1 /* 2 * Copyright (C) 2003 Jana Saout <jana@saout.de> 3 * Copyright (C) 2004 Clemens Fruhwirth <clemens@endorphin.org> 4 * Copyright (C) 2006-2020 Red Hat, Inc. All rights reserved. 5 * Copyright (C) 2013-2020 Milan Broz <gmazyland@gmail.com> 6 * 7 * This file is released under the GPL. 8 */ 9 10 #include <linux/completion.h> 11 #include <linux/err.h> 12 #include <linux/module.h> 13 #include <linux/init.h> 14 #include <linux/kernel.h> 15 #include <linux/key.h> 16 #include <linux/bio.h> 17 #include <linux/blkdev.h> 18 #include <linux/mempool.h> 19 #include <linux/slab.h> 20 #include <linux/crypto.h> 21 #include <linux/workqueue.h> 22 #include <linux/kthread.h> 23 #include <linux/backing-dev.h> 24 #include <linux/atomic.h> 25 #include <linux/scatterlist.h> 26 #include <linux/rbtree.h> 27 #include <linux/ctype.h> 28 #include <asm/page.h> 29 #include <asm/unaligned.h> 30 #include <crypto/hash.h> 31 #include <crypto/md5.h> 32 #include <crypto/algapi.h> 33 #include <crypto/skcipher.h> 34 #include <crypto/aead.h> 35 #include <crypto/authenc.h> 36 #include <linux/rtnetlink.h> /* for struct rtattr and RTA macros only */ 37 #include <linux/key-type.h> 38 #include <keys/user-type.h> 39 #include <keys/encrypted-type.h> 40 #include <keys/trusted-type.h> 41 42 #include <linux/device-mapper.h> 43 44 #define DM_MSG_PREFIX "crypt" 45 46 /* 47 * context holding the current state of a multi-part conversion 48 */ 49 struct convert_context { 50 struct completion restart; 51 struct bio *bio_in; 52 struct bio *bio_out; 53 struct bvec_iter iter_in; 54 struct bvec_iter iter_out; 55 u64 cc_sector; 56 atomic_t cc_pending; 57 union { 58 struct skcipher_request *req; 59 struct aead_request *req_aead; 60 } r; 61 62 }; 63 64 /* 65 * per bio private data 66 */ 67 struct dm_crypt_io { 68 struct crypt_config *cc; 69 struct bio *base_bio; 70 u8 *integrity_metadata; 71 bool integrity_metadata_from_pool; 72 struct work_struct work; 73 struct tasklet_struct tasklet; 74 75 struct convert_context ctx; 76 77 atomic_t io_pending; 78 blk_status_t error; 79 sector_t sector; 80 81 struct rb_node rb_node; 82 } CRYPTO_MINALIGN_ATTR; 83 84 struct dm_crypt_request { 85 struct convert_context *ctx; 86 struct scatterlist sg_in[4]; 87 struct scatterlist sg_out[4]; 88 u64 iv_sector; 89 }; 90 91 struct crypt_config; 92 93 struct crypt_iv_operations { 94 int (*ctr)(struct crypt_config *cc, struct dm_target *ti, 95 const char *opts); 96 void (*dtr)(struct crypt_config *cc); 97 int (*init)(struct crypt_config *cc); 98 int (*wipe)(struct crypt_config *cc); 99 int (*generator)(struct crypt_config *cc, u8 *iv, 100 struct dm_crypt_request *dmreq); 101 int (*post)(struct crypt_config *cc, u8 *iv, 102 struct dm_crypt_request *dmreq); 103 }; 104 105 struct iv_benbi_private { 106 int shift; 107 }; 108 109 #define LMK_SEED_SIZE 64 /* hash + 0 */ 110 struct iv_lmk_private { 111 struct crypto_shash *hash_tfm; 112 u8 *seed; 113 }; 114 115 #define TCW_WHITENING_SIZE 16 116 struct iv_tcw_private { 117 struct crypto_shash *crc32_tfm; 118 u8 *iv_seed; 119 u8 *whitening; 120 }; 121 122 #define ELEPHANT_MAX_KEY_SIZE 32 123 struct iv_elephant_private { 124 struct crypto_skcipher *tfm; 125 }; 126 127 /* 128 * Crypt: maps a linear range of a block device 129 * and encrypts / decrypts at the same time. 130 */ 131 enum flags { DM_CRYPT_SUSPENDED, DM_CRYPT_KEY_VALID, 132 DM_CRYPT_SAME_CPU, DM_CRYPT_NO_OFFLOAD, 133 DM_CRYPT_NO_READ_WORKQUEUE, DM_CRYPT_NO_WRITE_WORKQUEUE, 134 DM_CRYPT_WRITE_INLINE }; 135 136 enum cipher_flags { 137 CRYPT_MODE_INTEGRITY_AEAD, /* Use authenticated mode for cipher */ 138 CRYPT_IV_LARGE_SECTORS, /* Calculate IV from sector_size, not 512B sectors */ 139 CRYPT_ENCRYPT_PREPROCESS, /* Must preprocess data for encryption (elephant) */ 140 }; 141 142 /* 143 * The fields in here must be read only after initialization. 144 */ 145 struct crypt_config { 146 struct dm_dev *dev; 147 sector_t start; 148 149 struct percpu_counter n_allocated_pages; 150 151 struct workqueue_struct *io_queue; 152 struct workqueue_struct *crypt_queue; 153 154 spinlock_t write_thread_lock; 155 struct task_struct *write_thread; 156 struct rb_root write_tree; 157 158 char *cipher_string; 159 char *cipher_auth; 160 char *key_string; 161 162 const struct crypt_iv_operations *iv_gen_ops; 163 union { 164 struct iv_benbi_private benbi; 165 struct iv_lmk_private lmk; 166 struct iv_tcw_private tcw; 167 struct iv_elephant_private elephant; 168 } iv_gen_private; 169 u64 iv_offset; 170 unsigned int iv_size; 171 unsigned short int sector_size; 172 unsigned char sector_shift; 173 174 union { 175 struct crypto_skcipher **tfms; 176 struct crypto_aead **tfms_aead; 177 } cipher_tfm; 178 unsigned tfms_count; 179 unsigned long cipher_flags; 180 181 /* 182 * Layout of each crypto request: 183 * 184 * struct skcipher_request 185 * context 186 * padding 187 * struct dm_crypt_request 188 * padding 189 * IV 190 * 191 * The padding is added so that dm_crypt_request and the IV are 192 * correctly aligned. 193 */ 194 unsigned int dmreq_start; 195 196 unsigned int per_bio_data_size; 197 198 unsigned long flags; 199 unsigned int key_size; 200 unsigned int key_parts; /* independent parts in key buffer */ 201 unsigned int key_extra_size; /* additional keys length */ 202 unsigned int key_mac_size; /* MAC key size for authenc(...) */ 203 204 unsigned int integrity_tag_size; 205 unsigned int integrity_iv_size; 206 unsigned int on_disk_tag_size; 207 208 /* 209 * pool for per bio private data, crypto requests, 210 * encryption requeusts/buffer pages and integrity tags 211 */ 212 unsigned tag_pool_max_sectors; 213 mempool_t tag_pool; 214 mempool_t req_pool; 215 mempool_t page_pool; 216 217 struct bio_set bs; 218 struct mutex bio_alloc_lock; 219 220 u8 *authenc_key; /* space for keys in authenc() format (if used) */ 221 u8 key[]; 222 }; 223 224 #define MIN_IOS 64 225 #define MAX_TAG_SIZE 480 226 #define POOL_ENTRY_SIZE 512 227 228 static DEFINE_SPINLOCK(dm_crypt_clients_lock); 229 static unsigned dm_crypt_clients_n = 0; 230 static volatile unsigned long dm_crypt_pages_per_client; 231 #define DM_CRYPT_MEMORY_PERCENT 2 232 #define DM_CRYPT_MIN_PAGES_PER_CLIENT (BIO_MAX_VECS * 16) 233 234 static void clone_init(struct dm_crypt_io *, struct bio *); 235 static void kcryptd_queue_crypt(struct dm_crypt_io *io); 236 static struct scatterlist *crypt_get_sg_data(struct crypt_config *cc, 237 struct scatterlist *sg); 238 239 static bool crypt_integrity_aead(struct crypt_config *cc); 240 241 /* 242 * Use this to access cipher attributes that are independent of the key. 243 */ 244 static struct crypto_skcipher *any_tfm(struct crypt_config *cc) 245 { 246 return cc->cipher_tfm.tfms[0]; 247 } 248 249 static struct crypto_aead *any_tfm_aead(struct crypt_config *cc) 250 { 251 return cc->cipher_tfm.tfms_aead[0]; 252 } 253 254 /* 255 * Different IV generation algorithms: 256 * 257 * plain: the initial vector is the 32-bit little-endian version of the sector 258 * number, padded with zeros if necessary. 259 * 260 * plain64: the initial vector is the 64-bit little-endian version of the sector 261 * number, padded with zeros if necessary. 262 * 263 * plain64be: the initial vector is the 64-bit big-endian version of the sector 264 * number, padded with zeros if necessary. 265 * 266 * essiv: "encrypted sector|salt initial vector", the sector number is 267 * encrypted with the bulk cipher using a salt as key. The salt 268 * should be derived from the bulk cipher's key via hashing. 269 * 270 * benbi: the 64-bit "big-endian 'narrow block'-count", starting at 1 271 * (needed for LRW-32-AES and possible other narrow block modes) 272 * 273 * null: the initial vector is always zero. Provides compatibility with 274 * obsolete loop_fish2 devices. Do not use for new devices. 275 * 276 * lmk: Compatible implementation of the block chaining mode used 277 * by the Loop-AES block device encryption system 278 * designed by Jari Ruusu. See http://loop-aes.sourceforge.net/ 279 * It operates on full 512 byte sectors and uses CBC 280 * with an IV derived from the sector number, the data and 281 * optionally extra IV seed. 282 * This means that after decryption the first block 283 * of sector must be tweaked according to decrypted data. 284 * Loop-AES can use three encryption schemes: 285 * version 1: is plain aes-cbc mode 286 * version 2: uses 64 multikey scheme with lmk IV generator 287 * version 3: the same as version 2 with additional IV seed 288 * (it uses 65 keys, last key is used as IV seed) 289 * 290 * tcw: Compatible implementation of the block chaining mode used 291 * by the TrueCrypt device encryption system (prior to version 4.1). 292 * For more info see: https://gitlab.com/cryptsetup/cryptsetup/wikis/TrueCryptOnDiskFormat 293 * It operates on full 512 byte sectors and uses CBC 294 * with an IV derived from initial key and the sector number. 295 * In addition, whitening value is applied on every sector, whitening 296 * is calculated from initial key, sector number and mixed using CRC32. 297 * Note that this encryption scheme is vulnerable to watermarking attacks 298 * and should be used for old compatible containers access only. 299 * 300 * eboiv: Encrypted byte-offset IV (used in Bitlocker in CBC mode) 301 * The IV is encrypted little-endian byte-offset (with the same key 302 * and cipher as the volume). 303 * 304 * elephant: The extended version of eboiv with additional Elephant diffuser 305 * used with Bitlocker CBC mode. 306 * This mode was used in older Windows systems 307 * https://download.microsoft.com/download/0/2/3/0238acaf-d3bf-4a6d-b3d6-0a0be4bbb36e/bitlockercipher200608.pdf 308 */ 309 310 static int crypt_iv_plain_gen(struct crypt_config *cc, u8 *iv, 311 struct dm_crypt_request *dmreq) 312 { 313 memset(iv, 0, cc->iv_size); 314 *(__le32 *)iv = cpu_to_le32(dmreq->iv_sector & 0xffffffff); 315 316 return 0; 317 } 318 319 static int crypt_iv_plain64_gen(struct crypt_config *cc, u8 *iv, 320 struct dm_crypt_request *dmreq) 321 { 322 memset(iv, 0, cc->iv_size); 323 *(__le64 *)iv = cpu_to_le64(dmreq->iv_sector); 324 325 return 0; 326 } 327 328 static int crypt_iv_plain64be_gen(struct crypt_config *cc, u8 *iv, 329 struct dm_crypt_request *dmreq) 330 { 331 memset(iv, 0, cc->iv_size); 332 /* iv_size is at least of size u64; usually it is 16 bytes */ 333 *(__be64 *)&iv[cc->iv_size - sizeof(u64)] = cpu_to_be64(dmreq->iv_sector); 334 335 return 0; 336 } 337 338 static int crypt_iv_essiv_gen(struct crypt_config *cc, u8 *iv, 339 struct dm_crypt_request *dmreq) 340 { 341 /* 342 * ESSIV encryption of the IV is now handled by the crypto API, 343 * so just pass the plain sector number here. 344 */ 345 memset(iv, 0, cc->iv_size); 346 *(__le64 *)iv = cpu_to_le64(dmreq->iv_sector); 347 348 return 0; 349 } 350 351 static int crypt_iv_benbi_ctr(struct crypt_config *cc, struct dm_target *ti, 352 const char *opts) 353 { 354 unsigned bs; 355 int log; 356 357 if (crypt_integrity_aead(cc)) 358 bs = crypto_aead_blocksize(any_tfm_aead(cc)); 359 else 360 bs = crypto_skcipher_blocksize(any_tfm(cc)); 361 log = ilog2(bs); 362 363 /* we need to calculate how far we must shift the sector count 364 * to get the cipher block count, we use this shift in _gen */ 365 366 if (1 << log != bs) { 367 ti->error = "cypher blocksize is not a power of 2"; 368 return -EINVAL; 369 } 370 371 if (log > 9) { 372 ti->error = "cypher blocksize is > 512"; 373 return -EINVAL; 374 } 375 376 cc->iv_gen_private.benbi.shift = 9 - log; 377 378 return 0; 379 } 380 381 static void crypt_iv_benbi_dtr(struct crypt_config *cc) 382 { 383 } 384 385 static int crypt_iv_benbi_gen(struct crypt_config *cc, u8 *iv, 386 struct dm_crypt_request *dmreq) 387 { 388 __be64 val; 389 390 memset(iv, 0, cc->iv_size - sizeof(u64)); /* rest is cleared below */ 391 392 val = cpu_to_be64(((u64)dmreq->iv_sector << cc->iv_gen_private.benbi.shift) + 1); 393 put_unaligned(val, (__be64 *)(iv + cc->iv_size - sizeof(u64))); 394 395 return 0; 396 } 397 398 static int crypt_iv_null_gen(struct crypt_config *cc, u8 *iv, 399 struct dm_crypt_request *dmreq) 400 { 401 memset(iv, 0, cc->iv_size); 402 403 return 0; 404 } 405 406 static void crypt_iv_lmk_dtr(struct crypt_config *cc) 407 { 408 struct iv_lmk_private *lmk = &cc->iv_gen_private.lmk; 409 410 if (lmk->hash_tfm && !IS_ERR(lmk->hash_tfm)) 411 crypto_free_shash(lmk->hash_tfm); 412 lmk->hash_tfm = NULL; 413 414 kfree_sensitive(lmk->seed); 415 lmk->seed = NULL; 416 } 417 418 static int crypt_iv_lmk_ctr(struct crypt_config *cc, struct dm_target *ti, 419 const char *opts) 420 { 421 struct iv_lmk_private *lmk = &cc->iv_gen_private.lmk; 422 423 if (cc->sector_size != (1 << SECTOR_SHIFT)) { 424 ti->error = "Unsupported sector size for LMK"; 425 return -EINVAL; 426 } 427 428 lmk->hash_tfm = crypto_alloc_shash("md5", 0, 429 CRYPTO_ALG_ALLOCATES_MEMORY); 430 if (IS_ERR(lmk->hash_tfm)) { 431 ti->error = "Error initializing LMK hash"; 432 return PTR_ERR(lmk->hash_tfm); 433 } 434 435 /* No seed in LMK version 2 */ 436 if (cc->key_parts == cc->tfms_count) { 437 lmk->seed = NULL; 438 return 0; 439 } 440 441 lmk->seed = kzalloc(LMK_SEED_SIZE, GFP_KERNEL); 442 if (!lmk->seed) { 443 crypt_iv_lmk_dtr(cc); 444 ti->error = "Error kmallocing seed storage in LMK"; 445 return -ENOMEM; 446 } 447 448 return 0; 449 } 450 451 