
677 | DMERR_LIMIT("io out of range"); | |
846785e6 | 678 | return DM_MAPIO_KILL; |
a4ffc152 MP |
679 | } |
680 | ||
681 | if (bio_data_dir(bio) == WRITE) | |
846785e6 | 682 | return DM_MAPIO_KILL; |
a4ffc152 | 683 | |
30187e1d | 684 | io = dm_per_bio_data(bio, ti->per_io_data_size); |
a4ffc152 | 685 | io->v = v; |
a4ffc152 | 686 | io->orig_bi_end_io = bio->bi_end_io; |
4f024f37 KO |
687 | io->block = bio->bi_iter.bi_sector >> (v->data_dev_block_bits - SECTOR_SHIFT); |
688 | io->n_blocks = bio->bi_iter.bi_size >> v->data_dev_block_bits; | |
a4ffc152 MP |
689 | |
690 | bio->bi_end_io = verity_end_io; | |
691 | bio->bi_private = io; | |
003b5c57 | 692 | io->iter = bio->bi_iter; |
a4ffc152 | 693 | |
a739ff3f ST |
694 | verity_fec_init_io(io); |
695 | ||
3b6b7813 | 696 | verity_submit_prefetch(v, io); |
a4ffc152 | 697 | |
ed00aabd | 698 | submit_bio_noacct(bio); |
a4ffc152 MP |
699 | |
700 | return DM_MAPIO_SUBMITTED; | |
701 | } | |
702 | ||
703 | /* | |
704 | * Status: V (valid) or C (corruption found) | |
705 | */ | |
fd7c092e MP |
706 | static void verity_status(struct dm_target *ti, status_type_t type, |
707 | unsigned status_flags, char *result, unsigned maxlen) | |
a4ffc152 MP |
708 | { |
709 | struct dm_verity *v = ti->private; | |
a739ff3f | 710 | unsigned args = 0; |
a4ffc152 MP |
711 | unsigned sz = 0; |
712 | unsigned x; | |
713 | ||
714 | switch (type) { | |
715 | case STATUSTYPE_INFO: | |
716 | DMEMIT("%c", v->hash_failed ? 'C' : 'V'); | |
717 | break; | |
718 | case STATUSTYPE_TABLE: | |
719 | DMEMIT("%u %s %s %u %u %llu %llu %s ", | |
720 | v->version, | |
721 | v->data_dev->name, | |
722 | v->hash_dev->name, | |
723 | 1 << v->data_dev_block_bits, | |
724 | 1 << v->hash_dev_block_bits, | |
725 | (unsigned long long)v->data_blocks, | |
726 | (unsigned long long)v->hash_start, | |
727 | v->alg_name | |
728 | ); | |
729 | for (x = 0; x < v->digest_size; x++) | |
730 | DMEMIT("%02x", v->root_digest[x]); | |
731 | DMEMIT(" "); | |
732 | if (!v->salt_size) | |
733 | DMEMIT("-"); | |
734 | else | |
735 | for (x = 0; x < v->salt_size; x++) | |
736 | DMEMIT("%02x", v->salt[x]); | |
a739ff3f ST |
737 | if (v->mode != DM_VERITY_MODE_EIO) |
738 | args++; | |
739 | if (verity_fec_is_enabled(v)) | |
740 | args += DM_VERITY_OPTS_FEC; | |
0cc37c2d ST |
741 | if (v->zero_digest) |
742 | args++; | |
843f38d3 PT |
743 | if (v->validated_blocks) |
744 | args++; | |
88cd3e6c JK |
745 | if (v->signature_key_desc) |
746 | args += DM_VERITY_ROOT_HASH_VERIFICATION_OPTS; | |
a739ff3f ST |
747 | if (!args) |
748 | return; | |
749 | DMEMIT(" %u", args); | |
65ff5b7d | 750 | if (v->mode != DM_VERITY_MODE_EIO) { |
a739ff3f | 751 | DMEMIT(" "); |
65ff5b7d ST |
752 | switch (v->mode) { |
753 | case DM_VERITY_MODE_LOGGING: | |
754 | DMEMIT(DM_VERITY_OPT_LOGGING); | |
755 | break; | |
756 | case DM_VERITY_MODE_RESTART: | |
757 | DMEMIT(DM_VERITY_OPT_RESTART); | |
758 | break; | |
e1fef0b0 JL |
759 | case DM_VERITY_MODE_PANIC: |
760 | DMEMIT(DM_VERITY_OPT_PANIC); | |
761 | break; | |
65ff5b7d ST |
762 | default: |
763 | BUG(); | |
