1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * Copyright (C) 2003 Jana Saout <jana@saout.de> 4 * Copyright (C) 2004 Clemens Fruhwirth <clemens@endorphin.org> 5 * Copyright (C) 2006-2020 Red Hat, Inc. All rights reserved. 6 * Copyright (C) 2013-2020 Milan Broz <gmazyland@gmail.com> 7 * 8 * This file is released under the GPL. 9 */ 10 11 #include <linux/completion.h> 12 #include <linux/err.h> 13 #include <linux/module.h> 14 #include <linux/init.h> 15 #include <linux/kernel.h> 16 #include <linux/key.h> 17 #include <linux/bio.h> 18 #include <linux/blkdev.h> 19 #include <linux/blk-integrity.h> 20 #include <linux/mempool.h> 21 #include <linux/slab.h> 22 #include <linux/crypto.h> 23 #include <linux/workqueue.h> 24 #include <linux/kthread.h> 25 #include <linux/backing-dev.h> 26 #include <linux/atomic.h> 27 #include <linux/scatterlist.h> 28 #include <linux/rbtree.h> 29 #include <linux/ctype.h> 30 #include <asm/page.h> 31 #include <asm/unaligned.h> 32 #include <crypto/hash.h> 33 #include <crypto/md5.h> 34 #include <crypto/algapi.h> 35 #include <crypto/skcipher.h> 36 #include <crypto/aead.h> 37 #include <crypto/authenc.h> 38 #include <linux/rtnetlink.h> /* for struct rtattr and RTA macros only */ 39 #include <linux/key-type.h> 40 #include <keys/user-type.h> 41 #include <keys/encrypted-type.h> 42 #include <keys/trusted-type.h> 43 44 #include <linux/device-mapper.h> 45 46 #include "dm-audit.h" 47 48 #define DM_MSG_PREFIX "crypt" 49 50 /* 51 * context holding the current state of a multi-part conversion 52 */ 53 struct convert_context { 54 struct completion restart; 55 struct bio *bio_in; 56 struct bio *bio_out; 57 struct bvec_iter iter_in; 58 struct bvec_iter iter_out; 59 u64 cc_sector; 60 atomic_t cc_pending; 61 union { 62 struct skcipher_request *req; 63 struct aead_request *req_aead; 64 } r; 65 66 }; 67 68 /* 69 * per bio private data 70 */ 71 struct dm_crypt_io { 72 struct crypt_config *cc; 73 struct bio *base_bio; 74 u8 *integrity_metadata; 75 bool integrity_metadata_from_pool:1; 76 bool in_tasklet:1; 77 78 struct work_struct work; 79 struct tasklet_struct tasklet; 80 81 struct convert_context ctx; 82 83 atomic_t io_pending; 84 blk_status_t error; 85 sector_t sector; 86 87 struct rb_node rb_node; 88 } CRYPTO_MINALIGN_ATTR; 89 90 struct dm_crypt_request { 91 struct convert_context *ctx; 92 struct scatterlist sg_in[4]; 93 struct scatterlist sg_out[4]; 94 u64 iv_sector; 95 }; 96 97 struct crypt_config; 98 99 struct crypt_iv_operations { 100 int (*ctr)(struct crypt_config *cc, struct dm_target *ti, 101 const char *opts); 102 void (*dtr)(struct crypt_config *cc); 103 int (*init)(struct crypt_config *cc); 104 int (*wipe)(struct crypt_config *cc); 105 int (*generator)(struct crypt_config *cc, u8 *iv, 106 struct dm_crypt_request *dmreq); 107 int (*post)(struct crypt_config *cc, u8 *iv, 108 struct dm_crypt_request *dmreq); 109 }; 110 111 struct iv_benbi_private { 112 int shift; 113 }; 114 115 #define LMK_SEED_SIZE 64 /* hash + 0 */ 116 struct iv_lmk_private { 117 struct crypto_shash *hash_tfm; 118 u8 *seed; 119 }; 120 121 #define TCW_WHITENING_SIZE 16 122 struct iv_tcw_private { 123 struct crypto_shash *crc32_tfm; 124 u8 *iv_seed; 125 u8 *whitening; 126 }; 127 128 #define ELEPHANT_MAX_KEY_SIZE 32 129 struct iv_elephant_private { 130 struct crypto_skcipher *tfm; 131 }; 132 133 /* 134 * Crypt: maps a linear range of a block device 135 * and encrypts / decrypts at the same time. 136 */ 137 enum flags { DM_CRYPT_SUSPENDED, DM_CRYPT_KEY_VALID, 138 DM_CRYPT_SAME_CPU, DM_CRYPT_NO_OFFLOAD, 139 DM_CRYPT_NO_READ_WORKQUEUE, DM_CRYPT_NO_WRITE_WORKQUEUE, 140 DM_CRYPT_WRITE_INLINE }; 141 142 enum cipher_flags { 143 CRYPT_MODE_INTEGRITY_AEAD, /* Use authenticated mode for cipher */ 144 CRYPT_IV_LARGE_SECTORS, /* Calculate IV from sector_size, not 512B sectors */ 145 CRYPT_ENCRYPT_PREPROCESS, /* Must preprocess data for encryption (elephant) */ 146 }; 147 148 /* 149 * The fields in here must be read only after initialization. 150 */ 151 struct crypt_config { 152 struct dm_dev *dev; 153 sector_t start; 154 155 struct percpu_counter n_allocated_pages; 156 157 struct workqueue_struct *io_queue; 158 struct workqueue_struct *crypt_queue; 159 160 spinlock_t write_thread_lock; 161 struct task_struct *write_thread; 162 struct rb_root write_tree; 163 164 char *cipher_string; 165 char *cipher_auth; 166 char *key_string; 167 168 const struct crypt_iv_operations *iv_gen_ops; 169 union { 170 struct iv_benbi_private benbi; 171 struct iv_lmk_private lmk; 172 struct iv_tcw_private tcw; 173 struct iv_elephant_private elephant; 174 } iv_gen_private; 175 u64 iv_offset; 176 unsigned int iv_size; 177 unsigned short sector_size; 178 unsigned char sector_shift; 179 180 union { 181 struct crypto_skcipher **tfms; 182 struct crypto_aead **tfms_aead; 183 } cipher_tfm; 184 unsigned int tfms_count; 185 unsigned long cipher_flags; 186 187 /* 188 * Layout of each crypto request: 189 * 190 * struct skcipher_request 191 * context 192 * padding 193 * struct dm_crypt_request 194 * padding 195 * IV 196 * 197 * The padding is added so that dm_crypt_request and the IV are 198 * correctly aligned. 199 */ 200 unsigned int dmreq_start; 201 202 unsigned int per_bio_data_size; 203 204 unsigned long flags; 205 unsigned int key_size; 206 unsigned int key_parts; /* independent parts in key buffer */ 207 unsigned int key_extra_size; /* additional keys length */ 208 unsigned int key_mac_size; /* MAC key size for authenc(...) */ 209 210 unsigned int integrity_tag_size; 211 unsigned int integrity_iv_size; 212 unsigned int on_disk_tag_size; 213 214 /* 215 * pool for per bio private data, crypto requests, 216 * encryption requeusts/buffer pages and integrity tags 217 */ 218 unsigned int tag_pool_max_sectors; 219 mempool_t tag_pool; 220 mempool_t req_pool; 221 mempool_t page_pool; 222 223 struct bio_set bs; 224 struct mutex bio_alloc_lock; 225 226 u8 *authenc_key; /* space for keys in authenc() format (if used) */ 227 u8 key[]; 228 }; 229 230 #define MIN_IOS 64 231 #define MAX_TAG_SIZE 480 232 #define POOL_ENTRY_SIZE 512 233 234 static DEFINE_SPINLOCK(dm_crypt_clients_lock); 235 static unsigned int dm_crypt_clients_n; 236 static volatile unsigned long dm_crypt_pages_per_client; 237 #define DM_CRYPT_MEMORY_PERCENT 2 238 #define DM_CRYPT_MIN_PAGES_PER_CLIENT (BIO_MAX_VECS * 16) 239 240 static void crypt_endio(struct bio *clone); 241 static void kcryptd_queue_crypt(struct dm_crypt_io *io); 242 static struct scatterlist *crypt_get_sg_data(struct crypt_config *cc, 243 struct scatterlist *sg); 244 245 static bool crypt_integrity_aead(struct crypt_config *cc); 246 247 /* 248 * Use this to access cipher attributes that are independent of the key. 249 */ 250 static struct crypto_skcipher *any_tfm(struct crypt_config *cc) 251 { 252 return cc->cipher_tfm.tfms[0]; 253 } 254 255 static struct crypto_aead *any_tfm_aead(struct crypt_config *cc) 256 { 257 return cc->cipher_tfm.tfms_aead[0]; 258 } 259 260 /* 261 * Different IV generation algorithms: 262 * 263 * plain: the initial vector is the 32-bit little-endian version of the sector 264 * number, padded with zeros if necessary. 265 * 266 * plain64: the initial vector is the 64-bit little-endian version of the sector 267 * number, padded with zeros if necessary. 268 * 269 * plain64be: the initial vector is the 64-bit big-endian version of the sector 270 * number, padded with zeros if necessary. 271 * 272 * essiv: "encrypted sector|salt initial vector", the sector number is 273 * encrypted with the bulk cipher using a salt as key. The salt 274 * should be derived from the bulk cipher's key via hashing. 275 * 276 * benbi: the 64-bit "big-endian 'narrow block'-count", starting at 1 277 * (needed for LRW-32-AES and possible other narrow block modes) 278 * 279 * null: the initial vector is always zero. Provides compatibility with 280 * obsolete loop_fish2 devices. Do not use for new devices. 281 * 282 * lmk: Compatible implementation of the block chaining mode used 283 * by the Loop-AES block device encryption system 284 * designed by Jari Ruusu. See http://loop-aes.sourceforge.net/ 285 * It operates on full 512 byte sectors and uses CBC 286 * with an IV derived from the sector number, the data and 287 * optionally extra IV seed. 288 * This means that after decryption the first block 289 * of sector must be tweaked according to decrypted data. 290 * Loop-AES can use three encryption schemes: 291 * version 1: is plain aes-cbc mode 292 * version 2: uses 64 multikey scheme with lmk IV generator 293 * version 3: the same as version 2 with additional IV seed 294 * (it uses 65 keys, last key is used as IV seed) 295 * 296 * tcw: Compatible implementation of the block chaining mode used 297 * by the TrueCrypt device encryption system (prior to version 4.1). 298 * For more info see: https://gitlab.com/cryptsetup/cryptsetup/wikis/TrueCryptOnDiskFormat 299 * It operates on full 512 byte sectors and uses CBC 300 * with an IV derived from initial key and the sector number. 301 * In addition, whitening value is applied on every sector, whitening 302 * is calculated from initial key, sector number and mixed using CRC32. 303 * Note that this encryption scheme is vulnerable to watermarking attacks 304 * and should be used for old compatible containers access only. 305 * 306 * eboiv: Encrypted byte-offset IV (used in Bitlocker in CBC mode) 307 * The IV is encrypted little-endian byte-offset (with the same key 308 * and cipher as the volume). 