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/blk-integrity.h> 19 #include <linux/mempool.h> 20 #include <linux/slab.h> 21 #include <linux/crypto.h> 22 #include <linux/workqueue.h> 23 #include <linux/kthread.h> 24 #include <linux/backing-dev.h> 25 #include <linux/atomic.h> 26 #include <linux/scatterlist.h> 27 #include <linux/rbtree.h> 28 #include <linux/ctype.h> 29 #include <asm/page.h> 30 #include <asm/unaligned.h> 31 #include <crypto/hash.h> 32 #include <crypto/md5.h> 33 #include <crypto/algapi.h> 34 #include <crypto/skcipher.h> 35 #include <crypto/aead.h> 36 #include <crypto/authenc.h> 37 #include <linux/rtnetlink.h> /* for struct rtattr and RTA macros only */ 38 #include <linux/key-type.h> 39 #include <keys/user-type.h> 40 #include <keys/encrypted-type.h> 41 #include <keys/trusted-type.h> 42 43 #include <linux/device-mapper.h> 44 45 #include "dm-audit.h" 46 47 #define DM_MSG_PREFIX "crypt" 48 49 /* 50 * context holding the current state of a multi-part conversion 51 */ 52 struct convert_context { 53 struct completion restart; 54 struct bio *bio_in; 55 struct bio *bio_out; 56 struct bvec_iter iter_in; 57 struct bvec_iter iter_out; 58 u64 cc_sector; 59 atomic_t cc_pending; 60 union { 61 struct skcipher_request *req; 62 struct aead_request *req_aead; 63 } r; 64 65 }; 66 67 /* 68 * per bio private data 69 */ 70 struct dm_crypt_io { 71 struct crypt_config *cc; 72 struct bio *base_bio; 73 u8 *integrity_metadata; 74 bool integrity_metadata_from_pool; 75 struct work_struct work; 76 struct tasklet_struct tasklet; 77 78 struct convert_context ctx; 79 80 atomic_t io_pending; 81 blk_status_t error; 82 sector_t sector; 83 84 struct rb_node rb_node; 85 } CRYPTO_MINALIGN_ATTR; 86 87 struct dm_crypt_request { 88 struct convert_context *ctx; 89 struct scatterlist sg_in[4]; 90 struct scatterlist sg_out[4]; 91 u64 iv_sector; 92 }; 93 94 struct crypt_config; 95 96 struct crypt_iv_operations { 97 int (*ctr)(struct crypt_config *cc, struct dm_target *ti, 98 const char *opts); 99 void (*dtr)(struct crypt_config *cc); 100 int (*init)(struct crypt_config *cc); 101 int (*wipe)(struct crypt_config *cc); 102 int (*generator)(struct crypt_config *cc, u8 *iv, 103 struct dm_crypt_request *dmreq); 104 int (*post)(struct crypt_config *cc, u8 *iv, 105 struct dm_crypt_request *dmreq); 106 }; 107 108 struct iv_benbi_private { 109 int shift; 110 }; 111 112 #define LMK_SEED_SIZE 64 /* hash + 0 */ 113 struct iv_lmk_private { 114 struct crypto_shash *hash_tfm; 115 u8 *seed; 116 }; 117 118 #define TCW_WHITENING_SIZE 16 119 struct iv_tcw_private { 120 struct crypto_shash *crc32_tfm; 121 u8 *iv_seed; 122 u8 *whitening; 123 }; 124 125 #define ELEPHANT_MAX_KEY_SIZE 32 126 struct iv_elephant_private { 127 struct crypto_skcipher *tfm; 128 }; 129 130 /* 131 * Crypt: maps a linear range of a block device 132 * and encrypts / decrypts at the same time. 133 */ 134 enum flags { DM_CRYPT_SUSPENDED, DM_CRYPT_KEY_VALID, 135 DM_CRYPT_SAME_CPU, DM_CRYPT_NO_OFFLOAD, 136 DM_CRYPT_NO_READ_WORKQUEUE, DM_CRYPT_NO_WRITE_WORKQUEUE, 137 DM_CRYPT_WRITE_INLINE }; 138 139 enum cipher_flags { 140 CRYPT_MODE_INTEGRITY_AEAD, /* Use authenticated mode for cipher */ 141 CRYPT_IV_LARGE_SECTORS, /* Calculate IV from sector_size, not 512B sectors */ 142 CRYPT_ENCRYPT_PREPROCESS, /* Must preprocess data for encryption (elephant) */ 143 }; 144 145 /* 146 * The fields in here must be read only after initialization. 147 */ 148 struct crypt_config { 149 struct dm_dev *dev; 150 sector_t start; 151 152 struct percpu_counter n_allocated_pages; 153 154 struct workqueue_struct *io_queue; 155 struct workqueue_struct *crypt_queue; 156 157 spinlock_t write_thread_lock; 158 struct task_struct *write_thread; 159 struct rb_root write_tree; 160 161 char *cipher_string; 162 char *cipher_auth; 163 char *key_string; 164 165 const struct crypt_iv_operations *iv_gen_ops; 166 union { 167 struct iv_benbi_private benbi; 168 struct iv_lmk_private lmk; 169 struct iv_tcw_private tcw; 170 struct iv_elephant_private elephant; 171 } iv_gen_private; 172 u64 iv_offset; 173 unsigned int iv_size; 174 unsigned short int sector_size; 175 unsigned char sector_shift; 176 177 union { 178 struct crypto_skcipher **tfms; 179 struct crypto_aead **tfms_aead; 180 } cipher_tfm; 181 unsigned tfms_count; 182 unsigned long cipher_flags; 183 184 /* 185 * Layout of each crypto request: 186 * 187 * struct skcipher_request 188 * context 189 * padding 190 * struct dm_crypt_request 191 * padding 192 * IV 193 * 194 * The padding is added so that dm_crypt_request and the IV are 195 * correctly aligned. 196 */ 197 unsigned int dmreq_start; 198 199 unsigned int per_bio_data_size; 200 201 unsigned long flags; 202 unsigned int key_size; 203 unsigned int key_parts; /* independent parts in key buffer */ 204 unsigned int key_extra_size; /* additional keys length */ 205 unsigned int key_mac_size; /* MAC key size for authenc(...) */ 206 207 unsigned int integrity_tag_size; 208 unsigned int integrity_iv_size; 209 unsigned int on_disk_tag_size; 210 211 /* 212 * pool for per bio private data, crypto requests, 213 * encryption requeusts/buffer pages and integrity tags 214 */ 215 unsigned tag_pool_max_sectors; 216 mempool_t tag_pool; 217 mempool_t req_pool; 218 mempool_t page_pool; 219 220 struct bio_set bs; 221 struct mutex bio_alloc_lock; 222 223 u8 *authenc_key; /* space for keys in authenc() format (if used) */ 224 u8 key[]; 225 }; 226 227 #define MIN_IOS 64 228 #define MAX_TAG_SIZE 480 229 #define POOL_ENTRY_SIZE 512 230 231 static DEFINE_SPINLOCK(dm_crypt_clients_lock); 232 static unsigned dm_crypt_clients_n = 0; 233 static volatile unsigned long dm_crypt_pages_per_client; 234 #define DM_CRYPT_MEMORY_PERCENT 2 235 #define DM_CRYPT_MIN_PAGES_PER_CLIENT (BIO_MAX_VECS * 16) 236 237 static void crypt_endio(struct bio *clone); 238 static void kcryptd_queue_crypt(struct dm_crypt_io *io); 239 static struct scatterlist *crypt_get_sg_data(struct crypt_config *cc, 240 struct scatterlist *sg); 241 242 static bool crypt_integrity_aead(struct crypt_config *cc); 243 244 /* 245 * Use this to access cipher attributes that are independent of the key. 246 */ 247 static struct crypto_skcipher *any_tfm(struct crypt_config *cc) 248 { 249 return cc->cipher_tfm.tfms[0]; 250 } 251 252 static struct crypto_aead *any_tfm_aead(struct crypt_config *cc) 253 { 254 return cc->cipher_tfm.tfms_aead[0]; 255 } 256 257 /* 258 * Different IV generation algorithms: 259 * 260 * plain: the initial vector is the 32-bit little-endian version of the sector 261 * number, padded with zeros if necessary. 262 * 263 * plain64: the initial vector is the 64-bit little-endian version of the sector 264 * number, padded with zeros if necessary. 265 * 266 * plain64be: the initial vector is the 64-bit big-endian version of the sector 267 * number, padded with zeros if necessary. 268 * 269 * essiv: "encrypted sector|salt initial vector", the sector number is 270 * encrypted with the bulk cipher using a salt as key. The salt 271 * should be derived from the bulk cipher's key via hashing. 272 * 273 * benbi: the 64-bit "big-endian 'narrow block'-count", starting at 1 274 * (needed for LRW-32-AES and possible other narrow block modes) 275 * 276 * null: the initial vector is always zero. Provides compatibility with 277 * obsolete loop_fish2 devices. Do not use for new devices. 278 * 279 * lmk: Compatible implementation of the block chaining mode used 280 * by the Loop-AES block device encryption system 281 * designed by Jari Ruusu. See http://loop-aes.sourceforge.net/ 282 * It operates on full 512 byte sectors and uses CBC 283 * with an IV derived from the sector number, the data and 284 * optionally extra IV seed. 285 * This means that after decryption the first block 286 * of sector must be tweaked according to decrypted data. 287 * Loop-AES can use three encryption schemes: 288 * version 1: is plain aes-cbc mode 289 * version 2: uses 64 multikey scheme with lmk IV generator 290 * version 3: the same as version 2 with additional IV seed 291 * (it uses 65 keys, last key is used as IV seed) 292 * 293 * tcw: Compatible implementation of the block chaining mode used 294 * by the TrueCrypt device encryption system (prior to version 4.1). 295 * For more info see: https://gitlab.com/cryptsetup/cryptsetup/wikis/TrueCryptOnDiskFormat 296 * It operates on full 512 byte sectors and uses CBC 297 * with an IV derived from initial key and the sector number. 298 * In addition, whitening value is applied on every sector, whitening 299 * is calculated from initial key, sector number and mixed using CRC32. 300 * Note that this encryption scheme is vulnerable to watermarking attacks 301 * and should be used for old compatible containers access only. 302 * 303 * eboiv: Encrypted byte-offset IV (used in Bitlocker in CBC mode) 304 * The IV is encrypted little-endian byte-offset (with the same key 305 * and cipher as the volume). 306 * 307 * elephant: The extended version of eboiv with additional Elephant diffuser 308 * used with Bitlocker CBC mode. 309 * This mode was used in older Windows systems 310 * https://download.microsoft.com/download/0/2/3/0238acaf-d3bf-4a6d-b3d6-0a0be4bbb36e/bitlockercipher200608.pdf 311 */ 312 313 static int crypt_iv_plain_gen(struct crypt_config *cc, u8 *iv, 314 struct dm_crypt_request *dmreq) 315 { 316 memset(iv, 0, cc->iv_size); 317 *(__le32 *)iv = cpu_to_le32(dmreq->iv_sector & 0xffffffff); 318 319 return 0; 320 } 321 322 static int crypt_iv_plain64_gen(struct crypt_config *cc, u8 *iv, 323 struct dm_crypt_request *dmreq) 324 { 325 memset(iv, 0, cc->iv_size); 326 *(__le64 *)iv = cpu_to_le64(dmreq->iv_sector); 327 328 return 0; 329 } 330 331 static int crypt_iv_plain64be_gen(struct crypt_config *cc, u8 *iv, 332 struct dm_crypt_request *dmreq) 333 { 334 memset(iv, 0, cc->iv_size); 335 /* iv_size is at least of size u64; usually it is 16 bytes */ 336 *(__be64 *)&iv[cc->iv_size - sizeof(u64)] = cpu_to_be64(dmreq->iv_sector); 337 338 return 0; 339 } 340 341 static int crypt_iv_essiv_gen(struct crypt_config *cc, u8 *iv, 342 struct dm_crypt_request *dmreq) 343 { 344 /* 345 * ESSIV encryption of the IV is now handled by the crypto API, 346 * so just pass the plain sector number here. 347 */ 348 memset(iv, 0, cc->iv_size); 349 *(__le64 *)iv = cpu_to_le64(dmreq->iv_sector); 350 351 return 0; 352 } 353 354 static int crypt_iv_benbi_ctr(struct crypt_config *cc, struct dm_target *ti, 355 const char *opts) 356 { 357 unsigned bs; 358 int log; 359 360 if (crypt_integrity_aead(cc)) 361 bs = crypto_aead_blocksize(any_tfm_aead(cc)); 362 else 363 bs = crypto_skcipher_blocksize(any_tfm(cc)); 364 log = ilog2(bs); 365 366 /* we need to calculate how far we must shift the sector count 367 * to get the cipher block count, we use this shift in _gen */ 368 369 if (1 << log != bs) { 370 ti->error = "cypher blocksize is not a power of 2"; 371 return -EINVAL; 372 } 373 374 if (log > 9) { 375 ti->error = "cypher blocksize is > 512"; 376 return -EINVAL; 377 } 378 379 cc->iv_gen_private.benbi.shift = 9 - log; 380 381 return 0; 382 } 383 384 static void crypt_iv_benbi_dtr(struct crypt_config *cc) 385 { 386 } 387 388 static int crypt_iv_benbi_gen(struct crypt_config *cc, u8 *iv, 389 struct dm_crypt_request *dmreq) 390 { 391 __be64 val; 392 393 memset(iv, 0, cc->iv_size - sizeof(u64)); /* rest is cleared below */ 394 395 val = cpu_to_be64(((u64)dmreq->iv_sector << cc->iv_gen_private.benbi.shift) + 1); 396 put_unaligned(val, (__be64 *)(iv + cc->iv_size - sizeof(u64))); 397 398 return 0; 399 } 400 401 static int crypt_iv_null_gen(struct crypt_config *cc, u8 *iv, 402 struct dm_crypt_request *dmreq) 403 { 404 memset(iv, 0, cc->iv_size); 405 406 return 0; 407 } 408 409 static void crypt_iv_lmk_dtr(struct crypt_config *cc) 410 { 411 struct iv_lmk_private *lmk = &cc->iv_gen_private.lmk; 412 413 if (lmk->hash_tfm && !IS_ERR(lmk->hash_tfm)) 414 crypto_free_shash(lmk->hash_tfm); 415 lmk->hash_tfm = NULL; 416 417 kfree_sensitive(lmk->seed); 418 lmk->seed = NULL; 419 } 420 421 static int crypt_iv_lmk_ctr(struct crypt_config *cc, struct dm_target *ti, 422 const char *opts) 423 { 424 struct iv_lmk_private *lmk = &cc->iv_gen_private.lmk; 425 426 if (cc->sector_size != (1 << SECTOR_SHIFT)) { 427 ti->error = "Unsupported sector size for LMK"; 428 return -EINVAL; 429 } 430 431 lmk->hash_tfm = crypto_alloc_shash("md5", 0, 432 CRYPTO_ALG_ALLOCATES_MEMORY); 433 if (IS_ERR(lmk->hash_tfm)) { 434 ti->error = "Error initializing LMK hash"; 435 return PTR_ERR(lmk->hash_tfm); 436 } 437 438 /* No seed in LMK version 2 */ 439 if (cc->key_parts == cc->tfms_count) { 440 lmk->seed = NULL; 441 return 0; 442 } 443 444 lmk->seed = kzalloc(LMK_SEED_SIZE, GFP_KERNEL); 445 if (!lmk->seed) { 446 crypt_iv_lmk_dtr(cc); 447 ti->error = "Error kmallocing seed storage in LMK"; 448 return -ENOMEM; 449 } 450 451 return 0; 452 } 453 454 static int crypt_iv_lmk_init(struct crypt_config *cc) 455 { 456 struct iv_lmk_private *lmk = &cc->iv_gen_private.lmk; 457 int subkey_size = cc->key_size / cc->key_parts; 458 459 /* LMK seed is on the position of LMK_KEYS + 1 key */ 460 if (lmk->seed) 461 memcpy(lmk->seed, cc->key + (cc->tfms_count * subkey_size), 462 crypto_shash_digestsize(lmk->hash_tfm)); 463 464 return 0; 465 } 466 467 static int crypt_iv_lmk_wipe(struct crypt_config *cc) 468 { 469 struct iv_lmk_private *lmk = &cc->iv_gen_private.lmk; 470 471 if (lmk->seed) 472 memset(lmk->seed, 0, LMK_SEED_SIZE); 473 474 return 0; 475 } 476 477 static int crypt_iv_lmk_one(struct