764 | } | |
765 | } | |
0cc37c2d ST |
766 | if (v->zero_digest) |
767 | DMEMIT(" " DM_VERITY_OPT_IGN_ZEROES); | |
843f38d3 PT |
768 | if (v->validated_blocks) |
769 | DMEMIT(" " DM_VERITY_OPT_AT_MOST_ONCE); | |
a739ff3f | 770 | sz = verity_fec_status_table(v, sz, result, maxlen); |
88cd3e6c JK |
771 | if (v->signature_key_desc) |
772 | DMEMIT(" " DM_VERITY_ROOT_HASH_VERIFICATION_OPT_SIG_KEY | |
773 | " %s", v->signature_key_desc); | |
a4ffc152 MP |
774 | break; |
775 | } | |
a4ffc152 MP |
776 | } |
777 | ||
5bd5e8d8 | 778 | static int verity_prepare_ioctl(struct dm_target *ti, struct block_device **bdev) |
a4ffc152 MP |
779 | { |
780 | struct dm_verity *v = ti->private; | |
e56f81e0 CH |
781 | |
782 | *bdev = v->data_dev->bdev; | |
a4ffc152 MP |
783 | |
784 | if (v->data_start || | |
785 | ti->len != i_size_read(v->data_dev->bdev->bd_inode) >> SECTOR_SHIFT) | |
e56f81e0 CH |
786 | return 1; |
787 | return 0; | |
a4ffc152 MP |
788 | } |
789 | ||
a4ffc152 MP |
790 | static int verity_iterate_devices(struct dm_target *ti, |
791 | iterate_devices_callout_fn fn, void *data) | |
792 | { | |
793 | struct dm_verity *v = ti->private; | |
794 | ||
795 | return fn(ti, v->data_dev, v->data_start, ti->len, data); | |
796 | } | |
797 | ||
798 | static void verity_io_hints(struct dm_target *ti, struct queue_limits *limits) | |
799 | { | |
800 | struct dm_verity *v = ti->private; | |
801 | ||
802 | if (limits->logical_block_size < 1 << v->data_dev_block_bits) | |
803 | limits->logical_block_size = 1 << v->data_dev_block_bits; | |
804 | ||
805 | if (limits->physical_block_size < 1 << v->data_dev_block_bits) | |
806 | limits->physical_block_size = 1 << v->data_dev_block_bits; | |
807 | ||
808 | blk_limits_io_min(limits, limits->logical_block_size); | |
809 | } | |
810 | ||
811 | static void verity_dtr(struct dm_target *ti) | |
812 | { | |
813 | struct dm_verity *v = ti->private; | |
814 | ||
815 | if (v->verify_wq) | |
816 | destroy_workqueue(v->verify_wq); | |
817 | ||
a4ffc152 MP |
818 | if (v->bufio) |
819 | dm_bufio_client_destroy(v->bufio); | |
820 | ||
843f38d3 | 821 | kvfree(v->validated_blocks); |
a4ffc152 MP |
822 | kfree(v->salt); |
823 | kfree(v->root_digest); | |
0cc37c2d | 824 | kfree(v->zero_digest); |
a4ffc152 MP |
825 | |
826 | if (v->tfm) | |
d1ac3ff0 | 827 | crypto_free_ahash(v->tfm); |
a4ffc152 MP |
828 | |
829 | kfree(v->alg_name); | |
830 | ||
831 | if (v->hash_dev) | |
832 | dm_put_device(ti, v->hash_dev); | |
833 | ||
834 | if (v->data_dev) | |
835 | dm_put_device(ti, v->data_dev); | |
836 | ||
a739ff3f ST |
837 | verity_fec_dtr(v); |
838 | ||
88cd3e6c JK |
839 | kfree(v->signature_key_desc); |
840 | ||
a4ffc152 MP |
841 | kfree(v); |
842 | } | |
843 | ||
843f38d3 PT |
844 | static int verity_alloc_most_once(struct dm_verity *v) |
845 | { | |
846 | struct dm_target *ti = v->ti; | |
847 | ||
848 | /* the bitset can only handle INT_MAX blocks */ | |
849 | if (v->data_blocks > INT_MAX) { | |
850 | ti->error = "device too large to use check_at_most_once"; | |
851 | return -E2BIG; | |
852 | } | |