309 * 310 * elephant: The extended version of eboiv with additional Elephant diffuser 311 * used with Bitlocker CBC mode. 312 * This mode was used in older Windows systems 313 * https://download.microsoft.com/download/0/2/3/0238acaf-d3bf-4a6d-b3d6-0a0be4bbb36e/bitlockercipher200608.pdf 314 */ 315 316 static int crypt_iv_plain_gen(struct crypt_config *cc, u8 *iv, 317 struct dm_crypt_request *dmreq) 318 { 319 memset(iv, 0, cc->iv_size); 320 *(__le32 *)iv = cpu_to_le32(dmreq->iv_sector & 0xffffffff); 321 322 return 0; 323 } 324 325 static int crypt_iv_plain64_gen(struct crypt_config *cc, u8 *iv, 326 struct dm_crypt_request *dmreq) 327 { 328 memset(iv, 0, cc->iv_size); 329 *(__le64 *)iv = cpu_to_le64(dmreq->iv_sector); 330 331 return 0; 332 } 333 334 static int crypt_iv_plain64be_gen(struct crypt_config *cc, u8 *iv, 335 struct dm_crypt_request *dmreq) 336 { 337 memset(iv, 0, cc->iv_size); 338 /* iv_size is at least of size u64; usually it is 16 bytes */ 339 *(__be64 *)&iv[cc->iv_size - sizeof(u64)] = cpu_to_be64(dmreq->iv_sector); 340 341 return 0; 342 } 343 344 static int crypt_iv_essiv_gen(struct crypt_config *cc, u8 *iv, 345 struct dm_crypt_request *dmreq) 346 { 347 /* 348 * ESSIV encryption of the IV is now handled by the crypto API, 349 * so just pass the plain sector number here. 350 */ 351 memset(iv, 0, cc->iv_size); 352 *(__le64 *)iv = cpu_to_le64(dmreq->iv_sector); 353 354 return 0; 355 } 356 357 static int crypt_iv_benbi_ctr(struct crypt_config *cc, struct dm_target *ti, 358 const char *opts) 359 { 360 unsigned int bs; 361 int log; 362 363 if (crypt_integrity_aead(cc)) 364 bs = crypto_aead_blocksize(any_tfm_aead(cc)); 365 else 366 bs = crypto_skcipher_blocksize(any_tfm(cc)); 367 log = ilog2(bs); 368 369 /* 370 * We need to calculate how far we must shift the sector count 371 * to get the cipher block count, we use this shift in _gen. 372 */ 373 if (1 << log != bs) { 374 ti->error = "cypher blocksize is not a power of 2"; 375 return -EINVAL; 376 } 377 378 if (log > 9) { 379 ti->error = "cypher blocksize is > 512"; 380 return -EINVAL; 381 } 382 383 cc->iv_gen_private.benbi.shift = 9 - log; 384 385 return 0; 386 } 387 388 static void crypt_iv_benbi_dtr(struct crypt_config *cc) 389 { 390 } 391 392 static int crypt_iv_benbi_gen(struct crypt_config *cc, u8 *iv, 393 struct dm_crypt_request *dmreq) 394 { 395 __be64 val; 396 397 memset(iv, 0, cc->iv_size - sizeof(u64)); /* rest is cleared below */ 398 399 val = cpu_to_be64(((u64)dmreq->iv_sector << cc->iv_gen_private.benbi.shift) + 1); 400 put_unaligned(val, (__be64 *)(iv + cc->iv_size - sizeof(u64))); 401 402 return 0; 403 } 404 405 static int crypt_iv_null_gen(struct crypt_config *cc, u8 *iv, 406 struct dm_crypt_request *dmreq) 407 { 408 memset(iv, 0, cc->iv_size); 409 410 return 0; 411 } 412 413 static void crypt_iv_lmk_dtr(struct crypt_config *cc) 414 { 415 struct iv_lmk_private *lmk = &cc->iv_gen_private.lmk; 416 417 if (lmk->hash_tfm && !IS_ERR(lmk->hash_tfm)) 418 crypto_free_shash(lmk->hash_tfm); 419 lmk->hash_tfm = NULL; 420 421 kfree_sensitive(lmk->seed); 422 lmk->seed = NULL; 423 } 424 425 static int crypt_iv_lmk_ctr(struct crypt_config *cc, struct dm_target *ti, 426 const char *opts) 427 { 428 struct iv_lmk_private *lmk = &cc->iv_gen_private.lmk; 429 430 if (cc->sector_size != (1 << SECTOR_SHIFT)) { 431 ti->error = "Unsupported sector size for LMK"; 432 return -EINVAL; 433 } 434 435 lmk->hash_tfm = crypto_alloc_shash("md5", 0, 436 CRYPTO_ALG_ALLOCATES_MEMORY); 437 if (IS_ERR(lmk->hash_tfm)) { 438 ti->error = "Error initializing LMK hash"; 439 return PTR_ERR(lmk->hash_tfm); 440 } 441 442 /* No seed in LMK version 2 */ 443 if (cc->key_parts == cc->tfms_count) { 444 lmk->seed = NULL; 445 return 0; 446 } 447 448 lmk->seed = kzalloc(LMK_SEED_SIZE, GFP_KERNEL); 449 if (!lmk->seed) { 450 crypt_iv_lmk_dtr(cc); 451 ti->error = "Error kmallocing seed storage in LMK"; 452 return -ENOMEM; 453 } 454 455 return 0; 456 } 457 458 static int crypt_iv_lmk_init(struct crypt_config *cc) 459 { 460 struct iv_lmk_private *lmk = &cc->iv_gen_private.lmk; 461 int subkey_size = cc->key_size / cc->key_parts; 462 463 /* LMK seed is on the position of LMK_KEYS + 1 key */ 464 if (lmk->seed) 465 memcpy(lmk->seed, cc->key + (cc->tfms_count * subkey_size), 466 crypto_shash_digestsize(lmk->hash_tfm)); 467 468 return 0; 469 } 470 471 static int crypt_iv_lmk_wipe(struct crypt_config *cc) 472 { 473 struct iv_lmk_private *lmk = &cc->iv_gen_private.lmk; 474 475 if (lmk->seed) 476 memset(lmk->seed, 0, LMK_SEED_SIZE); 477 478 return 0; 479 } 480 481 static int crypt_iv_lmk_one(struct crypt_config *cc, u8 *iv, 482 struct dm_crypt_request *dmreq, 483 u8 *data) 484 { 485 struct iv_lmk_private *lmk = &cc->iv_gen_private.lmk; 486 SHASH_DESC_ON_STACK(desc, lmk->hash_tfm); 487 struct md5_state md5state; 488 __le32 buf[4]; 489 int i, r; 490 491 desc->tfm = lmk->hash_tfm; 492 493 r = crypto_shash_init(desc); 494 if (r) 495 return r; 496 497 if (lmk->seed) { 498 r = crypto_shash_update(desc, lmk->seed, LMK_SEED_SIZE); 499 if (r) 500 return r; 501 } 502 503 /* Sector is always 512B, block size 16, add data of blocks 1-31 */ 504 r = crypto_shash_update(desc, data + 16, 16 * 31); 505 if (r) 506 return r; 507 508 /* Sector is cropped to 56 bits here */ 509 buf[0] = cpu_to_le32(dmreq->iv_sector & 0xFFFFFFFF); 510 buf[1] = cpu_to_le32((((u64)dmreq->iv_sector >> 32) & 0x00FFFFFF) | 0x80000000); 511 buf[2] = cpu_to_le32(4024); 512 buf[3] = 0; 513 r = crypto_shash_update(desc, (u8 *)buf, sizeof(buf)); 514 if (r) 515 return r; 516 517 /* No MD5 padding here */ 518 r = crypto_shash_export(desc, &md5state); 519 if (r) 520 return r; 521 522 for (i = 0; i < MD5_HASH_WORDS; i++) 523 __cpu_to_le32s(&md5state.hash[i]); 524 memcpy(iv, &md5state.hash, cc->iv_size); 525 526 return 0; 527 } 528 529 static int crypt_iv_lmk_gen(struct crypt_config *cc, u8 *iv, 530 struct dm_crypt_request *dmreq) 531 { 532 struct scatterlist *sg; 533 u8 *src; 534 int r = 0; 535 536 if (bio_data_dir(dmreq->ctx->bio_in) == WRITE) { 537 sg = crypt_get_sg_data(cc, dmreq->sg_in); 538 src = kmap_local_page(sg_page(sg)); 539 r = crypt_iv_lmk_one(cc, iv, dmreq, src + sg->offset); 540 kunmap_local(src); 541 } else 542 memset(iv, 0, cc->iv_size); 543 544 return r; 545 } 546 547 static int crypt_iv_lmk_post(struct crypt_config *cc, u8 *iv, 548 struct dm_crypt_request *dmreq) 549 { 550 struct scatterlist *sg; 551 u8 *dst; 552 int r; 553 554 if (bio_data_dir(dmreq->ctx->bio_in) == WRITE) 555 return 0; 556 557 sg = crypt_get_sg_data(cc, dmreq->sg_out); 558 dst = kmap_local_page(sg_page(sg)); 559 r = crypt_iv_lmk_one(cc, iv, dmreq, dst + sg->offset); 560 561 /* Tweak the first block of plaintext sector */ 562 if (!r) 563 crypto_xor(dst + sg->offset, iv, cc->iv_size); 564 565 kunmap_local(dst); 566 return r; 567 } 568 569 static void crypt_iv_tcw_dtr(struct crypt_config *cc) 570 { 571 struct iv_tcw_private *tcw = &cc->iv_gen_private.tcw; 572 573 kfree_sensitive(tcw->iv_seed); 574 tcw->iv_seed = NULL; 575 kfree_sensitive(tcw->whitening); 576 tcw->whitening = NULL; 577 578 if (tcw->crc32_tfm && !IS_ERR(tcw->crc32_tfm)) 579 crypto_free_shash(tcw->crc32_tfm); 580 tcw->crc32_tfm = NULL; 581 } 582 583 static int crypt_iv_tcw_ctr(struct crypt_config *cc, struct dm_target *ti, 584 const char *opts) 585 { 586 struct iv_tcw_private *tcw = &cc->iv_gen_private.tcw; 587 588 if (cc->sector_size != (1 << SECTOR_SHIFT)) { 589 ti->error = "Unsupported sector size for TCW"; 590 return -EINVAL; 591 } 592 593 if (cc->key_size <= (cc->iv_size + TCW_WHITENING_SIZE)) { 594 ti->error = "Wrong key size for TCW"; 595 return -EINVAL; 596 } 597 598 tcw->crc32_tfm = crypto_alloc_shash("crc32", 0, 599 CRYPTO_ALG_ALLOCATES_MEMORY); 600 if (IS_ERR(tcw->crc32_tfm)) { 601 ti->error = "Error initializing CRC32 in TCW"; 602 return PTR_ERR(tcw->crc32_tfm); 603 } 604 605 tcw->iv_seed = kzalloc(cc->iv_size, GFP_KERNEL); 606 tcw->whitening = kzalloc(TCW_WHITENING_SIZE, GFP_KERNEL); 607 if (!tcw->iv_seed || !tcw->whitening) { 608 crypt_iv_tcw_dtr(cc); 609 ti->error = "Error allocating seed storage in TCW"; 610 return -ENOMEM; 611 } 612 613 return 0; 614 } 615 616 static int crypt_iv_tcw_init(struct crypt_config *cc) 617 { 618 struct iv_tcw_private *tcw = &cc->iv_gen_private.tcw; 619 int key_offset = cc->key_size - cc->iv_size - TCW_WHITENING_SIZE; 620 621 memcpy(tcw->iv_seed, &cc->key[key_offset], cc->iv_size); 622 memcpy(tcw->whitening, &cc->key[key_offset + cc->iv_size], 623 TCW_WHITENING_SIZE); 624 625 return 0; 626 } 627 628 static int crypt_iv_tcw_wipe(struct crypt_config *cc) 629 { 630 struct iv_tcw_private *tcw = &cc->iv_gen_private.tcw; 631 632 memset(tcw->iv_seed, 0, cc->iv_size); 633 memset(tcw->whitening, 0, TCW_WHITENING_SIZE); 634 635 return 0; 636 } 637 638 static int crypt_iv_tcw_whitening(struct crypt_config *cc, 639 struct dm_crypt_request *dmreq, 640 u8 *data) 641 { 642 struct iv_tcw_private *tcw = &cc->iv_gen_private.tcw; 643 __le64 sector = cpu_to_le64(dmreq->iv_sector); 644 u8 buf[TCW_WHITENING_SIZE]; 645 SHASH_DESC_ON_STACK(desc, tcw->crc32_tfm); 646 int i, r; 647 648 /* xor whitening with sector number */ 649 crypto_xor_cpy(buf, tcw->whitening, (u8 *)§or, 8); 650 crypto_xor_cpy(&buf[8], tcw->whitening + 8, (u8 *)§or, 8); 651 652 /* calculate crc32 for every 32bit part and xor it */ 653 desc->tfm = tcw->crc32_tfm; 654 for (i = 0; i < 4; i++) { 655 r = crypto_shash_init(desc); 656 if (r) 657 goto out; 658 r = crypto_shash_update(desc, &buf[i * 4], 4); 659 if (r) 660 goto out; 661 r = crypto_shash_final(desc, &buf[i * 4]); 662 if (r) 663 goto out; 664 } 665 crypto_xor(&buf[0], &buf[12], 4); 666 crypto_xor(&buf[4], &buf[8], 4); 667 668 /* apply whitening (8 bytes) to whole sector */ 669 for (i = 0; i < ((1 << SECTOR_SHIFT) / 8); i++) 670 crypto_xor(data + i * 8, buf, 8); 671 out: 672 memzero_explicit(buf, sizeof(buf)); 673 return r; 674 } 675 676 static int crypt_iv_tcw_gen(struct crypt_config *cc, u8 *iv, 677 struct dm_crypt_request *dmreq) 678 { 679 struct scatterlist *sg; 680 struct iv_tcw_private *tcw = &cc->iv_gen_private.tcw; 681 __le64 sector = cpu_to_le64(dmreq->iv_sector); 682 u8 *src; 683 int r = 0; 684 685 /* Remove whitening from ciphertext */ 686 if (bio_data_dir(dmreq->ctx->bio_in) != WRITE) { 687 sg = crypt_get_sg_data(cc, dmreq->sg_in); 688 src = kmap_local_page(sg_page(sg)); 689 r = crypt_iv_tcw_whitening(cc, dmreq, src + sg->offset); 690 kunmap_local(src); 691 } 692 693 /* Calculate IV */ 694 crypto_xor_cpy(iv, tcw->iv_seed, (u8 *)§or, 8); 695 if (cc->iv_size > 8) 696 crypto_xor_cpy(&iv[8], tcw->iv_seed + 8, (u8 *)§or, 697 cc->iv_size - 8); 698 699 return r; 700 } 701 702 static int crypt_iv_tcw_post(struct crypt_config *cc, u8 *iv, 703 struct dm_crypt_request *dmreq) 704 { 705 struct scatterlist *sg; 706 u8 *dst; 707 int r; 708 709 if (bio_data_dir(dmreq->ctx->bio_in) != WRITE) 710 return 0; 711 712 /* Apply whitening on ciphertext */ 713 sg = crypt_get_sg_data(cc, dmreq->sg_out); 714 dst = kmap_local_page(sg_page(sg)); 715 r = crypt_iv_tcw_whitening(cc, dmreq, dst + sg->offset); 716 kunmap_local(dst); 717 718 return r; 719 } 720 721 static int crypt_iv_random_gen(struct crypt_config *cc, u8 *iv, 722 struct dm_crypt_request *dmreq) 723 { 724 /* Used only for writes, there must be an additional space to store IV */ 725 get_random_bytes(iv, cc->iv_size); 726 return 0; 727 } 728 729 static int crypt_iv_eboiv_ctr(struct crypt_config *cc, struct dm_target *ti, 730 const char *opts) 731 { 732 if (crypt_integrity_aead(cc)) { 733 ti->error = "AEAD transforms not supported for EBOIV"; 734 return -EINVAL; 735 } 736 737 if (crypto_skcipher_blocksize(any_tfm(cc)) != cc->iv_size) { 738 ti->error = "Block size of EBOIV cipher does not match IV size of