crypt_config *cc, u8 *iv, 478 struct dm_crypt_request *dmreq, 479 u8 *data) 480 { 481 struct iv_lmk_private *lmk = &cc->iv_gen_private.lmk; 482 SHASH_DESC_ON_STACK(desc, lmk->hash_tfm); 483 struct md5_state md5state; 484 __le32 buf[4]; 485 int i, r; 486 487 desc->tfm = lmk->hash_tfm; 488 489 r = crypto_shash_init(desc); 490 if (r) 491 return r; 492 493 if (lmk->seed) { 494 r = crypto_shash_update(desc, lmk->seed, LMK_SEED_SIZE); 495 if (r) 496 return r; 497 } 498 499 /* Sector is always 512B, block size 16, add data of blocks 1-31 */ 500 r = crypto_shash_update(desc, data + 16, 16 * 31); 501 if (r) 502 return r; 503 504 /* Sector is cropped to 56 bits here */ 505 buf[0] = cpu_to_le32(dmreq->iv_sector & 0xFFFFFFFF); 506 buf[1] = cpu_to_le32((((u64)dmreq->iv_sector >> 32) & 0x00FFFFFF) | 0x80000000); 507 buf[2] = cpu_to_le32(4024); 508 buf[3] = 0; 509 r = crypto_shash_update(desc, (u8 *)buf, sizeof(buf)); 510 if (r) 511 return r; 512 513 /* No MD5 padding here */ 514 r = crypto_shash_export(desc, &md5state); 515 if (r) 516 return r; 517 518 for (i = 0; i < MD5_HASH_WORDS; i++) 519 __cpu_to_le32s(&md5state.hash[i]); 520 memcpy(iv, &md5state.hash, cc->iv_size); 521 522 return 0; 523 } 524 525 static int crypt_iv_lmk_gen(struct crypt_config *cc, u8 *iv, 526 struct dm_crypt_request *dmreq) 527 { 528 struct scatterlist *sg; 529 u8 *src; 530 int r = 0; 531 532 if (bio_data_dir(dmreq->ctx->bio_in) == WRITE) { 533 sg = crypt_get_sg_data(cc, dmreq->sg_in); 534 src = kmap_atomic(sg_page(sg)); 535 r = crypt_iv_lmk_one(cc, iv, dmreq, src + sg->offset); 536 kunmap_atomic(src); 537 } else 538 memset(iv, 0, cc->iv_size); 539 540 return r; 541 } 542 543 static int crypt_iv_lmk_post(struct crypt_config *cc, u8 *iv, 544 struct dm_crypt_request *dmreq) 545 { 546 struct scatterlist *sg; 547 u8 *dst; 548 int r; 549 550 if (bio_data_dir(dmreq->ctx->bio_in) == WRITE) 551 return 0; 552 553 sg = crypt_get_sg_data(cc, dmreq->sg_out); 554 dst = kmap_atomic(sg_page(sg)); 555 r = crypt_iv_lmk_one(cc, iv, dmreq, dst + sg->offset); 556 557 /* Tweak the first block of plaintext sector */ 558 if (!r) 559 crypto_xor(dst + sg->offset, iv, cc->iv_size); 560 561 kunmap_atomic(dst); 562 return r; 563 } 564 565 static void crypt_iv_tcw_dtr(struct crypt_config *cc) 566 { 567 struct iv_tcw_private *tcw = &cc->iv_gen_private.tcw; 568 569 kfree_sensitive(tcw->iv_seed); 570 tcw->iv_seed = NULL; 571 kfree_sensitive(tcw->whitening); 572 tcw->whitening = NULL; 573 574 if (tcw->crc32_tfm && !IS_ERR(tcw->crc32_tfm)) 575 crypto_free_shash(tcw->crc32_tfm); 576 tcw->crc32_tfm = NULL; 577 } 578 579 static int crypt_iv_tcw_ctr(struct crypt_config *cc, struct dm_target *ti, 580 const char *opts) 581 { 582 struct iv_tcw_private *tcw = &cc->iv_gen_private.tcw; 583 584 if (cc->sector_size != (1 << SECTOR_SHIFT)) { 585 ti->error = "Unsupported sector size for TCW"; 586 return -EINVAL; 587 } 588 589 if (cc->key_size <= (cc->iv_size + TCW_WHITENING_SIZE)) { 590 ti->error = "Wrong key size for TCW"; 591 return -EINVAL; 592 } 593 594 tcw->crc32_tfm = crypto_alloc_shash("crc32", 0, 595 CRYPTO_ALG_ALLOCATES_MEMORY); 596 if (IS_ERR(tcw->crc32_tfm)) { 597 ti->error = "Error initializing CRC32 in TCW"; 598 return PTR_ERR(tcw->crc32_tfm); 599 } 600 601 tcw->iv_seed = kzalloc(cc->iv_size, GFP_KERNEL); 602 tcw->whitening = kzalloc(TCW_WHITENING_SIZE, GFP_KERNEL); 603 if (!tcw->iv_seed || !tcw->whitening) { 604 crypt_iv_tcw_dtr(cc); 605 ti->error = "Error allocating seed storage in TCW"; 606 return -ENOMEM; 607 } 608 609 return 0; 610 } 611 612 static int crypt_iv_tcw_init(struct crypt_config *cc) 613 { 614 struct iv_tcw_private *tcw = &cc->iv_gen_private.tcw; 615 int key_offset = cc->key_size - cc->iv_size - TCW_WHITENING_SIZE; 616 617 memcpy(tcw->iv_seed, &cc->key[key_offset], cc->iv_size); 618 memcpy(tcw->whitening, &cc->key[key_offset + cc->iv_size], 619 TCW_WHITENING_SIZE); 620 621 return 0; 622 } 623 624 static int crypt_iv_tcw_wipe(struct crypt_config *cc) 625 { 626 struct iv_tcw_private *tcw = &cc->iv_gen_private.tcw; 627 628 memset(tcw->iv_seed, 0, cc->iv_size); 629 memset(tcw->whitening, 0, TCW_WHITENING_SIZE); 630 631 return 0; 632 } 633 634 static int crypt_iv_tcw_whitening(struct crypt_config *cc, 635 struct dm_crypt_request *dmreq, 636 u8 *data) 637 { 638 struct iv_tcw_private *tcw = &cc->iv_gen_private.tcw; 639 __le64 sector = cpu_to_le64(dmreq->iv_sector); 640 u8 buf[TCW_WHITENING_SIZE]; 641 SHASH_DESC_ON_STACK(desc, tcw->crc32_tfm); 642 int i, r; 643 644 /* xor whitening with sector number */ 645 crypto_xor_cpy(buf, tcw->whitening, (u8 *)§or, 8); 646 crypto_xor_cpy(&buf[8], tcw->whitening + 8, (u8 *)§or, 8); 647 648 /* calculate crc32 for every 32bit part and xor it */ 649 desc->tfm = tcw->crc32_tfm; 650 for (i = 0; i < 4; i++) { 651 r = crypto_shash_init(desc); 652 if (r) 653 goto out; 654 r = crypto_shash_update(desc, &buf[i * 4], 4); 655 if (r) 656 goto out; 657 r = crypto_shash_final(desc, &buf[i * 4]); 658 if (r) 659 goto out; 660 } 661 crypto_xor(&buf[0], &buf[12], 4); 662 crypto_xor(&buf[4], &buf[8], 4); 663 664 /* apply whitening (8 bytes) to whole sector */ 665 for (i = 0; i < ((1 << SECTOR_SHIFT) / 8); i++) 666 crypto_xor(data + i * 8, buf, 8); 667 out: 668 memzero_explicit(buf, sizeof(buf)); 669 return r; 670 } 671 672 static int crypt_iv_tcw_gen(struct crypt_config *cc, u8 *iv, 673 struct dm_crypt_request *dmreq) 674 { 675 struct scatterlist *sg; 676 struct iv_tcw_private *tcw = &cc->iv_gen_private.tcw; 677 __le64 sector = cpu_to_le64(dmreq->iv_sector); 678 u8 *src; 679 int r = 0; 680 681 /* Remove whitening from ciphertext */ 682 if (bio_data_dir(dmreq->ctx->bio_in) != WRITE) { 683 sg = crypt_get_sg_data(cc, dmreq->sg_in); 684 src = kmap_atomic(sg_page(sg)); 685 r = crypt_iv_tcw_whitening(cc, dmreq, src + sg->offset); 686 kunmap_atomic(src); 687 } 688 689 /* Calculate IV */ 690 crypto_xor_cpy(iv, tcw->iv_seed, (u8 *)§or, 8); 691 if (cc->iv_size > 8) 692 crypto_xor_cpy(&iv[8], tcw->iv_seed + 8, (u8 *)§or, 693 cc->iv_size - 8); 694 695 return r; 696 } 697 698 static int crypt_iv_tcw_post(struct crypt_config *cc, u8 *iv, 699 struct dm_crypt_request *dmreq) 700 { 701 struct scatterlist *sg; 702 u8 *dst; 703 int r; 704 705 if (bio_data_dir(dmreq->ctx->bio_in) != WRITE) 706 return 0; 707 708 /* Apply whitening on ciphertext */ 709 sg = crypt_get_sg_data(cc, dmreq->sg_out); 710 dst = kmap_atomic(sg_page(sg)); 711 r = crypt_iv_tcw_whitening(cc, dmreq, dst + sg->offset); 712 kunmap_atomic(dst); 713 714 return r; 715 } 716 717 static int crypt_iv_random_gen(struct crypt_config *cc, u8 *iv, 718 struct dm_crypt_request *dmreq) 719 { 720 /* Used only for writes, there must be an additional space to store IV */ 721 get_random_bytes(iv, cc->iv_size); 722 return 0; 723 } 724 725 static int crypt_iv_eboiv_ctr(struct crypt_config *cc, struct dm_target *ti, 726 const char *opts) 727 { 728 if (crypt_integrity_aead(cc)) { 729 ti->error = "AEAD transforms not supported for EBOIV"; 730 return -EINVAL; 731 } 732 733 if (crypto_skcipher_blocksize(any_tfm(cc)) != cc->iv_size) { 734 ti->error = "Block size of EBOIV cipher does " 735 "not match IV size of block cipher"; 736 return -EINVAL; 737 } 738 739 return 0; 740 } 741 742 static int crypt_iv_eboiv_gen(struct crypt_config *cc, u8 *iv, 743 struct dm_crypt_request *dmreq) 744 { 745 u8 buf[MAX_CIPHER_BLOCKSIZE] __aligned(__alignof__(__le64)); 746 struct skcipher_request *req; 747 struct scatterlist src, dst; 748 DECLARE_CRYPTO_WAIT(wait); 749 int err; 750 751 req = skcipher_request_alloc(any_tfm(cc), GFP_NOIO); 752 if (!req) 753 return -ENOMEM; 754 755 memset(buf, 0, cc->iv_size); 756 *(__le64 *)buf = cpu_to_le64(dmreq->iv_sector * cc->sector_size); 757 758 sg_init_one(&src, page_address(ZERO_PAGE(0)), cc->iv_size); 759 sg_init_one(&dst, iv, cc->iv_size); 760 skcipher_request_set_crypt(req, &src, &dst, cc->iv_size, buf); 761 skcipher_request_set_callback(req, 0, crypto_req_done, &wait); 762 err = crypto_wait_req(crypto_skcipher_encrypt(req), &wait); 763 skcipher_request_free(req); 764 765 return err; 766 } 767 768 static void crypt_iv_elephant_dtr(struct crypt_config *cc) 769 { 770 struct iv_elephant_private *elephant = &cc->iv_gen_private.elephant; 771 772 crypto_free_skcipher(elephant->tfm); 773 elephant->tfm = NULL; 774 } 775 776 static int crypt_iv_elephant_ctr(struct crypt_config *cc, struct dm_target *ti, 777 const char *opts) 778 { 779 struct iv_elephant_private *elephant = &cc->iv_gen_private.elephant; 780 int r; 781 782 elephant->tfm = crypto_alloc_skcipher("ecb(aes)", 0, 783 CRYPTO_ALG_ALLOCATES_MEMORY); 784 if (IS_ERR(elephant->tfm)) { 785 r = PTR_ERR(elephant->tfm); 786 elephant->tfm = NULL; 787 return r; 788 } 789 790 r = crypt_iv_eboiv_ctr(cc, ti, NULL); 791 if (r) 792 crypt_iv_elephant_dtr(cc); 793 return r; 794 } 795 796 static void diffuser_disk_to_cpu(u32 *d, size_t n) 797 { 798 #ifndef __LITTLE_ENDIAN 799 int i; 800 801 for (i = 0; i < n; i++) 802 d[i] = le32_to_cpu((__le32)d[i]); 803 #endif 804 } 805 806 static void diffuser_cpu_to_disk(__le32 *d, size_t n) 807 { 808 #ifndef __LITTLE_ENDIAN 809 int i; 810 811 for (i = 0; i < n; i++) 812 d[i] = cpu_to_le32((u32)d[i]); 813 #endif 814 } 815 816 static void diffuser_a_decrypt(u32 *d, size_t n) 817 { 818 int i, i1, i2, i3; 819 820 for (i = 0; i < 5; i++) { 821 i1 = 0; 822 i2 = n - 2; 823 i3 = n - 5; 824 825 while (i1 < (n - 1)) { 826 d[i1] += d[i2] ^ (d[i3] << 9 | d[i3] >> 23); 827 i1++; i2++; i3++; 828 829 if (i3 >= n) 830 i3 -= n; 831 832 d[i1] += d[i2] ^ d[i3]; 833 i1++; i2++; i3++; 834 835 if (i2 >= n) 836 i2 -= n; 837 838 d[i1] += d[i2] ^ (d[i3] << 13 | d[i3] >> 19); 839 i1++; i2++; i3++; 840 841 d[i1] += d[i2] ^ d[i3]; 842 i1++; i2++; i3++; 843 } 844 } 845 } 846 847 static void diffuser_a_encrypt(u32 *d, size_t n) 848 { 849 int i, i1, i2, i3; 850 851 for (i = 0; i < 5; i++) { 852 i1 = n - 1; 853 i2 = n - 2 - 1; 854 i3 = n - 5 - 1; 855 856 while (i1 > 0) { 857 d[i1] -= d[i2] ^ d[i3]; 858 i1--; i2--; i3--; 859 860 d[i1] -= d[i2] ^ (d[i3] << 13 | d[i3] >> 19); 861 i1--; i2--; i3--; 862 863 if (i2 < 0) 864 i2 += n; 865 866 d[i1] -= d[i2] ^ d[i3]; 867 i1--; i2--; i3--; 868 869 if (i3 < 0) 870 i3 += n; 871 872 d[i1] -= d[i2] ^ (d[i3] << 9 | d[i3] >> 23); 873 i1--; i2--; i3--; 874 } 875 } 876 } 877 878 static void diffuser_b_decrypt(u32 *d, size_t n) 879 { 880 int i, i1, i2, i3; 881 882 for (i = 0; i < 3; i++) { 883 i1 = 0; 884 i2 = 2; 885 i3 = 5; 886 887 while (i1 < (n - 1)) { 888 d[i1] += d[i2] ^ d[i3]; 889 i1++; i2++; i3++; 890 891 d[i1] += d[i2] ^ (d[i3] << 10 | d[i3] >> 22); 892 i1++; i2++; i3++; 893 894 if (i2 >= n) 895 i2 -= n; 896 897 d[i1] += d[i2] ^ d[i3]; 898 i1++; i2++; i3++; 899 900 if (i3 >= n) 901 i3 -= n; 902 903 d[i1] += d[i2] ^ (d[i3] << 25 | d[i3] >> 7); 904 i1++; i2++; i3++; 905 } 906 } 907 } 908 909 static void diffuser_b_encrypt(u32 *d, size_t n) 910 { 911 int i, i1, i2, i3; 912 913 for (i = 0; i < 3; i++) { 914 i1 = n - 1; 915 i2 = 2 - 1; 916 i3 = 5 - 1; 917 918 while (i1 > 0) { 919 d[i1] -= d[i2] ^ (d[i3] << 25 | d[i3] >> 7); 920 i1--; i2--; i3--; 921 922 if (i3 < 0) 923 i3 += n; 924 925 d[i1] -= d[i2] ^ d[i3]; 926 i1--; i2--; i3--; 927 928 if (i2 < 0) 929 i2 += n; 930 931 d[i1] -= d[i2] ^ (d[i3] << 10 | d[i3] >> 22); 932 i1--; i2--; i3--; 933 934 d[i1] -= d[i2] ^ d[i3]; 935 i1--; i2--; i3--; 936 } 937 } 938 } 939 940 static int crypt_iv_elephant(struct crypt_config *cc, struct dm_crypt_request *dmreq) 941 { 942 struct iv_elephant_private *elephant = &cc->iv_gen_private.elephant; 943 u8 *es, *ks, *data, *data2, *data_offset; 944 struct skcipher_request *req; 945 struct scatterlist *sg, *sg2, src, dst; 946 DECLARE_CRYPTO_WAIT(wait); 947 int i, r; 948 949 req = skcipher_request_alloc(elephant->tfm, GFP_NOIO); 950 es = kzalloc(16, GFP_NOIO); /* Key for AES */ 951 ks = kzalloc(32, GFP_NOIO); /* Elephant sector key */ 952 953 if (!req || !es || !ks) { 954 r = -ENOMEM; 955 goto out; 956 } 957 958 *(__le64 *)es = cpu_to_le64(dmreq->iv_sector * cc->sector_size); 959 960 /* E(Ks, e(s)) */ 961 sg_init_one(&src, es, 16); 962 sg_init_one(&dst, ks, 16); 963 skcipher_request_set_crypt(req, &src, &dst, 16, NULL); 964 skcipher_request_set_callback(req, 0, crypto_req_done, &wait); 965 r = crypto_wait_req(crypto_skcipher_encrypt(req), &wait); 966 if (r) 967 goto out; 968 969 /* E(Ks, e'(s)) */ 970 es[15] = 0x80; 971 sg_init_one(&dst, &ks[16], 16); 972 r = crypto_wait_req(crypto_skcipher_encrypt(req), &wait); 973 if (r) 974 goto out; 975 976 sg = crypt_get_sg_data(cc, dmreq->sg_out); 977 data = kmap_atomic(sg_page(sg)); 978 data_offset = data + sg->offset; 979 980 /* Cannot modify original bio, copy to sg_out and apply Elephant to it */ 981 if (bio_data_dir(dmreq->ctx->bio_in) == WRITE) { 982 sg2 = crypt_get_sg_data(cc, dmreq->sg_in); 983 data2 = kmap_atomic(sg_page(sg2)); 984 memcpy(data_offset, data2 + sg2->offset, cc->sector_size); 985 kunmap_atomic(data2); 986 } 987 988 if (bio_data_dir(dmreq->ctx->bio_in) != WRITE) { 989 diffuser_disk_to_cpu((u32*)data_offset, cc->sector_size / sizeof(u32)); 990 diffuser_b_decrypt((u32*)data_offset, cc->sector_size / sizeof(u32)); 991 diffuser_a_decrypt((u32*)data_offset, cc->sector_size / sizeof(u32)); 992 diffuser_cpu_to_disk((__le32*)data_offset, cc->sector_size / sizeof(u32)); 993 } 994 995 for (i = 0; i < (cc->sector_size / 32); i++) 996 crypto_xor(data_offset + i * 32, ks, 32); 997 998 if (bio_data_dir(dmreq->ctx->bio_in) == WRITE) { 999 diffuser_disk_to_cpu((u32*)data_offset, cc->sector_size / sizeof(u32)); 1000 