853 | ||
778e1cdd KC |
854 | v->validated_blocks = kvcalloc(BITS_TO_LONGS(v->data_blocks), |
855 | sizeof(unsigned long), | |
856 | GFP_KERNEL); | |
843f38d3 PT |
857 | if (!v->validated_blocks) { |
858 | ti->error = "failed to allocate bitset for check_at_most_once"; | |
859 | return -ENOMEM; | |
860 | } | |
861 | ||
862 | return 0; | |
863 | } | |
864 | ||
0cc37c2d ST |
865 | static int verity_alloc_zero_digest(struct dm_verity *v) |
866 | { | |
867 | int r = -ENOMEM; | |
d1ac3ff0 | 868 | struct ahash_request *req; |
0cc37c2d ST |
869 | u8 *zero_data; |
870 | ||
871 | v->zero_digest = kmalloc(v->digest_size, GFP_KERNEL); | |
872 | ||
873 | if (!v->zero_digest) | |
874 | return r; | |
875 | ||
d1ac3ff0 | 876 | req = kmalloc(v->ahash_reqsize, GFP_KERNEL); |
0cc37c2d | 877 | |
d1ac3ff0 | 878 | if (!req) |
0cc37c2d ST |
879 | return r; /* verity_dtr will free zero_digest */ |
880 | ||
881 | zero_data = kzalloc(1 << v->data_dev_block_bits, GFP_KERNEL); | |
882 | ||
883 | if (!zero_data) | |
884 | goto out; | |
885 | ||
d1ac3ff0 | 886 | r = verity_hash(v, req, zero_data, 1 << v->data_dev_block_bits, |
0cc37c2d ST |
887 | v->zero_digest); |
888 | ||
889 | out: | |
d1ac3ff0 | 890 | kfree(req); |
0cc37c2d ST |
891 | kfree(zero_data); |
892 | ||
893 | return r; | |
894 | } | |
895 | ||
219a9b5e JL |
896 | static inline bool verity_is_verity_mode(const char *arg_name) |
897 | { | |
898 | return (!strcasecmp(arg_name, DM_VERITY_OPT_LOGGING) || | |
899 | !strcasecmp(arg_name, DM_VERITY_OPT_RESTART) || | |
900 | !strcasecmp(arg_name, DM_VERITY_OPT_PANIC)); | |
901 | } | |
902 | ||
903 | static int verity_parse_verity_mode(struct dm_verity *v, const char *arg_name) | |
904 | { | |
905 | if (v->mode) | |
906 | return -EINVAL; | |
907 | ||
908 | if (!strcasecmp(arg_name, DM_VERITY_OPT_LOGGING)) | |
909 | v->mode = DM_VERITY_MODE_LOGGING; | |
910 | else if (!strcasecmp(arg_name, DM_VERITY_OPT_RESTART)) | |
911 | v->mode = DM_VERITY_MODE_RESTART; | |
912 | else if (!strcasecmp(arg_name, DM_VERITY_OPT_PANIC)) | |
913 | v->mode = DM_VERITY_MODE_PANIC; | |
914 | ||
915 | return 0; | |
916 | } | |
917 | ||
88cd3e6c JK |
918 | static int verity_parse_opt_args(struct dm_arg_set *as, struct dm_verity *v, |
919 | struct dm_verity_sig_opts *verify_args) | |
753c1fd0 ST |
920 | { |
921 | int r; | |
922 | unsigned argc; | |
923 | struct dm_target *ti = v->ti; | |
924 | const char *arg_name; | |
925 | ||
5916a22b | 926 | static const struct dm_arg _args[] = { |
753c1fd0 ST |
927 | {0, DM_VERITY_OPTS_MAX, "Invalid number of feature args"}, |
928 | }; | |
929 | ||
930 | r = dm_read_arg_group(_args, as, &argc, &ti->error); | |
931 | if (r) | |
932 | return -EINVAL; | |
933 | ||
934 | if (!argc) | |
935 | return 0; | |
936 | ||
937 | do { | |
938 | arg_name = dm_shift_arg(as); | |
939 | argc--; | |
940 | ||
219a9b5e JL |
941 | if (verity_is_verity_mode(arg_name)) { |
942 | r = verity_parse_verity_mode(v, arg_name); | |
943 | if (r) { | |
944 | ti->error = "Conflicting error handling parameters"; | |
945 | return r; | |
946 | } | |
e1fef0b0 JL |