static int crypt_iv_lmk_init(struct crypt_config *cc) 452 { 453 struct iv_lmk_private *lmk = &cc->iv_gen_private.lmk; 454 int subkey_size = cc->key_size / cc->key_parts; 455 456 /* LMK seed is on the position of LMK_KEYS + 1 key */ 457 if (lmk->seed) 458 memcpy(lmk->seed, cc->key + (cc->tfms_count * subkey_size), 459 crypto_shash_digestsize(lmk->hash_tfm)); 460 461 return 0; 462 } 463 464 static int crypt_iv_lmk_wipe(struct crypt_config *cc) 465 { 466 struct iv_lmk_private *lmk = &cc->iv_gen_private.lmk; 467 468 if (lmk->seed) 469 memset(lmk->seed, 0, LMK_SEED_SIZE); 470 471 return 0; 472 } 473 474 static int crypt_iv_lmk_one(struct crypt_config *cc, u8 *iv, 475 struct dm_crypt_request *dmreq, 476 u8 *data) 477 { 478 struct iv_lmk_private *lmk = &cc->iv_gen_private.lmk; 479 SHASH_DESC_ON_STACK(desc, lmk->hash_tfm); 480 struct md5_state md5state; 481 __le32 buf[4]; 482 int i, r; 483 484 desc->tfm = lmk->hash_tfm; 485 486 r = crypto_shash_init(desc); 487 if (r) 488 return r; 489 490 if (lmk->seed) { 491 r = crypto_shash_update(desc, lmk->seed, LMK_SEED_SIZE); 492 if (r) 493 return r; 494 } 495 496 /* Sector is always 512B, block size 16, add data of blocks 1-31 */ 497 r = crypto_shash_update(desc, data + 16, 16 * 31); 498 if (r) 499 return r; 500 501 /* Sector is cropped to 56 bits here */ 502 buf[0] = cpu_to_le32(dmreq->iv_sector & 0xFFFFFFFF); 503 buf[1] = cpu_to_le32((((u64)dmreq->iv_sector >> 32) & 0x00FFFFFF) | 0x80000000); 504 buf[2] = cpu_to_le32(4024); 505 buf[3] = 0; 506 r = crypto_shash_update(desc, (u8 *)buf, sizeof(buf)); 507 if (r) 508 return r; 509 510 /* No MD5 padding here */ 511 r = crypto_shash_export(desc, &md5state); 512 if (r) 513 return r; 514 515 for (i = 0; i < MD5_HASH_WORDS; i++) 516 __cpu_to_le32s(&md5state.hash[i]); 517 memcpy(iv, &md5state.hash, cc->iv_size); 518 519 return 0; 520 } 521 522 static int crypt_iv_lmk_gen(struct crypt_config *cc, u8 *iv, 523 struct dm_crypt_request *dmreq) 524 { 525 struct scatterlist *sg; 526 u8 *src; 527 int r = 0; 528 529 if (bio_data_dir(dmreq->ctx->bio_in) == WRITE) { 530 sg = crypt_get_sg_data(cc, dmreq->sg_in); 531 src = kmap_atomic(sg_page(sg)); 532 r = crypt_iv_lmk_one(cc, iv, dmreq, src + sg->offset); 533 kunmap_atomic(src); 534 } else 535 memset(iv, 0, cc->iv_size); 536 537 return r; 538 } 539 540 static int crypt_iv_lmk_post(struct crypt_config *cc, u8 *iv, 541 struct dm_crypt_request *dmreq) 542 { 543 struct scatterlist *sg; 544 u8 *dst; 545 int r; 546 547 if (bio_data_dir(dmreq->ctx->bio_in) == WRITE) 548 return 0; 549 550 sg = crypt_get_sg_data(cc, dmreq->sg_out); 551 dst = kmap_atomic(sg_page(sg)); 552 r = crypt_iv_lmk_one(cc, iv, dmreq, dst + sg->offset); 553 554 /* Tweak the first block of plaintext sector */ 555 if (!r) 556 crypto_xor(dst + sg->offset, iv, cc->iv_size); 557 558 kunmap_atomic(dst); 559 return r; 560 } 561 562 static void crypt_iv_tcw_dtr(struct crypt_config *cc) 563 { 564 struct iv_tcw_private *tcw = &cc->iv_gen_private.tcw; 565 566 kfree_sensitive(tcw->iv_seed); 567 tcw->iv_seed = NULL; 568 kfree_sensitive(tcw->whitening); 569 tcw->whitening = NULL; 570 571 if (tcw->crc32_tfm && !IS_ERR(tcw->crc32_tfm)) 572 crypto_free_shash(tcw->crc32_tfm); 573 tcw->crc32_tfm = NULL; 574 } 575 576 static int crypt_iv_tcw_ctr(struct crypt_config *cc, struct dm_target *ti, 577 const char *opts) 578 { 579 struct iv_tcw_private *tcw = &cc->iv_gen_private.tcw; 580 581 if (cc->sector_size != (1 << SECTOR_SHIFT)) { 582 ti->error = "Unsupported sector size for TCW"; 583 return -EINVAL; 584 } 585 586 if (cc->key_size <= (cc->iv_size + TCW_WHITENING_SIZE)) { 587 ti->error = "Wrong key size for TCW"; 588 return -EINVAL; 589 } 590 591 tcw->crc32_tfm = crypto_alloc_shash("crc32", 0, 592 CRYPTO_ALG_ALLOCATES_MEMORY); 593 if (IS_ERR(tcw->crc32_tfm)) { 594 ti->error = "Error initializing CRC32 in TCW"; 595 return PTR_ERR(tcw->crc32_tfm); 596 } 597 598 tcw->iv_seed = kzalloc(cc->iv_size, GFP_KERNEL); 599 tcw->whitening = kzalloc(TCW_WHITENING_SIZE, GFP_KERNEL); 600 if (!tcw->iv_seed || !tcw->whitening) { 601 crypt_iv_tcw_dtr(cc); 602 ti->error = "Error allocating seed storage in TCW"; 603 return -ENOMEM; 604 } 605 606 return 0; 607 } 608 609 static int crypt_iv_tcw_init(struct crypt_config *cc) 610 { 611 struct iv_tcw_private *tcw = &cc->iv_gen_private.tcw; 612 int key_offset = cc->key_size - cc->iv_size - TCW_WHITENING_SIZE; 613 614 memcpy(tcw->iv_seed, &cc->key[key_offset], cc->iv_size); 615 memcpy(tcw->whitening, &cc->key[key_offset + cc->iv_size], 616 TCW_WHITENING_SIZE); 617 618 return 0; 619 } 620 621 static int crypt_iv_tcw_wipe(struct crypt_config *cc) 622 { 623 struct iv_tcw_private *tcw = &cc->iv_gen_private.tcw; 624 625 memset(tcw->iv_seed, 0, cc->iv_size); 626 memset(tcw->whitening, 0, TCW_WHITENING_SIZE); 627 628 return 0; 629 } 630 631 static int crypt_iv_tcw_whitening(struct crypt_config *cc, 632 struct dm_crypt_request *dmreq, 633 u8 *data) 634 { 635 struct iv_tcw_private *tcw = &cc->iv_gen_private.tcw; 636 __le64 sector = cpu_to_le64(dmreq->iv_sector); 637 u8 buf[TCW_WHITENING_SIZE]; 638 SHASH_DESC_ON_STACK(desc, tcw->crc32_tfm); 639 int i, r; 640 641 /* xor whitening with sector number */ 642 crypto_xor_cpy(buf, tcw->whitening, (u8 *)§or, 8); 643 crypto_xor_cpy(&buf[8], tcw->whitening + 8, (u8 *)§or, 8); 644 645 /* calculate crc32 for every 32bit part and xor it */ 646 desc->tfm = tcw->crc32_tfm; 647 for (i = 0; i < 4; i++) { 648 r = crypto_shash_init(desc); 649 if (r) 650 goto out; 651 r = crypto_shash_update(desc, &buf[i * 4], 4); 652 if (r) 653 goto out; 654 r = crypto_shash_final(desc, &buf[i * 4]); 655 if (r) 656 goto out; 657 } 658 crypto_xor(&buf[0], &buf[12], 4); 659 crypto_xor(&buf[4], &buf[8], 4); 660 661 /* apply whitening (8 bytes) to whole sector */ 662 for (i = 0; i < ((1 << SECTOR_SHIFT) / 8); i++) 663 crypto_xor(data + i * 8, buf, 8); 664 out: 665 memzero_explicit(buf, sizeof(buf)); 666 return r; 667 } 668 669 static int crypt_iv_tcw_gen(struct crypt_config *cc, u8 *iv, 670 struct dm_crypt_request *dmreq) 671 { 672 struct scatterlist *sg; 673 struct iv_tcw_private *tcw = &cc->iv_gen_private.tcw; 674 __le64 sector = cpu_to_le64(dmreq->iv_sector); 675 u8 *src; 676 int r = 0; 677 678 /* Remove whitening from ciphertext */ 679 if (bio_data_dir(dmreq->ctx->bio_in) != WRITE) { 680 sg = crypt_get_sg_data(cc, dmreq->sg_in); 681 src = kmap_atomic(sg_page(sg)); 682 r = crypt_iv_tcw_whitening(cc, dmreq, src + sg->offset); 683 kunmap_atomic(src); 684 } 685 686 /* Calculate IV */ 687 crypto_xor_cpy(iv, tcw->iv_seed, (u8 *)§or, 8); 688 if (cc->iv_size > 8) 689 crypto_xor_cpy(&iv[8], tcw->iv_seed + 8, (u8 *)§or, 690 cc->iv_size - 8); 691 692 return r; 693 } 694 695 static int crypt_iv_tcw_post(struct crypt_config *cc, u8 *iv, 696 struct dm_crypt_request *dmreq) 697 { 698 struct scatterlist *sg; 699 u8 *dst; 700 int r; 701 702 if (bio_data_dir(dmreq->ctx->bio_in) != WRITE) 703 return 0; 704 705 /* Apply whitening on ciphertext */ 706 sg = crypt_get_sg_data(cc, dmreq->sg_out); 707 dst = kmap_atomic(sg_page(sg)); 708 r = crypt_iv_tcw_whitening(cc, dmreq, dst + sg->offset); 709 kunmap_atomic(dst); 710 711 return r; 712 } 713 714 static int crypt_iv_random_gen(struct crypt_config *cc, u8 *iv, 715 struct dm_crypt_request *dmreq) 716 { 717 /* Used only for writes, there must be an additional space to store IV */ 718 get_random_bytes(iv, cc->iv_size); 719 return 0; 720 } 721 722 static int crypt_iv_eboiv_ctr(struct crypt_config *cc, struct dm_target *ti, 723 const char *opts) 724 { 725 if (crypt_integrity_aead(cc)) { 726 ti->error = "AEAD transforms not supported for EBOIV"; 727 return -EINVAL; 728 } 729 730 if (crypto_skcipher_blocksize(any_tfm(cc)) != cc->iv_size) { 731 ti->error = "Block size of EBOIV cipher does " 732 "not match IV size of block cipher"; 733 return -EINVAL; 734 } 735 736 return 0; 737 } 738 739 static int crypt_iv_eboiv_gen(struct crypt_config *cc, u8 *iv, 740 struct dm_crypt_request *dmreq) 741 { 742 u8 buf[MAX_CIPHER_BLOCKSIZE] __aligned(__alignof__(__le64)); 743 struct skcipher_request *req; 744 struct scatterlist src, dst; 745 DECLARE_CRYPTO_WAIT(wait); 746 int err; 747 748 req = skcipher_request_alloc(any_tfm(cc), GFP_NOIO); 749 if (!req) 750 return -ENOMEM; 751 752 memset(buf, 0, cc->iv_size); 753 *(__le64 *)buf = cpu_to_le64(dmreq->iv_sector * cc->sector_size); 754 755 sg_init_one(&src, page_address(ZERO_PAGE(0)), cc->iv_size); 756 sg_init_one(&dst, iv, cc->iv_size); 757 skcipher_request_set_crypt(req, &src, &dst, cc->iv_size, buf); 758 skcipher_request_set_callback(req, 0, crypto_req_done, &wait); 759 err = crypto_wait_req(crypto_skcipher_encrypt(req), &wait); 760 skcipher_request_free(req); 761 762 return err; 763 } 764 765 static void crypt_iv_elephant_dtr(struct crypt_config *cc) 766 { 767 struct iv_elephant_private *elephant = &cc->iv_gen_private.elephant; 768 769 crypto_free_skcipher(elephant->tfm); 770 elephant->tfm = NULL; 771 } 772 773 static int crypt_iv_elephant_ctr(struct crypt_config *cc, struct dm_target *ti, 774 const char *opts) 775 { 776 struct iv_elephant_private *elephant = &cc->iv_gen_private.elephant; 777 int r; 778 779 elephant->tfm = crypto_alloc_skcipher("ecb(aes)", 0, 780 CRYPTO_ALG_ALLOCATES_MEMORY); 781 if (IS_ERR(elephant->tfm)) { 782 r = PTR_ERR(elephant->tfm); 783 elephant->tfm = NULL; 784 return r; 785 } 786 787 r = crypt_iv_eboiv_ctr(cc, ti, NULL); 788 if (r) 789 crypt_iv_elephant_dtr(cc); 790 return r; 791 } 792 793 static void diffuser_disk_to_cpu(u32 *d, size_t n) 794 { 795 #ifndef __LITTLE_ENDIAN 796 int i; 797 798 for (i = 0; i < n; i++) 799 d[i] = le32_to_cpu((__le32)d[i]); 800 #endif 801 } 802 803 static void diffuser_cpu_to_disk(__le32 *d, size_t n) 804 { 805 #ifndef __LITTLE_ENDIAN 806 int i; 807 808 for (i = 0; i < n; i++) 809 d[i] = cpu_to_le32((u32)d[i]); 810 #endif 811 } 812 813 static void diffuser_a_decrypt(u32 *d, size_t n) 814 { 815 int i, i1, i2, i3; 816 817 for (i = 0; i < 5; i++) { 818 i1 = 0; 819 i2 = n - 2; 820 i3 = n - 5; 821 822 while (i1 < (n - 1)) { 823 d[i1] += d[i2] ^ (d[i3] << 9 | d[i3] >> 23); 824 i1++; i2++; i3++; 825 826 if (i3 >= n) 827 i3 -= n; 828 829 d[i1] += d[i2] ^ d[i3]; 830 i1++; i2++; i3++; 831 832 if (i2 >= n) 833 i2 -= n; 834 835 d[i1] += d[i2] ^ (d[i3] << 13 | d[i3] >> 19); 836 i1++; i2++; i3++; 837 838 d[i1] += d[i2] ^ d[i3]; 839 i1++; i2++; i3++; 840 } 841 } 842 } 843 844 static void diffuser_a_encrypt(u32 *d, size_t n) 845 { 846 int i, i1, i2, i3; 847 848 for (i = 0; i < 5; i++) { 849 i1 = n - 1; 850 i2 = n - 2 - 1; 851 i3 = n - 5 - 1; 852 853 while (i1 > 0) { 854 d[i1] -= d[i2] ^ d[i3]; 855 i1--; i2--; i3--; 856 857 d[i1] -= d[i2] ^ (d[i3] << 13 | d[i3] >> 19); 858 i1--; i2--; i3--; 859 860 if (i2 < 0) 861 i2 += n; 862 863 d[i1] -= d[i2] ^ d[i3]; 864 i1--; i2--; i3--; 865 866 if (i3 < 0) 867 i3 += n; 868 869 d[i1] -= d[i2] ^ (d[i3] << 9 | d[i3] >> 23); 870 i1--; i2--; i3--; 871 } 872 } 873 } 874 875 static void diffuser_b_decrypt(u32 *d, size_t n) 876 { 877 int i, i1, i2, i3; 878 879 for (i = 0; i < 3; i++) { 880 i1 = 0; 881 i2 = 2; 882 i3 = 5; 883 884 while (i1 < (n - 1)) { 885 d[i1] += d[i2] ^ d[i3]; 886 i1++; i2++; i3++; 887 888 d[i1] += d[i2] ^ (d[i3] << 10 | d[i3] >> 22); 889 i1++; i2++; i3++; 890 891 if (i2 >= n) 892 i2 -= n; 893 894 d[i1] += d[i2] ^ d[i3]; 895 i1++; i2++; i3++; 896 897 if (i3 >= n) 898 i3 -= n; 899 900 d[i1] += d[i2] ^ (d[i3] << 25 | d[i3] >> 7); 901 i1++; i2++; i3++; 902 } 903 } 904 } 905 906 static void diffuser_b_encrypt(u32 *d, size_t n) 907 { 908 int i, i1, i2, i3; 909 910 for (i = 0; i < 3; i++) { 911 i1 = n - 1; 912 i2 = 2 - 1; 913 i3 = 5 - 1; 914 915 while (i1 > 0) { 916 d[i1] -= d[i2] ^ (d[i3] << 25 | d[i3] >> 7); 917 i1--; i2--; i3--; 918 919 if (i3 < 0) 920 i3 += n; 921 922 d[i1] -= d[i2] ^ d[i3]; 923 i1--; i2--; i3--; 924 925 if (i2 < 0) 926 i2 += n; 927 928 d[i1] -= d[i2] ^ (d[i3] << 10 | d[i3] >> 22); 929 i1--; i2--; i3--; 930 931 d[i1] -= d[i2] ^ d[i3]; 932 i1--; i2--; i3--; 933 } 934 } 935 } 936 937 static int crypt_iv_elephant(struct crypt_config *cc, struct dm_crypt_request *dmreq) 938 { 939 struct iv_elephant_private *elephant = &cc->iv_gen_private.elephant; 940 u8 *es, *ks, *data, *data2, *data_offset; 941 struct skcipher_request *req; 942 struct scatterlist *sg, *sg2, src, dst; 943 DECLARE_CRYPTO_WAIT(wait); 944 int i, r; 945 946 req = skcipher_request_alloc(elephant->tfm, GFP_NOIO); 947 es = kzalloc(16, GFP_NOIO); /* Key for AES */ 948 ks = kzalloc(32, GFP_NOIO); /* Elephant sector key */ 949 950 if (!req || !es || !ks) { 951 r = -ENOMEM; 952 goto out; 953 } 954 955 *(__le64 *)es = cpu_to_le64(dmreq->iv_sector * cc->sector_size); 956 957 /* E(Ks, e(s)) */ 958 sg_init_one(&src, es, 16); 959 sg_init_one(&dst, ks, 16); 960 skcipher_request_set_crypt(req, &src, &dst, 16, NULL); 961 skcipher_request_set_callback(req, 0, crypto_req_done, &wait); 962 r = crypto_wait_req(crypto_skcipher_encrypt(req), &wait); 963 if (r) 964 goto out; 965 966 /* E(Ks, e'(s)) */ 967 es[15] = 0x80; 968 sg_init_one(&dst, &ks[16], 16); 969 r = crypto_wait_req(crypto_skcipher_encrypt(req), &wait); 970 if (r) 971 goto out; 972 973 sg = crypt_get_sg_data(cc, dmreq->sg_out); 974 data = kmap_atomic(sg_page(sg)); 975 data_offset = data + sg->offset; 976 977 /* Cannot modify original bio, copy to sg_out and apply Elephant to it */ 978 if (bio_data_dir(dmreq->ctx->bio_in) == WRITE) { 979 sg2 = crypt_get_sg_data(cc, dmreq->sg_in); 980 data2 = kmap_atomic(sg_page(sg2)); 981 memcpy(data_offset, data2 + sg2->offset, cc->sector_size); 982 kunmap_atomic(data2); 983 } 984 985 if (bio_data_dir(dmreq->ctx->bio_in) != WRITE) { 986 diffuser_disk_to_cpu((u32*)data_offset, cc->sector_size / sizeof(u32)); 987 diffuser_b_decrypt((u32*)data_offset, cc->sector_size / sizeof(u32)); 988 diffuser_a_decrypt((u32*)data_offset, cc->sector_size / sizeof(u32)); 989 diffuser_cpu_to_disk((__le32*)data_offset, cc->sector_size / sizeof(u32)); 990 } 991 992 for (i = 0; i < (cc->sector_size / 32); i++) 993 crypto_xor(data_offset + i * 32, ks, 32); 994 995 if (bio_data_dir(dmreq->ctx->bio_in) == WRITE) { 996 diffuser_disk_to_cpu((u32*)data_offset, cc->sector_size / sizeof(u32)); 997 diffuser_a_encrypt((u32*)data_offset, cc->sector_size / sizeof(u32)); 998 diffuser_b_encrypt((u32*)data_offset, cc->sector_size / sizeof(u32)); 999 diffuser_cpu_to_disk((__le32*)data_offset, cc->sector_size / sizeof(u32)); 1000 } 1001 1002 kunmap_atomic(data); 1003 out: 1004 kfree_sensitive(ks); 1005 kfree_sensitive(es); 1006 skcipher_request_free(req); 1007 return r; 1008 } 1009 1010 static int crypt_iv_elephant_gen(struct crypt_config *cc, u8 *iv, 1011 struct dm_crypt_request *dmreq) 1012 { 1013 int r; 1014 1015 if (bio_data_dir(dmreq->ctx->bio_in) == WRITE) { 1016 r = crypt_iv_elephant(cc, dmreq); 1017 if (r) 1018 return r; 1019 } 1020 1021 return crypt_iv_eboiv_gen(cc, iv, dmreq); 1022 } 1023 1024 static int crypt_iv_elephant_post(struct crypt_config *cc, u8 *iv, 1025 struct dm_crypt_request *dmreq) 1026 { 1027 if (bio_data_dir(dmreq->ctx->bio_in) != WRITE) 1028 return crypt_iv_elephant(cc, dmreq); 1029 1030 return 0; 1031 } 1032 1033 static int crypt_iv_elephant_init(struct crypt_config *cc) 1034 { 1035 struct iv_elephant_private *elephant = &cc->iv_gen_private.elephant; 1036 int key_offset = cc->key_size - cc->key_extra_size; 1037 1038 return crypto_skcipher_setkey(elephant->tfm, &cc->key[key_offset], cc->key_extra_size); 1039 } 1040 1041 static int crypt_iv_elephant_wipe(struct crypt_config *cc) 1042 { 1043 struct iv_elephant_private *elephant = &cc->iv_gen_private.elephant; 1044 u8 key[ELEPHANT_MAX_KEY_SIZE]; 1045 1046 memset(key, 0, cc->key_extra_size); 1047 return crypto_skcipher_setkey(elephant->tfm, key, cc->key_extra_size); 1048 } 1049 1050 static const struct crypt_iv_operations crypt_iv_plain_ops = { 1051 .generator = crypt_iv_plain_gen 1052 }; 1053 1054 static const struct crypt_iv_operations crypt_iv_plain64_ops = { 1055 .generator = crypt_iv_plain64_gen 1056 }; 1057 1058 static const struct crypt_iv_operations crypt_iv_plain64be_ops = { 1059 .generator = crypt_iv_plain64be_gen 1060 }; 1061 1062 static const struct crypt_iv_operations crypt_iv_essiv_ops = { 1063 .generator = crypt_iv_essiv_gen 1064 }; 1065 1066 static const struct crypt_iv_operations crypt_iv_benbi_ops = { 1067 .ctr = crypt_iv_benbi_ctr, 1068 .dtr = crypt_iv_benbi_dtr, 1069 .generator = crypt_iv_benbi_gen 1070 }; 1071 1072 static const struct crypt_iv_operations crypt_iv_null_ops = { 1073 .generator = crypt_iv_null_gen 1074 }; 1075 1076 static const struct crypt_iv_operations crypt_iv_lmk_ops = { 1077 .ctr = crypt_iv_lmk_ctr, 1078 .dtr = crypt_iv_lmk_dtr, 1079 .init = crypt_iv_lmk_init, 1080 .wipe = crypt_iv_lmk_wipe, 1081 .generator = crypt_iv_lmk_gen, 1082 .post = crypt_iv_lmk_post 1083 }; 1084 1085 static const struct crypt_iv_operations crypt_iv_tcw_ops = { 1086 .ctr = crypt_iv_tcw_ctr, 1087 .dtr = crypt_iv_tcw_dtr, 1088 .init = crypt_iv_tcw_init, 1089 .wipe = crypt_iv_tcw_wipe, 1090 .generator = crypt_iv_tcw_gen, 1091 .post = crypt_iv_tcw_post 1092 }; 1093 1094 static const struct crypt_iv_operations crypt_iv_random_ops = { 1095 .generator = crypt_iv_random_gen 1096 }; 1097 1098 static const struct crypt_iv_operations crypt_iv_eboiv_ops = { 1099 .ctr = crypt_iv_eboiv_ctr, 1100 .generator = crypt_iv_eboiv_gen 1101 }; 1102 1103 static const struct crypt_iv_operations crypt_iv_elephant_ops = { 1104 .ctr = crypt_iv_elephant_ctr, 1105 .dtr = crypt_iv_elephant_dtr, 1106 .init = crypt_iv_elephant_init, 1107 .wipe = crypt_iv_elephant_wipe, 1108 .generator = crypt_iv_elephant_gen, 1109 .post = crypt_iv_elephant_post 1110 }; 1111 1112 /* 1113 * Integrity extensions 1114 */ 1115 static bool crypt_integrity_aead(struct crypt_config *cc) 1116 { 1117 return test_bit(CRYPT_MODE_INTEGRITY_AEAD, &cc->cipher_flags); 1118 } 1119 1120 static bool crypt_integrity_hmac(struct crypt_config *cc) 1121 { 1122 return crypt_integrity_aead(cc) && cc->key_mac_size; 1123 } 1124 1125 /* Get sg containing data */ 1126 static struct scatterlist *crypt_get_sg_data(struct crypt_config *cc, 1127 struct scatterlist *sg) 1128 { 1129 if (unlikely(crypt_integrity_aead(cc))) 1130 return &sg[2]; 1131 1132 return sg; 1133 } 1134 1135 static int dm_crypt_integrity_io_alloc(struct dm_crypt_io *io, struct bio *bio) 1136 { 1137 struct bio_integrity_payload *bip; 1138 unsigned int tag_len; 1139 int ret; 1140 1141 if (!bio_sectors(bio) || !io->cc->on_disk_tag_size) 1142 return 0; 1143 1144 bip = bio_integrity_alloc(bio, GFP_NOIO, 1); 1145 if (IS_ERR(bip)) 1146 return PTR_ERR(bip); 1147 1148 tag_len = io->cc->on_disk_tag_size * (bio_sectors(bio) >> io->cc->sector_shift); 1149 1150 bip->bip_iter.bi_size = tag_len; 1151 bip->bip_iter.bi_sector = io->cc->start + io->sector; 1152 1153 ret = bio_integrity_add_page(bio, virt_to_page(io->integrity_metadata), 1154 tag_len, offset_in_page(io->integrity_metadata)); 1155 if (unlikely(ret != tag_len)) 1156 return -ENOMEM; 1157 1158 return 0; 1159 } 1160 1161 static int crypt_integrity_ctr(struct crypt_config *cc, struct dm_target *ti) 1162 { 1163 #ifdef CONFIG_BLK_DEV_INTEGRITY 1164 struct blk_integrity *bi = blk_get_integrity(cc->dev->bdev->bd_disk); 1165 struct mapped_device *md = dm_table_get_md(ti->table); 1166 1167 /* From now we require underlying device with our integrity profile */ 1168 if (!bi || strcasecmp(bi->profile->name, "DM-DIF-EXT-TAG")) { 1169 ti->error = "Integrity profile not supported."; 1170 return -EINVAL; 1171 } 1172 1173 if (bi->tag_size != cc->on_disk_tag_size || 1174 bi->tuple_size != cc->on_disk_tag_size) { 1175 ti->error = "Integrity profile tag size mismatch."; 1176 return -EINVAL; 1177 } 1178 if (1 << bi->interval_exp != cc->sector_size) { 1179 ti->error = "Integrity profile sector size mismatch."; 1180 return -EINVAL; 1181 } 1182 1183 if (crypt_integrity_aead(cc)) { 1184 cc->integrity_tag_size = cc->on_disk_tag_size - cc->integrity_iv_size; 1185 DMDEBUG("%s: Integrity AEAD, tag size %u, IV size %u.", dm_device_name(md), 1186 cc->integrity_tag_size, cc->integrity_iv_size); 1187 1188 if (crypto_aead_setauthsize(any_tfm_aead(cc), cc->integrity_tag_size)) { 1189 ti->error = "Integrity AEAD auth tag size is not supported."; 1190 return -EINVAL; 1191 } 1192 } else if (cc->integrity_iv_size) 1193 DMDEBUG("%s: Additional per-sector space %u bytes for IV.", dm_device_name(md), 1194 cc->integrity_iv_size); 1195 1196 if ((cc->integrity_tag_size + cc->integrity_iv_size) != bi->tag_size) { 1197 ti->error = "Not enough space for integrity tag in the profile."; 1198 return -EINVAL; 1199 } 1200 1201 return 0; 1202 #else 1203 ti->error = "Integrity profile not supported."; 1204 return -EINVAL; 1205 #endif 1206 } 1207 1208 static void crypt_convert_init(struct crypt_config *cc, 1209 struct convert_context *ctx, 1210 struct bio *bio_out, struct bio *bio_in, 1211 sector_t sector) 1212 { 1213 ctx->bio_in = bio_in; 1214 ctx->bio_out = bio_out; 1215 if (bio_in) 1216 ctx->iter_in = bio_in->bi_iter; 1217 if (bio_out) 1218 ctx->iter_out = bio_out->bi_iter; 1219 ctx->cc_sector = sector + cc->iv_offset; 1220 init_completion(&ctx->restart); 1221 } 1222 1223 static struct dm_crypt_request *dmreq_of_req(struct crypt_config *cc, 1224 void *req) 1225 { 1226 return (struct dm_crypt_request *)((char *)req + cc->dmreq_start); 1227 } 1228 1229 static void *req_of_dmreq(struct crypt_config *cc, struct dm_crypt_request *dmreq) 1230 { 1231 return (void *)((char *)dmreq - cc->dmreq_start); 1232 } 1233 1234 static u8 *iv_of_dmreq(struct crypt_config *cc, 1235 struct dm_crypt_request *dmreq) 1236 { 1237 if (crypt_integrity_aead(cc)) 1238 return (u8 *)ALIGN((unsigned long)(dmreq + 1), 1239 crypto_aead_alignmask(any_tfm_aead(cc)) + 1); 1240 else 1241 return (u8 *)ALIGN((unsigned long)(dmreq + 1), 1242 crypto_skcipher_alignmask(any_tfm(cc)) + 1); 1243 } 1244 1245 static u8 *org_iv_of_dmreq(struct crypt_config *cc, 1246 struct dm_crypt_request *dmreq) 1247 { 1248 return iv_of_dmreq(cc, dmreq) + cc->iv_size; 1249 } 1250 1251 static __le64 *org_sector_of_dmreq(struct crypt_config *cc, 1252 struct dm_crypt_request *dmreq) 1253 { 1254 u8 *ptr = iv_of_dmreq(cc, dmreq) + cc->iv_size + cc->iv_size; 1255 return (__le64 *) ptr; 1256 } 1257 1258 static unsigned int *org_tag_of_dmreq(struct crypt_config *cc, 1259 struct dm_crypt_request *dmreq) 1260 { 1261 u8 *ptr = iv_of_dmreq(cc, dmreq) + cc->iv_size + 1262 cc->iv_size + sizeof(uint64_t); 1263 return (unsigned int*)ptr; 1264 } 1265 1266 static void *tag_from_dmreq(struct crypt_config *cc, 1267 struct dm_crypt_request *dmreq) 1268 { 1269 struct convert_context *ctx = dmreq->ctx; 1270 struct dm_crypt_io *io = container_of(ctx, struct dm_crypt_io, ctx); 1271 1272 return &io->integrity_metadata[*org_tag_of_dmreq(cc, dmreq) * 1273 cc->on_disk_tag_size]; 1274 } 1275 1276 static void *iv_tag_from_dmreq(struct crypt_config *cc, 1277 struct dm_crypt_request *dmreq) 1278 { 1279 return tag_from_dmreq(cc, dmreq) + cc->integrity_tag_size; 1280 } 1281 1282 static int crypt_convert_block_aead(struct crypt_config *cc, 1283 struct convert_context *ctx, 1284 struct aead_request *req, 1285 unsigned int tag_offset) 1286 { 1287 struct bio_vec bv_in = bio_iter_iovec(ctx->bio_in, ctx->iter_in); 1288 struct bio_vec bv_out = bio_iter_iovec(ctx->bio_out, ctx->iter_out); 1289 struct dm_crypt_request *dmreq; 1290 u8 *iv, *org_iv, *tag_iv, *tag; 1291 __le64 *sector; 1292 int r = 0; 1293 1294 BUG_ON(cc->integrity_iv_size && cc->integrity_iv_size != cc->iv_size); 1295 1296 /* Reject unexpected unaligned bio. */ 1297 if (unlikely(bv_in.bv_len & (cc->sector_size - 1))) 1298 return -EIO; 1299 1300 dmreq = dmreq_of_req(cc, req); 1301 dmreq->iv_sector = ctx->cc_sector; 1302 if (test_bit(CRYPT_IV_LARGE_SECTORS, &cc->cipher_flags)) 1303 dmreq->iv_sector >>= cc->sector_shift; 1304 dmreq->ctx = ctx; 1305 1306 *org_tag_of_dmreq(cc, dmreq) = tag_offset; 1307 1308 sector = org_sector_of_dmreq(cc, dmreq); 1309 *sector = cpu_to_le64(ctx->cc_sector - cc->iv_offset); 1310 1311 iv = iv_of_dmreq(cc, dmreq); 1312 org_iv = org_iv_of_dmreq(cc, dmreq); 1313 tag = tag_from_dmreq(cc, dmreq); 1314 tag_iv = iv_tag_from_dmreq(cc, dmreq); 1315 1316 /* AEAD request: 1317 * |----- AAD -------|------ DATA -------|-- AUTH TAG --| 1318 * | (authenticated) | (auth+encryption) | | 1319 * | sector_LE | IV | sector in/out | tag in/out | 1320 */ 1321 sg_init_table(dmreq->sg_in, 4); 1322 sg_set_buf(&dmreq->sg_in[0], sector, sizeof(uint64_t)); 1323 sg_set_buf(&dmreq->sg_in[1], org_iv, cc->iv_size); 1324 sg_set_page(&dmreq->sg_in[2], bv_in.bv_page, cc->sector_size, bv_in.bv_offset); 1325 sg_set_buf(&dmreq->sg_in[3], tag, cc->integrity_tag_size); 1326 1327 sg_init_table(dmreq->sg_out, 4); 1328 sg_set_buf(&dmreq->sg_out[0], sector, sizeof(uint64_t)); 1329 sg_set_buf(&dmreq->sg_out[1], org_iv, cc->iv_size); 1330 sg_set_page(&dmreq->sg_out[2], bv_out.bv_page, cc->sector_size, bv_out.bv_offset); 1331 sg_set_buf(&dmreq->sg_out[3], tag, cc->integrity_tag_size); 1332 1333 if (cc->iv_gen_ops) { 1334 /* For READs use IV stored in integrity metadata */ 1335 if (cc->integrity_iv_size && bio_data_dir(ctx->bio_in) != WRITE) { 1336 memcpy(org_iv, tag_iv, cc->iv_size); 1337 } else { 1338 r = cc->iv_gen_ops->generator(cc, org_iv, dmreq); 1339 if (r < 0) 1340 return r; 1341 /* Store generated IV in integrity metadata */ 1342 if (cc->integrity_iv_size) 1343 memcpy(tag_iv, org_iv, cc->iv_size); 1344 } 1345 /* Working copy of IV, to be modified in crypto API */ 1346 memcpy(iv, org_iv, cc->iv_size); 1347 } 1348 1349 aead_request_set_ad(req, sizeof(uint64_t) + cc->iv_size); 1350 if (bio_data_dir(ctx->bio_in) == WRITE) { 1351 aead_request_set_crypt(req, dmreq->sg_in, dmreq->sg_out, 1352 cc->sector_size, iv); 1353 r = crypto_aead_encrypt(req); 1354 if (cc->integrity_tag_size + cc->integrity_iv_size != cc->on_disk_tag_size) 1355 memset(tag + cc->integrity_tag_size + cc->integrity_iv_size, 0, 1356 cc->on_disk_tag_size - (cc->integrity_tag_size + cc->integrity_iv_size)); 1357 } else { 1358 aead_request_set_crypt(req, dmreq->sg_in, dmreq->sg_out, 1359 cc->sector_size + cc->integrity_tag_size, iv); 1360 r = crypto_aead_decrypt(req); 1361 } 1362 1363 if (r == -EBADMSG) { 1364 char b[BDEVNAME_SIZE]; 1365 DMERR_LIMIT("%s: INTEGRITY AEAD ERROR, sector %llu", bio_devname(ctx->bio_in, b), 1366 (unsigned long long)le64_to_cpu(*sector)); 1367 } 1368 1369 if (!r && cc->iv_gen_ops && cc->iv_gen_ops->post) 1370 r = cc->iv_gen_ops->post(cc, org_iv, dmreq); 1371 1372 bio_advance_iter(ctx->bio_in, &ctx->iter_in, cc->sector_size); 1373 bio_advance_iter(ctx->bio_out, &ctx->iter_out, cc->sector_size); 