block cipher"; 739 return -EINVAL; 740 } 741 742 return 0; 743 } 744 745 static int crypt_iv_eboiv_gen(struct crypt_config *cc, u8 *iv, 746 struct dm_crypt_request *dmreq) 747 { 748 u8 buf[MAX_CIPHER_BLOCKSIZE] __aligned(__alignof__(__le64)); 749 struct skcipher_request *req; 750 struct scatterlist src, dst; 751 DECLARE_CRYPTO_WAIT(wait); 752 int err; 753 754 req = skcipher_request_alloc(any_tfm(cc), GFP_NOIO); 755 if (!req) 756 return -ENOMEM; 757 758 memset(buf, 0, cc->iv_size); 759 *(__le64 *)buf = cpu_to_le64(dmreq->iv_sector * cc->sector_size); 760 761 sg_init_one(&src, page_address(ZERO_PAGE(0)), cc->iv_size); 762 sg_init_one(&dst, iv, cc->iv_size); 763 skcipher_request_set_crypt(req, &src, &dst, cc->iv_size, buf); 764 skcipher_request_set_callback(req, 0, crypto_req_done, &wait); 765 err = crypto_wait_req(crypto_skcipher_encrypt(req), &wait); 766 skcipher_request_free(req); 767 768 return err; 769 } 770 771 static void crypt_iv_elephant_dtr(struct crypt_config *cc) 772 { 773 struct iv_elephant_private *elephant = &cc->iv_gen_private.elephant; 774 775 crypto_free_skcipher(elephant->tfm); 776 elephant->tfm = NULL; 777 } 778 779 static int crypt_iv_elephant_ctr(struct crypt_config *cc, struct dm_target *ti, 780 const char *opts) 781 { 782 struct iv_elephant_private *elephant = &cc->iv_gen_private.elephant; 783 int r; 784 785 elephant->tfm = crypto_alloc_skcipher("ecb(aes)", 0, 786 CRYPTO_ALG_ALLOCATES_MEMORY); 787 if (IS_ERR(elephant->tfm)) { 788 r = PTR_ERR(elephant->tfm); 789 elephant->tfm = NULL; 790 return r; 791 } 792 793 r = crypt_iv_eboiv_ctr(cc, ti, NULL); 794 if (r) 795 crypt_iv_elephant_dtr(cc); 796 return r; 797 } 798 799 static void diffuser_disk_to_cpu(u32 *d, size_t n) 800 { 801 #ifndef __LITTLE_ENDIAN 802 int i; 803 804 for (i = 0; i < n; i++) 805 d[i] = le32_to_cpu((__le32)d[i]); 806 #endif 807 } 808 809 static void diffuser_cpu_to_disk(__le32 *d, size_t n) 810 { 811 #ifndef __LITTLE_ENDIAN 812 int i; 813 814 for (i = 0; i < n; i++) 815 d[i] = cpu_to_le32((u32)d[i]); 816 #endif 817 } 818 819 static void diffuser_a_decrypt(u32 *d, size_t n) 820 { 821 int i, i1, i2, i3; 822 823 for (i = 0; i < 5; i++) { 824 i1 = 0; 825 i2 = n - 2; 826 i3 = n - 5; 827 828 while (i1 < (n - 1)) { 829 d[i1] += d[i2] ^ (d[i3] << 9 | d[i3] >> 23); 830 i1++; i2++; i3++; 831 832 if (i3 >= n) 833 i3 -= n; 834 835 d[i1] += d[i2] ^ d[i3]; 836 i1++; i2++; i3++; 837 838 if (i2 >= n) 839 i2 -= n; 840 841 d[i1] += d[i2] ^ (d[i3] << 13 | d[i3] >> 19); 842 i1++; i2++; i3++; 843 844 d[i1] += d[i2] ^ d[i3]; 845 i1++; i2++; i3++; 846 } 847 } 848 } 849 850 static void diffuser_a_encrypt(u32 *d, size_t n) 851 { 852 int i, i1, i2, i3; 853 854 for (i = 0; i < 5; i++) { 855 i1 = n - 1; 856 i2 = n - 2 - 1; 857 i3 = n - 5 - 1; 858 859 while (i1 > 0) { 860 d[i1] -= d[i2] ^ d[i3]; 861 i1--; i2--; i3--; 862 863 d[i1] -= d[i2] ^ (d[i3] << 13 | d[i3] >> 19); 864 i1--; i2--; i3--; 865 866 if (i2 < 0) 867 i2 += n; 868 869 d[i1] -= d[i2] ^ d[i3]; 870 i1--; i2--; i3--; 871 872 if (i3 < 0) 873 i3 += n; 874 875 d[i1] -= d[i2] ^ (d[i3] << 9 | d[i3] >> 23); 876 i1--; i2--; i3--; 877 } 878 } 879 } 880 881 static void diffuser_b_decrypt(u32 *d, size_t n) 882 { 883 int i, i1, i2, i3; 884 885 for (i = 0; i < 3; i++) { 886 i1 = 0; 887 i2 = 2; 888 i3 = 5; 889 890 while (i1 < (n - 1)) { 891 d[i1] += d[i2] ^ d[i3]; 892 i1++; i2++; i3++; 893 894 d[i1] += d[i2] ^ (d[i3] << 10 | d[i3] >> 22); 895 i1++; i2++; i3++; 896 897 if (i2 >= n) 898 i2 -= n; 899 900 d[i1] += d[i2] ^ d[i3]; 901 i1++; i2++; i3++; 902 903 if (i3 >= n) 904 i3 -= n; 905 906 d[i1] += d[i2] ^ (d[i3] << 25 | d[i3] >> 7); 907 i1++; i2++; i3++; 908 } 909 } 910 } 911 912 static void diffuser_b_encrypt(u32 *d, size_t n) 913 { 914 int i, i1, i2, i3; 915 916 for (i = 0; i < 3; i++) { 917 i1 = n - 1; 918 i2 = 2 - 1; 919 i3 = 5 - 1; 920 921 while (i1 > 0) { 922 d[i1] -= d[i2] ^ (d[i3] << 25 | d[i3] >> 7); 923 i1--; i2--; i3--; 924 925 if (i3 < 0) 926 i3 += n; 927 928 d[i1] -= d[i2] ^ d[i3]; 929 i1--; i2--; i3--; 930 931 if (i2 < 0) 932 i2 += n; 933 934 d[i1] -= d[i2] ^ (d[i3] << 10 | d[i3] >> 22); 935 i1--; i2--; i3--; 936 937 d[i1] -= d[i2] ^ d[i3]; 938 i1--; i2--; i3--; 939 } 940 } 941 } 942 943 static int crypt_iv_elephant(struct crypt_config *cc, struct dm_crypt_request *dmreq) 944 { 945 struct iv_elephant_private *elephant = &cc->iv_gen_private.elephant; 946 u8 *es, *ks, *data, *data2, *data_offset; 947 struct skcipher_request *req; 948 struct scatterlist *sg, *sg2, src, dst; 949 DECLARE_CRYPTO_WAIT(wait); 950 int i, r; 951 952 req = skcipher_request_alloc(elephant->tfm, GFP_NOIO); 953 es = kzalloc(16, GFP_NOIO); /* Key for AES */ 954 ks = kzalloc(32, GFP_NOIO); /* Elephant sector key */ 955 956 if (!req || !es || !ks) { 957 r = -ENOMEM; 958 goto out; 959 } 960 961 *(__le64 *)es = cpu_to_le64(dmreq->iv_sector * cc->sector_size); 962 963 /* E(Ks, e(s)) */ 964 sg_init_one(&src, es, 16); 965 sg_init_one(&dst, ks, 16); 966 skcipher_request_set_crypt(req, &src, &dst, 16, NULL); 967 skcipher_request_set_callback(req, 0, crypto_req_done, &wait); 968 r = crypto_wait_req(crypto_skcipher_encrypt(req), &wait); 969 if (r) 970 goto out; 971 972 /* E(Ks, e'(s)) */ 973 es[15] = 0x80; 974 sg_init_one(&dst, &ks[16], 16); 975 r = crypto_wait_req(crypto_skcipher_encrypt(req), &wait); 976 if (r) 977 goto out; 978 979 sg = crypt_get_sg_data(cc, dmreq->sg_out); 980 data = kmap_local_page(sg_page(sg)); 981 data_offset = data + sg->offset; 982 983 /* Cannot modify original bio, copy to sg_out and apply Elephant to it */ 984 if (bio_data_dir(dmreq->ctx->bio_in) == WRITE) { 985 sg2 = crypt_get_sg_data(cc, dmreq->sg_in); 986 data2 = kmap_local_page(sg_page(sg2)); 987 memcpy(data_offset, data2 + sg2->offset, cc->sector_size); 988 kunmap_local(data2); 989 } 990 991 if (bio_data_dir(dmreq->ctx->bio_in) != WRITE) { 992 diffuser_disk_to_cpu((u32 *)data_offset, cc->sector_size / sizeof(u32)); 993 diffuser_b_decrypt((u32 *)data_offset, cc->sector_size / sizeof(u32)); 994 diffuser_a_decrypt((u32 *)data_offset, cc->sector_size / sizeof(u32)); 995 diffuser_cpu_to_disk((__le32 *)data_offset, cc->sector_size / sizeof(u32)); 996 } 997 998 for (i = 0; i < (cc->sector_size / 32); i++) 999 crypto_xor(data_offset + i * 32, ks, 32); 1000 1001 if (bio_data_dir(dmreq->ctx->bio_in) == WRITE) { 1002 diffuser_disk_to_cpu((u32 *)data_offset, cc->sector_size / sizeof(u32)); 1003 diffuser_a_encrypt((u32 *)data_offset, cc->sector_size / sizeof(u32)); 1004 diffuser_b_encrypt((u32 *)data_offset, cc->sector_size / sizeof(u32)); 1005 diffuser_cpu_to_disk((__le32 *)data_offset, cc->sector_size / sizeof(u32)); 1006 } 1007 1008 kunmap_local(data); 1009 out: 1010 kfree_sensitive(ks); 1011 kfree_sensitive(es); 1012 skcipher_request_free(req); 1013 return r; 1014 } 1015 1016 static int crypt_iv_elephant_gen(struct crypt_config *cc, u8 *iv, 1017 struct dm_crypt_request *dmreq) 1018 { 1019 int r; 1020 1021 if (bio_data_dir(dmreq->ctx->bio_in) == WRITE) { 1022 r = crypt_iv_elephant(cc, dmreq); 1023 if (r) 1024 return r; 1025 } 1026 1027 return crypt_iv_eboiv_gen(cc, iv, dmreq); 1028 } 1029 1030 static int crypt_iv_elephant_post(struct crypt_config *cc, u8 *iv, 1031 struct dm_crypt_request *dmreq) 1032 { 1033 if (bio_data_dir(dmreq->ctx->bio_in) != WRITE) 1034 return crypt_iv_elephant(cc, dmreq); 1035 1036 return 0; 1037 } 1038 1039 static int crypt_iv_elephant_init(struct crypt_config *cc) 1040 { 1041 struct iv_elephant_private *elephant = &cc->iv_gen_private.elephant; 1042 int key_offset = cc->key_size - cc->key_extra_size; 1043 1044 return crypto_skcipher_setkey(elephant->tfm, &cc->key[key_offset], cc->key_extra_size); 1045 } 1046 1047 static int crypt_iv_elephant_wipe(struct crypt_config *cc) 1048 { 1049 struct iv_elephant_private *elephant = &cc->iv_gen_private.elephant; 1050 u8 key[ELEPHANT_MAX_KEY_SIZE]; 1051 1052 memset(key, 0, cc->key_extra_size); 1053 return crypto_skcipher_setkey(elephant->tfm, key, cc->key_extra_size); 1054 } 1055 1056 static const struct crypt_iv_operations crypt_iv_plain_ops = { 1057 .generator = crypt_iv_plain_gen 1058 }; 1059 1060 static const struct crypt_iv_operations crypt_iv_plain64_ops = { 1061 .generator = crypt_iv_plain64_gen 1062 }; 1063 1064 static const struct crypt_iv_operations crypt_iv_plain64be_ops = { 1065 .generator = crypt_iv_plain64be_gen 1066 }; 1067 1068 static const struct crypt_iv_operations crypt_iv_essiv_ops = { 1069 .generator = crypt_iv_essiv_gen 1070 }; 1071 1072 static const struct crypt_iv_operations crypt_iv_benbi_ops = { 1073 .ctr = crypt_iv_benbi_ctr, 1074 .dtr = crypt_iv_benbi_dtr, 1075 .generator = crypt_iv_benbi_gen 1076 }; 1077 1078 static const struct crypt_iv_operations crypt_iv_null_ops = { 1079 .generator = crypt_iv_null_gen 1080 }; 1081 1082 static const struct crypt_iv_operations crypt_iv_lmk_ops = { 1083 .ctr = crypt_iv_lmk_ctr, 1084 .dtr = crypt_iv_lmk_dtr, 1085 .init = crypt_iv_lmk_init, 1086 .wipe = crypt_iv_lmk_wipe, 1087 .generator = crypt_iv_lmk_gen, 1088 .post = crypt_iv_lmk_post 1089 }; 1090 1091 static const struct crypt_iv_operations crypt_iv_tcw_ops = { 1092 .ctr = crypt_iv_tcw_ctr, 1093 .dtr = crypt_iv_tcw_dtr, 1094 .init = crypt_iv_tcw_init, 1095 .wipe = crypt_iv_tcw_wipe, 1096 .generator = crypt_iv_tcw_gen, 1097 .post = crypt_iv_tcw_post 1098 }; 1099 1100 static const struct crypt_iv_operations crypt_iv_random_ops = { 1101 .generator = crypt_iv_random_gen 1102 }; 1103 1104 static const struct crypt_iv_operations crypt_iv_eboiv_ops = { 1105 .ctr = crypt_iv_eboiv_ctr, 1106 .generator = crypt_iv_eboiv_gen 1107 }; 1108 1109 static const struct crypt_iv_operations crypt_iv_elephant_ops = { 1110 .ctr = crypt_iv_elephant_ctr, 1111 .dtr = crypt_iv_elephant_dtr, 1112 .init = crypt_iv_elephant_init, 1113 .wipe = crypt_iv_elephant_wipe, 1114 .generator = crypt_iv_elephant_gen, 1115 .post = crypt_iv_elephant_post 1116 }; 1117 1118 /* 1119 * Integrity extensions 1120 */ 1121 static bool crypt_integrity_aead(struct crypt_config *cc) 1122 { 1123 return test_bit(CRYPT_MODE_INTEGRITY_AEAD, &cc->cipher_flags); 1124 } 1125 1126 static bool crypt_integrity_hmac(struct crypt_config *cc) 1127 { 1128 return crypt_integrity_aead(cc) && cc->key_mac_size; 1129 } 1130 1131 /* Get sg containing data */ 1132 static struct scatterlist *crypt_get_sg_data(struct crypt_config *cc, 1133 struct scatterlist *sg) 1134 { 1135 if (unlikely(crypt_integrity_aead(cc))) 1136 return &sg[2]; 1137 1138 return sg; 1139 } 1140 1141 static int dm_crypt_integrity_io_alloc(struct dm_crypt_io *io, struct bio *bio) 1142 { 1143 struct bio_integrity_payload *bip; 1144 unsigned int tag_len; 1145 int ret; 