diffuser_a_encrypt((u32*)data_offset, cc->sector_size / sizeof(u32)); 1001 diffuser_b_encrypt((u32*)data_offset, cc->sector_size / sizeof(u32)); 1002 diffuser_cpu_to_disk((__le32*)data_offset, cc->sector_size / sizeof(u32)); 1003 } 1004 1005 kunmap_atomic(data); 1006 out: 1007 kfree_sensitive(ks); 1008 kfree_sensitive(es); 1009 skcipher_request_free(req); 1010 return r; 1011 } 1012 1013 static int crypt_iv_elephant_gen(struct crypt_config *cc, u8 *iv, 1014 struct dm_crypt_request *dmreq) 1015 { 1016 int r; 1017 1018 if (bio_data_dir(dmreq->ctx->bio_in) == WRITE) { 1019 r = crypt_iv_elephant(cc, dmreq); 1020 if (r) 1021 return r; 1022 } 1023 1024 return crypt_iv_eboiv_gen(cc, iv, dmreq); 1025 } 1026 1027 static int crypt_iv_elephant_post(struct crypt_config *cc, u8 *iv, 1028 struct dm_crypt_request *dmreq) 1029 { 1030 if (bio_data_dir(dmreq->ctx->bio_in) != WRITE) 1031 return crypt_iv_elephant(cc, dmreq); 1032 1033 return 0; 1034 } 1035 1036 static int crypt_iv_elephant_init(struct crypt_config *cc) 1037 { 1038 struct iv_elephant_private *elephant = &cc->iv_gen_private.elephant; 1039 int key_offset = cc->key_size - cc->key_extra_size; 1040 1041 return crypto_skcipher_setkey(elephant->tfm, &cc->key[key_offset], cc->key_extra_size); 1042 } 1043 1044 static int crypt_iv_elephant_wipe(struct crypt_config *cc) 1045 { 1046 struct iv_elephant_private *elephant = &cc->iv_gen_private.elephant; 1047 u8 key[ELEPHANT_MAX_KEY_SIZE]; 1048 1049 memset(key, 0, cc->key_extra_size); 1050 return crypto_skcipher_setkey(elephant->tfm, key, cc->key_extra_size); 1051 } 1052 1053 static const struct crypt_iv_operations crypt_iv_plain_ops = { 1054 .generator = crypt_iv_plain_gen 1055 }; 1056 1057 static const struct crypt_iv_operations crypt_iv_plain64_ops = { 1058 .generator = crypt_iv_plain64_gen 1059 }; 1060 1061 static const struct crypt_iv_operations crypt_iv_plain64be_ops = { 1062 .generator = crypt_iv_plain64be_gen 1063 }; 1064 1065 static const struct crypt_iv_operations crypt_iv_essiv_ops = { 1066 .generator = crypt_iv_essiv_gen 1067 }; 1068 1069 static const struct crypt_iv_operations crypt_iv_benbi_ops = { 1070 .ctr = crypt_iv_benbi_ctr, 1071 .dtr = crypt_iv_benbi_dtr, 1072 .generator = crypt_iv_benbi_gen 1073 }; 1074 1075 static const struct crypt_iv_operations crypt_iv_null_ops = { 1076 .generator = crypt_iv_null_gen 1077 }; 1078 1079 static const struct crypt_iv_operations crypt_iv_lmk_ops = { 1080 .ctr = crypt_iv_lmk_ctr, 1081 .dtr = crypt_iv_lmk_dtr, 1082 .init = crypt_iv_lmk_init, 1083 .wipe = crypt_iv_lmk_wipe, 1084 .generator = crypt_iv_lmk_gen, 1085 .post = crypt_iv_lmk_post 1086 }; 1087 1088 static const struct crypt_iv_operations crypt_iv_tcw_ops = { 1089 .ctr = crypt_iv_tcw_ctr, 1090 .dtr = crypt_iv_tcw_dtr, 1091 .init = crypt_iv_tcw_init, 1092 .wipe = crypt_iv_tcw_wipe, 1093 .generator = crypt_iv_tcw_gen, 1094 .post = crypt_iv_tcw_post 1095 }; 1096 1097 static const struct crypt_iv_operations crypt_iv_random_ops = { 1098 .generator = crypt_iv_random_gen 1099 }; 1100 1101 static const struct crypt_iv_operations crypt_iv_eboiv_ops = { 1102 .ctr = crypt_iv_eboiv_ctr, 1103 .generator = crypt_iv_eboiv_gen 1104 }; 1105 1106 static const struct crypt_iv_operations crypt_iv_elephant_ops = { 1107 .ctr = crypt_iv_elephant_ctr, 1108 .dtr = crypt_iv_elephant_dtr, 1109 .init = crypt_iv_elephant_init, 1110 .wipe = crypt_iv_elephant_wipe, 1111 .generator = crypt_iv_elephant_gen, 1112 .post = crypt_iv_elephant_post 1113 }; 1114 1115 /* 1116 * Integrity extensions 1117 */ 1118 static bool crypt_integrity_aead(struct crypt_config *cc) 1119 { 1120 return test_bit(CRYPT_MODE_INTEGRITY_AEAD, &cc->cipher_flags); 1121 } 1122 1123 static bool crypt_integrity_hmac(struct crypt_config *cc) 1124 { 1125 return crypt_integrity_aead(cc) && cc->key_mac_size; 1126 } 1127 1128 /* Get sg containing data */ 1129 static struct scatterlist *crypt_get_sg_data(struct crypt_config *cc, 1130 struct scatterlist *sg) 1131 { 1132 if (unlikely(crypt_integrity_aead(cc))) 1133 return &sg[2]; 1134 1135 return sg; 1136 } 1137 1138 static int dm_crypt_integrity_io_alloc(struct dm_crypt_io *io, struct bio *bio) 1139 { 1140 struct bio_integrity_payload *bip; 1141 unsigned int tag_len; 1142 int ret; 1143 1144 if (!bio_sectors(bio) || !io->cc->on_disk_tag_size) 1145 return 0; 1146 1147 bip = bio_integrity_alloc(bio, GFP_NOIO, 1); 1148 if (IS_ERR(bip)) 1149 return PTR_ERR(bip); 1150 1151 tag_len = io->cc->on_disk_tag_size * (bio_sectors(bio) >> io->cc->sector_shift); 1152 1153 bip->bip_iter.bi_size = tag_len; 1154 bip->bip_iter.bi_sector = io->cc->start + io->sector; 1155 1156 ret = bio_integrity_add_page(bio, virt_to_page(io->integrity_metadata), 1157 tag_len, offset_in_page(io->integrity_metadata)); 1158 if (unlikely(ret != tag_len)) 1159 return -ENOMEM; 1160 1161 return 0; 1162 } 1163 1164 static int crypt_integrity_ctr(struct crypt_config *cc, struct dm_target *ti) 1165 { 1166 #ifdef CONFIG_BLK_DEV_INTEGRITY 1167 struct blk_integrity *bi = blk_get_integrity(cc->dev->bdev->bd_disk); 1168 struct mapped_device *md = dm_table_get_md(ti->table); 1169 1170 /* From now we require underlying device with our integrity profile */ 1171 if (!bi || strcasecmp(bi->profile->name, "DM-DIF-EXT-TAG")) { 1172 ti->error = "Integrity profile not supported."; 1173 return -EINVAL; 1174 } 1175 1176 if (bi->tag_size != cc->on_disk_tag_size || 1177 bi->tuple_size != cc->on_disk_tag_size) { 1178 ti->error = "Integrity profile tag size mismatch."; 1179 return -EINVAL; 1180 } 1181 if (1 << bi->interval_exp != cc->sector_size) { 1182 ti->error = "Integrity profile sector size mismatch."; 1183 return -EINVAL; 1184 } 1185 1186 if (crypt_integrity_aead(cc)) { 1187 cc->integrity_tag_size = cc->on_disk_tag_size - cc->integrity_iv_size; 1188 DMDEBUG("%s: Integrity AEAD, tag size %u, IV size %u.", dm_device_name(md), 1189 cc->integrity_tag_size, cc->integrity_iv_size); 1190 1191 if (crypto_aead_setauthsize(any_tfm_aead(cc), cc->integrity_tag_size)) { 1192 ti->error = "Integrity AEAD auth tag size is not supported."; 1193 return -EINVAL; 1194 } 1195 } else if (cc->integrity_iv_size) 1196 DMDEBUG("%s: Additional per-sector space %u bytes for IV.", dm_device_name(md), 1197 cc->integrity_iv_size); 1198 1199 if ((cc->integrity_tag_size + cc->integrity_iv_size) != bi->tag_size) { 1200 ti->error = "Not enough space for integrity tag in the profile."; 1201 return -EINVAL; 1202 } 1203 1204 return 0; 1205 #else 1206 ti->error = "Integrity profile not supported."; 1207 return -EINVAL; 1208 #endif 1209 } 1210 1211 static void crypt_convert_init(struct crypt_config *cc, 1212 struct convert_context *ctx, 1213 struct bio *bio_out, struct bio *bio_in, 1214 sector_t sector) 1215 { 1216 ctx->bio_in = bio_in; 1217 ctx->bio_out = bio_out; 1218 if (bio_in) 1219 ctx->iter_in = bio_in->bi_iter; 1220 if (bio_out) 1221 ctx->iter_out = bio_out->bi_iter; 1222 ctx->cc_sector = sector + cc->iv_offset; 1223 init_completion(&ctx->restart); 1224 } 1225 1226 static struct dm_crypt_request *dmreq_of_req(struct crypt_config *cc, 1227 void *req) 1228 { 1229 return (struct dm_crypt_request *)((char *)req + cc->dmreq_start); 1230 } 1231 1232 static void *req_of_dmreq(struct crypt_config *cc, struct dm_crypt_request *dmreq) 1233 { 1234 return (void *)((char *)dmreq - cc->dmreq_start); 1235 } 1236 1237 static u8 *iv_of_dmreq(struct crypt_config *cc, 1238 struct dm_crypt_request *dmreq) 1239 { 1240 if (crypt_integrity_aead(cc)) 1241 return (u8 *)ALIGN((unsigned long)(dmreq + 1), 1242 crypto_aead_alignmask(any_tfm_aead(cc)) + 1); 1243 else 1244 return (u8 *)ALIGN((unsigned long)(dmreq + 1), 1245 crypto_skcipher_alignmask(any_tfm(cc)) + 1); 1246 } 1247 1248 static u8 *org_iv_of_dmreq(struct crypt_config *cc, 1249 struct dm_crypt_request *dmreq) 1250 { 1251 return iv_of_dmreq(cc, dmreq) + cc->iv_size; 1252 } 1253 1254 static __le64 *org_sector_of_dmreq(struct crypt_config *cc, 1255 struct dm_crypt_request *dmreq) 1256 { 1257 u8 *ptr = iv_of_dmreq(cc, dmreq) + cc->iv_size + cc->iv_size; 1258 return (__le64 *) ptr; 1259 } 1260 1261 static unsigned int *org_tag_of_dmreq(struct crypt_config *cc, 1262 struct dm_crypt_request *dmreq) 1263 { 1264 u8 *ptr = iv_of_dmreq(cc, dmreq) + cc->iv_size + 1265 cc->iv_size + sizeof(uint64_t); 1266 return (unsigned int*)ptr; 1267 } 1268 1269 static void *tag_from_dmreq(struct crypt_config *cc, 1270 struct dm_crypt_request *dmreq) 1271 { 1272 struct convert_context *ctx = dmreq->ctx; 1273 struct dm_crypt_io *io = container_of(ctx, struct dm_crypt_io, ctx); 1274 1275 return &io->integrity_metadata[*org_tag_of_dmreq(cc, dmreq) * 1276 cc->on_disk_tag_size]; 1277 } 1278 1279 static void *iv_tag_from_dmreq(struct crypt_config *cc, 1280 struct dm_crypt_request *dmreq) 1281 { 1282 return tag_from_dmreq(cc, dmreq) + cc->integrity_tag_size; 1283 } 1284 1285 static int crypt_convert_block_aead(struct crypt_config *cc, 1286 struct convert_context *ctx, 1287 struct aead_request *req, 1288 unsigned int tag_offset) 1289 { 1290 struct bio_vec bv_in = bio_iter_iovec(ctx->bio_in, ctx->iter_in); 1291 struct bio_vec bv_out = bio_iter_iovec(ctx->bio_out, ctx->iter_out); 1292 struct dm_crypt_request *dmreq; 1293 u8 *iv, *org_iv, *tag_iv, *tag; 1294 __le64 *sector; 1295 int r = 0; 1296 1297 BUG_ON(cc->integrity_iv_size && cc->integrity_iv_size != cc->iv_size); 1298 1299 /* Reject unexpected unaligned bio. */ 1300 if (unlikely(bv_in.bv_len & (cc->sector_size - 1))) 1301 return -EIO; 1302 1303 dmreq = dmreq_of_req(cc, req); 1304 dmreq->iv_sector = ctx->cc_sector; 1305 if (test_bit(CRYPT_IV_LARGE_SECTORS, &cc->cipher_flags)) 1306 dmreq->iv_sector >>= cc->sector_shift; 1307 dmreq->ctx = ctx; 1308 1309 *org_tag_of_dmreq(cc, dmreq) = tag_offset; 1310 1311 sector = org_sector_of_dmreq(cc, dmreq); 1312 *sector = cpu_to_le64(ctx->cc_sector - cc->iv_offset); 1313 1314 iv = iv_of_dmreq(cc, dmreq); 1315 org_iv = org_iv_of_dmreq(cc, dmreq); 1316 tag = tag_from_dmreq(cc, dmreq); 1317 tag_iv = iv_tag_from_dmreq(cc, dmreq); 1318 1319 /* AEAD request: 1320 * |----- AAD -------|------ DATA -------|-- AUTH TAG --| 1321 * | (authenticated) | (auth+encryption) | | 1322 * | sector_LE | IV | sector in/out | tag in/out | 1323 */ 1324 sg_init_table(dmreq->sg_in, 4); 1325 sg_set_buf(&dmreq->sg_in[0], sector, sizeof(uint64_t)); 1326 sg_set_buf(&dmreq->sg_in[1], org_iv, cc->iv_size); 1327 sg_set_page(&dmreq->sg_in[2], bv_in.bv_page, cc->sector_size, bv_in.bv_offset); 1328 sg_set_buf(&dmreq->sg_in[3], tag, cc->integrity_tag_size); 1329 1330 sg_init_table(dmreq->sg_out, 4); 1331 sg_set_buf(&dmreq->sg_out[0], sector, sizeof(uint64_t)); 1332 sg_set_buf(&dmreq->sg_out[1], org_iv, cc->iv_size); 1333 sg_set_page(&dmreq->sg_out[2], bv_out.bv_page, cc->sector_size, bv_out.bv_offset); 1334 sg_set_buf(&dmreq->sg_out[3], tag, cc->integrity_tag_size); 1335 1336 if (cc->iv_gen_ops) { 1337 /* For READs use IV stored in integrity metadata */ 1338 if (cc->integrity_iv_size && bio_data_dir(ctx->bio_in) != WRITE) { 1339 memcpy(org_iv, tag_iv, cc->iv_size); 1340 } else { 1341 r = cc->iv_gen_ops->generator(cc, org_iv, dmreq); 1342 if (r < 0) 1343 return r; 1344 /* Store generated IV in integrity metadata */ 1345 if (cc->integrity_iv_size) 1346 memcpy(tag_iv, org_iv, cc->iv_size); 1347 } 1348 /* Working copy of IV, to be modified in crypto API */ 1349 memcpy(iv, org_iv, cc->iv_size); 1350 } 1351 1352 aead_request_set_ad(req, sizeof(uint64_t) + cc->iv_size); 1353 if (bio_data_dir(ctx->bio_in) == WRITE) { 1354 aead_request_set_crypt(req, dmreq->sg_in, dmreq->sg_out, 1355 cc->sector_size, iv); 1356 r = crypto_aead_encrypt(req); 1357 if (cc->integrity_tag_size + cc->integrity_iv_size != cc->on_disk_tag_size) 1358 memset(tag + cc->integrity_tag_size + cc->integrity_iv_size, 0, 1359 cc->on_disk_tag_size - (cc->integrity_tag_size + cc->integrity_iv_size)); 1360 } else { 1361 aead_request_set_crypt(req, dmreq->sg_in, dmreq->sg_out, 1362 cc->sector_size + cc->integrity_tag_size, iv); 1363 r = crypto_aead_decrypt(req); 1364 } 1365 1366 if (r == -EBADMSG) { 1367 sector_t s = le64_to_cpu(*sector); 1368 1369 DMERR_LIMIT("%pg: INTEGRITY AEAD ERROR, sector %llu", 1370 ctx->bio_in->bi_bdev, s); 1371 dm_audit_log_bio(DM_MSG_PREFIX, "integrity-aead", 1372 ctx->bio_in, s, 0); 1373 } 1374 1375 if (!r && cc->iv_gen_ops && cc->iv_gen_ops->post) 1376 r = cc->iv_gen_ops->post(cc, org_iv, dmreq); 1377 1378 bio_advance_iter(ctx->bio_in, &ctx->iter_in, cc->sector_size); 1379 bio_advance_iter(ctx->bio_out, &ctx->iter_out, cc->sector_size); 1380 1381 return r; 1382 } 1383 1384 static int crypt_convert_block_skcipher(struct crypt_config *cc, 1385 struct convert_context *ctx, 1386 struct skcipher_request *req, 1387 unsigned int tag_offset) 1388 { 1389 struct bio_vec bv_in = bio_iter_iovec(ctx->bio_in, ctx->iter_in); 1390 struct bio_vec bv_out = bio_iter_iovec(ctx->bio_out, ctx->iter_out); 1391 struct scatterlist *sg_in, *sg_out; 1392 struct dm_crypt_request *dmreq; 1393 u8 *iv, *org_iv, *tag_iv; 1394 __le64 *sector; 1395 int r = 0; 1396 1397 /* Reject unexpected unaligned bio. */ 1398 if (unlikely(bv_in.bv_len & (cc->sector_size - 1))) 1399 return -EIO; 1400 1401 dmreq = dmreq_of_req(cc, req); 1402 dmreq->iv_sector = ctx->cc_sector; 1403 if (test_bit(CRYPT_IV_LARGE_SECTORS, &cc->cipher_flags)) 1404 dmreq->iv_sector >>= cc->sector_shift; 1405 dmreq->ctx = ctx; 1406 1407 *org_tag_of_dmreq(cc, dmreq) = tag_offset; 1408 1409 iv = iv_of_dmreq(cc, dmreq); 1410 org_iv = org_iv_of_dmreq(cc, dmreq); 1411 tag_iv = iv_tag_from_dmreq(cc, dmreq); 1412 1413 sector = org_sector_of_dmreq(cc, dmreq); 1414 *sector = cpu_to_le64(ctx->cc_sector - cc->iv_offset); 1415 1416 /* For skcipher we use only the first sg item */ 1417 sg_in = &dmreq->sg_in[0]; 1418 sg_out = &dmreq->sg_out[0]; 1419 1420 sg_init_table(sg_in, 1); 1421 sg_set_page(sg_in, bv_in.bv_page, cc->sector_size, bv_in.bv_offset); 1422 1423 sg_init_table(sg_out, 1); 1424 sg_set_page(sg_out, bv_out.bv_page, cc->sector_size, bv_out.bv_offset); 1425 1426 if (cc->iv_gen_ops) { 1427 /* For READs use IV stored in integrity metadata */ 1428 if (cc->integrity_iv_size && bio_data_dir(ctx->bio_in) != WRITE) { 1429 memcpy(org_iv, tag_iv, cc->integrity_iv_size); 1430 } else { 1431 r = cc->iv_gen_ops->generator(cc, org_iv, dmreq); 1432 if (r < 0) 1433 return r; 1434 /* Data can be already preprocessed in generator */ 1435 if (test_bit(CRYPT_ENCRYPT_PREPROCESS, &cc->cipher_flags)) 1436 sg_in = sg_out; 1437 /* Store generated IV in integrity metadata */ 1438 if (cc->integrity_iv_size) 1439 memcpy(tag_iv, org_iv, cc->integrity_iv_size); 1440 } 1441 /* Working copy of IV, to be modified in crypto API */ 1442 memcpy(iv, org_iv, cc->iv_size); 1443 } 1444 1445 skcipher_request_set_crypt(req, sg_in, sg_out, cc->sector_size, iv); 1446 1447 if (bio_data_dir(ctx->bio_in) == WRITE) 1448 r = crypto_skcipher_encrypt(req); 1449 else 1450 r = crypto_skcipher_decrypt(req); 1451 1452 if (!r && cc->iv_gen_ops && cc->iv_gen_ops->post) 1453 r = cc->iv_gen_ops->post(cc, org_iv, dmreq); 1454 1455 bio_advance_iter(ctx->bio_in, &ctx->iter_in, cc->sector_size); 1456 bio_advance_iter(ctx->bio_out, &ctx->iter_out, cc->sector_size); 1457 1458 return r; 1459 } 1460 1461 static void kcryptd_async_done(struct crypto_async_request *async_req, 1462 int error); 1463 1464 static int crypt_alloc_req_skcipher(struct crypt_config *cc, 1465 struct convert_context *ctx) 1466 { 1467 unsigned key_index = ctx->cc_sector & (cc->tfms_count - 1); 1468 1469 if (!ctx->r.req) { 1470 ctx->r.req = mempool_alloc(&cc->req_pool, in_interrupt() ? GFP_ATOMIC : GFP_NOIO); 1471 if (!ctx->r.req) 1472 return -ENOMEM; 1473 } 1474 1475 skcipher_request_set_tfm(ctx->r.req, cc->cipher_tfm.tfms[key_index]); 1476 1477 /* 1478 * Use REQ_MAY_BACKLOG so a cipher driver internally backlogs 1479 * requests if driver request queue is full. 1480 */ 1481 skcipher_request_set_callback(ctx->r.req, 1482 CRYPTO_TFM_REQ_MAY_BACKLOG, 1483 kcryptd_async_done, dmreq_of_req(cc, ctx->r.req)); 1484 1485 return 0; 1486 } 1487 1488 static int crypt_alloc_req_aead(struct crypt_config *cc, 1489 struct convert_context *ctx) 1490 { 1491 if (!ctx->r.req_aead) { 1492 ctx->r.req_aead = mempool_alloc(&cc->req_pool, in_interrupt() ? GFP_ATOMIC : GFP_NOIO); 1493 if (!ctx->r.req_aead) 1494 return -ENOMEM; 1495 } 1496 1497 aead_request_set_tfm(ctx->r.req_aead, cc->cipher_tfm.tfms_aead[0]); 1498 1499 /* 1500 * Use REQ_MAY_BACKLOG so a cipher driver internally backlogs 1501 * requests if driver request queue is full. 1502 */ 1503 aead_request_set_callback(ctx->r.req_aead, 1504 CRYPTO_TFM_REQ_MAY_BACKLOG, 1505 kcryptd_async_done, dmreq_of_req(cc, ctx->r.req_aead)); 1506 1507 return 0; 1508 } 1509 1510 static int crypt_alloc_req(struct crypt_config *cc, 1511 struct convert_context *ctx) 1512 { 1513 if (crypt_integrity_aead(cc)) 1514 return crypt_alloc_req_aead(cc, ctx); 1515 else 1516 return crypt_alloc_req_skcipher(cc, ctx); 1517 } 1518 1519 static void crypt_free_req_skcipher(struct crypt_config *cc, 1520 struct skcipher_request *req, struct bio *base_bio) 1521 { 1522 struct dm_crypt_io *io = dm_per_bio_data(base_bio, cc->per_bio_data_size); 1523 1524 if ((struct skcipher_request *)(io + 1) != req) 1525 mempool_free(req, &cc->req_pool); 1526 } 1527 1528 static void crypt_free_req_aead(struct crypt_config *cc, 1529 struct aead_request *req, struct bio *base_bio) 1530 { 1531 struct dm_crypt_io *io = dm_per_bio_data(base_bio, cc->per_bio_data_size); 1532 1533 if ((struct aead_request *)(io + 1) != req) 1534 mempool_free(req, &cc->req_pool); 1535 } 1536 1537 static void crypt_free_req(struct crypt_config *cc, void *req, struct bio *base_bio) 1538 { 1539 if (crypt_integrity_aead(cc)) 1540 crypt_free_req_aead(cc, req, base_bio); 1541 else 1542 crypt_free_req_skcipher(cc, req, base_bio); 1543 } 1544 1545 /* 1546 * Encrypt / decrypt data from one bio to another one (can be the same one) 1547 */ 1548 static blk_status_t crypt_convert(struct crypt_config *cc, 1549 struct convert_context *ctx, bool atomic, bool reset_pending) 1550 { 1551 unsigned int tag_offset = 0; 1552 unsigned int sector_step = cc->sector_size >> SECTOR_SHIFT; 1553 int r; 1554 1555 /* 1556 * if reset_pending is set we are dealing with the bio for the first time, 1557 * else we're continuing to work on the previous bio, so don't mess with 1558 * the cc_pending counter 1559 */ 1560 if (reset_pending) 1561 atomic_set(&ctx->cc_pending, 1); 1562 1563 while (ctx->iter_in.bi_size && ctx->iter_out.bi_size) { 1564 1565 r = crypt_alloc_req(cc, ctx); 1566 if (r) { 1567 complete(&ctx->restart); 1568 return BLK_STS_DEV_RESOURCE; 1569 } 1570 1571 atomic_inc(&ctx->cc_pending); 1572 1573 if (crypt_integrity_aead(cc)) 1574 r = crypt_convert_block_aead(cc, ctx, ctx->r.req_aead, tag_offset); 1575 else 1576 r = crypt_convert_block_skcipher(cc, ctx, ctx->r.req, tag_offset); 1577 1578 switch (r) { 1579 /* 1580 * The request was queued by a crypto driver 1581 * but the driver request queue is full, let's wait. 1582 */ 1583 case -EBUSY: 1584 if (in_interrupt()) { 1585 if (try_wait_for_completion(&ctx->restart)) { 1586 /* 1587 * we don't have to block to wait for completion, 1588 * so proceed 1589 */ 1590 } else { 1591 /* 1592 * we can't wait for completion without blocking 1593 * exit and continue processing in a workqueue 1594 */ 1595 ctx->r.req = NULL; 1596 ctx->cc_sector += sector_step; 1597 tag_offset++; 1598 return BLK_STS_DEV_RESOURCE; 1599 } 1600 } else { 1601 wait_for_completion(&ctx->restart); 1602 } 1603 reinit_completion(&ctx->restart); 1604 fallthrough; 1605 /* 1606 * The request is queued and processed asynchronously, 1607 * completion function kcryptd_async_done() will be called. 1608 */ 1609 case -EINPROGRESS: 1610 ctx->r.req = NULL; 1611 ctx->cc_sector += sector_step; 1612 tag_offset++; 1613 continue; 1614 /* 1615 * The request was already processed (synchronously). 1616 */ 1617 case 0: 1618 atomic_dec(&ctx->cc_pending); 1619 ctx->cc_sector += sector_step; 1620 tag_offset++; 1621 if (!atomic) 1622 cond_resched(); 1623 continue; 1624 /* 1625 * There was a data integrity error. 1626 */ 1627 case -EBADMSG: 1628 atomic_dec(&ctx->cc_pending); 1629 return BLK_STS_PROTECTION; 1630 /* 1631 * There was an error while processing the request. 1632 */ 1633 default: 1634 atomic_dec(&ctx->cc_pending); 1635 return BLK_STS_IOERR; 1636 } 1637 } 1638 1639 return 0; 1640 } 1641 1642 static void crypt_free_buffer_pages(struct crypt_config *cc, struct bio *clone); 1643 1644 /* 1645 * Generate a new unfragmented bio with the given size 1646 * This should never violate the device limitations (but only because 1647 * max_segment_size is being constrained to PAGE_SIZE). 1648 * 1649 * This function may be called concurrently. If we allocate from the mempool 1650 * concurrently, there is a possibility of deadlock. For example, if we have 1651 * mempool of 256 pages, two processes, each wanting 256, pages allocate from 1652 * the mempool concurrently, it may deadlock in a situation where both processes 1653 * have allocated 128 pages and the mempool is exhausted. 1654 * 1655 * In order to avoid this scenario we allocate the pages under a mutex. 1656 * 1657 * In order to not degrade performance with excessive locking, we try 1658 * non-blocking allocations without a mutex first but on failure we fallback 1659 * to blocking allocations with a mutex. 1660 */ 1661 static struct bio *crypt_alloc_buffer(struct dm_crypt_io *io, unsigned size) 1662 { 1663 struct crypt_config *cc = io->cc; 1664 struct bio *clone; 1665 unsigned int nr_iovecs = (size + PAGE_SIZE - 1) >> PAGE_SHIFT; 1666 gfp_t gfp_mask = GFP_NOWAIT | __GFP_HIGHMEM; 1667 unsigned i, len, remaining_size; 1668 struct page *page; 1669 1670 retry: 1671 if (unlikely(gfp_mask & __GFP_DIRECT_RECLAIM)) 1672 mutex_lock(&cc->bio_alloc_lock); 1673 1674 clone = bio_alloc_bioset(cc->dev->bdev, nr_iovecs, io->base_bio->bi_opf, 1675 GFP_NOIO, &cc->bs); 1676 clone->bi_private = io; 1677 clone->bi_end_io = crypt_endio; 1678 1679 remaining_size = size; 1680 1681 for (i = 0; i < nr_iovecs; i++) { 1682 page = mempool_alloc(&cc->page_pool, gfp_mask); 1683 if (!page) { 1684 crypt_free_buffer_pages(cc, clone); 1685 bio_put(clone); 1686 gfp_mask |= __GFP_DIRECT_RECLAIM; 1687 goto retry; 1688 } 1689 1690 len = (remaining_size > PAGE_SIZE) ? PAGE_SIZE : remaining_size; 1691 1692 bio_add_page(clone, page, len, 0); 1693 1694 remaining_size -= len; 1695 } 1696 1697 /* Allocate space for integrity tags */ 1698 if (dm_crypt_integrity_io_alloc(io, clone)) { 1699 crypt_free_buffer_pages(cc, clone); 1700 bio_put(clone); 1701 clone = NULL; 1702 } 1703 1704 if (unlikely(gfp_mask & __GFP_DIRECT_RECLAIM)) 1705 mutex_unlock(&cc->bio_alloc_lock); 1706 1707 return clone; 1708 } 1709 1710 static void crypt_free_buffer_pages(struct crypt_config *cc, struct bio *clone) 1711 { 1712 struct bio_vec *bv; 1713 struct bvec_iter_all iter_all; 1714 1715 bio_for_each_segment_all(bv, clone, iter_all) { 1716 BUG_ON(!bv->bv_page); 1717 mempool_free(bv->bv_page, &cc->page_pool); 1718 } 1719 } 1720 1721 static void crypt_io_init(struct dm_crypt_io *io, struct crypt_config *cc, 1722 struct bio *bio, sector_t sector) 1723 { 1724 io->cc = cc; 1725 io->base_bio = bio; 1726 io->sector = sector; 1727 io->error = 0; 1728 io->ctx.r.req = NULL; 1729 io->integrity_metadata = NULL; 1730 io->integrity_metadata_from_pool = false; 1731 atomic_set(&io->io_pending, 0); 1732 } 1733 1734 static void crypt_inc_pending(struct dm_crypt_io *io) 1735 { 1736 atomic_inc(&io->io_pending); 1737 } 1738 1739 static void kcryptd_io_bio_endio(struct work_struct *work) 1740 { 1741 struct dm_crypt_io *io = container_of(work, struct dm_crypt_io, work); 1742 bio_endio(io->base_bio); 1743 } 1744 1745 /* 1746 * One of the bios was finished. Check for completion of 1747 * the whole request and correctly clean up the buffer. 1748 */ 1749 static void crypt_dec_pending(struct dm_crypt_io *io) 1750 { 1751 struct crypt_config *cc = io->cc; 1752 struct bio *base_bio = io->base_bio; 1753 blk_status_t error = io->error; 1754 1755 if (!atomic_dec_and_test(&io->io_pending)) 1756 return; 1757 1758 if (io->ctx.r.req) 1759 crypt_free_req(cc, io->ctx.r.req, base_bio); 1760 1761 if (unlikely(io->integrity_metadata_from_pool)) 1762 mempool_free(io->integrity_metadata, &io->cc->tag_pool); 1763 else 1764 kfree(io->integrity_metadata); 1765 1766 base_bio->bi_status = error; 1767 1768 /* 1769 * If we are running this function from our tasklet, 1770 * we can't call bio_endio() here, because it will call 1771 * clone_endio() from dm.c, which in turn will 1772 * free the current struct dm_crypt_io structure with 1773 * our tasklet. In this case we need to delay bio_endio() 1774 * execution to after the tasklet is done and dequeued. 1775 */ 1776 if (tasklet_trylock(&io->tasklet)) { 1777 tasklet_unlock(&io->tasklet); 1778 bio_endio(base_bio); 1779 return; 1780 } 1781 1782 INIT_WORK(&io->work, kcryptd_io_bio_endio); 1783 queue_work(cc->io_queue, &io->work); 1784 } 1785 1786 /* 1787 * kcryptd/kcryptd_io: 1788 * 1789 * Needed because it would be very unwise to do decryption in an 1790 * interrupt context. 1791 * 1792 * kcryptd performs the actual encryption or decryption. 1793 * 1794 * kcryptd_io performs the IO submission. 1795 * 1796 * They must be separated as otherwise the final stages could be 1797 * starved by new requests which can block in the first stages due 1798 * to memory allocation. 1799 * 1800 * The work is done per CPU global for all dm-crypt instances. 1801 * They should not depend on each other and do not block. 1802 */ 1803 static void crypt_endio(struct bio *clone) 1804 { 1805 struct dm_crypt_io *io = clone->bi_private; 1806 struct crypt_config *cc = io->cc; 1807 unsigned rw = bio_data_dir(clone); 1808 blk_status_t error; 1809 1810 /* 1811 * free the processed pages 1812 */ 1813 if (rw == WRITE) 1814 crypt_free_buffer_pages(cc, clone); 1815 1816 error = clone->bi_status; 1817 bio_put(clone); 1818 1819 if (rw == READ && !error) { 1820 kcryptd_queue_crypt(io); 1821 return; 1822 } 1823 1824 if (unlikely(error)) 1825 io->error = error; 1826 1827 crypt_dec_pending(io); 1828 } 1829 1830 static int kcryptd_io_read(struct dm_crypt_io *io, gfp_t gfp) 1831 { 1832 struct crypt_config *cc = io->cc; 1833 struct bio *clone; 1834 1835 /* 1836 * We need the original biovec array in order to decrypt the whole bio 1837 * data *afterwards* -- thanks to immutable biovecs we don't need to 1838 * worry about the block layer modifying the biovec array; so leverage 1839 * bio_alloc_clone(). 