1374 1375 return r; 1376 } 1377 1378 static int crypt_convert_block_skcipher(struct crypt_config *cc, 1379 struct convert_context *ctx, 1380 struct skcipher_request *req, 1381 unsigned int tag_offset) 1382 { 1383 struct bio_vec bv_in = bio_iter_iovec(ctx->bio_in, ctx->iter_in); 1384 struct bio_vec bv_out = bio_iter_iovec(ctx->bio_out, ctx->iter_out); 1385 struct scatterlist *sg_in, *sg_out; 1386 struct dm_crypt_request *dmreq; 1387 u8 *iv, *org_iv, *tag_iv; 1388 __le64 *sector; 1389 int r = 0; 1390 1391 /* Reject unexpected unaligned bio. */ 1392 if (unlikely(bv_in.bv_len & (cc->sector_size - 1))) 1393 return -EIO; 1394 1395 dmreq = dmreq_of_req(cc, req); 1396 dmreq->iv_sector = ctx->cc_sector; 1397 if (test_bit(CRYPT_IV_LARGE_SECTORS, &cc->cipher_flags)) 1398 dmreq->iv_sector >>= cc->sector_shift; 1399 dmreq->ctx = ctx; 1400 1401 *org_tag_of_dmreq(cc, dmreq) = tag_offset; 1402 1403 iv = iv_of_dmreq(cc, dmreq); 1404 org_iv = org_iv_of_dmreq(cc, dmreq); 1405 tag_iv = iv_tag_from_dmreq(cc, dmreq); 1406 1407 sector = org_sector_of_dmreq(cc, dmreq); 1408 *sector = cpu_to_le64(ctx->cc_sector - cc->iv_offset); 1409 1410 /* For skcipher we use only the first sg item */ 1411 sg_in = &dmreq->sg_in[0]; 1412 sg_out = &dmreq->sg_out[0]; 1413 1414 sg_init_table(sg_in, 1); 1415 sg_set_page(sg_in, bv_in.bv_page, cc->sector_size, bv_in.bv_offset); 1416 1417 sg_init_table(sg_out, 1); 1418 sg_set_page(sg_out, bv_out.bv_page, cc->sector_size, bv_out.bv_offset); 1419 1420 if (cc->iv_gen_ops) { 1421 /* For READs use IV stored in integrity metadata */ 1422 if (cc->integrity_iv_size && bio_data_dir(ctx->bio_in) != WRITE) { 1423 memcpy(org_iv, tag_iv, cc->integrity_iv_size); 1424 } else { 1425 r = cc->iv_gen_ops->generator(cc, org_iv, dmreq); 1426 if (r < 0) 1427 return r; 1428 /* Data can be already preprocessed in generator */ 1429 if (test_bit(CRYPT_ENCRYPT_PREPROCESS, &cc->cipher_flags)) 1430 sg_in = sg_out; 1431 /* Store generated IV in integrity metadata */ 1432 if (cc->integrity_iv_size) 1433 memcpy(tag_iv, org_iv, cc->integrity_iv_size); 1434 } 1435 /* Working copy of IV, to be modified in crypto API */ 1436 memcpy(iv, org_iv, cc->iv_size); 1437 } 1438 1439 skcipher_request_set_crypt(req, sg_in, sg_out, cc->sector_size, iv); 1440 1441 if (bio_data_dir(ctx->bio_in) == WRITE) 1442 r = crypto_skcipher_encrypt(req); 1443 else 1444 r = crypto_skcipher_decrypt(req); 1445 1446 if (!r && cc->iv_gen_ops && cc->iv_gen_ops->post) 1447 r = cc->iv_gen_ops->post(cc, org_iv, dmreq); 1448 1449 bio_advance_iter(ctx->bio_in, &ctx->iter_in, cc->sector_size); 1450 bio_advance_iter(ctx->bio_out, &ctx->iter_out, cc->sector_size); 1451 1452 return r; 1453 } 1454 1455 static void kcryptd_async_done(struct crypto_async_request *async_req, 1456 int error); 1457 1458 static int crypt_alloc_req_skcipher(struct crypt_config *cc, 1459 struct convert_context *ctx) 1460 { 1461 unsigned key_index = ctx->cc_sector & (cc->tfms_count - 1); 1462 1463 if (!ctx->r.req) { 1464 ctx->r.req = mempool_alloc(&cc->req_pool, in_interrupt() ? GFP_ATOMIC : GFP_NOIO); 1465 if (!ctx->r.req) 1466 return -ENOMEM; 1467 } 1468 1469 skcipher_request_set_tfm(ctx->r.req, cc->cipher_tfm.tfms[key_index]); 1470 1471 /* 1472 * Use REQ_MAY_BACKLOG so a cipher driver internally backlogs 1473 * requests if driver request queue is full. 1474 */ 1475 skcipher_request_set_callback(ctx->r.req, 1476 CRYPTO_TFM_REQ_MAY_BACKLOG, 1477 kcryptd_async_done, dmreq_of_req(cc, ctx->r.req)); 1478 1479 return 0; 1480 } 1481 1482 static int crypt_alloc_req_aead(struct crypt_config *cc, 1483 struct convert_context *ctx) 1484 { 1485 if (!ctx->r.req_aead) { 1486 ctx->r.req_aead = mempool_alloc(&cc->req_pool, in_interrupt() ? GFP_ATOMIC : GFP_NOIO); 1487 if (!ctx->r.req_aead) 1488 return -ENOMEM; 1489 } 1490 1491 aead_request_set_tfm(ctx->r.req_aead, cc->cipher_tfm.tfms_aead[0]); 1492 1493 /* 1494 * Use REQ_MAY_BACKLOG so a cipher driver internally backlogs 1495 * requests if driver request queue is full. 1496 */ 1497 aead_request_set_callback(ctx->r.req_aead, 1498 CRYPTO_TFM_REQ_MAY_BACKLOG, 1499 kcryptd_async_done, dmreq_of_req(cc, ctx->r.req_aead)); 1500 1501 return 0; 1502 } 1503 1504 static int crypt_alloc_req(struct crypt_config *cc, 1505 struct convert_context *ctx) 1506 { 1507 if (crypt_integrity_aead(cc)) 1508 return crypt_alloc_req_aead(cc, ctx); 1509 else 1510 return crypt_alloc_req_skcipher(cc, ctx); 1511 } 1512 1513 static void crypt_free_req_skcipher(struct crypt_config *cc, 1514 struct skcipher_request *req, struct bio *base_bio) 1515 { 1516 struct dm_crypt_io *io = dm_per_bio_data(base_bio, cc->per_bio_data_size); 1517 1518 if ((struct skcipher_request *)(io + 1) != req) 1519 mempool_free(req, &cc->req_pool); 1520 } 1521 1522 static void crypt_free_req_aead(struct crypt_config *cc, 1523 struct aead_request *req, struct bio *base_bio) 1524 { 1525 struct dm_crypt_io *io = dm_per_bio_data(base_bio, cc->per_bio_data_size); 1526 1527 if ((struct aead_request *)(io + 1) != req) 1528 mempool_free(req, &cc->req_pool); 1529 } 1530 1531 static void crypt_free_req(struct crypt_config *cc, void *req, struct bio *base_bio) 1532 { 1533 if (crypt_integrity_aead(cc)) 1534 crypt_free_req_aead(cc, req, base_bio); 1535 else 1536 crypt_free_req_skcipher(cc, req, base_bio); 1537 } 1538 1539 /* 1540 * Encrypt / decrypt data from one bio to another one (can be the same one) 1541 */ 1542 static blk_status_t crypt_convert(struct crypt_config *cc, 1543 struct convert_context *ctx, bool atomic, bool reset_pending) 1544 { 1545 unsigned int tag_offset = 0; 1546 unsigned int sector_step = cc->sector_size >> SECTOR_SHIFT; 1547 int r; 1548 1549 /* 1550 * if reset_pending is set we are dealing with the bio for the first time, 1551 * else we're continuing to work on the previous bio, so don't mess with 1552 * the cc_pending counter 1553 */ 1554 if (reset_pending) 1555 atomic_set(&ctx->cc_pending, 1); 1556 1557 while (ctx->iter_in.bi_size && ctx->iter_out.bi_size) { 1558 1559 r = crypt_alloc_req(cc, ctx); 1560 if (r) { 1561 complete(&ctx->restart); 1562 return BLK_STS_DEV_RESOURCE; 1563 } 1564 1565 atomic_inc(&ctx->cc_pending); 1566 1567 if (crypt_integrity_aead(cc)) 1568 r = crypt_convert_block_aead(cc, ctx, ctx->r.req_aead, tag_offset); 1569 else 1570 r = crypt_convert_block_skcipher(cc, ctx, ctx->r.req, tag_offset); 1571 1572 switch (r) { 1573 /* 1574 * The request was queued by a crypto driver 1575 * but the driver request queue is full, let's wait. 1576 */ 1577 case -EBUSY: 1578 if (in_interrupt()) { 1579 if (try_wait_for_completion(&ctx->restart)) { 1580 /* 1581 * we don't have to block to wait for completion, 1582 * so proceed 1583 */ 1584 } else { 1585 /* 1586 * we can't wait for completion without blocking 1587 * exit and continue processing in a workqueue 1588 */ 1589 ctx->r.req = NULL; 1590 ctx->cc_sector += sector_step; 1591 tag_offset++; 1592 return BLK_STS_DEV_RESOURCE; 1593 } 1594 } else { 1595 wait_for_completion(&ctx->restart); 1596 } 1597 reinit_completion(&ctx->restart); 1598 fallthrough; 1599 /* 1600 * The request is queued and processed asynchronously, 1601 * completion function kcryptd_async_done() will be called. 1602 */ 1603 case -EINPROGRESS: 1604 ctx->r.req = NULL; 1605 ctx->cc_sector += sector_step; 1606 tag_offset++; 1607 continue; 1608 /* 1609 * The request was already processed (synchronously). 1610 */ 1611 case 0: 1612 atomic_dec(&ctx->cc_pending); 1613 ctx->cc_sector += sector_step; 1614 tag_offset++; 1615 if (!atomic) 1616 cond_resched(); 1617 continue; 1618 /* 1619 * There was a data integrity error. 1620 */ 1621 case -EBADMSG: 1622 atomic_dec(&ctx->cc_pending); 1623 return BLK_STS_PROTECTION; 1624 /* 1625 * There was an error while processing the request. 1626 */ 1627 default: 1628 atomic_dec(&ctx->cc_pending); 1629 return BLK_STS_IOERR; 1630 } 1631 } 1632 1633 return 0; 1634 } 1635 1636 static void crypt_free_buffer_pages(struct crypt_config *cc, struct bio *clone); 1637 1638 /* 1639 * Generate a new unfragmented bio with the given size 1640 * This should never violate the device limitations (but only because 1641 * max_segment_size is being constrained to PAGE_SIZE). 1642 * 1643 * This function may be called concurrently. If we allocate from the mempool 1644 * concurrently, there is a possibility of deadlock. For example, if we have 1645 * mempool of 256 pages, two processes, each wanting 256, pages allocate from 1646 * the mempool concurrently, it may deadlock in a situation where both processes 1647 * have allocated 128 pages and the mempool is exhausted. 1648 * 1649 * In order to avoid this scenario we allocate the pages under a mutex. 1650 * 1651 * In order to not degrade performance with excessive locking, we try 1652 * non-blocking allocations without a mutex first but on failure we fallback 1653 * to blocking allocations with a mutex. 1654 */ 1655 static struct bio *crypt_alloc_buffer(struct dm_crypt_io *io, unsigned size) 1656 { 1657 struct crypt_config *cc = io->cc; 1658 struct bio *clone; 1659 unsigned int nr_iovecs = (size + PAGE_SIZE - 1) >> PAGE_SHIFT; 1660 gfp_t gfp_mask = GFP_NOWAIT | __GFP_HIGHMEM; 1661 unsigned i, len, remaining_size; 1662 struct page *page; 1663 1664 retry: 1665 if (unlikely(gfp_mask & __GFP_DIRECT_RECLAIM)) 1666 mutex_lock(&cc->bio_alloc_lock); 1667 1668 clone = bio_alloc_bioset(GFP_NOIO, nr_iovecs, &cc->bs); 1669 if (!clone) 1670 goto out; 1671 1672 clone_init(io, clone); 1673 1674 remaining_size = size; 1675 1676 for (i = 0; i < nr_iovecs; i++) { 1677 page = mempool_alloc(&cc->page_pool, gfp_mask); 1678 if (!page) { 1679 crypt_free_buffer_pages(cc, clone); 1680 bio_put(clone); 1681 gfp_mask |= __GFP_DIRECT_RECLAIM; 1682 goto retry; 1683 } 1684 1685 len = (remaining_size > PAGE_SIZE) ? PAGE_SIZE : remaining_size; 1686 1687 bio_add_page(clone, page, len, 0); 1688 1689 remaining_size -= len; 1690 } 1691 1692 /* Allocate space for integrity tags */ 1693 if (dm_crypt_integrity_io_alloc(io, clone)) { 1694 crypt_free_buffer_pages(cc, clone); 1695 bio_put(clone); 1696 clone = NULL; 1697 } 1698 out: 1699 if (unlikely(gfp_mask & __GFP_DIRECT_RECLAIM)) 1700 mutex_unlock(&cc->bio_alloc_lock); 1701 1702 return clone; 1703 } 1704 1705 static void crypt_free_buffer_pages(struct crypt_config *cc, struct bio *clone) 1706 { 1707 struct bio_vec *bv; 1708 struct bvec_iter_all iter_all; 1709 1710 bio_for_each_segment_all(bv, clone, iter_all) { 1711 BUG_ON(!bv->bv_page); 1712 mempool_free(bv->bv_page, &cc->page_pool); 1713 } 1714 } 1715 1716 static void crypt_io_init(struct dm_crypt_io *io, struct crypt_config *cc, 1717 struct bio *bio, sector_t sector) 1718 { 1719 io->cc = cc; 1720 io->base_bio = bio; 1721 io->sector = sector; 1722 io->error = 0; 1723 io->ctx.r.req = NULL; 1724 io->integrity_metadata = NULL; 1725 io->integrity_metadata_from_pool = false; 1726 atomic_set(&io->io_pending, 0); 1727 } 1728 1729 static void crypt_inc_pending(struct dm_crypt_io *io) 1730 { 1731 atomic_inc(&io->io_pending); 1732 } 1733 1734 static void kcryptd_io_bio_endio(struct work_struct *work) 1735 { 1736 struct dm_crypt_io *io = container_of(work, struct dm_crypt_io, work); 1737 bio_endio(io->base_bio); 1738 } 1739 1740 /* 1741 * One of the bios was finished. Check for completion of 1742 * the whole request and correctly clean up the buffer. 1743 */ 1744 static void crypt_dec_pending(struct dm_crypt_io *io) 1745 { 1746 struct crypt_config *cc = io->cc; 1747 struct bio *base_bio = io->base_bio; 1748 blk_status_t error = io->error; 1749 1750 if (!atomic_dec_and_test(&io->io_pending)) 1751 return; 1752 1753 if (io->ctx.r.req) 1754 crypt_free_req(cc, io->ctx.r.req, base_bio); 1755 1756 if (unlikely(io->integrity_metadata_from_pool)) 1757 mempool_free(io->integrity_metadata, &io->cc->tag_pool); 1758 else 1759 kfree(io->integrity_metadata); 1760 1761 base_bio->bi_status = error; 1762 1763 /* 1764 * If we are running this function from our tasklet, 1765 * we can't call bio_endio() here, because it will call 1766 * clone_endio() from dm.c, which in turn will 1767 * free the current struct dm_crypt_io structure with 1768 * our tasklet. In this case we need to delay bio_endio() 1769 * execution to after the tasklet is done and dequeued. 1770 */ 1771 if (tasklet_trylock(&io->tasklet)) { 1772 tasklet_unlock(&io->tasklet); 1773 bio_endio(base_bio); 1774 return; 1775 } 1776 1777 INIT_WORK(&io->work, kcryptd_io_bio_endio); 1778 queue_work(cc->io_queue, &io->work); 1779 } 1780 1781 /* 1782 * kcryptd/kcryptd_io: 1783 * 1784 * Needed because it would be very unwise to do decryption in an 1785 * interrupt context. 1786 * 1787 * kcryptd performs the actual encryption or decryption. 1788 * 1789 * kcryptd_io performs the IO submission. 1790 * 1791 * They must be separated as otherwise the final stages could be 1792 * starved by new requests which can block in the first stages due 1793 * to memory allocation. 1794 * 1795 * The work is done per CPU global for all dm-crypt instances. 1796 * They should not depend on each other and do not block. 