1146 1147 if (!bio_sectors(bio) || !io->cc->on_disk_tag_size) 1148 return 0; 1149 1150 bip = bio_integrity_alloc(bio, GFP_NOIO, 1); 1151 if (IS_ERR(bip)) 1152 return PTR_ERR(bip); 1153 1154 tag_len = io->cc->on_disk_tag_size * (bio_sectors(bio) >> io->cc->sector_shift); 1155 1156 bip->bip_iter.bi_size = tag_len; 1157 bip->bip_iter.bi_sector = io->cc->start + io->sector; 1158 1159 ret = bio_integrity_add_page(bio, virt_to_page(io->integrity_metadata), 1160 tag_len, offset_in_page(io->integrity_metadata)); 1161 if (unlikely(ret != tag_len)) 1162 return -ENOMEM; 1163 1164 return 0; 1165 } 1166 1167 static int crypt_integrity_ctr(struct crypt_config *cc, struct dm_target *ti) 1168 { 1169 #ifdef CONFIG_BLK_DEV_INTEGRITY 1170 struct blk_integrity *bi = blk_get_integrity(cc->dev->bdev->bd_disk); 1171 struct mapped_device *md = dm_table_get_md(ti->table); 1172 1173 /* From now we require underlying device with our integrity profile */ 1174 if (!bi || strcasecmp(bi->profile->name, "DM-DIF-EXT-TAG")) { 1175 ti->error = "Integrity profile not supported."; 1176 return -EINVAL; 1177 } 1178 1179 if (bi->tag_size != cc->on_disk_tag_size || 1180 bi->tuple_size != cc->on_disk_tag_size) { 1181 ti->error = "Integrity profile tag size mismatch."; 1182 return -EINVAL; 1183 } 1184 if (1 << bi->interval_exp != cc->sector_size) { 1185 ti->error = "Integrity profile sector size mismatch."; 1186 return -EINVAL; 1187 } 1188 1189 if (crypt_integrity_aead(cc)) { 1190 cc->integrity_tag_size = cc->on_disk_tag_size - cc->integrity_iv_size; 1191 DMDEBUG("%s: Integrity AEAD, tag size %u, IV size %u.", dm_device_name(md), 1192 cc->integrity_tag_size, cc->integrity_iv_size); 1193 1194 if (crypto_aead_setauthsize(any_tfm_aead(cc), cc->integrity_tag_size)) { 1195 ti->error = "Integrity AEAD auth tag size is not supported."; 1196 return -EINVAL; 1197 } 1198 } else if (cc->integrity_iv_size) 1199 DMDEBUG("%s: Additional per-sector space %u bytes for IV.", dm_device_name(md), 1200 cc->integrity_iv_size); 1201 1202 if ((cc->integrity_tag_size + cc->integrity_iv_size) != bi->tag_size) { 1203 ti->error = "Not enough space for integrity tag in the profile."; 1204 return -EINVAL; 1205 } 1206 1207 return 0; 1208 #else 1209 ti->error = "Integrity profile not supported."; 1210 return -EINVAL; 1211 #endif 1212 } 1213 1214 static void crypt_convert_init(struct crypt_config *cc, 1215 struct convert_context *ctx, 1216 struct bio *bio_out, struct bio *bio_in, 1217 sector_t sector) 1218 { 1219 ctx->bio_in = bio_in; 1220 ctx->bio_out = bio_out; 1221 if (bio_in) 1222 ctx->iter_in = bio_in->bi_iter; 1223 if (bio_out) 1224 ctx->iter_out = bio_out->bi_iter; 1225 ctx->cc_sector = sector + cc->iv_offset; 1226 init_completion(&ctx->restart); 1227 } 1228 1229 static struct dm_crypt_request *dmreq_of_req(struct crypt_config *cc, 1230 void *req) 1231 { 1232 return (struct dm_crypt_request *)((char *)req + cc->dmreq_start); 1233 } 1234 1235 static void *req_of_dmreq(struct crypt_config *cc, struct dm_crypt_request *dmreq) 1236 { 1237 return (void *)((char *)dmreq - cc->dmreq_start); 1238 } 1239 1240 static u8 *iv_of_dmreq(struct crypt_config *cc, 1241 struct dm_crypt_request *dmreq) 1242 { 1243 if (crypt_integrity_aead(cc)) 1244 return (u8 *)ALIGN((unsigned long)(dmreq + 1), 1245 crypto_aead_alignmask(any_tfm_aead(cc)) + 1); 1246 else 1247 return (u8 *)ALIGN((unsigned long)(dmreq + 1), 1248 crypto_skcipher_alignmask(any_tfm(cc)) + 1); 1249 } 1250 1251 static u8 *org_iv_of_dmreq(struct crypt_config *cc, 1252 struct dm_crypt_request *dmreq) 1253 { 1254 return iv_of_dmreq(cc, dmreq) + cc->iv_size; 1255 } 1256 1257 static __le64 *org_sector_of_dmreq(struct crypt_config *cc, 1258 struct dm_crypt_request *dmreq) 1259 { 1260 u8 *ptr = iv_of_dmreq(cc, dmreq) + cc->iv_size + cc->iv_size; 1261 1262 return (__le64 *) ptr; 1263 } 1264 1265 static unsigned int *org_tag_of_dmreq(struct crypt_config *cc, 1266 struct dm_crypt_request *dmreq) 1267 { 1268 u8 *ptr = iv_of_dmreq(cc, dmreq) + cc->iv_size + 1269 cc->iv_size + sizeof(uint64_t); 1270 1271 return (unsigned int *)ptr; 1272 } 1273 1274 static void *tag_from_dmreq(struct crypt_config *cc, 1275 struct dm_crypt_request *dmreq) 1276 { 1277 struct convert_context *ctx = dmreq->ctx; 1278 struct dm_crypt_io *io = container_of(ctx, struct dm_crypt_io, ctx); 1279 1280 return &io->integrity_metadata[*org_tag_of_dmreq(cc, dmreq) * 1281 cc->on_disk_tag_size]; 1282 } 1283 1284 static void *iv_tag_from_dmreq(struct crypt_config *cc, 1285 struct dm_crypt_request *dmreq) 1286 { 1287 return tag_from_dmreq(cc, dmreq) + cc->integrity_tag_size; 1288 } 1289 1290 static int crypt_convert_block_aead(struct crypt_config *cc, 1291 struct convert_context *ctx, 1292 struct aead_request *req, 1293 unsigned int tag_offset) 1294 { 1295 struct bio_vec bv_in = bio_iter_iovec(ctx->bio_in, ctx->iter_in); 1296 struct bio_vec bv_out = bio_iter_iovec(ctx->bio_out, ctx->iter_out); 1297 struct dm_crypt_request *dmreq; 1298 u8 *iv, *org_iv, *tag_iv, *tag; 1299 __le64 *sector; 1300 int r = 0; 1301 1302 BUG_ON(cc->integrity_iv_size && cc->integrity_iv_size != cc->iv_size); 1303 1304 /* Reject unexpected unaligned bio. */ 1305 if (unlikely(bv_in.bv_len & (cc->sector_size - 1))) 1306 return -EIO; 1307 1308 dmreq = dmreq_of_req(cc, req); 1309 dmreq->iv_sector = ctx->cc_sector; 1310 if (test_bit(CRYPT_IV_LARGE_SECTORS, &cc->cipher_flags)) 1311 dmreq->iv_sector >>= cc->sector_shift; 1312 dmreq->ctx = ctx; 1313 1314 *org_tag_of_dmreq(cc, dmreq) = tag_offset; 1315 1316 sector = org_sector_of_dmreq(cc, dmreq); 1317 *sector = cpu_to_le64(ctx->cc_sector - cc->iv_offset); 1318 1319 iv = iv_of_dmreq(cc, dmreq); 1320 org_iv = org_iv_of_dmreq(cc, dmreq); 1321 tag = tag_from_dmreq(cc, dmreq); 1322 tag_iv = iv_tag_from_dmreq(cc, dmreq); 1323 1324 /* AEAD request: 1325 * |----- AAD -------|------ DATA -------|-- AUTH TAG --| 1326 * | (authenticated) | (auth+encryption) | | 1327 * | sector_LE | IV | sector in/out | tag in/out | 1328 */ 1329 sg_init_table(dmreq->sg_in, 4); 1330 sg_set_buf(&dmreq->sg_in[0], sector, sizeof(uint64_t)); 1331 sg_set_buf(&dmreq->sg_in[1], org_iv, cc->iv_size); 1332 sg_set_page(&dmreq->sg_in[2], bv_in.bv_page, cc->sector_size, bv_in.bv_offset); 1333 sg_set_buf(&dmreq->sg_in[3], tag, cc->integrity_tag_size); 1334 1335 sg_init_table(dmreq->sg_out, 4); 1336 sg_set_buf(&dmreq->sg_out[0], sector, sizeof(uint64_t)); 1337 sg_set_buf(&dmreq->sg_out[1], org_iv, cc->iv_size); 1338 sg_set_page(&dmreq->sg_out[2], bv_out.bv_page, cc->sector_size, bv_out.bv_offset); 1339 sg_set_buf(&dmreq->sg_out[3], tag, cc->integrity_tag_size); 1340 1341 if (cc->iv_gen_ops) { 1342 /* For READs use IV stored in integrity metadata */ 1343 if (cc->integrity_iv_size && bio_data_dir(ctx->bio_in) != WRITE) { 1344 memcpy(org_iv, tag_iv, cc->iv_size); 1345 } else { 1346 r = cc->iv_gen_ops->generator(cc, org_iv, dmreq); 1347 if (r < 0) 1348 return r; 1349 /* Store generated IV in integrity metadata */ 1350 if (cc->integrity_iv_size) 1351 memcpy(tag_iv, org_iv, cc->iv_size); 1352 } 1353 /* Working copy of IV, to be modified in crypto API */ 1354 memcpy(iv, org_iv, cc->iv_size); 1355 } 1356 1357 aead_request_set_ad(req, sizeof(uint64_t) + cc->iv_size); 1358 if (bio_data_dir(ctx->bio_in) == WRITE) { 1359 aead_request_set_crypt(req, dmreq->sg_in, dmreq->sg_out, 1360 cc->sector_size, iv); 1361 r = crypto_aead_encrypt(req); 1362 if (cc->integrity_tag_size + cc->integrity_iv_size != cc->on_disk_tag_size) 1363 memset(tag + cc->integrity_tag_size + cc->integrity_iv_size, 0, 1364 cc->on_disk_tag_size - (cc->integrity_tag_size + cc->integrity_iv_size)); 1365 } else { 1366 aead_request_set_crypt(req, dmreq->sg_in, dmreq->sg_out, 1367 cc->sector_size + cc->integrity_tag_size, iv); 1368 r = crypto_aead_decrypt(req); 1369 } 1370 1371 if (r == -EBADMSG) { 1372 sector_t s = le64_to_cpu(*sector); 1373 1374 DMERR_LIMIT("%pg: INTEGRITY AEAD ERROR, sector %llu", 1375 ctx->bio_in->bi_bdev, s); 1376 dm_audit_log_bio(DM_MSG_PREFIX, "integrity-aead", 1377 ctx->bio_in, s, 0); 1378 } 1379 1380 if (!r && cc->iv_gen_ops && cc->iv_gen_ops->post) 1381 r = cc->iv_gen_ops->post(cc, org_iv, dmreq); 1382 1383 bio_advance_iter(ctx->bio_in, &ctx->iter_in, cc->sector_size); 1384 bio_advance_iter(ctx->bio_out, &ctx->iter_out, cc->sector_size); 1385 1386 return r; 1387 } 1388 1389 static int crypt_convert_block_skcipher(struct crypt_config *cc, 1390 struct convert_context *ctx, 1391 struct skcipher_request *req, 1392 unsigned int tag_offset) 1393 { 1394 struct bio_vec bv_in = bio_iter_iovec(ctx->bio_in, ctx->iter_in); 1395 struct bio_vec bv_out = bio_iter_iovec(ctx->bio_out, ctx->iter_out); 1396 struct scatterlist *sg_in, *sg_out; 1397 struct dm_crypt_request *dmreq; 1398 u8 *iv, *org_iv, *tag_iv; 1399 __le64 *sector; 1400 int r = 0; 1401 1402 /* Reject unexpected unaligned bio. */ 1403 if (unlikely(bv_in.bv_len & (cc->sector_size - 1))) 1404 return -EIO; 1405 1406 dmreq = dmreq_of_req(cc, req); 1407 dmreq->iv_sector = ctx->cc_sector; 1408 if (test_bit(CRYPT_IV_LARGE_SECTORS, &cc->cipher_flags)) 1409 dmreq->iv_sector >>= cc->sector_shift; 1410 dmreq->ctx = ctx; 1411 1412 *org_tag_of_dmreq(cc, dmreq) = tag_offset; 1413 1414 iv = iv_of_dmreq(cc, dmreq); 1415 org_iv = org_iv_of_dmreq(cc, dmreq); 1416 tag_iv = iv_tag_from_dmreq(cc, dmreq); 1417 1418 sector = org_sector_of_dmreq(cc, dmreq); 1419 *sector = cpu_to_le64(ctx->cc_sector - cc->iv_offset); 1420 1421 /* For skcipher we use only the first sg item */ 1422 sg_in = &dmreq->sg_in[0]; 1423 sg_out = &dmreq->sg_out[0]; 1424 1425 sg_init_table(sg_in, 1); 1426 sg_set_page(sg_in, bv_in.bv_page, cc->sector_size, bv_in.bv_offset); 1427 1428 sg_init_table(sg_out, 1); 1429 sg_set_page(sg_out, bv_out.bv_page, cc->sector_size, bv_out.bv_offset); 1430 1431 if (cc->iv_gen_ops) { 1432 /* For READs use IV stored in integrity metadata */ 1433 if (cc->integrity_iv_size && bio_data_dir(ctx->bio_in) != WRITE) { 1434 memcpy(org_iv, tag_iv, cc->integrity_iv_size); 1435 } else { 1436 r = cc->iv_gen_ops->generator(cc, org_iv, dmreq); 1437 if (r < 0) 1438 return r; 1439 /* Data can be already preprocessed in generator */ 1440 if (test_bit(CRYPT_ENCRYPT_PREPROCESS, &cc->cipher_flags)) 1441 sg_in = sg_out; 1442 /* Store generated IV in integrity metadata */ 1443 if (cc->integrity_iv_size) 1444 memcpy(tag_iv, org_iv, cc->integrity_iv_size); 1445 } 1446 /* Working copy of IV, to be modified in crypto API */ 1447 memcpy(iv, org_iv, cc->iv_size); 1448 } 1449 1450 skcipher_request_set_crypt(req, sg_in, sg_out, cc->sector_size, iv); 1451 1452 if (bio_data_dir(ctx->bio_in) == WRITE) 1453 r = crypto_skcipher_encrypt(req); 1454 else 1455 r = crypto_skcipher_decrypt(req); 1456 1457 if (!r && cc->iv_gen_ops && cc->iv_gen_ops->post) 1458 r = cc->iv_gen_ops->post(cc, org_iv, dmreq); 1459 1460 bio_advance_iter(ctx->bio_in, &ctx->iter_in, cc->sector_size); 1461 bio_advance_iter(ctx->bio_out, &ctx->iter_out, cc->sector_size); 1462 1463 return r; 1464 } 1465 1466 static void kcryptd_async_done(void *async_req, int error); 1467 1468 static int crypt_alloc_req_skcipher(struct crypt_config *cc, 1469 struct convert_context *ctx) 1470 { 1471 unsigned int key_index = ctx->cc_sector & (cc->tfms_count - 1); 1472 1473 if (!ctx->r.req) { 1474 ctx->r.req = mempool_alloc(&cc->req_pool, in_interrupt() ? GFP_ATOMIC : GFP_NOIO); 1475 if (!ctx->r.req) 1476 return -ENOMEM; 1477 } 1478 1479 skcipher_request_set_tfm(ctx->r.req, cc->cipher_tfm.tfms[key_index]); 1480 1481 /* 1482 * Use REQ_MAY_BACKLOG so a cipher driver internally backlogs 1483 * requests if driver request queue is full. 1484 */ 1485 skcipher_request_set_callback(ctx->r.req, 1486 CRYPTO_TFM_REQ_MAY_BACKLOG, 1487 kcryptd_async_done, dmreq_of_req(cc, ctx->r.req)); 1488 1489 return 0; 1490 } 1491 1492 static int crypt_alloc_req_aead(struct crypt_config *cc, 1493 struct convert_context *ctx) 1494 { 1495 if (!ctx->r.req_aead) { 1496 ctx->r.req_aead = mempool_alloc(&cc->req_pool, in_interrupt() ? GFP_ATOMIC : GFP_NOIO); 1497 if (!ctx->r.req_aead) 1498 return -ENOMEM; 1499 } 1500 1501 aead_request_set_tfm(ctx->r.req_aead, cc->cipher_tfm.tfms_aead[0]); 1502 1503 /* 1504 * Use REQ_MAY_BACKLOG so a cipher driver internally backlogs 1505 * requests if driver request queue is full. 1506 */ 1507 aead_request_set_callback(ctx->r.req_aead, 1508 CRYPTO_TFM_REQ_MAY_BACKLOG, 1509 kcryptd_async_done, dmreq_of_req(cc, ctx->r.req_aead)); 1510 1511 return 0; 1512 } 1513 1514 static int crypt_alloc_req(struct crypt_config *cc, 1515 struct convert_context *ctx) 1516 { 1517 if (crypt_integrity_aead(cc)) 1518 return crypt_alloc_req_aead(cc, ctx); 1519 else 1520 return crypt_alloc_req_skcipher(cc, ctx); 1521 } 1522 1523 static void crypt_free_req_skcipher(struct crypt_config *cc, 1524 struct skcipher_request *req, struct bio *base_bio) 1525 { 1526 struct dm_crypt_io *io = dm_per_bio_data(base_bio, cc->per_bio_data_size); 1527 1528 if ((struct skcipher_request *)(io + 1) != req) 1529 mempool_free(req, &cc->req_pool); 1530 } 1531 1532 static void crypt_free_req_aead(struct crypt_config *cc, 1533 struct aead_request *req, struct bio *base_bio) 1534 { 1535 struct dm_crypt_io *io = dm_per_bio_data(base_bio, cc->per_bio_data_size); 1536 1537 if ((struct aead_request *)(io + 1) != req) 1538 mempool_free(req, &cc->req_pool); 1539 } 1540 1541 static void crypt_free_req(struct crypt_config *cc, void *req, struct bio *base_bio) 1542 { 1543 if (crypt_integrity_aead(cc)) 1544 crypt_free_req_aead(cc, req, base_bio); 1545 else 1546 crypt_free_req_skcipher(cc, req, base_bio); 1547 } 1548 1549 /* 1550 * Encrypt / decrypt data from one bio to another one (can be the same one) 1551 */ 1552 static blk_status_t crypt_convert(struct crypt_config *cc, 1553 struct convert_context *ctx, bool atomic, bool reset_pending) 1554 { 1555 unsigned int tag_offset = 0; 1556 unsigned int sector_step = cc->sector_size >> SECTOR_SHIFT; 1557 int r; 1558 1559 /* 1560 * if reset_pending is set we are dealing with the bio for the first time, 1561 * else we're continuing to work on the previous bio, so don't mess with 1562 * the cc_pending counter 1563 */ 1564 if (reset_pending) 1565 atomic_set(&ctx->cc_pending, 1); 1566 1567 while (ctx->iter_in.bi_size && ctx->iter_out.bi_size) { 1568 1569 r = crypt_alloc_req(cc, ctx); 1570 if (r) { 1571 complete(&ctx->restart); 1572 return BLK_STS_DEV_RESOURCE; 1573 } 1574 1575 atomic_inc(&ctx->cc_pending); 1576 1577 if (crypt_integrity_aead(cc)) 1578 r = crypt_convert_block_aead(cc, ctx, ctx->r.req_aead, tag_offset); 1579 else 1580 r = crypt_convert_block_skcipher(cc, ctx, ctx->r.req, tag_offset); 1581 1582 switch (r) { 1583 /* 1584 * The request was queued by a crypto driver 1585 * but the driver request queue is full, let's wait. 1586 */ 1587 case -EBUSY: 1588 if (in_interrupt()) { 1589 if (try_wait_for_completion(&ctx->restart)) { 1590 /* 1591 * we don't have to block to wait for completion, 1592 * so proceed 1593 */ 1594 } else { 1595 /* 1596 * we can't wait for completion without blocking 1597 * exit and continue processing in a workqueue 1598 */ 1599 ctx->r.req = NULL; 1600 ctx->cc_sector += sector_step; 1601 tag_offset++; 1602 return BLK_STS_DEV_RESOURCE; 1603 } 1604 } else { 1605 wait_for_completion(&ctx->restart); 1606 } 1607 reinit_completion(&ctx->restart); 1608 fallthrough; 1609 /* 1610 * The request is queued and processed asynchronously, 1611 * completion function kcryptd_async_done() will be called. 1612 */ 1613 case -EINPROGRESS: 1614 ctx->r.req = NULL; 1615 ctx->cc_sector += sector_step; 1616 tag_offset++; 1617 continue; 1618 /* 1619 * The request was already processed (synchronously). 1620 */ 1621 case 0: 1622 atomic_dec(&ctx->cc_pending); 1623 ctx->cc_sector += sector_step; 1624 tag_offset++; 1625 if (!atomic) 1626 cond_resched(); 1627 continue; 1628 /* 1629 * There was a data integrity error. 1630 */ 1631 case -EBADMSG: 1632 atomic_dec(&ctx->cc_pending); 1633 return BLK_STS_PROTECTION; 1634 /* 1635 * There was an error while processing the request. 1636 */ 1637 default: 1638 atomic_dec(&ctx->cc_pending); 1639 return BLK_STS_IOERR; 1640 } 1641 } 1642 1643 return 0; 1644 } 1645 1646 static void crypt_free_buffer_pages(struct crypt_config *cc, struct bio *clone); 1647 1648 /* 1649 * Generate a new unfragmented bio with the given size 1650 * This should never violate the device limitations (but only because 1651 * max_segment_size is being constrained to PAGE_SIZE). 1652 * 1653 * This function may be called concurrently. If we allocate from the mempool 1654 * concurrently, there is a possibility of deadlock. For example, if we have 1655 * mempool of 256 pages, two processes, each wanting 256, pages allocate from 1656 * the mempool concurrently, it may deadlock in a situation where both processes 1657 * have allocated 128 pages and the mempool is exhausted. 1658 * 1659 * In order to avoid this scenario we allocate the pages under a mutex. 1660 * 1661 * In order to not degrade performance with excessive locking, we try 1662 * non-blocking allocations without a mutex first but on failure we fallback 1663 * to blocking allocations with a mutex. 1664 */ 1665 static struct bio *crypt_alloc_buffer(struct dm_crypt_io *io, unsigned int size) 1666 { 1667 struct crypt_config *cc = io->cc; 1668 struct bio *clone; 1669 unsigned int nr_iovecs = (size + PAGE_SIZE - 1) >> PAGE_SHIFT; 1670 gfp_t gfp_mask = GFP_NOWAIT | __GFP_HIGHMEM; 1671 unsigned int i, len, remaining_size; 1672 struct page *page; 1673 1674 retry: 1675 if (unlikely(gfp_mask & __GFP_DIRECT_RECLAIM)) 1676 mutex_lock(&cc->bio_alloc_lock); 1677 1678 clone = bio_alloc_bioset(cc->dev->bdev, nr_iovecs, io->base_bio->bi_opf, 1679 GFP_NOIO, &cc->bs); 1680 clone->bi_private = io; 1681 clone->bi_end_io = crypt_endio; 1682 1683 remaining_size = size; 1684 1685 for (i = 0; i < nr_iovecs; i++) { 1686 page = mempool_alloc(&cc->page_pool, gfp_mask); 1687 if (!page) { 1688 crypt_free_buffer_pages(cc, clone); 1689 bio_put(clone); 1690 gfp_mask |= __GFP_DIRECT_RECLAIM; 1691 goto retry; 1692 } 1693 1694 len = (remaining_size > PAGE_SIZE) ? PAGE_SIZE : remaining_size; 1695 1696 bio_add_page(clone, page, len, 0); 1697 1698 remaining_size -= len; 1699 } 1700 1701 /* Allocate space for integrity tags */ 1702 if (dm_crypt_integrity_io_alloc(io, clone)) { 1703 crypt_free_buffer_pages(cc, clone); 1704 bio_put(clone); 1705 clone = NULL; 1706 } 1707 1708 if (unlikely(gfp_mask & __GFP_DIRECT_RECLAIM)) 1709 mutex_unlock(&cc->bio_alloc_lock); 1710 1711 return clone; 1712 } 1713 1714 static void crypt_free_buffer_pages(struct crypt_config *cc, struct bio *clone) 1715 { 1716 struct bio_vec *bv; 1717 struct bvec_iter_all iter_all; 1718 1719 bio_for_each_segment_all(bv, clone, iter_all) { 1720 BUG_ON(!bv->bv_page); 1721 mempool_free(bv->bv_page, &cc->page_pool); 1722 } 1723 } 1724 1725 static void crypt_io_init(struct dm_crypt_io *io, struct crypt_config *cc, 1726 struct bio *bio, sector_t sector) 1727 { 1728 io->cc = cc; 1729 io->base_bio = bio; 1730 io->sector = sector; 1731 io->error = 0; 1732 io->ctx.r.req = NULL; 1733 io->integrity_metadata = NULL; 1734 io->integrity_metadata_from_pool = false; 1735 io->in_tasklet = false; 1736 atomic_set(&io->io_pending, 0); 1737 } 1738 1739 static void crypt_inc_pending(struct dm_crypt_io *io) 1740 { 1741 atomic_inc(&io->io_pending); 1742 } 1743 1744 static void kcryptd_io_bio_endio(struct work_struct *work) 1745 { 1746 struct dm_crypt_io *io = container_of(work, struct dm_crypt_io, work); 1747 1748 bio_endio(io->base_bio); 1749 } 1750 1751 /* 1752 * One of the bios was finished. Check for completion of 1753 * the whole request and correctly clean up the buffer. 1754 */ 1755 static void crypt_dec_pending(struct dm_crypt_io *io) 1756 { 1757 struct crypt_config *cc = io->cc; 1758 struct bio *base_bio = io->base_bio; 1759 blk_status_t error = io->error; 1760 1761 if (!atomic_dec_and_test(&io->io_pending)) 1762 return; 1763 1764 if (io->ctx.r.req) 1765 crypt_free_req(cc, io->ctx.r.req, base_bio); 1766 1767 if (unlikely(io->integrity_metadata_from_pool)) 1768 mempool_free(io->integrity_metadata, &io->cc->tag_pool); 1769 else 1770 kfree(io->integrity_metadata); 1771 1772 base_bio->bi_status = error; 1773 1774 /* 1775 * If we are running this function from our tasklet, 1776 * we can't call bio_endio() here, because it will call 1777 * clone_endio() from dm.c, which in turn will 1778 * free the current struct dm_crypt_io structure with 1779 * our tasklet. In this case we need to delay bio_endio() 1780 * execution to after the tasklet is done and dequeued. 1781 */ 1782 if (io->in_tasklet) { 1783 INIT_WORK(&io->work, kcryptd_io_bio_endio); 1784 queue_work(cc->io_queue, &io->work); 1785 return; 1786 } 1787 1788 bio_endio(base_bio); 1789 } 1790 1791 /* 1792 * kcryptd/kcryptd_io: 1793 * 1794 * Needed because it would be very unwise to do decryption in an 1795 * interrupt context. 1796 * 1797 * kcryptd performs the actual encryption or decryption. 1798 * 1799 * kcryptd_io performs the IO submission. 1800 * 1801 * They must be separated as otherwise the final stages could be 1802 * starved by new requests which can block in the first stages due 1803 * to memory allocation. 1804 * 1805 * The work is done per CPU global for all dm-crypt instances. 