1840 */ 1841 clone = bio_alloc_clone(cc->dev->bdev, io->base_bio, gfp, &cc->bs); 1842 if (!clone) 1843 return 1; 1844 clone->bi_private = io; 1845 clone->bi_end_io = crypt_endio; 1846 1847 crypt_inc_pending(io); 1848 1849 clone->bi_iter.bi_sector = cc->start + io->sector; 1850 1851 if (dm_crypt_integrity_io_alloc(io, clone)) { 1852 crypt_dec_pending(io); 1853 bio_put(clone); 1854 return 1; 1855 } 1856 1857 submit_bio_noacct(clone); 1858 return 0; 1859 } 1860 1861 static void kcryptd_io_read_work(struct work_struct *work) 1862 { 1863 struct dm_crypt_io *io = container_of(work, struct dm_crypt_io, work); 1864 1865 crypt_inc_pending(io); 1866 if (kcryptd_io_read(io, GFP_NOIO)) 1867 io->error = BLK_STS_RESOURCE; 1868 crypt_dec_pending(io); 1869 } 1870 1871 static void kcryptd_queue_read(struct dm_crypt_io *io) 1872 { 1873 struct crypt_config *cc = io->cc; 1874 1875 INIT_WORK(&io->work, kcryptd_io_read_work); 1876 queue_work(cc->io_queue, &io->work); 1877 } 1878 1879 static void kcryptd_io_write(struct dm_crypt_io *io) 1880 { 1881 struct bio *clone = io->ctx.bio_out; 1882 1883 submit_bio_noacct(clone); 1884 } 1885 1886 #define crypt_io_from_node(node) rb_entry((node), struct dm_crypt_io, rb_node) 1887 1888 static int dmcrypt_write(void *data) 1889 { 1890 struct crypt_config *cc = data; 1891 struct dm_crypt_io *io; 1892 1893 while (1) { 1894 struct rb_root write_tree; 1895 struct blk_plug plug; 1896 1897 spin_lock_irq(&cc->write_thread_lock); 1898 continue_locked: 1899 1900 if (!RB_EMPTY_ROOT(&cc->write_tree)) 1901 goto pop_from_list; 1902 1903 set_current_state(TASK_INTERRUPTIBLE); 1904 1905 spin_unlock_irq(&cc->write_thread_lock); 1906 1907 if (unlikely(kthread_should_stop())) { 1908 set_current_state(TASK_RUNNING); 1909 break; 1910 } 1911 1912 schedule(); 1913 1914 set_current_state(TASK_RUNNING); 1915 spin_lock_irq(&cc->write_thread_lock); 1916 goto continue_locked; 1917 1918 pop_from_list: 1919 write_tree = cc->write_tree; 1920 cc->write_tree = RB_ROOT; 1921 spin_unlock_irq(&cc->write_thread_lock); 1922 1923 BUG_ON(rb_parent(write_tree.rb_node)); 1924 1925 /* 1926 * Note: we cannot walk the tree here with rb_next because 1927 * the structures may be freed when kcryptd_io_write is called. 1928 */ 1929 blk_start_plug(&plug); 1930 do { 1931 io = crypt_io_from_node(rb_first(&write_tree)); 1932 rb_erase(&io->rb_node, &write_tree); 1933 kcryptd_io_write(io); 1934 } while (!RB_EMPTY_ROOT(&write_tree)); 1935 blk_finish_plug(&plug); 1936 } 1937 return 0; 1938 } 1939 1940 static void kcryptd_crypt_write_io_submit(struct dm_crypt_io *io, int async) 1941 { 1942 struct bio *clone = io->ctx.bio_out; 1943 struct crypt_config *cc = io->cc; 1944 unsigned long flags; 1945 sector_t sector; 1946 struct rb_node **rbp, *parent; 1947 1948 if (unlikely(io->error)) { 1949 crypt_free_buffer_pages(cc, clone); 1950 bio_put(clone); 1951 crypt_dec_pending(io); 1952 return; 1953 } 1954 1955 /* crypt_convert should have filled the clone bio */ 1956 BUG_ON(io->ctx.iter_out.bi_size); 1957 1958 clone->bi_iter.bi_sector = cc->start + io->sector; 1959 1960 if ((likely(!async) && test_bit(DM_CRYPT_NO_OFFLOAD, &cc->flags)) || 1961 test_bit(DM_CRYPT_NO_WRITE_WORKQUEUE, &cc->flags)) { 1962 submit_bio_noacct(clone); 1963 return; 1964 } 1965 1966 spin_lock_irqsave(&cc->write_thread_lock, flags); 1967 if (RB_EMPTY_ROOT(&cc->write_tree)) 1968 wake_up_process(cc->write_thread); 1969 rbp = &cc->write_tree.rb_node; 1970 parent = NULL; 1971 sector = io->sector; 1972 while (*rbp) { 1973 parent = *rbp; 1974 if (sector < crypt_io_from_node(parent)->sector) 1975 rbp = &(*rbp)->rb_left; 1976 else 1977 rbp = &(*rbp)->rb_right; 1978 } 1979 rb_link_node(&io->rb_node, parent, rbp); 1980 rb_insert_color(&io->rb_node, &cc->write_tree); 1981 spin_unlock_irqrestore(&cc->write_thread_lock, flags); 1982 } 1983 1984 static bool kcryptd_crypt_write_inline(struct crypt_config *cc, 1985 struct convert_context *ctx) 1986 1987 { 1988 if (!test_bit(DM_CRYPT_WRITE_INLINE, &cc->flags)) 1989 return false; 1990 1991 /* 1992 * Note: zone append writes (REQ_OP_ZONE_APPEND) do not have ordering 1993 * constraints so they do not need to be issued inline by 1994 * kcryptd_crypt_write_convert(). 1995 */ 1996 switch (bio_op(ctx->bio_in)) { 1997 case REQ_OP_WRITE: 1998 case REQ_OP_WRITE_SAME: 1999 case REQ_OP_WRITE_ZEROES: 2000 return true; 2001 default: 2002 return false; 2003 } 2004 } 2005 2006 static void kcryptd_crypt_write_continue(struct work_struct *work) 2007 { 2008 struct dm_crypt_io *io = container_of(work, struct dm_crypt_io, work); 2009 struct crypt_config *cc = io->cc; 2010 struct convert_context *ctx = &io->ctx; 2011 int crypt_finished; 2012 sector_t sector = io->sector; 2013 blk_status_t r; 2014 2015 wait_for_completion(&ctx->restart); 2016 reinit_completion(&ctx->restart); 2017 2018 r = crypt_convert(cc, &io->ctx, true, false); 2019 if (r) 2020 io->error = r; 2021 crypt_finished = atomic_dec_and_test(&ctx->cc_pending); 2022 if (!crypt_finished && kcryptd_crypt_write_inline(cc, ctx)) { 2023 /* Wait for completion signaled by kcryptd_async_done() */ 2024 wait_for_completion(&ctx->restart); 2025 crypt_finished = 1; 2026 } 2027 2028 /* Encryption was already finished, submit io now */ 2029 if (crypt_finished) { 2030 kcryptd_crypt_write_io_submit(io, 0); 2031 io->sector = sector; 2032 } 2033 2034 crypt_dec_pending(io); 2035 } 2036 2037 static void kcryptd_crypt_write_convert(struct dm_crypt_io *io) 2038 { 2039 struct crypt_config *cc = io->cc; 2040 struct convert_context *ctx = &io->ctx; 2041 struct bio *clone; 2042 int crypt_finished; 2043 sector_t sector = io->sector; 2044 blk_status_t r; 2045 2046 /* 2047 * Prevent io from disappearing until this function completes. 2048 */ 2049 crypt_inc_pending(io); 2050 crypt_convert_init(cc, ctx, NULL, io->base_bio, sector); 2051 2052 clone = crypt_alloc_buffer(io, io->base_bio->bi_iter.bi_size); 2053 if (unlikely(!clone)) { 2054 io->error = BLK_STS_IOERR; 2055 goto dec; 2056 } 2057 2058 io->ctx.bio_out = clone; 2059 io->ctx.iter_out = clone->bi_iter; 2060 2061 sector += bio_sectors(clone); 2062 2063 crypt_inc_pending(io); 2064 r = crypt_convert(cc, ctx, 2065 test_bit(DM_CRYPT_NO_WRITE_WORKQUEUE, &cc->flags), true); 2066 /* 2067 * Crypto API backlogged the request, because its queue was full 2068 * and we're in softirq context, so continue from a workqueue 2069 * (TODO: is it actually possible to be in softirq in the write path?) 2070 */ 2071 if (r == BLK_STS_DEV_RESOURCE) { 2072 INIT_WORK(&io->work, kcryptd_crypt_write_continue); 2073 queue_work(cc->crypt_queue, &io->work); 2074 return; 2075 } 2076 if (r) 2077 io->error = r; 2078 crypt_finished = atomic_dec_and_test(&ctx->cc_pending); 2079 if (!crypt_finished && kcryptd_crypt_write_inline(cc, ctx)) { 2080 /* Wait for completion signaled by kcryptd_async_done() */ 2081 wait_for_completion(&ctx->restart); 2082 crypt_finished = 1; 2083 } 2084 2085 /* Encryption was already finished, submit io now */ 2086 if (crypt_finished) { 2087 kcryptd_crypt_write_io_submit(io, 0); 2088 io->sector = sector; 2089 } 2090 2091 dec: 2092 crypt_dec_pending(io); 2093 } 2094 2095 static void kcryptd_crypt_read_done(struct dm_crypt_io *io) 2096 { 2097 crypt_dec_pending(io); 2098 } 2099 2100 static void kcryptd_crypt_read_continue(struct work_struct *work) 2101 { 2102 struct dm_crypt_io *io = container_of(work, struct dm_crypt_io, work); 2103 struct crypt_config *cc = io->cc; 2104 blk_status_t r; 2105 2106 wait_for_completion(&io->ctx.restart); 2107 reinit_completion(&io->ctx.restart); 2108 2109 r = crypt_convert(cc, &io->ctx, true, false); 2110 if (r) 2111 io->error = r; 2112 2113 if (atomic_dec_and_test(&io->ctx.cc_pending)) 2114 kcryptd_crypt_read_done(io); 2115 2116 crypt_dec_pending(io); 2117 } 2118 2119 static void kcryptd_crypt_read_convert(struct dm_crypt_io *io) 2120 { 2121 struct crypt_config *cc = io->cc; 2122 blk_status_t r; 2123 2124 crypt_inc_pending(io); 2125 2126 crypt_convert_init(cc, &io->ctx, io->base_bio, io->base_bio, 2127 io->sector); 2128 2129 r = crypt_convert(cc, &io->ctx, 2130 test_bit(DM_CRYPT_NO_READ_WORKQUEUE, &cc->flags), true); 2131 /* 2132 * Crypto API backlogged the request, because its queue was full 2133 * and we're in softirq context, so continue from a workqueue 2134 */ 2135 if (r == BLK_STS_DEV_RESOURCE) { 2136 INIT_WORK(&io->work, kcryptd_crypt_read_continue); 2137 queue_work(cc->crypt_queue, &io->work); 2138 return; 2139 } 2140 if (r) 2141 io->error = r; 2142 2143 if (atomic_dec_and_test(&io->ctx.cc_pending)) 2144 kcryptd_crypt_read_done(io); 2145 2146 crypt_dec_pending(io); 2147 } 2148 2149 static void kcryptd_async_done(struct crypto_async_request *async_req, 2150 int error) 2151 { 2152 struct dm_crypt_request *dmreq = async_req->data; 2153 struct convert_context *ctx = dmreq->ctx; 2154 struct dm_crypt_io *io = container_of(ctx, struct dm_crypt_io, ctx); 2155 struct crypt_config *cc = io->cc; 2156 2157 /* 2158 * A request from crypto driver backlog is going to be processed now, 2159 * finish the completion and continue in crypt_convert(). 2160 * (Callback will be called for the second time for this request.) 2161 */ 2162 if (error == -EINPROGRESS) { 2163 complete(&ctx->restart); 2164 return; 2165 } 2166 2167 if (!error && cc->iv_gen_ops && cc->iv_gen_ops->post) 2168 error = cc->iv_gen_ops->post(cc, org_iv_of_dmreq(cc, dmreq), dmreq); 2169 2170 if (error == -EBADMSG) { 2171 sector_t s = le64_to_cpu(*org_sector_of_dmreq(cc, dmreq)); 2172 2173 DMERR_LIMIT("%pg: INTEGRITY AEAD ERROR, sector %llu", 2174 ctx->bio_in->bi_bdev, s); 2175 dm_audit_log_bio(DM_MSG_PREFIX, "integrity-aead", 2176 ctx->bio_in, s, 0); 2177 io->error = BLK_STS_PROTECTION; 2178 } else if (error < 0) 2179 io->error = BLK_STS_IOERR; 2180 2181 crypt_free_req(cc, req_of_dmreq(cc, dmreq), io->base_bio); 2182 2183 if (!atomic_dec_and_test(&ctx->cc_pending)) 2184 return; 2185 2186 /* 2187 * The request is fully completed: for inline writes, let 2188 * kcryptd_crypt_write_convert() do the IO submission. 2189 */ 2190 if (bio_data_dir(io->base_bio) == READ) { 2191 kcryptd_crypt_read_done(io); 2192 return; 2193 } 2194 2195 if (kcryptd_crypt_write_inline(cc, ctx)) { 2196 complete(&ctx->restart); 2197 return; 2198 } 2199 2200 kcryptd_crypt_write_io_submit(io, 1); 2201 } 2202 2203 static void kcryptd_crypt(struct work_struct *work) 2204 { 2205 struct dm_crypt_io *io = container_of(work, struct dm_crypt_io, work); 2206 2207 if (bio_data_dir(io->base_bio) == READ) 2208 kcryptd_crypt_read_convert(io); 2209 else 2210 kcryptd_crypt_write_convert(io); 2211 } 2212 2213 static void kcryptd_crypt_tasklet(unsigned long work) 2214 { 2215 kcryptd_crypt((struct work_struct *)work); 2216 } 2217 2218 static void kcryptd_queue_crypt(struct dm_crypt_io *io) 2219 { 2220 struct crypt_config *cc = io->cc; 2221 2222 if ((bio_data_dir(io->base_bio) == READ && test_bit(DM_CRYPT_NO_READ_WORKQUEUE, &cc->flags)) || 2223 (bio_data_dir(io->base_bio) == WRITE && test_bit(DM_CRYPT_NO_WRITE_WORKQUEUE, &cc->flags))) { 2224 /* 2225 * in_hardirq(): Crypto API's skcipher_walk_first() refuses to work in hard IRQ context. 2226 * irqs_disabled(): the kernel may run some IO completion from the idle thread, but 2227 * it is being executed with irqs disabled. 2228 */ 2229 if (in_hardirq() || irqs_disabled()) { 2230 tasklet_init(&io->tasklet, kcryptd_crypt_tasklet, (unsigned long)&io->work); 2231 tasklet_schedule(&io->tasklet); 2232 return; 2233 } 2234 2235 kcryptd_crypt(&io->work); 2236 return; 2237 } 2238 2239 INIT_WORK(&io->work, kcryptd_crypt); 2240 queue_work(cc->crypt_queue, &io->work); 2241 } 2242 2243 static void crypt_free_tfms_aead(struct crypt_config *cc) 2244 { 2245 if (!cc->cipher_tfm.tfms_aead) 2246 return; 2247 2248 if (cc->cipher_tfm.tfms_aead[0] && !IS_ERR(cc->cipher_tfm.tfms_aead[0])) { 2249 crypto_free_aead(cc->cipher_tfm.tfms_aead[0]); 2250 cc->cipher_tfm.tfms_aead[0] = NULL; 2251 } 2252 2253 kfree(cc->cipher_tfm.tfms_aead); 2254 cc->cipher_tfm.tfms_aead = NULL; 2255 } 2256 2257 static void crypt_free_tfms_skcipher(struct crypt_config *cc) 2258 { 2259 unsigned i; 2260 2261 if (!cc->cipher_tfm.tfms) 2262 return; 2263 2264 for (i = 0; i < cc->tfms_count; i++) 2265 if (cc->cipher_tfm.tfms[i] && !IS_ERR(cc->cipher_tfm.tfms[i])) { 2266 crypto_free_skcipher(cc->cipher_tfm.tfms[i]); 2267 cc->cipher_tfm.tfms[i] = NULL; 2268 } 2269 2270 kfree(cc->cipher_tfm.tfms); 2271 cc->cipher_tfm.tfms = NULL; 2272 } 2273 2274 static void crypt_free_tfms(struct crypt_config *cc) 2275 { 2276 if (crypt_integrity_aead(cc)) 2277 crypt_free_tfms_aead(cc); 2278 else 2279 crypt_free_tfms_skcipher(cc); 2280 } 2281 2282 static int crypt_alloc_tfms_skcipher(struct crypt_config *cc, char *ciphermode) 2283 { 2284 unsigned i; 2285 int err; 2286 2287 cc->cipher_tfm.tfms = kcalloc(cc->tfms_count, 2288 sizeof(struct crypto_skcipher *), 2289 GFP_KERNEL); 2290 if (!cc->cipher_tfm.tfms) 2291 return -ENOMEM; 2292 2293 for (i = 0; i < cc->tfms_count; i++) { 2294 cc->cipher_tfm.tfms[i] = crypto_alloc_skcipher(ciphermode, 0, 2295 CRYPTO_ALG_ALLOCATES_MEMORY); 2296 if (IS_ERR(cc->cipher_tfm.tfms[i])) { 2297 err = PTR_ERR(cc->cipher_tfm.tfms[i]); 2298 crypt_free_tfms(cc); 2299 return err; 2300 } 2301 } 2302 2303 /* 2304 * dm-crypt performance can vary greatly depending on which crypto 2305 * algorithm implementation is used. Help people debug performance 2306 * problems by logging the ->cra_driver_name. 2307 */ 2308 DMDEBUG_LIMIT("%s using implementation \"%s\"", ciphermode, 2309 crypto_skcipher_alg(any_tfm(cc))->base.cra_driver_name); 2310 return 0; 2311 } 2312 2313 static int crypt_alloc_tfms_aead(struct crypt_config *cc, char *ciphermode) 2314 { 2315 int err; 2316 2317 cc->cipher_tfm.tfms = kmalloc(sizeof(struct crypto_aead *), GFP_KERNEL); 2318 if (!cc->cipher_tfm.tfms) 2319 return -ENOMEM; 2320 2321 cc->cipher_tfm.tfms_aead[0] = crypto_alloc_aead(ciphermode, 0, 2322 CRYPTO_ALG_ALLOCATES_MEMORY); 2323 if (IS_ERR(cc->cipher_tfm.tfms_aead[0])) { 2324 err = PTR_ERR(cc->cipher_tfm.tfms_aead[0]); 2325 crypt_free_tfms(cc); 2326 return err; 2327 } 2328 2329 DMDEBUG_LIMIT("%s using implementation \"%s\"", ciphermode, 2330 crypto_aead_alg(any_tfm_aead(cc))->base.cra_driver_name); 2331 return 0; 2332 } 2333 2334 static int crypt_alloc_tfms(struct crypt_config *cc, char *ciphermode) 2335 { 2336 if (crypt_integrity_aead(cc)) 2337 return crypt_alloc_tfms_aead(cc, ciphermode); 2338 else 2339 return crypt_alloc_tfms_skcipher(cc, ciphermode); 2340 } 2341 2342 static unsigned crypt_subkey_size(struct crypt_config *cc) 2343 { 2344 return (cc->key_size - cc->key_extra_size) >> ilog2(cc->tfms_count); 2345 } 2346 2347 static unsigned crypt_authenckey_size(struct crypt_config *cc) 2348 { 2349 return crypt_subkey_size(cc) + RTA_SPACE(sizeof(struct crypto_authenc_key_param)); 2350 } 2351 2352 /* 2353 * If AEAD is composed like authenc(hmac(sha256),xts(aes)), 2354 * the key must be for some reason in special format. 