1797 */ 1798 static void crypt_endio(struct bio *clone) 1799 { 1800 struct dm_crypt_io *io = clone->bi_private; 1801 struct crypt_config *cc = io->cc; 1802 unsigned rw = bio_data_dir(clone); 1803 blk_status_t error; 1804 1805 /* 1806 * free the processed pages 1807 */ 1808 if (rw == WRITE) 1809 crypt_free_buffer_pages(cc, clone); 1810 1811 error = clone->bi_status; 1812 bio_put(clone); 1813 1814 if (rw == READ && !error) { 1815 kcryptd_queue_crypt(io); 1816 return; 1817 } 1818 1819 if (unlikely(error)) 1820 io->error = error; 1821 1822 crypt_dec_pending(io); 1823 } 1824 1825 static void clone_init(struct dm_crypt_io *io, struct bio *clone) 1826 { 1827 struct crypt_config *cc = io->cc; 1828 1829 clone->bi_private = io; 1830 clone->bi_end_io = crypt_endio; 1831 bio_set_dev(clone, cc->dev->bdev); 1832 clone->bi_opf = io->base_bio->bi_opf; 1833 } 1834 1835 static int kcryptd_io_read(struct dm_crypt_io *io, gfp_t gfp) 1836 { 1837 struct crypt_config *cc = io->cc; 1838 struct bio *clone; 1839 1840 /* 1841 * We need the original biovec array in order to decrypt 1842 * the whole bio data *afterwards* -- thanks to immutable 1843 * biovecs we don't need to worry about the block layer 1844 * modifying the biovec array; so leverage bio_clone_fast(). 1845 */ 1846 clone = bio_clone_fast(io->base_bio, gfp, &cc->bs); 1847 if (!clone) 1848 return 1; 1849 1850 crypt_inc_pending(io); 1851 1852 clone_init(io, clone); 1853 clone->bi_iter.bi_sector = cc->start + io->sector; 1854 1855 if (dm_crypt_integrity_io_alloc(io, clone)) { 1856 crypt_dec_pending(io); 1857 bio_put(clone); 1858 return 1; 1859 } 1860 1861 submit_bio_noacct(clone); 1862 return 0; 1863 } 1864 1865 static void kcryptd_io_read_work(struct work_struct *work) 1866 { 1867 struct dm_crypt_io *io = container_of(work, struct dm_crypt_io, work); 1868 1869 crypt_inc_pending(io); 1870 if (kcryptd_io_read(io, GFP_NOIO)) 1871 io->error = BLK_STS_RESOURCE; 1872 crypt_dec_pending(io); 1873 } 1874 1875 static void kcryptd_queue_read(struct dm_crypt_io *io) 1876 { 1877 struct crypt_config *cc = io->cc; 1878 1879 INIT_WORK(&io->work, kcryptd_io_read_work); 1880 queue_work(cc->io_queue, &io->work); 1881 } 1882 1883 static void kcryptd_io_write(struct dm_crypt_io *io) 1884 { 1885 struct bio *clone = io->ctx.bio_out; 1886 1887 submit_bio_noacct(clone); 1888 } 1889 1890 #define crypt_io_from_node(node) rb_entry((node), struct dm_crypt_io, rb_node) 1891 1892 static int dmcrypt_write(void *data) 1893 { 1894 struct crypt_config *cc = data; 1895 struct dm_crypt_io *io; 1896 1897 while (1) { 1898 struct rb_root write_tree; 1899 struct blk_plug plug; 1900 1901 spin_lock_irq(&cc->write_thread_lock); 1902 continue_locked: 1903 1904 if (!RB_EMPTY_ROOT(&cc->write_tree)) 1905 goto pop_from_list; 1906 1907 set_current_state(TASK_INTERRUPTIBLE); 1908 1909 spin_unlock_irq(&cc->write_thread_lock); 1910 1911 if (unlikely(kthread_should_stop())) { 1912 set_current_state(TASK_RUNNING); 1913 break; 1914 } 1915 1916 schedule(); 1917 1918 set_current_state(TASK_RUNNING); 1919 spin_lock_irq(&cc->write_thread_lock); 1920 goto continue_locked; 1921 1922 pop_from_list: 1923 write_tree = cc->write_tree; 1924 cc->write_tree = RB_ROOT; 1925 spin_unlock_irq(&cc->write_thread_lock); 1926 1927 BUG_ON(rb_parent(write_tree.rb_node)); 1928 1929 /* 1930 * Note: we cannot walk the tree here with rb_next because 1931 * the structures may be freed when kcryptd_io_write is called. 1932 */ 1933 blk_start_plug(&plug); 1934 do { 1935 io = crypt_io_from_node(rb_first(&write_tree)); 1936 rb_erase(&io->rb_node, &write_tree); 1937 kcryptd_io_write(io); 1938 } while (!RB_EMPTY_ROOT(&write_tree)); 1939 blk_finish_plug(&plug); 1940 } 1941 return 0; 1942 } 1943 1944 static void kcryptd_crypt_write_io_submit(struct dm_crypt_io *io, int async) 1945 { 1946 struct bio *clone = io->ctx.bio_out; 1947 struct crypt_config *cc = io->cc; 1948 unsigned long flags; 1949 sector_t sector; 1950 struct rb_node **rbp, *parent; 1951 1952 if (unlikely(io->error)) { 1953 crypt_free_buffer_pages(cc, clone); 1954 bio_put(clone); 1955 crypt_dec_pending(io); 1956 return; 1957 } 1958 1959 /* crypt_convert should have filled the clone bio */ 1960 BUG_ON(io->ctx.iter_out.bi_size); 1961 1962 clone->bi_iter.bi_sector = cc->start + io->sector; 1963 1964 if ((likely(!async) && test_bit(DM_CRYPT_NO_OFFLOAD, &cc->flags)) || 1965 test_bit(DM_CRYPT_NO_WRITE_WORKQUEUE, &cc->flags)) { 1966 submit_bio_noacct(clone); 1967 return; 1968 } 1969 1970 spin_lock_irqsave(&cc->write_thread_lock, flags); 1971 if (RB_EMPTY_ROOT(&cc->write_tree)) 1972 wake_up_process(cc->write_thread); 1973 rbp = &cc->write_tree.rb_node; 1974 parent = NULL; 1975 sector = io->sector; 1976 while (*rbp) { 1977 parent = *rbp; 1978 if (sector < crypt_io_from_node(parent)->sector) 1979 rbp = &(*rbp)->rb_left; 1980 else 1981 rbp = &(*rbp)->rb_right; 1982 } 1983 rb_link_node(&io->rb_node, parent, rbp); 1984 rb_insert_color(&io->rb_node, &cc->write_tree); 1985 spin_unlock_irqrestore(&cc->write_thread_lock, flags); 1986 } 1987 1988 static bool kcryptd_crypt_write_inline(struct crypt_config *cc, 1989 struct convert_context *ctx) 1990 1991 { 1992 if (!test_bit(DM_CRYPT_WRITE_INLINE, &cc->flags)) 1993 return false; 1994 1995 /* 1996 * Note: zone append writes (REQ_OP_ZONE_APPEND) do not have ordering 1997 * constraints so they do not need to be issued inline by 1998 * kcryptd_crypt_write_convert(). 1999 */ 2000 switch (bio_op(ctx->bio_in)) { 2001 case REQ_OP_WRITE: 2002 case REQ_OP_WRITE_SAME: 2003 case REQ_OP_WRITE_ZEROES: 2004 return true; 2005 default: 2006 return false; 2007 } 2008 } 2009 2010 static void kcryptd_crypt_write_continue(struct work_struct *work) 2011 { 2012 struct dm_crypt_io *io = container_of(work, struct dm_crypt_io, work); 2013 struct crypt_config *cc = io->cc; 2014 struct convert_context *ctx = &io->ctx; 2015 int crypt_finished; 2016 sector_t sector = io->sector; 2017 blk_status_t r; 2018 2019 wait_for_completion(&ctx->restart); 2020 reinit_completion(&ctx->restart); 2021 2022 r = crypt_convert(cc, &io->ctx, true, false); 2023 if (r) 2024 io->error = r; 2025 crypt_finished = atomic_dec_and_test(&ctx->cc_pending); 2026 if (!crypt_finished && kcryptd_crypt_write_inline(cc, ctx)) { 2027 /* Wait for completion signaled by kcryptd_async_done() */ 2028 wait_for_completion(&ctx->restart); 2029 crypt_finished = 1; 2030 } 2031 2032 /* Encryption was already finished, submit io now */ 2033 if (crypt_finished) { 2034 kcryptd_crypt_write_io_submit(io, 0); 2035 io->sector = sector; 2036 } 2037 2038 crypt_dec_pending(io); 2039 } 2040 2041 static void kcryptd_crypt_write_convert(struct dm_crypt_io *io) 2042 { 2043 struct crypt_config *cc = io->cc; 2044 struct convert_context *ctx = &io->ctx; 2045 struct bio *clone; 2046 int crypt_finished; 2047 sector_t sector = io->sector; 2048 blk_status_t r; 2049 2050 /* 2051 * Prevent io from disappearing until this function completes. 2052 */ 2053 crypt_inc_pending(io); 2054 crypt_convert_init(cc, ctx, NULL, io->base_bio, sector); 2055 2056 clone = crypt_alloc_buffer(io, io->base_bio->bi_iter.bi_size); 2057 if (unlikely(!clone)) { 2058 io->error = BLK_STS_IOERR; 2059 goto dec; 2060 } 2061 2062 io->ctx.bio_out = clone; 2063 io->ctx.iter_out = clone->bi_iter; 2064 2065 sector += bio_sectors(clone); 2066 2067 crypt_inc_pending(io); 2068 r = crypt_convert(cc, ctx, 2069 test_bit(DM_CRYPT_NO_WRITE_WORKQUEUE, &cc->flags), true); 2070 /* 2071 * Crypto API backlogged the request, because its queue was full 2072 * and we're in softirq context, so continue from a workqueue 2073 * (TODO: is it actually possible to be in softirq in the write path?) 2074 */ 2075 if (r == BLK_STS_DEV_RESOURCE) { 2076 INIT_WORK(&io->work, kcryptd_crypt_write_continue); 2077 queue_work(cc->crypt_queue, &io->work); 2078 return; 2079 } 2080 if (r) 2081 io->error = r; 2082 crypt_finished = atomic_dec_and_test(&ctx->cc_pending); 2083 if (!crypt_finished && kcryptd_crypt_write_inline(cc, ctx)) { 2084 /* Wait for completion signaled by kcryptd_async_done() */ 2085 wait_for_completion(&ctx->restart); 2086 crypt_finished = 1; 2087 } 2088 2089 /* Encryption was already finished, submit io now */ 2090 if (crypt_finished) { 2091 kcryptd_crypt_write_io_submit(io, 0); 2092 io->sector = sector; 2093 } 2094 2095 dec: 2096 crypt_dec_pending(io); 2097 } 2098 2099 static void kcryptd_crypt_read_done(struct dm_crypt_io *io) 2100 { 2101 crypt_dec_pending(io); 2102 } 2103 2104 static void kcryptd_crypt_read_continue(struct work_struct *work) 2105 { 2106 struct dm_crypt_io *io = container_of(work, struct dm_crypt_io, work); 2107 struct crypt_config *cc = io->cc; 2108 blk_status_t r; 2109 2110 wait_for_completion(&io->ctx.restart); 2111 reinit_completion(&io->ctx.restart); 2112 2113 r = crypt_convert(cc, &io->ctx, true, false); 2114 if (r) 2115 io->error = r; 2116 2117 if (atomic_dec_and_test(&io->ctx.cc_pending)) 2118 kcryptd_crypt_read_done(io); 2119 2120 crypt_dec_pending(io); 2121 } 2122 2123 static void kcryptd_crypt_read_convert(struct dm_crypt_io *io) 2124 { 2125 struct crypt_config *cc = io->cc; 2126 blk_status_t r; 2127 2128 crypt_inc_pending(io); 2129 2130 crypt_convert_init(cc, &io->ctx, io->base_bio, io->base_bio, 2131 io->sector); 2132 2133 r = crypt_convert(cc, &io->ctx, 2134 test_bit(DM_CRYPT_NO_READ_WORKQUEUE, &cc->flags), true); 2135 /* 2136 * Crypto API backlogged the request, because its queue was full 2137 * and we're in softirq context, so continue from a workqueue 2138 */ 2139 if (r == BLK_STS_DEV_RESOURCE) { 2140 INIT_WORK(&io->work, kcryptd_crypt_read_continue); 2141 queue_work(cc->crypt_queue, &io->work); 2142 return; 2143 } 2144 if (r) 2145 io->error = r; 2146 2147 if (atomic_dec_and_test(&io->ctx.cc_pending)) 2148 kcryptd_crypt_read_done(io); 2149 2150 crypt_dec_pending(io); 2151 } 2152 2153 static void kcryptd_async_done(struct crypto_async_request *async_req, 2154 int error) 2155 { 2156 struct dm_crypt_request *dmreq = async_req->data; 2157 struct convert_context *ctx = dmreq->ctx; 2158 struct dm_crypt_io *io = container_of(ctx, struct dm_crypt_io, ctx); 2159 struct crypt_config *cc = io->cc; 2160 2161 /* 2162 * A request from crypto driver backlog is going to be processed now, 2163 * finish the completion and continue in crypt_convert(). 2164 * (Callback will be called for the second time for this request.) 2165 */ 2166 if (error == -EINPROGRESS) { 2167 complete(&ctx->restart); 2168 return; 2169 } 2170 2171 if (!error && cc->iv_gen_ops && cc->iv_gen_ops->post) 2172 error = cc->iv_gen_ops->post(cc, org_iv_of_dmreq(cc, dmreq), dmreq); 2173 2174 if (error == -EBADMSG) { 2175 char b[BDEVNAME_SIZE]; 2176 DMERR_LIMIT("%s: INTEGRITY AEAD ERROR, sector %llu", bio_devname(ctx->bio_in, b), 2177 (unsigned long long)le64_to_cpu(*org_sector_of_dmreq(cc, dmreq))); 2178 io->error = BLK_STS_PROTECTION; 2179 } else if (error < 0) 2180 io->error = BLK_STS_IOERR; 2181 2182 crypt_free_req(cc, req_of_dmreq(cc, dmreq), io->base_bio); 2183 2184 if (!atomic_dec_and_test(&ctx->cc_pending)) 2185 return; 2186 2187 /* 2188 * The request is fully completed: for inline writes, let 2189 * kcryptd_crypt_write_convert() do the IO submission. 2190 */ 2191 if (bio_data_dir(io->base_bio) == READ) { 2192 kcryptd_crypt_read_done(io); 2193 return; 2194 } 2195 2196 if (kcryptd_crypt_write_inline(cc, ctx)) { 2197 complete(&ctx->restart); 2198 return; 2199 } 2200 2201 kcryptd_crypt_write_io_submit(io, 1); 2202 } 2203 2204 static void kcryptd_crypt(struct work_struct *work) 2205 { 2206 struct dm_crypt_io *io = container_of(work, struct dm_crypt_io, work); 2207 2208 if (bio_data_dir(io->base_bio) == READ) 2209 kcryptd_crypt_read_convert(io); 2210 else 2211 kcryptd_crypt_write_convert(io); 2212 } 2213 2214 static void kcryptd_crypt_tasklet(unsigned long work) 2215 { 2216 kcryptd_crypt((struct work_struct *)work); 2217 } 2218 2219 static void kcryptd_queue_crypt(struct dm_crypt_io *io) 2220 { 2221 struct crypt_config *cc = io->cc; 2222 2223 if ((bio_data_dir(io->base_bio) == READ && test_bit(DM_CRYPT_NO_READ_WORKQUEUE, &cc->flags)) || 2224 (bio_data_dir(io->base_bio) == WRITE && test_bit(DM_CRYPT_NO_WRITE_WORKQUEUE, &cc->flags))) { 2225 /* 2226 * in_irq(): Crypto API's skcipher_walk_first() refuses to work in hard IRQ context. 2227 * irqs_disabled(): the kernel may run some IO completion from the idle thread, but 2228 * it is being executed with irqs disabled. 