1806 * They should not depend on each other and do not block. 1807 */ 1808 static void crypt_endio(struct bio *clone) 1809 { 1810 struct dm_crypt_io *io = clone->bi_private; 1811 struct crypt_config *cc = io->cc; 1812 unsigned int rw = bio_data_dir(clone); 1813 blk_status_t error; 1814 1815 /* 1816 * free the processed pages 1817 */ 1818 if (rw == WRITE) 1819 crypt_free_buffer_pages(cc, clone); 1820 1821 error = clone->bi_status; 1822 bio_put(clone); 1823 1824 if (rw == READ && !error) { 1825 kcryptd_queue_crypt(io); 1826 return; 1827 } 1828 1829 if (unlikely(error)) 1830 io->error = error; 1831 1832 crypt_dec_pending(io); 1833 } 1834 1835 #define CRYPT_MAP_READ_GFP GFP_NOWAIT 1836 1837 static int kcryptd_io_read(struct dm_crypt_io *io, gfp_t gfp) 1838 { 1839 struct crypt_config *cc = io->cc; 1840 struct bio *clone; 1841 1842 /* 1843 * We need the original biovec array in order to decrypt the whole bio 1844 * data *afterwards* -- thanks to immutable biovecs we don't need to 1845 * worry about the block layer modifying the biovec array; so leverage 1846 * bio_alloc_clone(). 1847 */ 1848 clone = bio_alloc_clone(cc->dev->bdev, io->base_bio, gfp, &cc->bs); 1849 if (!clone) 1850 return 1; 1851 clone->bi_private = io; 1852 clone->bi_end_io = crypt_endio; 1853 1854 crypt_inc_pending(io); 1855 1856 clone->bi_iter.bi_sector = cc->start + io->sector; 1857 1858 if (dm_crypt_integrity_io_alloc(io, clone)) { 1859 crypt_dec_pending(io); 1860 bio_put(clone); 1861 return 1; 1862 } 1863 1864 dm_submit_bio_remap(io->base_bio, clone); 1865 return 0; 1866 } 1867 1868 static void kcryptd_io_read_work(struct work_struct *work) 1869 { 1870 struct dm_crypt_io *io = container_of(work, struct dm_crypt_io, work); 1871 1872 crypt_inc_pending(io); 1873 if (kcryptd_io_read(io, GFP_NOIO)) 1874 io->error = BLK_STS_RESOURCE; 1875 crypt_dec_pending(io); 1876 } 1877 1878 static void kcryptd_queue_read(struct dm_crypt_io *io) 1879 { 1880 struct crypt_config *cc = io->cc; 1881 1882 INIT_WORK(&io->work, kcryptd_io_read_work); 1883 queue_work(cc->io_queue, &io->work); 1884 } 1885 1886 static void kcryptd_io_write(struct dm_crypt_io *io) 1887 { 1888 struct bio *clone = io->ctx.bio_out; 1889 1890 dm_submit_bio_remap(io->base_bio, clone); 1891 } 1892 1893 #define crypt_io_from_node(node) rb_entry((node), struct dm_crypt_io, rb_node) 1894 1895 static int dmcrypt_write(void *data) 1896 { 1897 struct crypt_config *cc = data; 1898 struct dm_crypt_io *io; 1899 1900 while (1) { 1901 struct rb_root write_tree; 1902 struct blk_plug plug; 1903 1904 spin_lock_irq(&cc->write_thread_lock); 1905 continue_locked: 1906 1907 if (!RB_EMPTY_ROOT(&cc->write_tree)) 1908 goto pop_from_list; 1909 1910 set_current_state(TASK_INTERRUPTIBLE); 1911 1912 spin_unlock_irq(&cc->write_thread_lock); 1913 1914 if (unlikely(kthread_should_stop())) { 1915 set_current_state(TASK_RUNNING); 1916 break; 1917 } 1918 1919 schedule(); 1920 1921 set_current_state(TASK_RUNNING); 1922 spin_lock_irq(&cc->write_thread_lock); 1923 goto continue_locked; 1924 1925 pop_from_list: 1926 write_tree = cc->write_tree; 1927 cc->write_tree = RB_ROOT; 1928 spin_unlock_irq(&cc->write_thread_lock); 1929 1930 BUG_ON(rb_parent(write_tree.rb_node)); 1931 1932 /* 1933 * Note: we cannot walk the tree here with rb_next because 1934 * the structures may be freed when kcryptd_io_write is called. 1935 */ 1936 blk_start_plug(&plug); 1937 do { 1938 io = crypt_io_from_node(rb_first(&write_tree)); 1939 rb_erase(&io->rb_node, &write_tree); 1940 kcryptd_io_write(io); 1941 cond_resched(); 1942 } while (!RB_EMPTY_ROOT(&write_tree)); 1943 blk_finish_plug(&plug); 1944 } 1945 return 0; 1946 } 1947 1948 static void kcryptd_crypt_write_io_submit(struct dm_crypt_io *io, int async) 1949 { 1950 struct bio *clone = io->ctx.bio_out; 1951 struct crypt_config *cc = io->cc; 1952 unsigned long flags; 1953 sector_t sector; 1954 struct rb_node **rbp, *parent; 1955 1956 if (unlikely(io->error)) { 1957 crypt_free_buffer_pages(cc, clone); 1958 bio_put(clone); 1959 crypt_dec_pending(io); 1960 return; 1961 } 1962 1963 /* crypt_convert should have filled the clone bio */ 1964 BUG_ON(io->ctx.iter_out.bi_size); 1965 1966 clone->bi_iter.bi_sector = cc->start + io->sector; 1967 1968 if ((likely(!async) && test_bit(DM_CRYPT_NO_OFFLOAD, &cc->flags)) || 1969 test_bit(DM_CRYPT_NO_WRITE_WORKQUEUE, &cc->flags)) { 1970 dm_submit_bio_remap(io->base_bio, clone); 1971 return; 1972 } 1973 1974 spin_lock_irqsave(&cc->write_thread_lock, flags); 1975 if (RB_EMPTY_ROOT(&cc->write_tree)) 1976 wake_up_process(cc->write_thread); 1977 rbp = &cc->write_tree.rb_node; 1978 parent = NULL; 1979 sector = io->sector; 1980 while (*rbp) { 1981 parent = *rbp; 1982 if (sector < crypt_io_from_node(parent)->sector) 1983 rbp = &(*rbp)->rb_left; 1984 else 1985 rbp = &(*rbp)->rb_right; 1986 } 1987 rb_link_node(&io->rb_node, parent, rbp); 1988 rb_insert_color(&io->rb_node, &cc->write_tree); 1989 spin_unlock_irqrestore(&cc->write_thread_lock, flags); 1990 } 1991 1992 static bool kcryptd_crypt_write_inline(struct crypt_config *cc, 1993 struct convert_context *ctx) 1994 1995 { 1996 if (!test_bit(DM_CRYPT_WRITE_INLINE, &cc->flags)) 1997 return false; 1998 1999 /* 2000 * Note: zone append writes (REQ_OP_ZONE_APPEND) do not have ordering 2001 * constraints so they do not need to be issued inline by 2002 * kcryptd_crypt_write_convert(). 2003 */ 2004 switch (bio_op(ctx->bio_in)) { 2005 case REQ_OP_WRITE: 2006 case REQ_OP_WRITE_ZEROES: 2007 return true; 2008 default: 2009 return false; 2010 } 2011 } 2012 2013 static void kcryptd_crypt_write_continue(struct work_struct *work) 2014 { 2015 struct dm_crypt_io *io = container_of(work, struct dm_crypt_io, work); 2016 struct crypt_config *cc = io->cc; 2017 struct convert_context *ctx = &io->ctx; 2018 int crypt_finished; 2019 sector_t sector = io->sector; 2020 blk_status_t r; 2021 2022 wait_for_completion(&ctx->restart); 2023 reinit_completion(&ctx->restart); 2024 2025 r = crypt_convert(cc, &io->ctx, true, false); 2026 if (r) 2027 io->error = r; 2028 crypt_finished = atomic_dec_and_test(&ctx->cc_pending); 2029 if (!crypt_finished && kcryptd_crypt_write_inline(cc, ctx)) { 2030 /* Wait for completion signaled by kcryptd_async_done() */ 2031 wait_for_completion(&ctx->restart); 2032 crypt_finished = 1; 2033 } 2034 2035 /* Encryption was already finished, submit io now */ 2036 if (crypt_finished) { 2037 kcryptd_crypt_write_io_submit(io, 0); 2038 io->sector = sector; 2039 } 2040 2041 crypt_dec_pending(io); 2042 } 2043 2044 static void kcryptd_crypt_write_convert(struct dm_crypt_io *io) 2045 { 2046 struct crypt_config *cc = io->cc; 2047 struct convert_context *ctx = &io->ctx; 2048 struct bio *clone; 2049 int crypt_finished; 2050 sector_t sector = io->sector; 2051 blk_status_t r; 2052 2053 /* 2054 * Prevent io from disappearing until this function completes. 2055 */ 2056 crypt_inc_pending(io); 2057 crypt_convert_init(cc, ctx, NULL, io->base_bio, sector); 2058 2059 clone = crypt_alloc_buffer(io, io->base_bio->bi_iter.bi_size); 2060 if (unlikely(!clone)) { 2061 io->error = BLK_STS_IOERR; 2062 goto dec; 2063 } 2064 2065 io->ctx.bio_out = clone; 2066 io->ctx.iter_out = clone->bi_iter; 2067 2068 sector += bio_sectors(clone); 2069 2070 crypt_inc_pending(io); 2071 r = crypt_convert(cc, ctx, 2072 test_bit(DM_CRYPT_NO_WRITE_WORKQUEUE, &cc->flags), true); 2073 /* 2074 * Crypto API backlogged the request, because its queue was full 2075 * and we're in softirq context, so continue from a workqueue 2076 * (TODO: is it actually possible to be in softirq in the write path?) 2077 */ 2078 if (r == BLK_STS_DEV_RESOURCE) { 2079 INIT_WORK(&io->work, kcryptd_crypt_write_continue); 2080 queue_work(cc->crypt_queue, &io->work); 2081 return; 2082 } 2083 if (r) 2084 io->error = r; 2085 crypt_finished = atomic_dec_and_test(&ctx->cc_pending); 2086 if (!crypt_finished && kcryptd_crypt_write_inline(cc, ctx)) { 2087 /* Wait for completion signaled by kcryptd_async_done() */ 2088 wait_for_completion(&ctx->restart); 2089 crypt_finished = 1; 2090 } 2091 2092 /* Encryption was already finished, submit io now */ 2093 if (crypt_finished) { 2094 kcryptd_crypt_write_io_submit(io, 0); 2095 io->sector = sector; 2096 } 2097 2098 dec: 2099 crypt_dec_pending(io); 2100 } 2101 2102 static void kcryptd_crypt_read_done(struct dm_crypt_io *io) 2103 { 2104 crypt_dec_pending(io); 2105 } 2106 2107 static void kcryptd_crypt_read_continue(struct work_struct *work) 2108 { 2109 struct dm_crypt_io *io = container_of(work, struct dm_crypt_io, work); 2110 struct crypt_config *cc = io->cc; 2111 blk_status_t r; 2112 2113 wait_for_completion(&io->ctx.restart); 2114 reinit_completion(&io->ctx.restart); 2115 2116 r = crypt_convert(cc, &io->ctx, true, false); 2117 if (r) 2118 io->error = r; 2119 2120 if (atomic_dec_and_test(&io->ctx.cc_pending)) 2121 kcryptd_crypt_read_done(io); 2122 2123 crypt_dec_pending(io); 2124 } 2125 2126 static void kcryptd_crypt_read_convert(struct dm_crypt_io *io) 2127 { 2128 struct crypt_config *cc = io->cc; 2129 blk_status_t r; 2130 2131 crypt_inc_pending(io); 2132 2133 crypt_convert_init(cc, &io->ctx, io->base_bio, io->base_bio, 2134 io->sector); 2135 2136 r = crypt_convert(cc, &io->ctx, 2137 test_bit(DM_CRYPT_NO_READ_WORKQUEUE, &cc->flags), true); 2138 /* 2139 * Crypto API backlogged the request, because its queue was full 2140 * and we're in softirq context, so continue from a workqueue 2141 */ 2142 if (r == BLK_STS_DEV_RESOURCE) { 2143 INIT_WORK(&io->work, kcryptd_crypt_read_continue); 2144 queue_work(cc->crypt_queue, &io->work); 2145 return; 2146 } 2147 if (r) 2148 io->error = r; 2149 2150 if (atomic_dec_and_test(&io->ctx.cc_pending)) 2151 kcryptd_crypt_read_done(io); 2152 2153 crypt_dec_pending(io); 2154 } 2155 2156 static void kcryptd_async_done(void *data, int error) 2157 { 2158 struct dm_crypt_request *dmreq = data; 2159 struct convert_context *ctx = dmreq->ctx; 2160 struct dm_crypt_io *io = container_of(ctx, struct dm_crypt_io, ctx); 2161 struct crypt_config *cc = io->cc; 2162 2163 /* 2164 * A request from crypto driver backlog is going to be processed now, 2165 * finish the completion and continue in crypt_convert(). 2166 * (Callback will be called for the second time for this request.) 