2355 * This funcion converts cc->key to this special format. 2356 */ 2357 static void crypt_copy_authenckey(char *p, const void *key, 2358 unsigned enckeylen, unsigned authkeylen) 2359 { 2360 struct crypto_authenc_key_param *param; 2361 struct rtattr *rta; 2362 2363 rta = (struct rtattr *)p; 2364 param = RTA_DATA(rta); 2365 param->enckeylen = cpu_to_be32(enckeylen); 2366 rta->rta_len = RTA_LENGTH(sizeof(*param)); 2367 rta->rta_type = CRYPTO_AUTHENC_KEYA_PARAM; 2368 p += RTA_SPACE(sizeof(*param)); 2369 memcpy(p, key + enckeylen, authkeylen); 2370 p += authkeylen; 2371 memcpy(p, key, enckeylen); 2372 } 2373 2374 static int crypt_setkey(struct crypt_config *cc) 2375 { 2376 unsigned subkey_size; 2377 int err = 0, i, r; 2378 2379 /* Ignore extra keys (which are used for IV etc) */ 2380 subkey_size = crypt_subkey_size(cc); 2381 2382 if (crypt_integrity_hmac(cc)) { 2383 if (subkey_size < cc->key_mac_size) 2384 return -EINVAL; 2385 2386 crypt_copy_authenckey(cc->authenc_key, cc->key, 2387 subkey_size - cc->key_mac_size, 2388 cc->key_mac_size); 2389 } 2390 2391 for (i = 0; i < cc->tfms_count; i++) { 2392 if (crypt_integrity_hmac(cc)) 2393 r = crypto_aead_setkey(cc->cipher_tfm.tfms_aead[i], 2394 cc->authenc_key, crypt_authenckey_size(cc)); 2395 else if (crypt_integrity_aead(cc)) 2396 r = crypto_aead_setkey(cc->cipher_tfm.tfms_aead[i], 2397 cc->key + (i * subkey_size), 2398 subkey_size); 2399 else 2400 r = crypto_skcipher_setkey(cc->cipher_tfm.tfms[i], 2401 cc->key + (i * subkey_size), 2402 subkey_size); 2403 if (r) 2404 err = r; 2405 } 2406 2407 if (crypt_integrity_hmac(cc)) 2408 memzero_explicit(cc->authenc_key, crypt_authenckey_size(cc)); 2409 2410 return err; 2411 } 2412 2413 #ifdef CONFIG_KEYS 2414 2415 static bool contains_whitespace(const char *str) 2416 { 2417 while (*str) 2418 if (isspace(*str++)) 2419 return true; 2420 return false; 2421 } 2422 2423 static int set_key_user(struct crypt_config *cc, struct key *key) 2424 { 2425 const struct user_key_payload *ukp; 2426 2427 ukp = user_key_payload_locked(key); 2428 if (!ukp) 2429 return -EKEYREVOKED; 2430 2431 if (cc->key_size != ukp->datalen) 2432 return -EINVAL; 2433 2434 memcpy(cc->key, ukp->data, cc->key_size); 2435 2436 return 0; 2437 } 2438 2439 static int set_key_encrypted(struct crypt_config *cc, struct key *key) 2440 { 2441 const struct encrypted_key_payload *ekp; 2442 2443 ekp = key->payload.data[0]; 2444 if (!ekp) 2445 return -EKEYREVOKED; 2446 2447 if (cc->key_size != ekp->decrypted_datalen) 2448 return -EINVAL; 2449 2450 memcpy(cc->key, ekp->decrypted_data, cc->key_size); 2451 2452 return 0; 2453 } 2454 2455 static int set_key_trusted(struct crypt_config *cc, struct key *key) 2456 { 2457 const struct trusted_key_payload *tkp; 2458 2459 tkp = key->payload.data[0]; 2460 if (!tkp) 2461 return -EKEYREVOKED; 2462 2463 if (cc->key_size != tkp->key_len) 2464 return -EINVAL; 2465 2466 memcpy(cc->key, tkp->key, cc->key_size); 2467 2468 return 0; 2469 } 2470 2471 static int crypt_set_keyring_key(struct crypt_config *cc, const char *key_string) 2472 { 2473 char *new_key_string, *key_desc; 2474 int ret; 2475 struct key_type *type; 2476 struct key *key; 2477 int (*set_key)(struct crypt_config *cc, struct key *key); 2478 2479 /* 2480 * Reject key_string with whitespace. dm core currently lacks code for 2481 * proper whitespace escaping in arguments on DM_TABLE_STATUS path. 2482 */ 2483 if (contains_whitespace(key_string)) { 2484 DMERR("whitespace chars not allowed in key string"); 2485 return -EINVAL; 2486 } 2487 2488 /* look for next ':' separating key_type from key_description */ 2489 key_desc = strpbrk(key_string, ":"); 2490 if (!key_desc || key_desc == key_string || !strlen(key_desc + 1)) 2491 return -EINVAL; 2492 2493 if (!strncmp(key_string, "logon:", key_desc - key_string + 1)) { 2494 type = &key_type_logon; 2495 set_key = set_key_user; 2496 } else if (!strncmp(key_string, "user:", key_desc - key_string + 1)) { 2497 type = &key_type_user; 2498 set_key = set_key_user; 2499 } else if (IS_ENABLED(CONFIG_ENCRYPTED_KEYS) && 2500 !strncmp(key_string, "encrypted:", key_desc - key_string + 1)) { 2501 type = &key_type_encrypted; 2502 set_key = set_key_encrypted; 2503 } else if (IS_ENABLED(CONFIG_TRUSTED_KEYS) && 2504 !strncmp(key_string, "trusted:", key_desc - key_string + 1)) { 2505 type = &key_type_trusted; 2506 set_key = set_key_trusted; 2507 } else { 2508 return -EINVAL; 2509 } 2510 2511 new_key_string = kstrdup(key_string, GFP_KERNEL); 2512 if (!new_key_string) 2513 return -ENOMEM; 2514 2515 key = request_key(type, key_desc + 1, NULL); 2516 if (IS_ERR(key)) { 2517 kfree_sensitive(new_key_string); 2518 return PTR_ERR(key); 2519 } 2520 2521 down_read(&key->sem); 2522 2523 ret = set_key(cc, key); 2524 if (ret < 0) { 2525 up_read(&key->sem); 2526 key_put(key); 2527 kfree_sensitive(new_key_string); 2528 return ret; 2529 } 2530 2531 up_read(&key->sem); 2532 key_put(key); 2533 2534 /* clear the flag since following operations may invalidate previously valid key */ 2535 clear_bit(DM_CRYPT_KEY_VALID, &cc->flags); 2536 2537 ret = crypt_setkey(cc); 2538 2539 if (!ret) { 2540 set_bit(DM_CRYPT_KEY_VALID, &cc->flags); 2541 kfree_sensitive(cc->key_string); 2542 cc->key_string = new_key_string; 2543 } else 2544 kfree_sensitive(new_key_string); 2545 2546 return ret; 2547 } 2548 2549 static int get_key_size(char **key_string) 2550 { 2551 char *colon, dummy; 2552 int ret; 2553 2554 if (*key_string[0] != ':') 2555 return strlen(*key_string) >> 1; 2556 2557 /* look for next ':' in key string */ 2558 colon = strpbrk(*key_string + 1, ":"); 2559 if (!colon) 2560 return -EINVAL; 2561 2562 if (sscanf(*key_string + 1, "%u%c", &ret, &dummy) != 2 || dummy != ':') 2563 return -EINVAL; 2564 2565 *key_string = colon; 2566 2567 /* remaining key string should be :<logon|user>:<key_desc> */ 2568 2569 return ret; 2570 } 2571 2572 #else 2573 2574 static int crypt_set_keyring_key(struct crypt_config *cc, const char *key_string) 2575 { 2576 return -EINVAL; 2577 } 2578 2579 static int get_key_size(char **key_string) 2580 { 2581 return (*key_string[0] == ':') ? -EINVAL : strlen(*key_string) >> 1; 2582 } 2583 2584 #endif /* CONFIG_KEYS */ 2585 2586 static int crypt_set_key(struct crypt_config *cc, char *key) 2587 { 2588 int r = -EINVAL; 2589 int key_string_len = strlen(key); 2590 2591 /* Hyphen (which gives a key_size of zero) means there is no key. */ 2592 if (!cc->key_size && strcmp(key, "-")) 2593 goto out; 2594 2595 /* ':' means the key is in kernel keyring, short-circuit normal key processing */ 2596 if (key[0] == ':') { 2597 r = crypt_set_keyring_key(cc, key + 1); 2598 goto out; 2599 } 2600 2601 /* clear the flag since following operations may invalidate previously valid key */ 2602 clear_bit(DM_CRYPT_KEY_VALID, &cc->flags); 2603 2604 /* wipe references to any kernel keyring key */ 2605 kfree_sensitive(cc->key_string); 2606 cc->key_string = NULL; 2607 2608 /* Decode key from its hex representation. */ 2609 if (cc->key_size && hex2bin(cc->key, key, cc->key_size) < 0) 2610 goto out; 2611 2612 r = crypt_setkey(cc); 2613 if (!r) 2614 set_bit(DM_CRYPT_KEY_VALID, &cc->flags); 2615 2616 out: 2617 /* Hex key string not needed after here, so wipe it. */ 2618 memset(key, '0', key_string_len); 2619 2620 return r; 2621 } 2622 2623 static int crypt_wipe_key(struct crypt_config *cc) 2624 { 2625 int r; 2626 2627 clear_bit(DM_CRYPT_KEY_VALID, &cc->flags); 2628 get_random_bytes(&cc->key, cc->key_size); 2629 2630 /* Wipe IV private keys */ 2631 if (cc->iv_gen_ops && cc->iv_gen_ops->wipe) { 2632 r = cc->iv_gen_ops->wipe(cc); 2633 if (r) 2634 return r; 2635 } 2636 2637 kfree_sensitive(cc->key_string); 2638 cc->key_string = NULL; 2639 r = crypt_setkey(cc); 2640 memset(&cc->key, 0, cc->key_size * sizeof(u8)); 2641 2642 return r; 2643 } 2644 2645 static void crypt_calculate_pages_per_client(void) 2646 { 2647 unsigned long pages = (totalram_pages() - totalhigh_pages()) * DM_CRYPT_MEMORY_PERCENT / 100; 2648 2649 if (!dm_crypt_clients_n) 2650 return; 2651 2652 pages /= dm_crypt_clients_n; 2653 if (pages < DM_CRYPT_MIN_PAGES_PER_CLIENT) 2654 pages = DM_CRYPT_MIN_PAGES_PER_CLIENT; 2655 dm_crypt_pages_per_client = pages; 2656 } 2657 2658 static void *crypt_page_alloc(gfp_t gfp_mask, void *pool_data) 2659 { 2660 struct crypt_config *cc = pool_data; 2661 struct page *page; 2662 2663 /* 2664 * Note, percpu_counter_read_positive() may over (and under) estimate 2665 * the current usage by at most (batch - 1) * num_online_cpus() pages, 2666 * but avoids potential spinlock contention of an exact result. 2667 */ 2668 if (unlikely(percpu_counter_read_positive(&cc->n_allocated_pages) >= dm_crypt_pages_per_client) && 2669 likely(gfp_mask & __GFP_NORETRY)) 2670 return NULL; 2671 2672 page = alloc_page(gfp_mask); 2673 if (likely(page != NULL)) 2674 percpu_counter_add(&cc->n_allocated_pages, 1); 2675 2676 return page; 2677 } 2678 2679 static void crypt_page_free(void *page, void *pool_data) 2680 { 2681 struct crypt_config *cc = pool_data; 2682 2683 __free_page(page); 2684 percpu_counter_sub(&cc->n_allocated_pages, 1); 2685 } 2686 2687 static void crypt_dtr(struct dm_target *ti) 2688 { 2689 struct crypt_config *cc = ti->private; 2690 2691 ti->private = NULL; 2692 2693 if (!cc) 2694 return; 2695 2696 if (cc->write_thread) 2697 kthread_stop(cc->write_thread); 2698 2699 if (cc->io_queue) 2700 destroy_workqueue(cc->io_queue); 2701 if (cc->crypt_queue) 2702 destroy_workqueue(cc->crypt_queue); 2703 2704 crypt_free_tfms(cc); 2705 2706 bioset_exit(&cc->bs); 2707 2708 mempool_exit(&cc->page_pool); 2709 mempool_exit(&cc->req_pool); 2710 mempool_exit(&cc->tag_pool); 2711 2712 WARN_ON(percpu_counter_sum(&cc->n_allocated_pages) != 0); 2713 percpu_counter_destroy(&cc->n_allocated_pages); 2714 2715 if (cc->iv_gen_ops && cc->iv_gen_ops->dtr) 2716 cc->iv_gen_ops->dtr(cc); 2717 2718 if (cc->dev) 2719 dm_put_device(ti, cc->dev); 2720 2721 kfree_sensitive(cc->cipher_string); 2722 kfree_sensitive(cc->key_string); 2723 kfree_sensitive(cc->cipher_auth); 2724 kfree_sensitive(cc->authenc_key); 2725 2726 mutex_destroy(&cc->bio_alloc_lock); 2727 2728 /* Must zero key material before freeing */ 2729 kfree_sensitive(cc); 2730 2731 spin_lock(&dm_crypt_clients_lock); 2732 WARN_ON(!dm_crypt_clients_n); 2733 dm_crypt_clients_n--; 2734 crypt_calculate_pages_per_client(); 2735 spin_unlock(&dm_crypt_clients_lock); 2736 2737 dm_audit_log_dtr(DM_MSG_PREFIX, ti, 1); 2738 } 2739 2740 static int crypt_ctr_ivmode(struct dm_target *ti, const char *ivmode) 2741 { 2742 struct crypt_config *cc = ti->private; 2743 2744 if (crypt_integrity_aead(cc)) 2745 cc->iv_size = crypto_aead_ivsize(any_tfm_aead(cc)); 2746 else 2747 cc->iv_size = crypto_skcipher_ivsize(any_tfm(cc)); 2748 2749 if (cc->iv_size) 2750 /* at least a 64 bit sector number should fit in our buffer */ 2751 cc->iv_size = max(cc->iv_size, 2752 (unsigned int)(sizeof(u64) / sizeof(u8))); 2753 else if (ivmode) { 2754 DMWARN("Selected cipher does not support IVs"); 2755 ivmode = NULL; 2756 } 2757 2758 /* Choose ivmode, see comments at iv code. */ 2759 if (ivmode == NULL) 2760 cc->iv_gen_ops = NULL; 2761 else if (strcmp(ivmode, "plain") == 0) 2762 cc->iv_gen_ops = &crypt_iv_plain_ops; 2763 else if (strcmp(ivmode, "plain64") == 0) 2764 cc->iv_gen_ops = &crypt_iv_plain64_ops; 2765 else if (strcmp(ivmode, "plain64be") == 0) 2766 cc->iv_gen_ops = &crypt_iv_plain64be_ops; 2767 else if (strcmp(ivmode, "essiv") == 0) 2768 cc->iv_gen_ops = &crypt_iv_essiv_ops; 2769 else if (strcmp(ivmode, "benbi") == 0) 2770 cc->iv_gen_ops = &crypt_iv_benbi_ops; 2771 else if (strcmp(ivmode, "null") == 0) 2772 cc->iv_gen_ops = &crypt_iv_null_ops; 2773 else if (strcmp(ivmode, "eboiv") == 0) 2774 cc->iv_gen_ops = &crypt_iv_eboiv_ops; 2775 else if (strcmp(ivmode, "elephant") == 0) { 2776 cc->iv_gen_ops = &crypt_iv_elephant_ops; 2777 cc->key_parts = 2; 2778 cc->key_extra_size = cc->key_size / 2; 2779 if (cc->key_extra_size > ELEPHANT_MAX_KEY_SIZE) 2780 return -EINVAL; 2781 set_bit(CRYPT_ENCRYPT_PREPROCESS, &cc->cipher_flags); 2782 } else if (strcmp(ivmode, "lmk") == 0) { 2783 cc->iv_gen_ops = &crypt_iv_lmk_ops; 2784 /* 2785 * Version 2 and 3 is recognised according 2786 * to length of provided multi-key string. 