2229 */ 2230 if (in_irq() || irqs_disabled()) { 2231 tasklet_init(&io->tasklet, kcryptd_crypt_tasklet, (unsigned long)&io->work); 2232 tasklet_schedule(&io->tasklet); 2233 return; 2234 } 2235 2236 kcryptd_crypt(&io->work); 2237 return; 2238 } 2239 2240 INIT_WORK(&io->work, kcryptd_crypt); 2241 queue_work(cc->crypt_queue, &io->work); 2242 } 2243 2244 static void crypt_free_tfms_aead(struct crypt_config *cc) 2245 { 2246 if (!cc->cipher_tfm.tfms_aead) 2247 return; 2248 2249 if (cc->cipher_tfm.tfms_aead[0] && !IS_ERR(cc->cipher_tfm.tfms_aead[0])) { 2250 crypto_free_aead(cc->cipher_tfm.tfms_aead[0]); 2251 cc->cipher_tfm.tfms_aead[0] = NULL; 2252 } 2253 2254 kfree(cc->cipher_tfm.tfms_aead); 2255 cc->cipher_tfm.tfms_aead = NULL; 2256 } 2257 2258 static void crypt_free_tfms_skcipher(struct crypt_config *cc) 2259 { 2260 unsigned i; 2261 2262 if (!cc->cipher_tfm.tfms) 2263 return; 2264 2265 for (i = 0; i < cc->tfms_count; i++) 2266 if (cc->cipher_tfm.tfms[i] && !IS_ERR(cc->cipher_tfm.tfms[i])) { 2267 crypto_free_skcipher(cc->cipher_tfm.tfms[i]); 2268 cc->cipher_tfm.tfms[i] = NULL; 2269 } 2270 2271 kfree(cc->cipher_tfm.tfms); 2272 cc->cipher_tfm.tfms = NULL; 2273 } 2274 2275 static void crypt_free_tfms(struct crypt_config *cc) 2276 { 2277 if (crypt_integrity_aead(cc)) 2278 crypt_free_tfms_aead(cc); 2279 else 2280 crypt_free_tfms_skcipher(cc); 2281 } 2282 2283 static int crypt_alloc_tfms_skcipher(struct crypt_config *cc, char *ciphermode) 2284 { 2285 unsigned i; 2286 int err; 2287 2288 cc->cipher_tfm.tfms = kcalloc(cc->tfms_count, 2289 sizeof(struct crypto_skcipher *), 2290 GFP_KERNEL); 2291 if (!cc->cipher_tfm.tfms) 2292 return -ENOMEM; 2293 2294 for (i = 0; i < cc->tfms_count; i++) { 2295 cc->cipher_tfm.tfms[i] = crypto_alloc_skcipher(ciphermode, 0, 2296 CRYPTO_ALG_ALLOCATES_MEMORY); 2297 if (IS_ERR(cc->cipher_tfm.tfms[i])) { 2298 err = PTR_ERR(cc->cipher_tfm.tfms[i]); 2299 crypt_free_tfms(cc); 2300 return err; 2301 } 2302 } 2303 2304 /* 2305 * dm-crypt performance can vary greatly depending on which crypto 2306 * algorithm implementation is used. Help people debug performance 2307 * problems by logging the ->cra_driver_name. 2308 */ 2309 DMDEBUG_LIMIT("%s using implementation \"%s\"", ciphermode, 2310 crypto_skcipher_alg(any_tfm(cc))->base.cra_driver_name); 2311 return 0; 2312 } 2313 2314 static int crypt_alloc_tfms_aead(struct crypt_config *cc, char *ciphermode) 2315 { 2316 int err; 2317 2318 cc->cipher_tfm.tfms = kmalloc(sizeof(struct crypto_aead *), GFP_KERNEL); 2319 if (!cc->cipher_tfm.tfms) 2320 return -ENOMEM; 2321 2322 cc->cipher_tfm.tfms_aead[0] = crypto_alloc_aead(ciphermode, 0, 2323 CRYPTO_ALG_ALLOCATES_MEMORY); 2324 if (IS_ERR(cc->cipher_tfm.tfms_aead[0])) { 2325 err = PTR_ERR(cc->cipher_tfm.tfms_aead[0]); 2326 crypt_free_tfms(cc); 2327 return err; 2328 } 2329 2330 DMDEBUG_LIMIT("%s using implementation \"%s\"", ciphermode, 2331 crypto_aead_alg(any_tfm_aead(cc))->base.cra_driver_name); 2332 return 0; 2333 } 2334 2335 static int crypt_alloc_tfms(struct crypt_config *cc, char *ciphermode) 2336 { 2337 if (crypt_integrity_aead(cc)) 2338 return crypt_alloc_tfms_aead(cc, ciphermode); 2339 else 2340 return crypt_alloc_tfms_skcipher(cc, ciphermode); 2341 } 2342 2343 static unsigned crypt_subkey_size(struct crypt_config *cc) 2344 { 2345 return (cc->key_size - cc->key_extra_size) >> ilog2(cc->tfms_count); 2346 } 2347 2348 static unsigned crypt_authenckey_size(struct crypt_config *cc) 2349 { 2350 return crypt_subkey_size(cc) + RTA_SPACE(sizeof(struct crypto_authenc_key_param)); 2351 } 2352 2353 /* 2354 * If AEAD is composed like authenc(hmac(sha256),xts(aes)), 2355 * the key must be for some reason in special format. 2356 * This funcion converts cc->key to this special format. 2357 */ 2358 static void crypt_copy_authenckey(char *p, const void *key, 2359 unsigned enckeylen, unsigned authkeylen) 2360 { 2361 struct crypto_authenc_key_param *param; 2362 struct rtattr *rta; 2363 2364 rta = (struct rtattr *)p; 2365 param = RTA_DATA(rta); 2366 param->enckeylen = cpu_to_be32(enckeylen); 2367 rta->rta_len = RTA_LENGTH(sizeof(*param)); 2368 rta->rta_type = CRYPTO_AUTHENC_KEYA_PARAM; 2369 p += RTA_SPACE(sizeof(*param)); 2370 memcpy(p, key + enckeylen, authkeylen); 2371 p += authkeylen; 2372 memcpy(p, key, enckeylen); 2373 } 2374 2375 static int crypt_setkey(struct crypt_config *cc) 2376 { 2377 unsigned subkey_size; 2378 int err = 0, i, r; 2379 2380 /* Ignore extra keys (which are used for IV etc) */ 2381 subkey_size = crypt_subkey_size(cc); 2382 2383 if (crypt_integrity_hmac(cc)) { 2384 if (subkey_size < cc->key_mac_size) 2385 return -EINVAL; 2386 2387 crypt_copy_authenckey(cc->authenc_key, cc->key, 2388 subkey_size - cc->key_mac_size, 2389 cc->key_mac_size); 2390 } 2391 2392 for (i = 0; i < cc->tfms_count; i++) { 2393 if (crypt_integrity_hmac(cc)) 2394 r = crypto_aead_setkey(cc->cipher_tfm.tfms_aead[i], 2395 cc->authenc_key, crypt_authenckey_size(cc)); 2396 else if (crypt_integrity_aead(cc)) 2397 r = crypto_aead_setkey(cc->cipher_tfm.tfms_aead[i], 2398 cc->key + (i * subkey_size), 2399 subkey_size); 2400 else 2401 r = crypto_skcipher_setkey(cc->cipher_tfm.tfms[i], 2402 cc->key + (i * subkey_size), 2403 subkey_size); 2404 if (r) 2405 err = r; 2406 } 2407 2408 if (crypt_integrity_hmac(cc)) 2409 memzero_explicit(cc->authenc_key, crypt_authenckey_size(cc)); 2410 2411 return err; 2412 } 2413 2414 #ifdef CONFIG_KEYS 2415 2416 static bool contains_whitespace(const char *str) 2417 { 2418 while (*str) 2419 if (isspace(*str++)) 2420 return true; 2421 return false; 2422 } 2423 2424 static int set_key_user(struct crypt_config *cc, struct key *key) 2425 { 2426 const struct user_key_payload *ukp; 2427 2428 ukp = user_key_payload_locked(key); 2429 if (!ukp) 2430 return -EKEYREVOKED; 2431 2432 if (cc->key_size != ukp->datalen) 2433 return -EINVAL; 2434 2435 memcpy(cc->key, ukp->data, cc->key_size); 2436 2437 return 0; 2438 } 2439 2440 static int set_key_encrypted(struct crypt_config *cc, struct key *key) 2441 { 2442 const struct encrypted_key_payload *ekp; 2443 2444 ekp = key->payload.data[0]; 2445 if (!ekp) 2446 return -EKEYREVOKED; 2447 2448 if (cc->key_size != ekp->decrypted_datalen) 2449 return -EINVAL; 2450 2451 memcpy(cc->key, ekp->decrypted_data, cc->key_size); 2452 2453 return 0; 2454 } 2455 2456 static int set_key_trusted(struct crypt_config *cc, struct key *key) 2457 { 2458 const struct trusted_key_payload *tkp; 2459 2460 tkp = key->payload.data[0]; 2461 if (!tkp) 2462 return -EKEYREVOKED; 2463 2464 if (cc->key_size != tkp->key_len) 2465 return -EINVAL; 2466 2467 memcpy(cc->key, tkp->key, cc->key_size); 2468 2469 return 0; 2470 } 2471 2472 static int crypt_set_keyring_key(struct crypt_config *cc, const char *key_string) 2473 { 2474 char *new_key_string, *key_desc; 2475 int ret; 2476 struct key_type *type; 2477 struct key *key; 2478 int (*set_key)(struct crypt_config *cc, struct key *key); 2479 2480 /* 2481 * Reject key_string with whitespace. dm core currently lacks code for 2482 * proper whitespace escaping in arguments on DM_TABLE_STATUS path. 2483 */ 2484 if (contains_whitespace(key_string)) { 2485 DMERR("whitespace chars not allowed in key string"); 2486 return -EINVAL; 2487 } 2488 2489 /* look for next ':' separating key_type from key_description */ 2490 key_desc = strpbrk(key_string, ":"); 2491 if (!key_desc || key_desc == key_string || !strlen(key_desc + 1)) 2492 return -EINVAL; 2493 2494 if (!strncmp(key_string, "logon:", key_desc - key_string + 1)) { 2495 type = &key_type_logon; 2496 set_key = set_key_user; 2497 } else if (!strncmp(key_string, "user:", key_desc - key_string + 1)) { 2498 type = &key_type_user; 2499 set_key = set_key_user; 2500 } else if (IS_ENABLED(CONFIG_ENCRYPTED_KEYS) && 2501 !strncmp(key_string, "encrypted:", key_desc - key_string + 1)) { 2502 type = &key_type_encrypted; 2503 set_key = set_key_encrypted; 2504 } else if (IS_ENABLED(CONFIG_TRUSTED_KEYS) && 2505 !strncmp(key_string, "trusted:", key_desc - key_string + 1)) { 2506 type = &key_type_trusted; 2507 set_key = set_key_trusted; 2508 } else { 2509 return -EINVAL; 2510 } 2511 2512 new_key_string = kstrdup(key_string, GFP_KERNEL); 2513 if (!new_key_string) 2514 return -ENOMEM; 2515 2516 key = request_key(type, key_desc + 1, NULL); 2517 if (IS_ERR(key)) { 2518 kfree_sensitive(new_key_string); 2519 return PTR_ERR(key); 2520 } 2521 2522 down_read(&key->sem); 2523 2524 ret = set_key(cc, key); 2525 if (ret < 0) { 2526 up_read(&key->sem); 2527 key_put(key); 2528 kfree_sensitive(new_key_string); 2529 return ret; 2530 } 2531 2532 up_read(&key->sem); 2533 key_put(key); 2534 2535 /* clear the flag since following operations may invalidate previously valid key */ 2536 clear_bit(DM_CRYPT_KEY_VALID, &cc->flags); 2537 2538 ret = crypt_setkey(cc); 2539 2540 if (!ret) { 2541 set_bit(DM_CRYPT_KEY_VALID, &cc->flags); 2542 kfree_sensitive(cc->key_string); 2543 cc->key_string = new_key_string; 2544 } else 2545 kfree_sensitive(new_key_string); 2546 2547 return ret; 2548 } 2549 2550 static int get_key_size(char **key_string) 2551 { 2552 char *colon, dummy; 2553 int ret; 2554 2555 if (*key_string[0] != ':') 2556 return strlen(*key_string) >> 1; 2557 2558 /* look for next ':' in key string */ 2559 colon = strpbrk(*key_string + 1, ":"); 2560 if (!colon) 2561 return -EINVAL; 2562 2563 if (sscanf(*key_string + 1, "%u%c", &ret, &dummy) != 2 || dummy != ':') 2564 return -EINVAL; 2565 2566 *key_string = colon; 2567 2568 /* remaining key string should be :<logon|user>:<key_desc> */ 2569 2570 return ret; 2571 } 2572 2573 #else 2574 2575 static int crypt_set_keyring_key(struct crypt_config *cc, const char *key_string) 2576 { 2577 return -EINVAL; 2578 } 2579 2580 static int get_key_size(char **key_string) 2581 { 2582 return (*key_string[0] == ':') ? -EINVAL : strlen(*key_string) >> 1; 2583 } 2584 2585 #endif /* CONFIG_KEYS */ 2586 2587 static int crypt_set_key(struct crypt_config *cc, char *key) 2588 { 2589 int r = -EINVAL; 2590 int key_string_len = strlen(key); 2591 2592 /* Hyphen (which gives a key_size of zero) means there is no key. */ 2593 if (!cc->key_size && strcmp(key, "-")) 2594 goto out; 2595 2596 /* ':' means the key is in kernel keyring, short-circuit normal key processing */ 2597 if (key[0] == ':') { 2598 r = crypt_set_keyring_key(cc, key + 1); 2599 goto out; 2600 } 2601 2602 /* clear the flag since following operations may invalidate previously valid key */ 2603 clear_bit(DM_CRYPT_KEY_VALID, &cc->flags); 2604 2605 /* wipe references to any kernel keyring key */ 2606 kfree_sensitive(cc->key_string); 2607 cc->key_string = NULL; 2608 2609 /* Decode key from its hex representation. */ 2610 if (cc->key_size && hex2bin(cc->key, key, cc->key_size) < 0) 2611 goto out; 2612 2613 r = crypt_setkey(cc); 2614 if (!r) 2615 set_bit(DM_CRYPT_KEY_VALID, &cc->flags); 2616 2617 out: 2618 /* Hex key string not needed after here, so wipe it. */ 2619 memset(key, '0', key_string_len); 2620 2621 return r; 2622 } 2623 2624 static int crypt_wipe_key(struct crypt_config *cc) 2625 { 2626 int r; 2627 2628 clear_bit(DM_CRYPT_KEY_VALID, &cc->flags); 2629 get_random_bytes(&cc->key, cc->key_size); 2630 2631 /* Wipe IV private keys */ 2632 if (cc->iv_gen_ops && cc->iv_gen_ops->wipe) { 2633 r = cc->iv_gen_ops->wipe(cc); 2634 if (r) 2635 return r; 2636 } 2637 2638 kfree_sensitive(cc->key_string); 2639 cc->key_string = NULL; 2640 r = crypt_setkey(cc); 2641 memset(&cc->key, 0, cc->key_size * sizeof(u8)); 2642 2643 return r; 2644 } 2645 2646 static void crypt_calculate_pages_per_client(void) 2647 { 2648 unsigned long pages = (totalram_pages() - totalhigh_pages()) * DM_CRYPT_MEMORY_PERCENT / 100; 2649 2650 if (!dm_crypt_clients_n) 2651 return; 2652 2653 pages /= dm_crypt_clients_n; 2654 if (pages < DM_CRYPT_MIN_PAGES_PER_CLIENT) 2655 pages = DM_CRYPT_MIN_PAGES_PER_CLIENT; 2656 dm_crypt_pages_per_client = pages; 2657 } 2658 2659 static void *crypt_page_alloc(gfp_t gfp_mask, void *pool_data) 2660 { 2661 struct crypt_config *cc = pool_data; 2662 struct page *page; 2663 2664 if (unlikely(percpu_counter_compare(&cc->n_allocated_pages, dm_crypt_pages_per_client) >= 0) && 2665 likely(gfp_mask & __GFP_NORETRY)) 2666 return NULL; 2667 2668 page = alloc_page(gfp_mask); 2669 if (likely(page != NULL)) 2670 percpu_counter_add(&cc->n_allocated_pages, 1); 2671 2672 return page; 2673 } 2674 2675 static void crypt_page_free(void *page, void *pool_data) 2676 { 2677 struct crypt_config *cc = pool_data; 2678 2679 __free_page(page); 2680 percpu_counter_sub(&cc->n_allocated_pages, 1); 2681 } 2682 2683 static void crypt_dtr(struct dm_target *ti) 2684 { 2685 struct crypt_config *cc = ti->private; 2686 2687 ti->private = NULL; 2688 2689 if (!cc) 2690 return; 2691 2692 if (cc->write_thread) 2693 kthread_stop(cc->write_thread); 2694 2695 if (cc->io_queue) 2696 destroy_workqueue(cc->io_queue); 2697 if (cc->crypt_queue) 2698 destroy_workqueue(cc->crypt_queue); 2699 2700 crypt_free_tfms(cc); 2701 2702 bioset_exit(&cc->bs); 2703 2704 mempool_exit(&cc->page_pool); 2705 mempool_exit(&cc->req_pool); 2706 mempool_exit(&cc->tag_pool); 2707 2708 WARN_ON(percpu_counter_sum(&cc->n_allocated_pages) != 0); 2709 percpu_counter_destroy(&cc->n_allocated_pages); 2710 2711 if (cc->iv_gen_ops && cc->iv_gen_ops->dtr) 2712 cc->iv_gen_ops->dtr(cc); 2713 2714 if (cc->dev) 2715 dm_put_device(ti, cc->dev); 2716 2717 kfree_sensitive(cc->cipher_string); 2718 kfree_sensitive(cc->key_string); 2719 kfree_sensitive(cc->cipher_auth); 2720 kfree_sensitive(cc->authenc_key); 2721 2722 mutex_destroy(&cc->bio_alloc_lock); 2723 2724 /* Must zero key material before freeing */ 2725 kfree_sensitive(cc); 2726 2727 spin_lock(&dm_crypt_clients_lock); 2728 WARN_ON(!dm_crypt_clients_n); 2729 dm_crypt_clients_n--; 2730 crypt_calculate_pages_per_client(); 2731 spin_unlock(&dm_crypt_clients_lock); 2732 } 2733 2734 static int crypt_ctr_ivmode(struct dm_target *ti, const char *ivmode) 2735 { 2736 struct crypt_config *cc = ti->private; 2737 2738 if (crypt_integrity_aead(cc)) 2739 cc->iv_size = crypto_aead_ivsize(any_tfm_aead(cc)); 2740 else 2741 cc->iv_size = crypto_skcipher_ivsize(any_tfm(cc)); 2742 2743 if (cc->iv_size) 2744 /* at least a 64 bit sector number should fit in our buffer */ 2745 cc->iv_size = max(cc->iv_size, 2746 (unsigned int)(sizeof(u64) / sizeof(u8))); 2747 else if (ivmode) { 2748 DMWARN("Selected cipher does not support IVs"); 2749 ivmode = NULL; 2750 } 2751 2752 /* Choose ivmode, see comments at iv code. */ 2753 if (ivmode == NULL) 2754 cc->iv_gen_ops = NULL; 2755 else if (strcmp(ivmode, "plain") == 0) 2756 cc->iv_gen_ops = &crypt_iv_plain_ops; 2757 else if (strcmp(ivmode, "plain64") == 0) 2758 cc->iv_gen_ops = &crypt_iv_plain64_ops; 2759 else if (strcmp(ivmode, "plain64be") == 0) 2760 cc->iv_gen_ops = &crypt_iv_plain64be_ops; 2761 else if (strcmp(ivmode, "essiv") == 0) 2762 cc->iv_gen_ops = &crypt_iv_essiv_ops; 2763 else if (strcmp(ivmode, "benbi") == 0) 2764 cc->iv_gen_ops = &crypt_iv_benbi_ops; 2765 else if (strcmp(ivmode, "null") == 0) 2766 cc->iv_gen_ops = &crypt_iv_null_ops; 2767 else if (strcmp(ivmode, "eboiv") == 0) 2768 cc->iv_gen_ops = &crypt_iv_eboiv_ops; 2769 else if (strcmp(ivmode, "elephant") == 0) { 2770 cc->iv_gen_ops = &crypt_iv_elephant_ops; 2771 cc->key_parts = 2; 2772 cc->key_extra_size = cc->key_size / 2; 2773 if (cc->key_extra_size > ELEPHANT_MAX_KEY_SIZE) 2774 return -EINVAL; 2775 set_bit(CRYPT_ENCRYPT_PREPROCESS, &cc->cipher_flags); 2776 } else if (strcmp(ivmode, "lmk") == 0) { 2777 cc->iv_gen_ops = &crypt_iv_lmk_ops; 2778 /* 2779 * Version 2 and 3 is recognised according 2780 * to length of provided multi-key string. 