2167 */ 2168 if (error == -EINPROGRESS) { 2169 complete(&ctx->restart); 2170 return; 2171 } 2172 2173 if (!error && cc->iv_gen_ops && cc->iv_gen_ops->post) 2174 error = cc->iv_gen_ops->post(cc, org_iv_of_dmreq(cc, dmreq), dmreq); 2175 2176 if (error == -EBADMSG) { 2177 sector_t s = le64_to_cpu(*org_sector_of_dmreq(cc, dmreq)); 2178 2179 DMERR_LIMIT("%pg: INTEGRITY AEAD ERROR, sector %llu", 2180 ctx->bio_in->bi_bdev, s); 2181 dm_audit_log_bio(DM_MSG_PREFIX, "integrity-aead", 2182 ctx->bio_in, s, 0); 2183 io->error = BLK_STS_PROTECTION; 2184 } else if (error < 0) 2185 io->error = BLK_STS_IOERR; 2186 2187 crypt_free_req(cc, req_of_dmreq(cc, dmreq), io->base_bio); 2188 2189 if (!atomic_dec_and_test(&ctx->cc_pending)) 2190 return; 2191 2192 /* 2193 * The request is fully completed: for inline writes, let 2194 * kcryptd_crypt_write_convert() do the IO submission. 2195 */ 2196 if (bio_data_dir(io->base_bio) == READ) { 2197 kcryptd_crypt_read_done(io); 2198 return; 2199 } 2200 2201 if (kcryptd_crypt_write_inline(cc, ctx)) { 2202 complete(&ctx->restart); 2203 return; 2204 } 2205 2206 kcryptd_crypt_write_io_submit(io, 1); 2207 } 2208 2209 static void kcryptd_crypt(struct work_struct *work) 2210 { 2211 struct dm_crypt_io *io = container_of(work, struct dm_crypt_io, work); 2212 2213 if (bio_data_dir(io->base_bio) == READ) 2214 kcryptd_crypt_read_convert(io); 2215 else 2216 kcryptd_crypt_write_convert(io); 2217 } 2218 2219 static void kcryptd_crypt_tasklet(unsigned long work) 2220 { 2221 kcryptd_crypt((struct work_struct *)work); 2222 } 2223 2224 static void kcryptd_queue_crypt(struct dm_crypt_io *io) 2225 { 2226 struct crypt_config *cc = io->cc; 2227 2228 if ((bio_data_dir(io->base_bio) == READ && test_bit(DM_CRYPT_NO_READ_WORKQUEUE, &cc->flags)) || 2229 (bio_data_dir(io->base_bio) == WRITE && test_bit(DM_CRYPT_NO_WRITE_WORKQUEUE, &cc->flags))) { 2230 /* 2231 * in_hardirq(): Crypto API's skcipher_walk_first() refuses to work in hard IRQ context. 2232 * irqs_disabled(): the kernel may run some IO completion from the idle thread, but 2233 * it is being executed with irqs disabled. 2234 */ 2235 if (in_hardirq() || irqs_disabled()) { 2236 io->in_tasklet = true; 2237 tasklet_init(&io->tasklet, kcryptd_crypt_tasklet, (unsigned long)&io->work); 2238 tasklet_schedule(&io->tasklet); 2239 return; 2240 } 2241 2242 kcryptd_crypt(&io->work); 2243 return; 2244 } 2245 2246 INIT_WORK(&io->work, kcryptd_crypt); 2247 queue_work(cc->crypt_queue, &io->work); 2248 } 2249 2250 static void crypt_free_tfms_aead(struct crypt_config *cc) 2251 { 2252 if (!cc->cipher_tfm.tfms_aead) 2253 return; 2254 2255 if (cc->cipher_tfm.tfms_aead[0] && !IS_ERR(cc->cipher_tfm.tfms_aead[0])) { 2256 crypto_free_aead(cc->cipher_tfm.tfms_aead[0]); 2257 cc->cipher_tfm.tfms_aead[0] = NULL; 2258 } 2259 2260 kfree(cc->cipher_tfm.tfms_aead); 2261 cc->cipher_tfm.tfms_aead = NULL; 2262 } 2263 2264 static void crypt_free_tfms_skcipher(struct crypt_config *cc) 2265 { 2266 unsigned int i; 2267 2268 if (!cc->cipher_tfm.tfms) 2269 return; 2270 2271 for (i = 0; i < cc->tfms_count; i++) 2272 if (cc->cipher_tfm.tfms[i] && !IS_ERR(cc->cipher_tfm.tfms[i])) { 2273 crypto_free_skcipher(cc->cipher_tfm.tfms[i]); 2274 cc->cipher_tfm.tfms[i] = NULL; 2275 } 2276 2277 kfree(cc->cipher_tfm.tfms); 2278 cc->cipher_tfm.tfms = NULL; 2279 } 2280 2281 static void crypt_free_tfms(struct crypt_config *cc) 2282 { 2283 if (crypt_integrity_aead(cc)) 2284 crypt_free_tfms_aead(cc); 2285 else 2286 crypt_free_tfms_skcipher(cc); 2287 } 2288 2289 static int crypt_alloc_tfms_skcipher(struct crypt_config *cc, char *ciphermode) 2290 { 2291 unsigned int i; 2292 int err; 2293 2294 cc->cipher_tfm.tfms = kcalloc(cc->tfms_count, 2295 sizeof(struct crypto_skcipher *), 2296 GFP_KERNEL); 2297 if (!cc->cipher_tfm.tfms) 2298 return -ENOMEM; 2299 2300 for (i = 0; i < cc->tfms_count; i++) { 2301 cc->cipher_tfm.tfms[i] = crypto_alloc_skcipher(ciphermode, 0, 2302 CRYPTO_ALG_ALLOCATES_MEMORY); 2303 if (IS_ERR(cc->cipher_tfm.tfms[i])) { 2304 err = PTR_ERR(cc->cipher_tfm.tfms[i]); 2305 crypt_free_tfms(cc); 2306 return err; 2307 } 2308 } 2309 2310 /* 2311 * dm-crypt performance can vary greatly depending on which crypto 2312 * algorithm implementation is used. Help people debug performance 2313 * problems by logging the ->cra_driver_name. 2314 */ 2315 DMDEBUG_LIMIT("%s using implementation \"%s\"", ciphermode, 2316 crypto_skcipher_alg(any_tfm(cc))->base.cra_driver_name); 2317 return 0; 2318 } 2319 2320 static int crypt_alloc_tfms_aead(struct crypt_config *cc, char *ciphermode) 2321 { 2322 int err; 2323 2324 cc->cipher_tfm.tfms = kmalloc(sizeof(struct crypto_aead *), GFP_KERNEL); 2325 if (!cc->cipher_tfm.tfms) 2326 return -ENOMEM; 2327 2328 cc->cipher_tfm.tfms_aead[0] = crypto_alloc_aead(ciphermode, 0, 2329 CRYPTO_ALG_ALLOCATES_MEMORY); 2330 if (IS_ERR(cc->cipher_tfm.tfms_aead[0])) { 2331 err = PTR_ERR(cc->cipher_tfm.tfms_aead[0]); 2332 crypt_free_tfms(cc); 2333 return err; 2334 } 2335 2336 DMDEBUG_LIMIT("%s using implementation \"%s\"", ciphermode, 2337 crypto_aead_alg(any_tfm_aead(cc))->base.cra_driver_name); 2338 return 0; 2339 } 2340 2341 static int crypt_alloc_tfms(struct crypt_config *cc, char *ciphermode) 2342 { 2343 if (crypt_integrity_aead(cc)) 2344 return crypt_alloc_tfms_aead(cc, ciphermode); 2345 else 2346 return crypt_alloc_tfms_skcipher(cc, ciphermode); 2347 } 2348 2349 static unsigned int crypt_subkey_size(struct crypt_config *cc) 2350 { 2351 return (cc->key_size - cc->key_extra_size) >> ilog2(cc->tfms_count); 2352 } 2353 2354 static unsigned int crypt_authenckey_size(struct crypt_config *cc) 2355 { 2356 return crypt_subkey_size(cc) + RTA_SPACE(sizeof(struct crypto_authenc_key_param)); 2357 } 2358 2359 /* 2360 * If AEAD is composed like authenc(hmac(sha256),xts(aes)), 2361 * the key must be for some reason in special format. 2362 * This funcion converts cc->key to this special format. 2363 */ 2364 static void crypt_copy_authenckey(char *p, const void *key, 2365 unsigned int enckeylen, unsigned int authkeylen) 2366 { 2367 struct crypto_authenc_key_param *param; 2368 struct rtattr *rta; 2369 2370 rta = (struct rtattr *)p; 2371 param = RTA_DATA(rta); 2372 param->enckeylen = cpu_to_be32(enckeylen); 2373 rta->rta_len = RTA_LENGTH(sizeof(*param)); 2374 rta->rta_type = CRYPTO_AUTHENC_KEYA_PARAM; 2375 p += RTA_SPACE(sizeof(*param)); 2376 memcpy(p, key + enckeylen, authkeylen); 2377 p += authkeylen; 2378 memcpy(p, key, enckeylen); 2379 } 2380 2381 static int crypt_setkey(struct crypt_config *cc) 2382 { 2383 unsigned int subkey_size; 2384 int err = 0, i, r; 2385 2386 /* Ignore extra keys (which are used for IV etc) */ 2387 subkey_size = crypt_subkey_size(cc); 2388 2389 if (crypt_integrity_hmac(cc)) { 2390 if (subkey_size < cc->key_mac_size) 2391 return -EINVAL; 2392 2393 crypt_copy_authenckey(cc->authenc_key, cc->key, 2394 subkey_size - cc->key_mac_size, 2395 cc->key_mac_size); 2396 } 2397 2398 for (i = 0; i < cc->tfms_count; i++) { 2399 if (crypt_integrity_hmac(cc)) 2400 r = crypto_aead_setkey(cc->cipher_tfm.tfms_aead[i], 2401 cc->authenc_key, crypt_authenckey_size(cc)); 2402 else if (crypt_integrity_aead(cc)) 2403 r = crypto_aead_setkey(cc->cipher_tfm.tfms_aead[i], 2404 cc->key + (i * subkey_size), 2405 subkey_size); 2406 else 2407 r = crypto_skcipher_setkey(cc->cipher_tfm.tfms[i], 2408 cc->key + (i * subkey_size), 2409 subkey_size); 2410 if (r) 2411 err = r; 2412 } 2413 2414 if (crypt_integrity_hmac(cc)) 2415 memzero_explicit(cc->authenc_key, crypt_authenckey_size(cc)); 2416 2417 return err; 2418 } 2419 2420 #ifdef CONFIG_KEYS 2421 2422 static bool contains_whitespace(const char *str) 2423 { 2424 while (*str) 2425 if (isspace(*str++)) 2426 return true; 2427 return false; 2428 } 2429 2430 static int set_key_user(struct crypt_config *cc, struct key *key) 2431 { 2432 const struct user_key_payload *ukp; 2433 2434 ukp = user_key_payload_locked(key); 2435 if (!ukp) 2436 return -EKEYREVOKED; 2437 2438 if (cc->key_size != ukp->datalen) 2439 return -EINVAL; 2440 2441 memcpy(cc->key, ukp->data, cc->key_size); 2442 2443 return 0; 2444 } 2445 2446 static int set_key_encrypted(struct crypt_config *cc, struct key *key) 2447 { 2448 const struct encrypted_key_payload *ekp; 2449 2450 ekp = key->payload.data[0]; 2451 if (!ekp) 2452 return -EKEYREVOKED; 2453 2454 if (cc->key_size != ekp->decrypted_datalen) 2455 return -EINVAL; 2456 2457 memcpy(cc->key, ekp->decrypted_data, cc->key_size); 2458 2459 return 0; 2460 } 2461 2462 static int set_key_trusted(struct crypt_config *cc, struct key *key) 2463 { 2464 const struct trusted_key_payload *tkp; 2465 2466 tkp = key->payload.data[0]; 2467 if (!tkp) 2468 return -EKEYREVOKED; 2469 2470 if (cc->key_size != tkp->key_len) 2471 return -EINVAL; 2472 2473 memcpy(cc->key, tkp->key, cc->key_size); 2474 2475 return 0; 2476 } 2477 2478 static int crypt_set_keyring_key(struct crypt_config *cc, const char *key_string) 2479 { 2480 char *new_key_string, *key_desc; 2481 int ret; 2482 struct key_type *type; 2483 struct key *key; 2484 int (*set_key)(struct crypt_config *cc, struct key *key); 2485 2486 /* 2487 * Reject key_string with whitespace. dm core currently lacks code for 2488 * proper whitespace escaping in arguments on DM_TABLE_STATUS path. 2489 */ 2490 if (contains_whitespace(key_string)) { 2491 DMERR("whitespace chars not allowed in key string"); 2492 return -EINVAL; 2493 } 2494 2495 /* look for next ':' separating key_type from key_description */ 2496 key_desc = strchr(key_string, ':'); 2497 if (!key_desc || key_desc == key_string || !strlen(key_desc + 1)) 2498 return -EINVAL; 2499 2500 if (!strncmp(key_string, "logon:", key_desc - key_string + 1)) { 2501 type = &key_type_logon; 2502 set_key = set_key_user; 2503 } else if (!strncmp(key_string, "user:", key_desc - key_string + 1)) { 2504 type = &key_type_user; 2505 set_key = set_key_user; 2506 } else if (IS_ENABLED(CONFIG_ENCRYPTED_KEYS) && 2507 !strncmp(key_string, "encrypted:", key_desc - key_string + 1)) { 2508 type = &key_type_encrypted; 2509 set_key = set_key_encrypted; 2510 } else if (IS_ENABLED(CONFIG_TRUSTED_KEYS) && 2511 !strncmp(key_string, "trusted:", key_desc - key_string + 1)) { 2512 type = &key_type_trusted; 2513 set_key = set_key_trusted; 2514 } else { 2515 return -EINVAL; 2516 } 2517 2518 new_key_string = kstrdup(key_string, GFP_KERNEL); 2519 if (!new_key_string) 2520 return -ENOMEM; 2521 2522 key = request_key(type, key_desc + 1, NULL); 2523 if (IS_ERR(key)) { 2524 kfree_sensitive(new_key_string); 2525 return PTR_ERR(key); 2526 } 2527 2528 down_read(&key->sem); 2529 2530 ret = set_key(cc, key); 2531 if (ret < 0) { 2532 up_read(&key->sem); 2533 key_put(key); 2534 kfree_sensitive(new_key_string); 2535 return ret; 2536 } 2537 2538 up_read(&key->sem); 2539 key_put(key); 2540 2541 /* clear the flag since following operations may invalidate previously valid key */ 2542 clear_bit(DM_CRYPT_KEY_VALID, &cc->flags); 2543 2544 ret = crypt_setkey(cc); 2545 2546 if (!ret) { 