947 | continue; |
948 | ||
0cc37c2d ST |
949 | } else if (!strcasecmp(arg_name, DM_VERITY_OPT_IGN_ZEROES)) { |
950 | r = verity_alloc_zero_digest(v); | |
951 | if (r) { | |
952 | ti->error = "Cannot allocate zero digest"; | |
953 | return r; | |
954 | } | |
955 | continue; | |
956 | ||
843f38d3 PT |
957 | } else if (!strcasecmp(arg_name, DM_VERITY_OPT_AT_MOST_ONCE)) { |
958 | r = verity_alloc_most_once(v); | |
959 | if (r) | |
960 | return r; | |
961 | continue; | |
962 | ||
a739ff3f ST |
963 | } else if (verity_is_fec_opt_arg(arg_name)) { |
964 | r = verity_fec_parse_opt_args(as, v, &argc, arg_name); | |
965 | if (r) | |
966 | return r; | |
967 | continue; | |
88cd3e6c JK |
968 | } else if (verity_verify_is_sig_opt_arg(arg_name)) { |
969 | r = verity_verify_sig_parse_opt_args(as, v, | |
970 | verify_args, | |
971 | &argc, arg_name); | |
972 | if (r) | |
973 | return r; | |
974 | continue; | |
975 | ||
753c1fd0 ST |
976 | } |
977 | ||
978 | ti->error = "Unrecognized verity feature request"; | |
979 | return -EINVAL; | |
980 | } while (argc && !r); | |
981 | ||
982 | return r; | |
983 | } | |
984 | ||
a4ffc152 MP |
985 | /* |
986 | * Target parameters: | |
987 | * <version> The current format is version 1. | |
988 | * Vsn 0 is compatible with original Chromium OS releases. | |
989 | * <data device> | |
990 | * <hash device> | |
991 | * <data block size> | |
992 | * <hash block size> | |
993 | * <the number of data blocks> | |
994 | * <hash start block> | |
995 | * <algorithm> | |
996 | * <digest> | |
997 | * <salt> Hex string or "-" if no salt. | |
998 | */ | |
999 | static int verity_ctr(struct dm_target *ti, unsigned argc, char **argv) | |
1000 | { | |
1001 | struct dm_verity *v; | |
88cd3e6c | 1002 | struct dm_verity_sig_opts verify_args = {0}; |
65ff5b7d | 1003 | struct dm_arg_set as; |
753c1fd0 | 1004 | unsigned int num; |
a4ffc152 MP |
1005 | unsigned long long num_ll; |
1006 | int r; | |
1007 | int i; | |
1008 | sector_t hash_position; | |
1009 | char dummy; | |
88cd3e6c | 1010 | char *root_hash_digest_to_validate; |
a4ffc152 MP |
1011 | |
1012 | v = kzalloc(sizeof(struct dm_verity), GFP_KERNEL); | |
1013 | if (!v) { | |
1014 | ti->error = "Cannot allocate verity structure"; | |
1015 | return -ENOMEM; | |
1016 | } | |
1017 | ti->private = v; | |
1018 | v->ti = ti; | |
1019 | ||
a739ff3f ST |
1020 | r = verity_fec_ctr_alloc(v); |
1021 | if (r) | |
1022 | goto bad; | |
1023 | ||
a4ffc152 MP |
1024 | if ((dm_table_get_mode(ti->table) & ~FMODE_READ)) { |
1025 | ti->error = "Device must be readonly"; | |
1026 | r = -EINVAL; | |
1027 | goto bad; | |
1028 | } | |
1029 | ||
65ff5b7d ST |
1030 | if (argc < 10) { |
1031 | ti->error = "Not enough arguments"; | |
a4ffc152 MP |
1032 | r = -EINVAL; |
1033 | goto bad; | |
1034 | } | |
1035 | ||
5d8be843 MP |
1036 | if (sscanf(argv[0], "%u%c", &num, &dummy) != 1 || |
1037 | num > 1) { | |
a4ffc152 MP |
1038 | ti->error = "Invalid version"; |
1039 | r = -EINVAL; | |
1040 | goto bad; | |
1041 | } | |
1042 | v->version = num; | |
1043 | ||