2781 * If present (version 3), last key is used as IV seed. 2782 * All keys (including IV seed) are always the same size. 2783 */ 2784 if (cc->key_size % cc->key_parts) { 2785 cc->key_parts++; 2786 cc->key_extra_size = cc->key_size / cc->key_parts; 2787 } 2788 } else if (strcmp(ivmode, "tcw") == 0) { 2789 cc->iv_gen_ops = &crypt_iv_tcw_ops; 2790 cc->key_parts += 2; /* IV + whitening */ 2791 cc->key_extra_size = cc->iv_size + TCW_WHITENING_SIZE; 2792 } else if (strcmp(ivmode, "random") == 0) { 2793 cc->iv_gen_ops = &crypt_iv_random_ops; 2794 /* Need storage space in integrity fields. */ 2795 cc->integrity_iv_size = cc->iv_size; 2796 } else { 2797 ti->error = "Invalid IV mode"; 2798 return -EINVAL; 2799 } 2800 2801 return 0; 2802 } 2803 2804 /* 2805 * Workaround to parse HMAC algorithm from AEAD crypto API spec. 2806 * The HMAC is needed to calculate tag size (HMAC digest size). 2807 * This should be probably done by crypto-api calls (once available...) 2808 */ 2809 static int crypt_ctr_auth_cipher(struct crypt_config *cc, char *cipher_api) 2810 { 2811 char *start, *end, *mac_alg = NULL; 2812 struct crypto_ahash *mac; 2813 2814 if (!strstarts(cipher_api, "authenc(")) 2815 return 0; 2816 2817 start = strchr(cipher_api, '('); 2818 end = strchr(cipher_api, ','); 2819 if (!start || !end || ++start > end) 2820 return -EINVAL; 2821 2822 mac_alg = kzalloc(end - start + 1, GFP_KERNEL); 2823 if (!mac_alg) 2824 return -ENOMEM; 2825 strncpy(mac_alg, start, end - start); 2826 2827 mac = crypto_alloc_ahash(mac_alg, 0, CRYPTO_ALG_ALLOCATES_MEMORY); 2828 kfree(mac_alg); 2829 2830 if (IS_ERR(mac)) 2831 return PTR_ERR(mac); 2832 2833 cc->key_mac_size = crypto_ahash_digestsize(mac); 2834 crypto_free_ahash(mac); 2835 2836 cc->authenc_key = kmalloc(crypt_authenckey_size(cc), GFP_KERNEL); 2837 if (!cc->authenc_key) 2838 return -ENOMEM; 2839 2840 return 0; 2841 } 2842 2843 static int crypt_ctr_cipher_new(struct dm_target *ti, char *cipher_in, char *key, 2844 char **ivmode, char **ivopts) 2845 { 2846 struct crypt_config *cc = ti->private; 2847 char *tmp, *cipher_api, buf[CRYPTO_MAX_ALG_NAME]; 2848 int ret = -EINVAL; 2849 2850 cc->tfms_count = 1; 2851 2852 /* 2853 * New format (capi: prefix) 2854 * capi:cipher_api_spec-iv:ivopts 2855 */ 2856 tmp = &cipher_in[strlen("capi:")]; 2857 2858 /* Separate IV options if present, it can contain another '-' in hash name */ 2859 *ivopts = strrchr(tmp, ':'); 2860 if (*ivopts) { 2861 **ivopts = '\0'; 2862 (*ivopts)++; 2863 } 2864 /* Parse IV mode */ 2865 *ivmode = strrchr(tmp, '-'); 2866 if (*ivmode) { 2867 **ivmode = '\0'; 2868 (*ivmode)++; 2869 } 2870 /* The rest is crypto API spec */ 2871 cipher_api = tmp; 2872 2873 /* Alloc AEAD, can be used only in new format. */ 2874 if (crypt_integrity_aead(cc)) { 2875 ret = crypt_ctr_auth_cipher(cc, cipher_api); 2876 if (ret < 0) { 2877 ti->error = "Invalid AEAD cipher spec"; 2878 return -ENOMEM; 2879 } 2880 } 2881 2882 if (*ivmode && !strcmp(*ivmode, "lmk")) 2883 cc->tfms_count = 64; 2884 2885 if (*ivmode && !strcmp(*ivmode, "essiv")) { 2886 if (!*ivopts) { 2887 ti->error = "Digest algorithm missing for ESSIV mode"; 2888 return -EINVAL; 2889 } 2890 ret = snprintf(buf, CRYPTO_MAX_ALG_NAME, "essiv(%s,%s)", 2891 cipher_api, *ivopts); 2892 if (ret < 0 || ret >= CRYPTO_MAX_ALG_NAME) { 2893 ti->error = "Cannot allocate cipher string"; 2894 return -ENOMEM; 2895 } 2896 cipher_api = buf; 2897 } 2898 2899 cc->key_parts = cc->tfms_count; 2900 2901 /* Allocate cipher */ 2902 ret = crypt_alloc_tfms(cc, cipher_api); 2903 if (ret < 0) { 2904 ti->error = "Error allocating crypto tfm"; 2905 return ret; 2906 } 2907 2908 if (crypt_integrity_aead(cc)) 2909 cc->iv_size = crypto_aead_ivsize(any_tfm_aead(cc)); 2910 else 2911 cc->iv_size = crypto_skcipher_ivsize(any_tfm(cc)); 2912 2913 return 0; 2914 } 2915 2916 static int crypt_ctr_cipher_old(struct dm_target *ti, char *cipher_in, char *key, 2917 char **ivmode, char **ivopts) 2918 { 2919 struct crypt_config *cc = ti->private; 2920 char *tmp, *cipher, *chainmode, *keycount; 2921 char *cipher_api = NULL; 2922 int ret = -EINVAL; 2923 char dummy; 2924 2925 if (strchr(cipher_in, '(') || crypt_integrity_aead(cc)) { 2926 ti->error = "Bad cipher specification"; 2927 return -EINVAL; 2928 } 2929 2930 /* 2931 * Legacy dm-crypt cipher specification 2932 * cipher[:keycount]-mode-iv:ivopts 2933 */ 2934 tmp = cipher_in; 2935 keycount = strsep(&tmp, "-"); 2936 cipher = strsep(&keycount, ":"); 2937 2938 if (!keycount) 2939 cc->tfms_count = 1; 2940 else if (sscanf(keycount, "%u%c", &cc->tfms_count, &dummy) != 1 || 2941 !is_power_of_2(cc->tfms_count)) { 2942 ti->error = "Bad cipher key count specification"; 2943 return -EINVAL; 2944 } 2945 cc->key_parts = cc->tfms_count; 2946 2947 chainmode = strsep(&tmp, "-"); 2948 *ivmode = strsep(&tmp, ":"); 2949 *ivopts = tmp; 2950 2951 /* 2952 * For compatibility with the original dm-crypt mapping format, if 2953 * only the cipher name is supplied, use cbc-plain. 2954 */ 2955 if (!chainmode || (!strcmp(chainmode, "plain") && !*ivmode)) { 2956 chainmode = "cbc"; 2957 *ivmode = "plain"; 2958 } 2959 2960 if (strcmp(chainmode, "ecb") && !*ivmode) { 2961 ti->error = "IV mechanism required"; 2962 return -EINVAL; 2963 } 2964 2965 cipher_api = kmalloc(CRYPTO_MAX_ALG_NAME, GFP_KERNEL); 2966 if (!cipher_api) 2967 goto bad_mem; 2968 2969 if (*ivmode && !strcmp(*ivmode, "essiv")) { 2970 if (!*ivopts) { 2971 ti->error = "Digest algorithm missing for ESSIV mode"; 2972 kfree(cipher_api); 2973 return -EINVAL; 2974 } 2975 ret = snprintf(cipher_api, CRYPTO_MAX_ALG_NAME, 2976 "essiv(%s(%s),%s)", chainmode, cipher, *ivopts); 2977 } else { 2978 ret = snprintf(cipher_api, CRYPTO_MAX_ALG_NAME, 2979 "%s(%s)", chainmode, cipher); 2980 } 2981 if (ret < 0 || ret >= CRYPTO_MAX_ALG_NAME) { 2982 kfree(cipher_api); 2983 goto bad_mem; 2984 } 2985 2986 /* Allocate cipher */ 2987 ret = crypt_alloc_tfms(cc, cipher_api); 2988 if (ret < 0) { 2989 ti->error = "Error allocating crypto tfm"; 2990 kfree(cipher_api); 2991 return ret; 2992 } 2993 kfree(cipher_api); 2994 2995 return 0; 2996 bad_mem: 2997 ti->error = "Cannot allocate cipher strings"; 2998 return -ENOMEM; 2999 } 3000 3001 static int crypt_ctr_cipher(struct dm_target *ti, char *cipher_in, char *key) 3002 { 3003 struct crypt_config *cc = ti->private; 3004 char *ivmode = NULL, *ivopts = NULL; 3005 int ret; 3006 3007 cc->cipher_string = kstrdup(cipher_in, GFP_KERNEL); 3008 if (!cc->cipher_string) { 3009 ti->error = "Cannot allocate cipher strings"; 3010 return -ENOMEM; 3011 } 3012 3013 if (strstarts(cipher_in, "capi:")) 3014 ret = crypt_ctr_cipher_new(ti, cipher_in, key, &ivmode, &ivopts); 3015 else 3016 ret = crypt_ctr_cipher_old(ti, cipher_in, key, &ivmode, &ivopts); 3017 if (ret) 3018 return ret; 3019 3020 /* Initialize IV */ 3021 ret = crypt_ctr_ivmode(ti, ivmode); 3022 if (ret < 0) 3023 return ret; 3024 3025 /* Initialize and set key */ 3026 ret = crypt_set_key(cc, key); 3027 if (ret < 0) { 3028 ti->error = "Error decoding and setting key"; 3029 return ret; 3030 } 3031 3032 /* Allocate IV */ 3033 if (cc->iv_gen_ops && cc->iv_gen_ops->ctr) { 3034 ret = cc->iv_gen_ops->ctr(cc, ti, ivopts); 3035 if (ret < 0) { 3036 ti->error = "Error creating IV"; 3037 return ret; 3038 } 3039 } 3040 3041 /* Initialize IV (set keys for ESSIV etc) */ 3042 if (cc->iv_gen_ops && cc->iv_gen_ops->init) { 3043 ret = cc->iv_gen_ops->init(cc); 3044 if (ret < 0) { 3045 ti->error = "Error initialising IV"; 3046 return ret; 3047 } 3048 } 3049 3050 /* wipe the kernel key payload copy */ 3051 if (cc->key_string) 3052 memset(cc->key, 0, cc->key_size * sizeof(u8)); 3053 3054 return ret; 3055 } 3056 3057 static int crypt_ctr_optional(struct dm_target *ti, unsigned int argc, char **argv) 3058 { 3059 struct crypt_config *cc = ti->private; 3060 struct dm_arg_set as; 3061 static const struct dm_arg _args[] = { 3062 {0, 8, "Invalid number of feature args"}, 3063 }; 3064 unsigned int opt_params, val; 3065 const char *opt_string, *sval; 3066 char dummy; 3067 int ret; 3068 3069 /* Optional parameters */ 3070 as.argc = argc; 3071 as.argv = argv; 3072 3073 ret = dm_read_arg_group(_args, &as, &opt_params, &ti->error); 3074 if (ret) 3075 return ret; 3076 3077 while (opt_params--) { 3078 opt_string = dm_shift_arg(&as); 3079 if (!opt_string) { 3080 ti->error = "Not enough feature arguments"; 3081 return -EINVAL; 3082 } 3083 3084 if (!strcasecmp(opt_string, "allow_discards")) 3085 ti->num_discard_bios = 1; 3086 3087 else if (!strcasecmp(opt_string, "same_cpu_crypt")) 3088 set_bit(DM_CRYPT_SAME_CPU, &cc->flags); 3089 3090 else if (!strcasecmp(opt_string, "submit_from_crypt_cpus")) 3091 set_bit(DM_CRYPT_NO_OFFLOAD, &cc->flags); 3092 else if (!strcasecmp(opt_string, "no_read_workqueue")) 3093 set_bit(DM_CRYPT_NO_READ_WORKQUEUE, &cc->flags); 3094 else if (!strcasecmp(opt_string, "no_write_workqueue")) 3095 set_bit(DM_CRYPT_NO_WRITE_WORKQUEUE, &cc->flags); 3096 else if (sscanf(opt_string, "integrity:%u:", &val) == 1) { 3097 if (val == 0 || val > MAX_TAG_SIZE) { 3098 ti->error = "Invalid integrity arguments"; 3099 return -EINVAL; 3100 } 3101 cc->on_disk_tag_size = val; 3102 sval = strchr(opt_string + strlen("integrity:"), ':') + 1; 3103 if (!strcasecmp(sval, "aead")) { 3104 set_bit(CRYPT_MODE_INTEGRITY_AEAD, &cc->cipher_flags); 3105 } else if (strcasecmp(sval, "none")) { 3106 ti->error = "Unknown integrity profile"; 3107 return -EINVAL; 3108 } 3109 3110 cc->cipher_auth = kstrdup(sval, GFP_KERNEL); 3111 if (!cc->cipher_auth) 3112 return -ENOMEM; 3113 } else if (sscanf(opt_string, "sector_size:%hu%c", &cc->sector_size, &dummy) == 1) { 3114 if (cc->sector_size < (1 << SECTOR_SHIFT) || 3115 cc->sector_size > 4096 || 3116 (cc->sector_size & (cc->sector_size - 1))) { 3117 ti->error = "Invalid feature value for sector_size"; 3118 return -EINVAL; 3119 } 3120 if (ti->len & ((cc->sector_size >> SECTOR_SHIFT) - 1)) { 3121 ti->error = "Device size is not multiple of sector_size feature"; 3122 return -EINVAL; 3123 } 3124 cc->sector_shift = __ffs(cc->sector_size) - SECTOR_SHIFT; 3125 } else if (!strcasecmp(opt_string, "iv_large_sectors")) 3126 set_bit(CRYPT_IV_LARGE_SECTORS, &cc->cipher_flags); 3127 else { 3128 ti->error = "Invalid feature arguments"; 3129 return -EINVAL; 3130 } 3131 } 3132 3133 return 0; 3134 } 3135 3136 #ifdef CONFIG_BLK_DEV_ZONED 3137 static int crypt_report_zones(struct dm_target *ti, 3138 struct dm_report_zones_args *args, unsigned int nr_zones) 3139 { 3140 struct crypt_config *cc = ti->private; 3141 sector_t sector = cc->start + dm_target_offset(ti, args->next_sector); 3142 3143 args->start = cc->start; 3144 return blkdev_report_zones(cc->dev->bdev, sector, nr_zones, 3145 dm_report_zones_cb, args); 3146 } 3147 #else 3148 #define crypt_report_zones NULL 3149 #endif 3150 3151 /* 3152 * Construct an encryption mapping: 3153 * <cipher> [<key>|:<key_size>:<user|logon>:<key_description>] <iv_offset> <dev_path> <start> 3154 */ 3155 static int crypt_ctr(struct dm_target *ti, unsigned int argc, char **argv) 3156 { 3157 struct crypt_config *cc; 3158 const char *devname = dm_table_device_name(ti->table); 3159 int key_size; 3160 unsigned int align_mask; 3161 unsigned long long tmpll; 3162 int ret; 3163 size_t iv_size_padding, additional_req_size; 3164 char dummy; 3165 3166 if (argc < 5) { 3167 ti->error = "Not enough arguments"; 3168 return -EINVAL; 3169 } 3170 3171 key_size = get_key_size(&argv[1]); 3172 if (key_size < 0) { 3173 ti->error = "Cannot parse key size"; 3174 return -EINVAL; 3175 } 3176 3177 cc = kzalloc(struct_size(cc, key, key_size), GFP_KERNEL); 3178 if (!cc) { 3179 ti->error = "Cannot allocate encryption context"; 3180 return -ENOMEM; 3181 } 3182 cc->key_size = key_size; 3183 cc->sector_size = (1 << SECTOR_SHIFT); 3184 cc->sector_shift = 0; 3185 3186 ti->private = cc; 3187 3188 spin_lock(&dm_crypt_clients_lock); 3189 dm_crypt_clients_n++; 3190 crypt_calculate_pages_per_client(); 3191 spin_unlock(&dm_crypt_clients_lock); 3192 3193 ret = percpu_counter_init(&cc->n_allocated_pages, 0, GFP_KERNEL); 3194 if (ret < 0) 3195 goto bad; 3196 3197 /* Optional parameters need to be read before cipher constructor */ 3198 if (argc > 5) { 3199 ret = crypt_ctr_optional(ti, argc - 5, &argv[5]); 3200 if (ret) 3201 goto bad; 3202 } 3203 3204 ret = crypt_ctr_cipher(ti, argv[0], argv[1]); 3205 if (ret < 0) 3206 goto bad; 3207 3208 if (crypt_integrity_aead(cc)) { 3209 cc->dmreq_start = sizeof(struct aead_request); 3210 cc->dmreq_start += crypto_aead_reqsize(any_tfm_aead(cc)); 3211 align_mask = crypto_aead_alignmask(any_tfm_aead(cc)); 3212 } else { 3213 cc->dmreq_start = sizeof(struct skcipher_request); 3214 cc->dmreq_start += crypto_skcipher_reqsize(any_tfm(cc)); 3215 align_mask = crypto_skcipher_alignmask(any_tfm(cc)); 3216 } 3217 cc->dmreq_start = ALIGN(cc->dmreq_start, __alignof__(struct dm_crypt_request)); 3218 3219 if (align_mask < CRYPTO_MINALIGN) { 3220 /* Allocate the padding exactly */ 3221 iv_size_padding = -(cc->dmreq_start + sizeof(struct dm_crypt_request)) 3222 & align_mask; 3223 } else { 3224 /* 3225 * If the cipher requires greater alignment than kmalloc 3226 * alignment, we don't know the exact position of the 3227 * initialization vector. We must assume worst case. 3228 */ 3229 iv_size_padding = align_mask; 3230 } 3231 3232 /* ...