2787 * If present (version 3), last key is used as IV seed. 2788 * All keys (including IV seed) are always the same size. 2789 */ 2790 if (cc->key_size % cc->key_parts) { 2791 cc->key_parts++; 2792 cc->key_extra_size = cc->key_size / cc->key_parts; 2793 } 2794 } else if (strcmp(ivmode, "tcw") == 0) { 2795 cc->iv_gen_ops = &crypt_iv_tcw_ops; 2796 cc->key_parts += 2; /* IV + whitening */ 2797 cc->key_extra_size = cc->iv_size + TCW_WHITENING_SIZE; 2798 } else if (strcmp(ivmode, "random") == 0) { 2799 cc->iv_gen_ops = &crypt_iv_random_ops; 2800 /* Need storage space in integrity fields. */ 2801 cc->integrity_iv_size = cc->iv_size; 2802 } else { 2803 ti->error = "Invalid IV mode"; 2804 return -EINVAL; 2805 } 2806 2807 return 0; 2808 } 2809 2810 /* 2811 * Workaround to parse HMAC algorithm from AEAD crypto API spec. 2812 * The HMAC is needed to calculate tag size (HMAC digest size). 2813 * This should be probably done by crypto-api calls (once available...) 2814 */ 2815 static int crypt_ctr_auth_cipher(struct crypt_config *cc, char *cipher_api) 2816 { 2817 char *start, *end, *mac_alg = NULL; 2818 struct crypto_ahash *mac; 2819 2820 if (!strstarts(cipher_api, "authenc(")) 2821 return 0; 2822 2823 start = strchr(cipher_api, '('); 2824 end = strchr(cipher_api, ','); 2825 if (!start || !end || ++start > end) 2826 return -EINVAL; 2827 2828 mac_alg = kzalloc(end - start + 1, GFP_KERNEL); 2829 if (!mac_alg) 2830 return -ENOMEM; 2831 strncpy(mac_alg, start, end - start); 2832 2833 mac = crypto_alloc_ahash(mac_alg, 0, CRYPTO_ALG_ALLOCATES_MEMORY); 2834 kfree(mac_alg); 2835 2836 if (IS_ERR(mac)) 2837 return PTR_ERR(mac); 2838 2839 cc->key_mac_size = crypto_ahash_digestsize(mac); 2840 crypto_free_ahash(mac); 2841 2842 cc->authenc_key = kmalloc(crypt_authenckey_size(cc), GFP_KERNEL); 2843 if (!cc->authenc_key) 2844 return -ENOMEM; 2845 2846 return 0; 2847 } 2848 2849 static int crypt_ctr_cipher_new(struct dm_target *ti, char *cipher_in, char *key, 2850 char **ivmode, char **ivopts) 2851 { 2852 struct crypt_config *cc = ti->private; 2853 char *tmp, *cipher_api, buf[CRYPTO_MAX_ALG_NAME]; 2854 int ret = -EINVAL; 2855 2856 cc->tfms_count = 1; 2857 2858 /* 2859 * New format (capi: prefix) 2860 * capi:cipher_api_spec-iv:ivopts 2861 */ 2862 tmp = &cipher_in[strlen("capi:")]; 2863 2864 /* Separate IV options if present, it can contain another '-' in hash name */ 2865 *ivopts = strrchr(tmp, ':'); 2866 if (*ivopts) { 2867 **ivopts = '\0'; 2868 (*ivopts)++; 2869 } 2870 /* Parse IV mode */ 2871 *ivmode = strrchr(tmp, '-'); 2872 if (*ivmode) { 2873 **ivmode = '\0'; 2874 (*ivmode)++; 2875 } 2876 /* The rest is crypto API spec */ 2877 cipher_api = tmp; 2878 2879 /* Alloc AEAD, can be used only in new format. */ 2880 if (crypt_integrity_aead(cc)) { 2881 ret = crypt_ctr_auth_cipher(cc, cipher_api); 2882 if (ret < 0) { 2883 ti->error = "Invalid AEAD cipher spec"; 2884 return -ENOMEM; 2885 } 2886 } 2887 2888 if (*ivmode && !strcmp(*ivmode, "lmk")) 2889 cc->tfms_count = 64; 2890 2891 if (*ivmode && !strcmp(*ivmode, "essiv")) { 2892 if (!*ivopts) { 2893 ti->error = "Digest algorithm missing for ESSIV mode"; 2894 return -EINVAL; 2895 } 2896 ret = snprintf(buf, CRYPTO_MAX_ALG_NAME, "essiv(%s,%s)", 2897 cipher_api, *ivopts); 2898 if (ret < 0 || ret >= CRYPTO_MAX_ALG_NAME) { 2899 ti->error = "Cannot allocate cipher string"; 2900 return -ENOMEM; 2901 } 2902 cipher_api = buf; 2903 } 2904 2905 cc->key_parts = cc->tfms_count; 2906 2907 /* Allocate cipher */ 2908 ret = crypt_alloc_tfms(cc, cipher_api); 2909 if (ret < 0) { 2910 ti->error = "Error allocating crypto tfm"; 2911 return ret; 2912 } 2913 2914 if (crypt_integrity_aead(cc)) 2915 cc->iv_size = crypto_aead_ivsize(any_tfm_aead(cc)); 2916 else 2917 cc->iv_size = crypto_skcipher_ivsize(any_tfm(cc)); 2918 2919 return 0; 2920 } 2921 2922 static int crypt_ctr_cipher_old(struct dm_target *ti, char *cipher_in, char *key, 2923 char **ivmode, char **ivopts) 2924 { 2925 struct crypt_config *cc = ti->private; 2926 char *tmp, *cipher, *chainmode, *keycount; 2927 char *cipher_api = NULL; 2928 int ret = -EINVAL; 2929 char dummy; 2930 2931 if (strchr(cipher_in, '(') || crypt_integrity_aead(cc)) { 2932 ti->error = "Bad cipher specification"; 2933 return -EINVAL; 2934 } 2935 2936 /* 2937 * Legacy dm-crypt cipher specification 2938 * cipher[:keycount]-mode-iv:ivopts 2939 */ 2940 tmp = cipher_in; 2941 keycount = strsep(&tmp, "-"); 2942 cipher = strsep(&keycount, ":"); 2943 2944 if (!keycount) 2945 cc->tfms_count = 1; 2946 else if (sscanf(keycount, "%u%c", &cc->tfms_count, &dummy) != 1 || 2947 !is_power_of_2(cc->tfms_count)) { 2948 ti->error = "Bad cipher key count specification"; 2949 return -EINVAL; 2950 } 2951 cc->key_parts = cc->tfms_count; 2952 2953 chainmode = strsep(&tmp, "-"); 2954 *ivmode = strsep(&tmp, ":"); 2955 *ivopts = tmp; 2956 2957 /* 2958 * For compatibility with the original dm-crypt mapping format, if 2959 * only the cipher name is supplied, use cbc-plain. 2960 */ 2961 if (!chainmode || (!strcmp(chainmode, "plain") && !*ivmode)) { 2962 chainmode = "cbc"; 2963 *ivmode = "plain"; 2964 } 2965 2966 if (strcmp(chainmode, "ecb") && !*ivmode) { 2967 ti->error = "IV mechanism required"; 2968 return -EINVAL; 2969 } 2970 2971 cipher_api = kmalloc(CRYPTO_MAX_ALG_NAME, GFP_KERNEL); 2972 if (!cipher_api) 2973 goto bad_mem; 2974 2975 if (*ivmode && !strcmp(*ivmode, "essiv")) { 2976 if (!*ivopts) { 2977 ti->error = "Digest algorithm missing for ESSIV mode"; 2978 kfree(cipher_api); 2979 return -EINVAL; 2980 } 2981 ret = snprintf(cipher_api, CRYPTO_MAX_ALG_NAME, 2982 "essiv(%s(%s),%s)", chainmode, cipher, *ivopts); 2983 } else { 2984 ret = snprintf(cipher_api, CRYPTO_MAX_ALG_NAME, 2985 "%s(%s)", chainmode, cipher); 2986 } 2987 if (ret < 0 || ret >= CRYPTO_MAX_ALG_NAME) { 2988 kfree(cipher_api); 2989 goto bad_mem; 2990 } 2991 2992 /* Allocate cipher */ 2993 ret = crypt_alloc_tfms(cc, cipher_api); 2994 if (ret < 0) { 2995 ti->error = "Error allocating crypto tfm"; 2996 kfree(cipher_api); 2997 return ret; 2998 } 2999 kfree(cipher_api); 3000 3001 return 0; 3002 bad_mem: 3003 ti->error = "Cannot allocate cipher strings"; 3004 return -ENOMEM; 3005 } 3006 3007 static int crypt_ctr_cipher(struct dm_target *ti, char *cipher_in, char *key) 3008 { 3009 struct crypt_config *cc = ti->private; 3010 char *ivmode = NULL, *ivopts = NULL; 3011 int ret; 3012 3013 cc->cipher_string = kstrdup(cipher_in, GFP_KERNEL); 3014 if (!cc->cipher_string) { 3015 ti->error = "Cannot allocate cipher strings"; 3016 return -ENOMEM; 3017 } 3018 3019 if (strstarts(cipher_in, "capi:")) 3020 ret = crypt_ctr_cipher_new(ti, cipher_in, key, &ivmode, &ivopts); 3021 else 3022 ret = crypt_ctr_cipher_old(ti, cipher_in, key, &ivmode, &ivopts); 3023 if (ret) 3024 return ret; 3025 3026 /* Initialize IV */ 3027 ret = crypt_ctr_ivmode(ti, ivmode); 3028 if (ret < 0) 3029 return ret; 3030 3031 /* Initialize and set key */ 3032 ret = crypt_set_key(cc, key); 3033 if (ret < 0) { 3034 ti->error = "Error decoding and setting key"; 3035 return ret; 3036 } 3037 3038 /* Allocate IV */ 3039 if (cc->iv_gen_ops && cc->iv_gen_ops->ctr) { 3040 ret = cc->iv_gen_ops->ctr(cc, ti, ivopts); 3041 if (ret < 0) { 3042 ti->error = "Error creating IV"; 3043 return ret; 3044 } 3045 } 3046 3047 /* Initialize IV (set keys for ESSIV etc) */ 3048 if (cc->iv_gen_ops && cc->iv_gen_ops->init) { 3049 ret = cc->iv_gen_ops->init(cc); 3050 if (ret < 0) { 3051 ti->error = "Error initialising IV"; 3052 return ret; 3053 } 3054 } 3055 3056 /* wipe the kernel key payload copy */ 3057 if (cc->key_string) 3058 memset(cc->key, 0, cc->key_size * sizeof(u8)); 3059 3060 return ret; 3061 } 3062 3063 static int crypt_ctr_optional(struct dm_target *ti, unsigned int argc, char **argv) 3064 { 3065 struct crypt_config *cc = ti->private; 3066 struct dm_arg_set as; 3067 static const struct dm_arg _args[] = { 3068 {0, 8, "Invalid number of feature args"}, 3069 }; 3070 unsigned int opt_params, val; 3071 const char *opt_string, *sval; 3072 char dummy; 3073 int ret; 3074 3075 /* Optional parameters */ 3076 as.argc = argc; 3077 as.argv = argv; 3078 3079 ret = dm_read_arg_group(_args, &as, &opt_params, &ti->error); 3080 if (ret) 3081 return ret; 3082 3083 while (opt_params--) { 3084 opt_string = dm_shift_arg(&as); 3085 if (!opt_string) { 3086 ti->error = "Not enough feature arguments"; 3087 return -EINVAL; 3088 } 3089 3090 if (!strcasecmp(opt_string, "allow_discards")) 3091 ti->num_discard_bios = 1; 3092 3093 else if (!strcasecmp(opt_string, "same_cpu_crypt")) 3094 set_bit(DM_CRYPT_SAME_CPU, &cc->flags); 3095 3096 else if (!strcasecmp(opt_string, "submit_from_crypt_cpus")) 3097 set_bit(DM_CRYPT_NO_OFFLOAD, &cc->flags); 3098 else if (!strcasecmp(opt_string, "no_read_workqueue")) 3099 set_bit(DM_CRYPT_NO_READ_WORKQUEUE, &cc->flags); 3100 else if (!strcasecmp(opt_string, "no_write_workqueue")) 3101 set_bit(DM_CRYPT_NO_WRITE_WORKQUEUE, &cc->flags); 3102 else if (sscanf(opt_string, "integrity:%u:", &val) == 1) { 3103 if (val == 0 || val > MAX_TAG_SIZE) { 3104 ti->error = "Invalid integrity arguments"; 3105 return -EINVAL; 3106 } 3107 cc->on_disk_tag_size = val; 3108 sval = strchr(opt_string + strlen("integrity:"), ':') + 1; 3109 if (!strcasecmp(sval, "aead")) { 3110 set_bit(CRYPT_MODE_INTEGRITY_AEAD, &cc->cipher_flags); 3111 } else if (strcasecmp(sval, "none")) { 3112 ti->error = "Unknown integrity profile"; 3113 return -EINVAL; 3114 } 3115 3116 cc->cipher_auth = kstrdup(sval, GFP_KERNEL); 3117 if (!cc->cipher_auth) 3118 return -ENOMEM; 3119 } else if (sscanf(opt_string, "sector_size:%hu%c", &cc->sector_size, &dummy) == 1) { 3120 if (cc->sector_size < (1 << SECTOR_SHIFT) || 3121 cc->sector_size > 4096 || 3122 (cc->sector_size & (cc->sector_size - 1))) { 3123 ti->error = "Invalid feature value for sector_size"; 3124 return -EINVAL; 3125 } 3126 if (ti->len & ((cc->sector_size >> SECTOR_SHIFT) - 1)) { 3127 ti->error = "Device size is not multiple of sector_size feature"; 3128 return -EINVAL; 3129 } 3130 cc->sector_shift = __ffs(cc->sector_size) - SECTOR_SHIFT; 3131 } else if (!strcasecmp(opt_string, "iv_large_sectors")) 3132 set_bit(CRYPT_IV_LARGE_SECTORS, &cc->cipher_flags); 3133 else { 3134 ti->error = "Invalid feature arguments"; 3135 return -EINVAL; 3136 } 3137 } 3138 3139 return 0; 3140 } 3141 3142 #ifdef CONFIG_BLK_DEV_ZONED 3143 static int crypt_report_zones(struct dm_target *ti, 3144 struct dm_report_zones_args *args, unsigned int nr_zones) 3145 { 3146 struct crypt_config *cc = ti->private; 3147 3148 return dm_report_zones(cc->dev->bdev, cc->start, 3149 cc->start + dm_target_offset(ti, args->next_sector), 3150 args, nr_zones); 3151 } 3152 #else 3153 #define crypt_report_zones NULL 3154 #endif 3155 3156 /* 3157 * Construct an encryption mapping: 3158 * <cipher> [<key>|:<key_size>:<user|logon>:<key_description>] <iv_offset> <dev_path> <start> 3159 */ 3160 static int crypt_ctr(struct dm_target *ti, unsigned int argc, char **argv) 3161 { 3162 struct crypt_config *cc; 3163 const char *devname = dm_table_device_name(ti->table); 3164 int key_size; 3165 unsigned int align_mask; 3166 unsigned long long tmpll; 3167 int ret; 3168 size_t iv_size_padding, additional_req_size; 3169 char dummy; 3170 3171 if (argc < 5) { 3172 ti->error = "Not enough arguments"; 3173 return -EINVAL; 3174 } 3175 3176 key_size = get_key_size(&argv[1]); 3177 if (key_size < 0) { 3178 ti->error = "Cannot parse key size"; 3179 return -EINVAL; 3180 } 3181 3182 cc = kzalloc(struct_size(cc, key, key_size), GFP_KERNEL); 3183 if (!cc) { 3184 ti->error = "Cannot allocate encryption context"; 3185 return -ENOMEM; 3186 } 3187 cc->key_size = key_size; 3188 cc->sector_size = (1 << SECTOR_SHIFT); 3189 cc->sector_shift = 0; 3190 3191 ti->private = cc; 3192 3193 spin_lock(&dm_crypt_clients_lock); 3194 dm_crypt_clients_n++; 3195 crypt_calculate_pages_per_client(); 3196 spin_unlock(&dm_crypt_clients_lock); 3197 3198 ret = percpu_counter_init(&cc->n_allocated_pages, 0, GFP_KERNEL); 3199 if (ret < 0) 3200 goto bad; 3201 3202 /* Optional parameters need to be read before cipher constructor */ 3203 if (argc > 5) { 3204 ret = crypt_ctr_optional(ti, argc - 5, &argv[5]); 3205 if (ret) 3206 goto bad; 3207 } 3208 3209 ret = crypt_ctr_cipher(ti, argv[0], argv[1]); 3210 if (ret < 0) 3211 goto bad; 3212 3213 if (crypt_integrity_aead(cc)) { 3214 cc->dmreq_start = sizeof(struct aead_request); 3215 cc->dmreq_start += crypto_aead_reqsize(any_tfm_aead(cc)); 3216 align_mask = crypto_aead_alignmask(any_tfm_aead(cc)); 3217 } else { 3218 cc->dmreq_start = sizeof(struct skcipher_request); 3219 cc->dmreq_start += crypto_skcipher_reqsize(any_tfm(cc)); 3220 align_mask = crypto_skcipher_alignmask(any_tfm(cc)); 3221 } 3222 cc->dmreq_start = ALIGN(cc->dmreq_start, __alignof__(struct dm_crypt_request)); 3223 3224 if (align_mask < CRYPTO_MINALIGN) { 3225 /* Allocate the padding exactly */ 3226 iv_size_padding = -(cc->dmreq_start + sizeof(struct dm_crypt_request)) 3227 & align_mask; 3228 } else { 3229 /* 3230 * If the cipher requires greater alignment than kmalloc 3231 * alignment, we don't know the exact position of the 3232 * initialization vector. We must assume worst case. 3233 */ 3234 iv_size_padding = align_mask; 3235 } 3236 3237 /* ...