1044 | r = dm_get_device(ti, argv[1], FMODE_READ, &v->data_dev); | |
1045 | if (r) { | |
1046 | ti->error = "Data device lookup failed"; | |
1047 | goto bad; | |
1048 | } | |
1049 | ||
1050 | r = dm_get_device(ti, argv[2], FMODE_READ, &v->hash_dev); | |
1051 | if (r) { | |
21ffe552 | 1052 | ti->error = "Hash device lookup failed"; |
a4ffc152 MP |
1053 | goto bad; |
1054 | } | |
1055 | ||
1056 | if (sscanf(argv[3], "%u%c", &num, &dummy) != 1 || | |
1057 | !num || (num & (num - 1)) || | |
1058 | num < bdev_logical_block_size(v->data_dev->bdev) || | |
1059 | num > PAGE_SIZE) { | |
1060 | ti->error = "Invalid data device block size"; | |
1061 | r = -EINVAL; | |
1062 | goto bad; | |
1063 | } | |
553d8fe0 | 1064 | v->data_dev_block_bits = __ffs(num); |
a4ffc152 MP |
1065 | |
1066 | if (sscanf(argv[4], "%u%c", &num, &dummy) != 1 || | |
1067 | !num || (num & (num - 1)) || | |
1068 | num < bdev_logical_block_size(v->hash_dev->bdev) || | |
1069 | num > INT_MAX) { | |
1070 | ti->error = "Invalid hash device block size"; | |
1071 | r = -EINVAL; | |
1072 | goto bad; | |
1073 | } | |
553d8fe0 | 1074 | v->hash_dev_block_bits = __ffs(num); |
a4ffc152 MP |
1075 | |
1076 | if (sscanf(argv[5], "%llu%c", &num_ll, &dummy) != 1 || | |
1d55f6bc MP |
1077 | (sector_t)(num_ll << (v->data_dev_block_bits - SECTOR_SHIFT)) |
1078 | >> (v->data_dev_block_bits - SECTOR_SHIFT) != num_ll) { | |
a4ffc152 MP |
1079 | ti->error = "Invalid data blocks"; |
1080 | r = -EINVAL; | |
1081 | goto bad; | |
1082 | } | |
1083 | v->data_blocks = num_ll; | |
1084 | ||
1085 | if (ti->len > (v->data_blocks << (v->data_dev_block_bits - SECTOR_SHIFT))) { | |
1086 | ti->error = "Data device is too small"; | |
1087 | r = -EINVAL; | |
1088 | goto bad; | |
1089 | } | |
1090 | ||
1091 | if (sscanf(argv[6], "%llu%c", &num_ll, &dummy) != 1 || | |
1d55f6bc MP |
1092 | (sector_t)(num_ll << (v->hash_dev_block_bits - SECTOR_SHIFT)) |
1093 | >> (v->hash_dev_block_bits - SECTOR_SHIFT) != num_ll) { | |
a4ffc152 MP |
1094 | ti->error = "Invalid hash start"; |
1095 | r = -EINVAL; | |
1096 | goto bad; | |
1097 | } | |
1098 | v->hash_start = num_ll; | |
1099 | ||
1100 | v->alg_name = kstrdup(argv[7], GFP_KERNEL); | |
1101 | if (!v->alg_name) { | |
1102 | ti->error = "Cannot allocate algorithm name"; | |
1103 | r = -ENOMEM; | |
1104 | goto bad; | |
1105 | } | |
1106 | ||
d1ac3ff0 | 1107 | v->tfm = crypto_alloc_ahash(v->alg_name, 0, 0); |
a4ffc152 MP |
1108 | if (IS_ERR(v->tfm)) { |
1109 | ti->error = "Cannot initialize hash function"; | |
1110 | r = PTR_ERR(v->tfm); | |
1111 | v->tfm = NULL; | |
1112 | goto bad; | |
1113 | } | |
bbf6a566 EB |
1114 | |
1115 | /* | |
1116 | * dm-verity performance can vary greatly depending on which hash | |
1117 | * algorithm implementation is used. Help people debug performance | |
1118 | * problems by logging the ->cra_driver_name. | |
1119 | */ | |
1120 | DMINFO("%s using implementation \"%s\"", v->alg_name, | |
1121 | crypto_hash_alg_common(v->tfm)->base.cra_driver_name); | |
1122 | ||
d1ac3ff0 | 1123 | v->digest_size = crypto_ahash_digestsize(v->tfm); |