| IV + padding | original IV | original sec. number | bio tag offset | */ 3233 additional_req_size = sizeof(struct dm_crypt_request) + 3234 iv_size_padding + cc->iv_size + 3235 cc->iv_size + 3236 sizeof(uint64_t) + 3237 sizeof(unsigned int); 3238 3239 ret = mempool_init_kmalloc_pool(&cc->req_pool, MIN_IOS, cc->dmreq_start + additional_req_size); 3240 if (ret) { 3241 ti->error = "Cannot allocate crypt request mempool"; 3242 goto bad; 3243 } 3244 3245 cc->per_bio_data_size = ti->per_io_data_size = 3246 ALIGN(sizeof(struct dm_crypt_io) + cc->dmreq_start + additional_req_size, 3247 ARCH_KMALLOC_MINALIGN); 3248 3249 ret = mempool_init(&cc->page_pool, BIO_MAX_VECS, crypt_page_alloc, crypt_page_free, cc); 3250 if (ret) { 3251 ti->error = "Cannot allocate page mempool"; 3252 goto bad; 3253 } 3254 3255 ret = bioset_init(&cc->bs, MIN_IOS, 0, BIOSET_NEED_BVECS); 3256 if (ret) { 3257 ti->error = "Cannot allocate crypt bioset"; 3258 goto bad; 3259 } 3260 3261 mutex_init(&cc->bio_alloc_lock); 3262 3263 ret = -EINVAL; 3264 if ((sscanf(argv[2], "%llu%c", &tmpll, &dummy) != 1) || 3265 (tmpll & ((cc->sector_size >> SECTOR_SHIFT) - 1))) { 3266 ti->error = "Invalid iv_offset sector"; 3267 goto bad; 3268 } 3269 cc->iv_offset = tmpll; 3270 3271 ret = dm_get_device(ti, argv[3], dm_table_get_mode(ti->table), &cc->dev); 3272 if (ret) { 3273 ti->error = "Device lookup failed"; 3274 goto bad; 3275 } 3276 3277 ret = -EINVAL; 3278 if (sscanf(argv[4], "%llu%c", &tmpll, &dummy) != 1 || tmpll != (sector_t)tmpll) { 3279 ti->error = "Invalid device sector"; 3280 goto bad; 3281 } 3282 cc->start = tmpll; 3283 3284 /* 3285 * For zoned block devices, we need to preserve the issuer write 3286 * ordering. To do so, disable write workqueues and force inline 3287 * encryption completion. 3288 */ 3289 if (bdev_is_zoned(cc->dev->bdev)) { 3290 set_bit(DM_CRYPT_NO_WRITE_WORKQUEUE, &cc->flags); 3291 set_bit(DM_CRYPT_WRITE_INLINE, &cc->flags); 3292 } 3293 3294 if (crypt_integrity_aead(cc) || cc->integrity_iv_size) { 3295 ret = crypt_integrity_ctr(cc, ti); 3296 if (ret) 3297 goto bad; 3298 3299 cc->tag_pool_max_sectors = POOL_ENTRY_SIZE / cc->on_disk_tag_size; 3300 if (!cc->tag_pool_max_sectors) 3301 cc->tag_pool_max_sectors = 1; 3302 3303 ret = mempool_init_kmalloc_pool(&cc->tag_pool, MIN_IOS, 3304 cc->tag_pool_max_sectors * cc->on_disk_tag_size); 3305 if (ret) { 3306 ti->error = "Cannot allocate integrity tags mempool"; 3307 goto bad; 3308 } 3309 3310 cc->tag_pool_max_sectors <<= cc->sector_shift; 3311 } 3312 3313 ret = -ENOMEM; 3314 cc->io_queue = alloc_workqueue("kcryptd_io/%s", WQ_MEM_RECLAIM, 1, devname); 3315 if (!cc->io_queue) { 3316 ti->error = "Couldn't create kcryptd io queue"; 3317 goto bad; 3318 } 3319 3320 if (test_bit(DM_CRYPT_SAME_CPU, &cc->flags)) 3321 cc->crypt_queue = alloc_workqueue("kcryptd/%s", WQ_CPU_INTENSIVE | WQ_MEM_RECLAIM, 3322 1, devname); 3323 else 3324 cc->crypt_queue = alloc_workqueue("kcryptd/%s", 3325 WQ_CPU_INTENSIVE | WQ_MEM_RECLAIM | WQ_UNBOUND, 3326 num_online_cpus(), devname); 3327 if (!cc->crypt_queue) { 3328 ti->error = "Couldn't create kcryptd queue"; 3329 goto bad; 3330 } 3331 3332 spin_lock_init(&cc->write_thread_lock); 3333 cc->write_tree = RB_ROOT; 3334 3335 cc->write_thread = kthread_create(dmcrypt_write, cc, "dmcrypt_write/%s", devname); 3336 if (IS_ERR(cc->write_thread)) { 3337 ret = PTR_ERR(cc->write_thread); 3338 cc->write_thread = NULL; 3339 ti->error = "Couldn't spawn write thread"; 3340 goto bad; 3341 } 3342 wake_up_process(cc->write_thread); 3343 3344 ti->num_flush_bios = 1; 3345 ti->limit_swap_bios = true; 3346 3347 return 0; 3348 3349 bad: 3350 crypt_dtr(ti); 3351 return ret; 3352 } 3353 3354 static int crypt_map(struct dm_target *ti, struct bio *bio) 3355 { 3356 struct dm_crypt_io *io; 3357 struct crypt_config *cc = ti->private; 3358 3359 /* 3360 * If bio is REQ_PREFLUSH or REQ_OP_DISCARD, just bypass crypt queues. 3361 * - for REQ_PREFLUSH device-mapper core ensures that no IO is in-flight 3362 * - for REQ_OP_DISCARD caller must use flush if IO ordering matters 3363 */ 3364 if (unlikely(bio->bi_opf & REQ_PREFLUSH || 3365 bio_op(bio) == REQ_OP_DISCARD)) { 3366 bio_set_dev(bio, cc->dev->bdev); 3367 if (bio_sectors(bio)) 3368 bio->bi_iter.bi_sector = cc->start + 3369 dm_target_offset(ti, bio->bi_iter.bi_sector); 3370 return DM_MAPIO_REMAPPED; 3371 } 3372 3373 /* 3374 * Check if bio is too large, split as needed. 3375 */ 3376 if (unlikely(bio->bi_iter.bi_size > (BIO_MAX_VECS << PAGE_SHIFT)) && 3377 (bio_data_dir(bio) == WRITE || cc->on_disk_tag_size)) 3378 dm_accept_partial_bio(bio, ((BIO_MAX_VECS << PAGE_SHIFT) >> SECTOR_SHIFT)); 3379 3380 /* 3381 * Ensure that bio is a multiple of internal sector encryption size 3382 * and is aligned to this size as defined in IO hints. 3383 */ 3384 if (unlikely((bio->bi_iter.bi_sector & ((cc->sector_size >> SECTOR_SHIFT) - 1)) != 0)) 3385 return DM_MAPIO_KILL; 3386 3387 if (unlikely(bio->bi_iter.bi_size & (cc->sector_size - 1))) 3388 return DM_MAPIO_KILL; 3389 3390 io = dm_per_bio_data(bio, cc->per_bio_data_size); 3391 crypt_io_init(io, cc, bio, dm_target_offset(ti, bio->bi_iter.bi_sector)); 3392 3393 if (cc->on_disk_tag_size) { 3394 unsigned tag_len = cc->on_disk_tag_size * (bio_sectors(bio) >> cc->sector_shift); 3395 3396 if (unlikely(tag_len > KMALLOC_MAX_SIZE) || 3397 unlikely(!(io->integrity_metadata = kmalloc(tag_len, 3398 GFP_NOIO | __GFP_NORETRY | __GFP_NOMEMALLOC | __GFP_NOWARN)))) { 3399 if (bio_sectors(bio) > cc->tag_pool_max_sectors) 3400 dm_accept_partial_bio(bio, cc->tag_pool_max_sectors); 3401 io->integrity_metadata = mempool_alloc(&cc->tag_pool, GFP_NOIO); 3402 io->integrity_metadata_from_pool = true; 3403 } 3404 } 3405 3406 if (crypt_integrity_aead(cc)) 3407 io->ctx.r.req_aead = (struct aead_request *)(io + 1); 3408 else 3409 io->ctx.r.req = (struct skcipher_request *)(io + 1); 3410 3411 if (bio_data_dir(io->base_bio) == READ) { 3412 if (kcryptd_io_read(io, GFP_NOWAIT)) 3413 kcryptd_queue_read(io); 3414 } else 3415 kcryptd_queue_crypt(io); 3416 3417 return DM_MAPIO_SUBMITTED; 3418 } 3419 3420 static void crypt_status(struct dm_target *ti, status_type_t type, 3421 unsigned status_flags, char *result, unsigned maxlen) 3422 { 3423 struct crypt_config *cc = ti->private; 3424 unsigned i, sz = 0; 3425 int num_feature_args = 0; 3426 3427 switch (type) { 3428 case STATUSTYPE_INFO: 3429 result[0] = '\0'; 3430 break; 3431 3432 case STATUSTYPE_TABLE: 3433 DMEMIT("%s ", cc->cipher_string); 3434 3435 if (cc->key_size > 0) { 3436 if (cc->key_string) 3437 DMEMIT(":%u:%s", cc->key_size, cc->key_string); 3438 else 3439 for (i = 0; i < cc->key_size; i++) 3440 DMEMIT("%02x", cc->key[i]); 3441 } else 3442 DMEMIT("-"); 3443 3444 DMEMIT(" %llu %s %llu", (unsigned long long)cc->iv_offset, 3445 cc->dev->name, (unsigned long long)cc->start); 3446 3447 num_feature_args += !!ti->num_discard_bios; 3448 num_feature_args += test_bit(DM_CRYPT_SAME_CPU, &cc->flags); 3449 num_feature_args += test_bit(DM_CRYPT_NO_OFFLOAD, &cc->flags); 3450 num_feature_args += test_bit(DM_CRYPT_NO_READ_WORKQUEUE, &cc->flags); 3451 num_feature_args += test_bit(DM_CRYPT_NO_WRITE_WORKQUEUE, &cc->flags); 3452 num_feature_args += cc->sector_size != (1 << SECTOR_SHIFT); 3453 num_feature_args += test_bit(CRYPT_IV_LARGE_SECTORS, &cc->cipher_flags); 3454 if (cc->on_disk_tag_size) 3455 num_feature_args++; 3456 if (num_feature_args) { 3457 DMEMIT(" %d", num_feature_args); 3458 if (ti->num_discard_bios) 3459 DMEMIT(" allow_discards"); 3460 if (test_bit(DM_CRYPT_SAME_CPU, &cc->flags)) 3461 DMEMIT(" same_cpu_crypt"); 3462 if (test_bit(DM_CRYPT_NO_OFFLOAD, &cc->flags)) 3463 DMEMIT(" submit_from_crypt_cpus"); 3464 if (test_bit(DM_CRYPT_NO_READ_WORKQUEUE, &cc->flags)) 3465 DMEMIT(" no_read_workqueue"); 3466 if (test_bit(DM_CRYPT_NO_WRITE_WORKQUEUE, &cc->flags)) 3467 DMEMIT(" no_write_workqueue"); 3468 if (cc->on_disk_tag_size) 3469 DMEMIT(" integrity:%u:%s", cc->on_disk_tag_size, cc->cipher_auth); 3470 if (cc->sector_size != (1 << SECTOR_SHIFT)) 3471 DMEMIT(" sector_size:%d", cc->sector_size); 3472 if (test_bit(CRYPT_IV_LARGE_SECTORS, &cc->cipher_flags)) 3473 DMEMIT(" iv_large_sectors"); 3474 } 3475 3476 break; 3477 } 3478 } 3479 3480 static void crypt_postsuspend(struct dm_target *ti) 3481 { 3482 struct crypt_config *cc = ti->private; 3483 3484 set_bit(DM_CRYPT_SUSPENDED, &cc->flags); 3485 } 3486 3487 static int crypt_preresume(struct dm_target *ti) 3488 { 3489 struct crypt_config *cc = ti->private; 3490 3491 if (!test_bit(DM_CRYPT_KEY_VALID, &cc->flags)) { 3492 DMERR("aborting resume - crypt key is not set."); 3493 return -EAGAIN; 3494 } 3495 3496 return 0; 3497 } 3498 3499 static void crypt_resume(struct dm_target *ti) 3500 { 3501 struct crypt_config *cc = ti->private; 3502 3503 clear_bit(DM_CRYPT_SUSPENDED, &cc->flags); 3504 } 3505 3506 /* Message interface 3507 * key set <key> 3508 * key wipe 3509 */ 3510 static int crypt_message(struct dm_target *ti, unsigned argc, char **argv, 3511 char *result, unsigned maxlen) 3512 { 3513 struct crypt_config *cc = ti->private; 3514 int key_size, ret = -EINVAL; 3515 3516 if (argc < 2) 3517 goto error; 3518 3519 if (!strcasecmp(argv[0], "key")) { 3520 if (!test_bit(DM_CRYPT_SUSPENDED, &cc->flags)) { 3521 DMWARN("not suspended during key manipulation."); 3522 return -EINVAL; 3523 } 3524 if (argc == 3 && !strcasecmp(argv[1], "set")) { 3525 /* The key size may not be changed. */ 3526 key_size = get_key_size(&argv[2]); 3527 if (key_size < 0 || cc->key_size != key_size) { 3528 memset(argv[2], '0', strlen(argv[2])); 3529 return -EINVAL; 3530 } 3531 3532 ret = crypt_set_key(cc, argv[2]); 3533 if (ret) 3534 return ret; 3535 if (cc->iv_gen_ops && cc->iv_gen_ops->init) 3536 ret = cc->iv_gen_ops->init(cc); 3537 /* wipe the kernel key payload copy */ 3538 if (cc->key_string) 3539 memset(cc->key, 0, cc->key_size * sizeof(u8)); 3540 return ret; 3541 } 3542 if (argc == 2 && !strcasecmp(argv[1], "wipe")) 3543 return crypt_wipe_key(cc); 3544 } 3545 3546 error: 3547 DMWARN("unrecognised message received."); 3548 return -EINVAL; 3549 } 3550 3551 static int crypt_iterate_devices(struct dm_target *ti, 3552 iterate_devices_callout_fn fn, void *data) 3553 { 3554 struct crypt_config *cc = ti->private; 3555 3556 return fn(ti, cc->dev, cc->start, ti->len, data); 3557 } 3558 3559 static void crypt_io_hints(struct dm_target *ti, struct queue_limits *limits) 3560 { 3561 struct crypt_config *cc = ti->private; 3562 3563 /* 3564 * Unfortunate constraint that is required to avoid the potential 3565 * for exceeding underlying device's max_segments limits -- due to 3566 * crypt_alloc_buffer() possibly allocating pages for the encryption 3567 * bio that are not as physically contiguous as the original bio. 3568 */ 3569 limits->max_segment_size = PAGE_SIZE; 3570 3571 limits->logical_block_size = 3572 max_t(unsigned, limits->logical_block_size, cc->sector_size); 3573 limits->physical_block_size = 3574 max_t(unsigned, limits->physical_block_size, cc->sector_size); 3575 limits->io_min = max_t(unsigned, limits->io_min, cc->sector_size); 3576 } 3577 3578 static struct target_type crypt_target = { 3579 .name = "crypt", 3580 .version = {1, 23, 0}, 3581 .module = THIS_MODULE, 3582 .ctr = crypt_ctr, 3583 .dtr = crypt_dtr, 3584 .features = DM_TARGET_ZONED_HM, 3585 .report_zones = crypt_report_zones, 3586 .map = crypt_map, 3587 .status = crypt_status, 3588 .postsuspend = crypt_postsuspend, 3589 .preresume = crypt_preresume, 3590 .resume = crypt_resume, 3591 .message = crypt_message, 3592 .iterate_devices = crypt_iterate_devices, 3593 .io_hints = crypt_io_hints, 3594 }; 3595 3596 static int __init dm_crypt_init(void) 3597 { 3598 int r; 3599 3600 r = dm_register_target(&crypt_target); 3601 if (r < 0) 3602 DMERR("register failed %d", r); 3603 3604 return r; 3605 } 3606 3607 static void __exit dm_crypt_exit(void) 3608 { 3609 dm_unregister_target(&crypt_target); 3610 } 3611 3612 module_init(dm_crypt_init); 3613 module_exit(dm_crypt_exit); 3614 3615 MODULE_AUTHOR("Jana Saout <jana@saout.de>"); 3616 MODULE_DESCRIPTION(DM_NAME " target for transparent encryption / decryption"); 3617 MODULE_LICENSE("GPL"); 3618