| IV + padding | original IV | original sec. number | bio tag offset | */ 3238 additional_req_size = sizeof(struct dm_crypt_request) + 3239 iv_size_padding + cc->iv_size + 3240 cc->iv_size + 3241 sizeof(uint64_t) + 3242 sizeof(unsigned int); 3243 3244 ret = mempool_init_kmalloc_pool(&cc->req_pool, MIN_IOS, cc->dmreq_start + additional_req_size); 3245 if (ret) { 3246 ti->error = "Cannot allocate crypt request mempool"; 3247 goto bad; 3248 } 3249 3250 cc->per_bio_data_size = ti->per_io_data_size = 3251 ALIGN(sizeof(struct dm_crypt_io) + cc->dmreq_start + additional_req_size, 3252 ARCH_KMALLOC_MINALIGN); 3253 3254 ret = mempool_init(&cc->page_pool, BIO_MAX_VECS, crypt_page_alloc, crypt_page_free, cc); 3255 if (ret) { 3256 ti->error = "Cannot allocate page mempool"; 3257 goto bad; 3258 } 3259 3260 ret = bioset_init(&cc->bs, MIN_IOS, 0, BIOSET_NEED_BVECS); 3261 if (ret) { 3262 ti->error = "Cannot allocate crypt bioset"; 3263 goto bad; 3264 } 3265 3266 mutex_init(&cc->bio_alloc_lock); 3267 3268 ret = -EINVAL; 3269 if ((sscanf(argv[2], "%llu%c", &tmpll, &dummy) != 1) || 3270 (tmpll & ((cc->sector_size >> SECTOR_SHIFT) - 1))) { 3271 ti->error = "Invalid iv_offset sector"; 3272 goto bad; 3273 } 3274 cc->iv_offset = tmpll; 3275 3276 ret = dm_get_device(ti, argv[3], dm_table_get_mode(ti->table), &cc->dev); 3277 if (ret) { 3278 ti->error = "Device lookup failed"; 3279 goto bad; 3280 } 3281 3282 ret = -EINVAL; 3283 if (sscanf(argv[4], "%llu%c", &tmpll, &dummy) != 1 || tmpll != (sector_t)tmpll) { 3284 ti->error = "Invalid device sector"; 3285 goto bad; 3286 } 3287 cc->start = tmpll; 3288 3289 if (bdev_is_zoned(cc->dev->bdev)) { 3290 /* 3291 * For zoned block devices, we need to preserve the issuer write 3292 * ordering. To do so, disable write workqueues and force inline 3293 * encryption completion. 3294 */ 3295 set_bit(DM_CRYPT_NO_WRITE_WORKQUEUE, &cc->flags); 3296 set_bit(DM_CRYPT_WRITE_INLINE, &cc->flags); 3297 3298 /* 3299 * All zone append writes to a zone of a zoned block device will 3300 * have the same BIO sector, the start of the zone. When the 3301 * cypher IV mode uses sector values, all data targeting a 3302 * zone will be encrypted using the first sector numbers of the 3303 * zone. This will not result in write errors but will 3304 * cause most reads to fail as reads will use the sector values 3305 * for the actual data locations, resulting in IV mismatch. 3306 * To avoid this problem, ask DM core to emulate zone append 3307 * operations with regular writes. 3308 */ 3309 DMDEBUG("Zone append operations will be emulated"); 3310 ti->emulate_zone_append = true; 3311 } 3312 3313 if (crypt_integrity_aead(cc) || cc->integrity_iv_size) { 3314 ret = crypt_integrity_ctr(cc, ti); 3315 if (ret) 3316 goto bad; 3317 3318 cc->tag_pool_max_sectors = POOL_ENTRY_SIZE / cc->on_disk_tag_size; 3319 if (!cc->tag_pool_max_sectors) 3320 cc->tag_pool_max_sectors = 1; 3321 3322 ret = mempool_init_kmalloc_pool(&cc->tag_pool, MIN_IOS, 3323 cc->tag_pool_max_sectors * cc->on_disk_tag_size); 3324 if (ret) { 3325 ti->error = "Cannot allocate integrity tags mempool"; 3326 goto bad; 3327 } 3328 3329 cc->tag_pool_max_sectors <<= cc->sector_shift; 3330 } 3331 3332 ret = -ENOMEM; 3333 cc->io_queue = alloc_workqueue("kcryptd_io/%s", WQ_MEM_RECLAIM, 1, devname); 3334 if (!cc->io_queue) { 3335 ti->error = "Couldn't create kcryptd io queue"; 3336 goto bad; 3337 } 3338 3339 if (test_bit(DM_CRYPT_SAME_CPU, &cc->flags)) 3340 cc->crypt_queue = alloc_workqueue("kcryptd/%s", WQ_CPU_INTENSIVE | WQ_MEM_RECLAIM, 3341 1, devname); 3342 else 3343 cc->crypt_queue = alloc_workqueue("kcryptd/%s", 3344 WQ_CPU_INTENSIVE | WQ_MEM_RECLAIM | WQ_UNBOUND, 3345 num_online_cpus(), devname); 3346 if (!cc->crypt_queue) { 3347 ti->error = "Couldn't create kcryptd queue"; 3348 goto bad; 3349 } 3350 3351 spin_lock_init(&cc->write_thread_lock); 3352 cc->write_tree = RB_ROOT; 3353 3354 cc->write_thread = kthread_run(dmcrypt_write, cc, "dmcrypt_write/%s", devname); 3355 if (IS_ERR(cc->write_thread)) { 3356 ret = PTR_ERR(cc->write_thread); 3357 cc->write_thread = NULL; 3358 ti->error = "Couldn't spawn write thread"; 3359 goto bad; 3360 } 3361 3362 ti->num_flush_bios = 1; 3363 ti->limit_swap_bios = true; 3364 3365 dm_audit_log_ctr(DM_MSG_PREFIX, ti, 1); 3366 return 0; 3367 3368 bad: 3369 dm_audit_log_ctr(DM_MSG_PREFIX, ti, 0); 3370 crypt_dtr(ti); 3371 return ret; 3372 } 3373 3374 static int crypt_map(struct dm_target *ti, struct bio *bio) 3375 { 3376 struct dm_crypt_io *io; 3377 struct crypt_config *cc = ti->private; 3378 3379 /* 3380 * If bio is REQ_PREFLUSH or REQ_OP_DISCARD, just bypass crypt queues. 3381 * - for REQ_PREFLUSH device-mapper core ensures that no IO is in-flight 3382 * - for REQ_OP_DISCARD caller must use flush if IO ordering matters 3383 */ 3384 if (unlikely(bio->bi_opf & REQ_PREFLUSH || 3385 bio_op(bio) == REQ_OP_DISCARD)) { 3386 bio_set_dev(bio, cc->dev->bdev); 3387 if (bio_sectors(bio)) 3388 bio->bi_iter.bi_sector = cc->start + 3389 dm_target_offset(ti, bio->bi_iter.bi_sector); 3390 return DM_MAPIO_REMAPPED; 3391 } 3392 3393 /* 3394 * Check if bio is too large, split as needed. 3395 */ 3396 if (unlikely(bio->bi_iter.bi_size > (BIO_MAX_VECS << PAGE_SHIFT)) && 3397 (bio_data_dir(bio) == WRITE || cc->on_disk_tag_size)) 3398 dm_accept_partial_bio(bio, ((BIO_MAX_VECS << PAGE_SHIFT) >> SECTOR_SHIFT)); 3399 3400 /* 3401 * Ensure that bio is a multiple of internal sector encryption size 3402 * and is aligned to this size as defined in IO hints. 3403 */ 3404 if (unlikely((bio->bi_iter.bi_sector & ((cc->sector_size >> SECTOR_SHIFT) - 1)) != 0)) 3405 return DM_MAPIO_KILL; 3406 3407 if (unlikely(bio->bi_iter.bi_size & (cc->sector_size - 1))) 3408 return DM_MAPIO_KILL; 3409 3410 io = dm_per_bio_data(bio, cc->per_bio_data_size); 3411 crypt_io_init(io, cc, bio, dm_target_offset(ti, bio->bi_iter.bi_sector)); 3412 3413 if (cc->on_disk_tag_size) { 3414 unsigned tag_len = cc->on_disk_tag_size * (bio_sectors(bio) >> cc->sector_shift); 3415 3416 if (unlikely(tag_len > KMALLOC_MAX_SIZE) || 3417 unlikely(!(io->integrity_metadata = kmalloc(tag_len, 3418 GFP_NOIO | __GFP_NORETRY | __GFP_NOMEMALLOC | __GFP_NOWARN)))) { 3419 if (bio_sectors(bio) > cc->tag_pool_max_sectors) 3420 dm_accept_partial_bio(bio, cc->tag_pool_max_sectors); 3421 io->integrity_metadata = mempool_alloc(&cc->tag_pool, GFP_NOIO); 3422 io->integrity_metadata_from_pool = true; 3423 } 3424 } 3425 3426 if (crypt_integrity_aead(cc)) 3427 io->ctx.r.req_aead = (struct aead_request *)(io + 1); 3428 else 3429 io->ctx.r.req = (struct skcipher_request *)(io + 1); 3430 3431 if (bio_data_dir(io->base_bio) == READ) { 3432 if (kcryptd_io_read(io, GFP_NOWAIT)) 3433 kcryptd_queue_read(io); 3434 } else 3435 kcryptd_queue_crypt(io); 3436 3437 return DM_MAPIO_SUBMITTED; 3438 } 3439 3440 static void crypt_status(struct dm_target *ti, status_type_t type, 3441 unsigned status_flags, char *result, unsigned maxlen) 3442 { 3443 struct crypt_config *cc = ti->private; 3444 unsigned i, sz = 0; 3445 int num_feature_args = 0; 3446 3447 switch (type) { 3448 case STATUSTYPE_INFO: 3449 result[0] = '\0'; 3450 break; 3451 3452 case STATUSTYPE_TABLE: 3453 DMEMIT("%s ", cc->cipher_string); 3454 3455 if (cc->key_size > 0) { 3456 if (cc->key_string) 3457 DMEMIT(":%u:%s", cc->key_size, cc->key_string); 3458 else 3459 for (i = 0; i < cc->key_size; i++) 3460 DMEMIT("%02x", cc->key[i]); 3461 } else 3462 DMEMIT("-"); 3463 3464 DMEMIT(" %llu %s %llu", (unsigned long long)cc->iv_offset, 3465 cc->dev->name, (unsigned long long)cc->start); 3466 3467 num_feature_args += !!ti->num_discard_bios; 3468 num_feature_args += test_bit(DM_CRYPT_SAME_CPU, &cc->flags); 3469 num_feature_args += test_bit(DM_CRYPT_NO_OFFLOAD, &cc->flags); 3470 num_feature_args += test_bit(DM_CRYPT_NO_READ_WORKQUEUE, &cc->flags); 3471 num_feature_args += test_bit(DM_CRYPT_NO_WRITE_WORKQUEUE, &cc->flags); 3472 num_feature_args += cc->sector_size != (1 << SECTOR_SHIFT); 3473 num_feature_args += test_bit(CRYPT_IV_LARGE_SECTORS, &cc->cipher_flags); 3474 if (cc->on_disk_tag_size) 3475 num_feature_args++; 3476 if (num_feature_args) { 3477 DMEMIT(" %d", num_feature_args); 3478 if (ti->num_discard_bios) 3479 DMEMIT(" allow_discards"); 3480 if (test_bit(DM_CRYPT_SAME_CPU, &cc->flags)) 3481 DMEMIT(" same_cpu_crypt"); 3482 if (test_bit(DM_CRYPT_NO_OFFLOAD, &cc->flags)) 3483 DMEMIT(" submit_from_crypt_cpus"); 3484 if (test_bit(DM_CRYPT_NO_READ_WORKQUEUE, &cc->flags)) 3485 DMEMIT(" no_read_workqueue"); 3486 if (test_bit(DM_CRYPT_NO_WRITE_WORKQUEUE, &cc->flags)) 3487 DMEMIT(" no_write_workqueue"); 3488 if (cc->on_disk_tag_size) 3489 DMEMIT(" integrity:%u:%s", cc->on_disk_tag_size, cc->cipher_auth); 3490 if (cc->sector_size != (1 << SECTOR_SHIFT)) 3491 DMEMIT(" sector_size:%d", cc->sector_size); 3492 if (test_bit(CRYPT_IV_LARGE_SECTORS, &cc->cipher_flags)) 3493 DMEMIT(" iv_large_sectors"); 3494 } 3495 break; 3496 3497 case STATUSTYPE_IMA: 3498 DMEMIT_TARGET_NAME_VERSION(ti->type); 3499 DMEMIT(",allow_discards=%c", ti->num_discard_bios ? 'y' : 'n'); 3500 DMEMIT(",same_cpu_crypt=%c", test_bit(DM_CRYPT_SAME_CPU, &cc->flags) ? 'y' : 'n'); 3501 DMEMIT(",submit_from_crypt_cpus=%c", test_bit(DM_CRYPT_NO_OFFLOAD, &cc->flags) ? 3502 'y' : 'n'); 3503 DMEMIT(",no_read_workqueue=%c", test_bit(DM_CRYPT_NO_READ_WORKQUEUE, &cc->flags) ? 3504 'y' : 'n'); 3505 DMEMIT(",no_write_workqueue=%c", test_bit(DM_CRYPT_NO_WRITE_WORKQUEUE, &cc->flags) ? 3506 'y' : 'n'); 3507 DMEMIT(",iv_large_sectors=%c", test_bit(CRYPT_IV_LARGE_SECTORS, &cc->cipher_flags) ? 3508 'y' : 'n'); 3509 3510 if (cc->on_disk_tag_size) 3511 DMEMIT(",integrity_tag_size=%u,cipher_auth=%s", 3512 cc->on_disk_tag_size, cc->cipher_auth); 3513 if (cc->sector_size != (1 << SECTOR_SHIFT)) 3514 DMEMIT(",sector_size=%d", cc->sector_size); 3515 if (cc->cipher_string) 3516 DMEMIT(",cipher_string=%s", cc->cipher_string); 3517 3518 DMEMIT(",key_size=%u", cc->key_size); 3519 DMEMIT(",key_parts=%u", cc->key_parts); 3520 DMEMIT(",key_extra_size=%u", cc->key_extra_size); 3521 DMEMIT(",key_mac_size=%u", cc->key_mac_size); 3522 DMEMIT(";"); 3523 break; 3524 } 3525 } 3526 3527 static void crypt_postsuspend(struct dm_target *ti) 3528 { 3529 struct crypt_config *cc = ti->private; 3530 3531 set_bit(DM_CRYPT_SUSPENDED, &cc->flags); 3532 } 3533 3534 static int crypt_preresume(struct dm_target *ti) 3535 { 3536 struct crypt_config *cc = ti->private; 3537 3538 if (!test_bit(DM_CRYPT_KEY_VALID, &cc->flags)) { 3539 DMERR("aborting resume - crypt key is not set."); 3540 return -EAGAIN; 3541 } 3542 3543 return 0; 3544 } 3545 3546 static void crypt_resume(struct dm_target *ti) 3547 { 3548 struct crypt_config *cc = ti->private; 3549 3550 clear_bit(DM_CRYPT_SUSPENDED, &cc->flags); 3551 } 3552 3553 /* Message interface 3554 * key set <key> 3555 * key wipe 3556 */ 3557 static int crypt_message(struct dm_target *ti, unsigned argc, char **argv, 3558 char *result, unsigned maxlen) 3559 { 3560 struct crypt_config *cc = ti->private; 3561 int key_size, ret = -EINVAL; 3562 3563 if (argc < 2) 3564 goto error; 3565 3566 if (!strcasecmp(argv[0], "key")) { 3567 if (!test_bit(DM_CRYPT_SUSPENDED, &cc->flags)) { 3568 DMWARN("not suspended during key manipulation."); 3569 return -EINVAL; 3570 } 3571 if (argc == 3 && !strcasecmp(argv[1], "set")) { 3572 /* The key size may not be changed. */ 3573 key_size = get_key_size(&argv[2]); 3574 if (key_size < 0 || cc->key_size != key_size) { 3575 memset(argv[2], '0', strlen(argv[2])); 3576 return -EINVAL; 3577 } 3578 3579 ret = crypt_set_key(cc, argv[2]); 3580 if (ret) 3581 return ret; 3582 if (cc->iv_gen_ops && cc->iv_gen_ops->init) 3583 ret = cc->iv_gen_ops->init(cc); 3584 /* wipe the kernel key payload copy */ 3585 if (cc->key_string) 3586 memset(cc->key, 0, cc->key_size * sizeof(u8)); 3587 return ret; 3588 } 3589 if (argc == 2 && !strcasecmp(argv[1], "wipe")) 3590 return crypt_wipe_key(cc); 3591 } 3592 3593 error: 3594 DMWARN("unrecognised message received."); 3595 return -EINVAL; 3596 } 3597 3598 static int crypt_iterate_devices(struct dm_target *ti, 3599 iterate_devices_callout_fn fn, void *data) 3600 { 3601 struct crypt_config *cc = ti->private; 3602 3603 return fn(ti, cc->dev, cc->start, ti->len, data); 3604 } 3605 3606 static void crypt_io_hints(struct dm_target *ti, struct queue_limits *limits) 3607 { 3608 struct crypt_config *cc = ti->private; 3609 3610 /* 3611 * Unfortunate constraint that is required to avoid the potential 3612 * for exceeding underlying device's max_segments limits -- due to 3613 * crypt_alloc_buffer() possibly allocating pages for the encryption 3614 * bio that are not as physically contiguous as the original bio. 3615 */ 3616 limits->max_segment_size = PAGE_SIZE; 3617 3618 limits->logical_block_size = 3619 max_t(unsigned, limits->logical_block_size, cc->sector_size); 3620 limits->physical_block_size = 3621 max_t(unsigned, limits->physical_block_size, cc->sector_size); 3622 limits->io_min = max_t(unsigned, limits->io_min, cc->sector_size); 3623 } 3624 3625 static struct target_type crypt_target = { 3626 .name = "crypt", 3627 .version = {1, 23, 0}, 3628 .module = THIS_MODULE, 3629 .ctr = crypt_ctr, 3630 .dtr = crypt_dtr, 3631 .features = DM_TARGET_ZONED_HM, 3632 .report_zones = crypt_report_zones, 3633 .map = crypt_map, 3634 .status = crypt_status, 3635 .postsuspend = crypt_postsuspend, 3636 .preresume = crypt_preresume, 3637 .resume = crypt_resume, 3638 .message = crypt_message, 3639 .iterate_devices = crypt_iterate_devices, 3640 .io_hints = crypt_io_hints, 3641 }; 3642 3643 static int __init dm_crypt_init(void) 3644 { 3645 int r; 3646 3647 r = dm_register_target(&crypt_target); 3648 if (r < 0) 3649 DMERR("register failed %d", r); 3650 3651 return r; 3652 } 3653 3654 static void __exit dm_crypt_exit(void) 3655 { 3656 dm_unregister_target(&crypt_target); 3657 } 3658 3659 module_init(dm_crypt_init); 3660 module_exit(dm_crypt_exit); 3661 3662 MODULE_AUTHOR("Jana Saout <jana@saout.de>"); 3663 MODULE_DESCRIPTION(DM_NAME " target for transparent encryption / decryption"); 3664 MODULE_LICENSE("GPL"); 3665