a4ffc152 MP |
1124 | if ((1 << v->hash_dev_block_bits) < v->digest_size * 2) { |
1125 | ti->error = "Digest size too big"; | |
1126 | r = -EINVAL; | |
1127 | goto bad; | |
1128 | } | |
d1ac3ff0 GBY |
1129 | v->ahash_reqsize = sizeof(struct ahash_request) + |
1130 | crypto_ahash_reqsize(v->tfm); | |
a4ffc152 MP |
1131 | |
1132 | v->root_digest = kmalloc(v->digest_size, GFP_KERNEL); | |
1133 | if (!v->root_digest) { | |
1134 | ti->error = "Cannot allocate root digest"; | |
1135 | r = -ENOMEM; | |
1136 | goto bad; | |
1137 | } | |
1138 | if (strlen(argv[8]) != v->digest_size * 2 || | |
1139 | hex2bin(v->root_digest, argv[8], v->digest_size)) { | |
1140 | ti->error = "Invalid root digest"; | |
1141 | r = -EINVAL; | |
1142 | goto bad; | |
1143 | } | |
88cd3e6c | 1144 | root_hash_digest_to_validate = argv[8]; |
a4ffc152 MP |
1145 | |
1146 | if (strcmp(argv[9], "-")) { | |
1147 | v->salt_size = strlen(argv[9]) / 2; | |
1148 | v->salt = kmalloc(v->salt_size, GFP_KERNEL); | |
1149 | if (!v->salt) { | |
1150 | ti->error = "Cannot allocate salt"; | |
1151 | r = -ENOMEM; | |
1152 | goto bad; | |
1153 | } | |
1154 | if (strlen(argv[9]) != v->salt_size * 2 || | |
1155 | hex2bin(v->salt, argv[9], v->salt_size)) { | |
1156 | ti->error = "Invalid salt"; | |
1157 | r = -EINVAL; | |
1158 | goto bad; | |
1159 | } | |
1160 | } | |
1161 | ||
65ff5b7d ST |
1162 | argv += 10; |
1163 | argc -= 10; | |
1164 | ||
1165 | /* Optional parameters */ | |
1166 | if (argc) { | |
1167 | as.argc = argc; | |
1168 | as.argv = argv; | |
1169 | ||
88cd3e6c | 1170 | r = verity_parse_opt_args(&as, v, &verify_args); |
753c1fd0 | 1171 | if (r < 0) |
65ff5b7d | 1172 | goto bad; |
65ff5b7d ST |
1173 | } |
1174 | ||
88cd3e6c JK |
1175 | /* Root hash signature is a optional parameter*/ |
1176 | r = verity_verify_root_hash(root_hash_digest_to_validate, | |
1177 | strlen(root_hash_digest_to_validate), | |
1178 | verify_args.sig, | |
1179 | verify_args.sig_size); | |
1180 | if (r < 0) { | |
1181 | ti->error = "Root hash verification failed"; | |
1182 | goto bad; | |
1183 | } | |
a4ffc152 | 1184 | v->hash_per_block_bits = |
553d8fe0 | 1185 | __fls((1 << v->hash_dev_block_bits) / v->digest_size); |
a4ffc152 MP |
1186 | |
1187 | v->levels = 0; | |
1188 | if (v->data_blocks) | |
1189 | while (v->hash_per_block_bits * v->levels < 64 && | |
1190 | (unsigned long long)(v->data_blocks - 1) >> | |
1191 | (v->hash_per_block_bits * v->levels)) | |
1192 | v->levels++; | |
1193 | ||
1194 | if (v->levels > DM_VERITY_MAX_LEVELS) { | |
1195 | ti->error = "Too many tree levels"; | |
1196 | r = -E2BIG; | |
1197 | goto bad; | |
1198 | } | |
1199 | ||
1200 | hash_position = v->hash_start; | |
1201 | for (i = v->levels - 1; i >= 0; i--) { | |
1202 | sector_t s; | |
1203 | v->hash_level_block[i] = hash_position; | |
b1bf2de0 MP |
1204 | s = (v->data_blocks + ((sector_t)1 << ((i + 1) * v->hash_per_block_bits)) - 1) |
1205 | >> ((i + 1) * v->hash_per_block_bits); | |
a4ffc152 MP |
1206 | if (hash_position + s < hash_position) { |
1207 | ti->error = "Hash device offset overflow"; | |
1208 | r = -E2BIG; | |
1209 | goto bad; | |
1210 | } | |
1211 | hash_position += s; | |
1212 | } | |
1213 | v->hash_blocks = hash_position; | |
1214 | ||
1215 | v->bufio = dm_bufio_client_create(v->hash_dev->bdev, | |
1216 | 1 << v->hash_dev_block_bits, 1, sizeof(struct buffer_aux), | |
1217 | dm_bufio_alloc_callback, NULL); | |
1218 | if (IS_ERR(v->bufio)) { | |
1219 | ti->error = "Cannot initialize dm-bufio"; | |
1220 | r = PTR_ERR(v->bufio); | |
1221 | v->bufio = NULL; | |
1222 | goto bad; | |
1223 | } | |
1224 | ||
1225 | if (dm_bufio_get_device_size(v->bufio) < v->hash_blocks) { | |
1226 | ti->error = "Hash device is too small"; | |
1227 | r = -E2BIG; | |
1228 | goto bad; | |
1229 | } | |
1230 | ||
a4ffc152 MP |
1231 | /* WQ_UNBOUND greatly improves performance when running on ramdisk */ |
1232 | v->verify_wq = alloc_workqueue("kverityd", WQ_CPU_INTENSIVE | WQ_MEM_RECLAIM | WQ_UNBOUND, num_online_cpus()); | |
1233 | if (!v->verify_wq) { | |
1234 | ti->error = "Cannot allocate workqueue"; | |
1235 | r = -ENOMEM; | |
1236 | goto bad; | |
1237 | } | |
1238 | ||
30187e1d | 1239 | ti->per_io_data_size = sizeof(struct dm_verity_io) + |
d1ac3ff0 | 1240 | v->ahash_reqsize + v->digest_size * 2; |
a739ff3f ST |
1241 | |
1242 | r = verity_fec_ctr(v); | |
1243 | if (r) | |
1244 | goto bad; | |
1245 | ||
30187e1d MS |
1246 | ti->per_io_data_size = roundup(ti->per_io_data_size, |
1247 | __alignof__(struct dm_verity_io)); | |
a739ff3f | 1248 | |
88cd3e6c JK |
1249 | verity_verify_sig_opts_cleanup(&verify_args); |
1250 | ||
a4ffc152 MP |
1251 | return 0; |
1252 | ||
1253 | bad: | |
88cd3e6c JK |
1254 | |
1255 | verity_verify_sig_opts_cleanup(&verify_args); | |
a4ffc152 MP |
1256 | verity_dtr(ti); |
1257 | ||
1258 | return r; | |
1259 | } | |
1260 | ||
1261 | static struct target_type verity_target = { | |
1262 | .name = "verity", | |
219a9b5e | 1263 | .version = {1, 8, 0}, |
a4ffc152 MP |
1264 | .module = THIS_MODULE, |
1265 | .ctr = verity_ctr, | |
1266 | .dtr = verity_dtr, | |
1267 | .map = verity_map, | |
1268 | .status = verity_status, | |
e56f81e0 | 1269 | .prepare_ioctl = verity_prepare_ioctl, |
a4ffc152 MP |
1270 | .iterate_devices = verity_iterate_devices, |
1271 | .io_hints = verity_io_hints, | |
1272 | }; | |
1273 | ||
1274 | static int __init dm_verity_init(void) | |
1275 | { | |
1276 | int r; | |
1277 | ||
1278 | r = dm_register_target(&verity_target); | |
1279 | if (r < 0) | |
1280 | DMERR("register failed %d", r); | |
1281 | ||
1282 | return r; | |
1283 | } | |
1284 | ||
1285 | static void __exit dm_verity_exit(void) | |
1286 | { | |
1287 | dm_unregister_target(&verity_target); | |
1288 | } | |
1289 | ||
1290 | module_init(dm_verity_init); | |
1291 | module_exit(dm_verity_exit); | |
1292 | ||
1293 | MODULE_AUTHOR("Mikulas Patocka <mpatocka@redhat.com>"); | |
1294 | MODULE_AUTHOR("Mandeep Baines <msb@chromium.org>"); | |
1295 | MODULE_AUTHOR("Will Drewry <wad@chromium.org>"); | |
1296 | MODULE_DESCRIPTION(DM_NAME " target for transparent disk integrity checking"); | |
1297 | MODULE_LICENSE("GPL"); |