2547 set_bit(DM_CRYPT_KEY_VALID, &cc->flags); 2548 kfree_sensitive(cc->key_string); 2549 cc->key_string = new_key_string; 2550 } else 2551 kfree_sensitive(new_key_string); 2552 2553 return ret; 2554 } 2555 2556 static int get_key_size(char **key_string) 2557 { 2558 char *colon, dummy; 2559 int ret; 2560 2561 if (*key_string[0] != ':') 2562 return strlen(*key_string) >> 1; 2563 2564 /* look for next ':' in key string */ 2565 colon = strpbrk(*key_string + 1, ":"); 2566 if (!colon) 2567 return -EINVAL; 2568 2569 if (sscanf(*key_string + 1, "%u%c", &ret, &dummy) != 2 || dummy != ':') 2570 return -EINVAL; 2571 2572 *key_string = colon; 2573 2574 /* remaining key string should be :<logon|user>:<key_desc> */ 2575 2576 return ret; 2577 } 2578 2579 #else 2580 2581 static int crypt_set_keyring_key(struct crypt_config *cc, const char *key_string) 2582 { 2583 return -EINVAL; 2584 } 2585 2586 static int get_key_size(char **key_string) 2587 { 2588 return (*key_string[0] == ':') ? -EINVAL : (int)(strlen(*key_string) >> 1); 2589 } 2590 2591 #endif /* CONFIG_KEYS */ 2592 2593 static int crypt_set_key(struct crypt_config *cc, char *key) 2594 { 2595 int r = -EINVAL; 2596 int key_string_len = strlen(key); 2597 2598 /* Hyphen (which gives a key_size of zero) means there is no key. */ 2599 if (!cc->key_size && strcmp(key, "-")) 2600 goto out; 2601 2602 /* ':' means the key is in kernel keyring, short-circuit normal key processing */ 2603 if (key[0] == ':') { 2604 r = crypt_set_keyring_key(cc, key + 1); 2605 goto out; 2606 } 2607 2608 /* clear the flag since following operations may invalidate previously valid key */ 2609 clear_bit(DM_CRYPT_KEY_VALID, &cc->flags); 2610 2611 /* wipe references to any kernel keyring key */ 2612 kfree_sensitive(cc->key_string); 2613 cc->key_string = NULL; 2614 2615 /* Decode key from its hex representation. */ 2616 if (cc->key_size && hex2bin(cc->key, key, cc->key_size) < 0) 2617 goto out; 2618 2619 r = crypt_setkey(cc); 2620 if (!r) 2621 set_bit(DM_CRYPT_KEY_VALID, &cc->flags); 2622 2623 out: 2624 /* Hex key string not needed after here, so wipe it. */ 2625 memset(key, '0', key_string_len); 2626 2627 return r; 2628 } 2629 2630 static int crypt_wipe_key(struct crypt_config *cc) 2631 { 2632 int r; 2633 2634 clear_bit(DM_CRYPT_KEY_VALID, &cc->flags); 2635 get_random_bytes(&cc->key, cc->key_size); 2636 2637 /* Wipe IV private keys */ 2638 if (cc->iv_gen_ops && cc->iv_gen_ops->wipe) { 2639 r = cc->iv_gen_ops->wipe(cc); 2640 if (r) 2641 return r; 2642 } 2643 2644 kfree_sensitive(cc->key_string); 2645 cc->key_string = NULL; 2646 r = crypt_setkey(cc); 2647 memset(&cc->key, 0, cc->key_size * sizeof(u8)); 2648 2649 return r; 2650 } 2651 2652 static void crypt_calculate_pages_per_client(void) 2653 { 2654 unsigned long pages = (totalram_pages() - totalhigh_pages()) * DM_CRYPT_MEMORY_PERCENT / 100; 2655 2656 if (!dm_crypt_clients_n) 2657 return; 2658 2659 pages /= dm_crypt_clients_n; 2660 if (pages < DM_CRYPT_MIN_PAGES_PER_CLIENT) 2661 pages = DM_CRYPT_MIN_PAGES_PER_CLIENT; 2662 dm_crypt_pages_per_client = pages; 2663 } 2664 2665 static void *crypt_page_alloc(gfp_t gfp_mask, void *pool_data) 2666 { 2667 struct crypt_config *cc = pool_data; 2668 struct page *page; 2669 2670 /* 2671 * Note, percpu_counter_read_positive() may over (and under) estimate 2672 * the current usage by at most (batch - 1) * num_online_cpus() pages, 2673 * but avoids potential spinlock contention of an exact result. 2674 */ 2675 if (unlikely(percpu_counter_read_positive(&cc->n_allocated_pages) >= dm_crypt_pages_per_client) && 2676 likely(gfp_mask & __GFP_NORETRY)) 2677 return NULL; 2678 2679 page = alloc_page(gfp_mask); 2680 if (likely(page != NULL)) 2681 percpu_counter_add(&cc->n_allocated_pages, 1); 2682 2683 return page; 2684 } 2685 2686 static void crypt_page_free(void *page, void *pool_data) 2687 { 2688 struct crypt_config *cc = pool_data; 2689 2690 __free_page(page); 2691 percpu_counter_sub(&cc->n_allocated_pages, 1); 2692 } 2693 2694 static void crypt_dtr(struct dm_target *ti) 2695 { 2696 struct crypt_config *cc = ti->private; 2697 2698 ti->private = NULL; 2699 2700 if (!cc) 2701 return; 2702 2703 if (cc->write_thread) 2704 kthread_stop(cc->write_thread); 2705 2706 if (cc->io_queue) 2707 destroy_workqueue(cc->io_queue); 2708 if (cc->crypt_queue) 2709 destroy_workqueue(cc->crypt_queue); 2710 2711 crypt_free_tfms(cc); 2712 2713 bioset_exit(&cc->bs); 2714 2715 mempool_exit(&cc->page_pool); 2716 mempool_exit(&cc->req_pool); 2717 mempool_exit(&cc->tag_pool); 2718 2719 WARN_ON(percpu_counter_sum(&cc->n_allocated_pages) != 0); 2720 percpu_counter_destroy(&cc->n_allocated_pages); 2721 2722 if (cc->iv_gen_ops && cc->iv_gen_ops->dtr) 2723 cc->iv_gen_ops->dtr(cc); 2724 2725 if (cc->dev) 2726 dm_put_device(ti, cc->dev); 2727 2728 kfree_sensitive(cc->cipher_string); 2729 kfree_sensitive(cc->key_string); 2730 kfree_sensitive(cc->cipher_auth); 2731 kfree_sensitive(cc->authenc_key); 2732 2733 mutex_destroy(&cc->bio_alloc_lock); 2734 2735 /* Must zero key material before freeing */ 2736 kfree_sensitive(cc); 2737 2738 spin_lock(&dm_crypt_clients_lock); 2739 WARN_ON(!dm_crypt_clients_n); 2740 dm_crypt_clients_n--; 2741 crypt_calculate_pages_per_client(); 2742 spin_unlock(&dm_crypt_clients_lock); 2743 2744 dm_audit_log_dtr(DM_MSG_PREFIX, ti, 1); 2745 } 2746 2747 static int crypt_ctr_ivmode(struct dm_target *ti, const char *ivmode) 2748 { 2749 struct crypt_config *cc = ti->private; 2750 2751 if (crypt_integrity_aead(cc)) 2752 cc->iv_size = crypto_aead_ivsize(any_tfm_aead(cc)); 2753 else 2754 cc->iv_size = crypto_skcipher_ivsize(any_tfm(cc)); 2755 2756 if (cc->iv_size) 2757 /* at least a 64 bit sector number should fit in our buffer */ 2758 cc->iv_size = max(cc->iv_size, 2759 (unsigned int)(sizeof(u64) / sizeof(u8))); 2760 else if (ivmode) { 2761 DMWARN("Selected cipher does not support IVs"); 2762 ivmode = NULL; 2763 } 2764 2765 /* Choose ivmode, see comments at iv code. */ 2766 if (ivmode == NULL) 2767 cc->iv_gen_ops = NULL; 2768 else if (strcmp(ivmode, "plain") == 0) 2769 cc->iv_gen_ops = &crypt_iv_plain_ops; 2770 else if (strcmp(ivmode, "plain64") == 0) 2771 cc->iv_gen_ops = &crypt_iv_plain64_ops; 2772 else if (strcmp(ivmode, "plain64be") == 0) 2773 cc->iv_gen_ops = &crypt_iv_plain64be_ops; 2774 else if (strcmp(ivmode, "essiv") == 0) 2775 cc->iv_gen_ops = &crypt_iv_essiv_ops; 2776 else if (strcmp(ivmode, "benbi") == 0) 2777 cc->iv_gen_ops = &crypt_iv_benbi_ops; 2778 else if (strcmp(ivmode, "null") == 0) 2779 cc->iv_gen_ops = &crypt_iv_null_ops; 2780 else if (strcmp(ivmode, "eboiv") == 0) 2781 cc->iv_gen_ops = &crypt_iv_eboiv_ops; 2782 else if (strcmp(ivmode, "elephant") == 0) { 2783 cc->iv_gen_ops = &crypt_iv_elephant_ops; 2784 cc->key_parts = 2; 2785 cc->key_extra_size = cc->key_size / 2; 2786 if (cc->key_extra_size > ELEPHANT_MAX_KEY_SIZE) 2787 return -EINVAL; 2788 set_bit(CRYPT_ENCRYPT_PREPROCESS, &cc->cipher_flags); 2789 } else if (strcmp(ivmode, "lmk") == 0) { 2790 cc->iv_gen_ops = &crypt_iv_lmk_ops; 2791 /* 2792 * Version 2 and 3 is recognised according 2793 * to length of provided multi-key string. 2794 * If present (version 3), last key is used as IV seed. 2795 * All keys (including IV seed) are always the same size. 2796 */ 2797 if (cc->key_size % cc->key_parts) { 2798 cc->key_parts++; 2799 cc->key_extra_size = cc->key_size / cc->key_parts; 2800 } 2801 } else if (strcmp(ivmode, "tcw") == 0) { 2802 cc->iv_gen_ops = &crypt_iv_tcw_ops; 2803 cc->key_parts += 2; /* IV + whitening */ 2804 cc->key_extra_size = cc->iv_size + TCW_WHITENING_SIZE; 2805 } else if (strcmp(ivmode, "random") == 0) { 2806 cc->iv_gen_ops = &crypt_iv_random_ops; 2807 /* Need storage space in integrity fields. */ 2808 cc->integrity_iv_size = cc->iv_size; 2809 } else { 2810 ti->error = "Invalid IV mode"; 2811 return -EINVAL; 2812 } 2813 2814 return 0; 2815 } 2816 2817 /* 2818 * Workaround to parse HMAC algorithm from AEAD crypto API spec. 2819 * The HMAC is needed to calculate tag size (HMAC digest size). 2820 * This should be probably done by crypto-api calls (once available...) 2821 */ 2822 static int crypt_ctr_auth_cipher(struct crypt_config *cc, char *cipher_api) 2823 { 2824 char *start, *end, *mac_alg = NULL; 2825 struct crypto_ahash *mac; 2826 2827 if (!strstarts(cipher_api, "authenc(")) 2828 return 0; 2829 2830 start = strchr(cipher_api, '('); 2831 end = strchr(cipher_api, ','); 2832 if (!start || !end || ++start > end) 2833 return -EINVAL; 2834 2835 mac_alg = kzalloc(end - start + 1, GFP_KERNEL); 2836 if (!mac_alg) 2837 return -ENOMEM; 2838 strncpy(mac_alg, start, end - start); 2839 2840 mac = crypto_alloc_ahash(mac_alg, 0, CRYPTO_ALG_ALLOCATES_MEMORY); 2841 kfree(mac_alg); 2842 2843 if (IS_ERR(mac)) 2844 return PTR_ERR(mac); 2845 2846 cc->key_mac_size = crypto_ahash_digestsize(mac); 2847 crypto_free_ahash(mac); 2848 2849 cc->authenc_key = kmalloc(crypt_authenckey_size(cc), GFP_KERNEL); 2850 if (!cc->authenc_key) 2851 return -ENOMEM; 2852 2853 return 0; 2854 } 2855 2856 static int crypt_ctr_cipher_new(struct dm_target *ti, char *cipher_in, char *key, 2857 char **ivmode, char **ivopts) 2858 { 2859 struct crypt_config *cc = ti->private; 2860 char *tmp, *cipher_api, buf[CRYPTO_MAX_ALG_NAME]; 2861 int ret = -EINVAL; 2862 2863 cc->tfms_count = 1; 2864 2865 /* 2866 * New format (capi: prefix) 2867 * capi:cipher_api_spec-iv:ivopts 2868 */ 2869 tmp = &cipher_in[strlen("capi:")]; 2870 2871 /* Separate IV options if present, it can contain another '-' in hash name */ 2872 *ivopts = strrchr(tmp, ':'); 2873 if (*ivopts) { 2874 **ivopts = '\0'; 2875 (*ivopts)++; 2876 } 2877 /* Parse IV mode */ 2878 *ivmode = strrchr(tmp, '-'); 2879 if (*ivmode) { 2880 **ivmode = '\0'; 2881 (*ivmode)++; 2882 } 2883 /* The rest is crypto API spec */ 2884 cipher_api = tmp; 2885 2886 /* Alloc AEAD, can be used only in new format. */ 2887 if (crypt_integrity_aead(cc)) { 2888 ret = crypt_ctr_auth_cipher(cc, cipher_api); 2889 if (ret < 0) { 2890 ti->error = "Invalid AEAD cipher spec"; 2891 return -ENOMEM; 2892 } 2893 } 2894 2895 if (*ivmode && !strcmp(*ivmode, "lmk")) 2896 cc->tfms_count = 64; 2897 2898 if (*ivmode && !strcmp(*ivmode, "essiv")) { 2899 if (!*ivopts) { 2900 ti->error = "Digest algorithm missing for ESSIV mode"; 2901 return -EINVAL; 2902 } 2903 ret = snprintf(buf, CRYPTO_MAX_ALG_NAME, "essiv(%s,%s)", 2904 cipher_api, *ivopts); 2905 if (ret < 0 || ret >= CRYPTO_MAX_ALG_NAME) { 2906 ti->error = "Cannot allocate cipher string"; 2907 return -ENOMEM; 2908 } 2909 cipher_api = buf; 2910 } 2911 2912 cc->key_parts = cc->tfms_count; 2913 2914 /* Allocate cipher */ 2915 ret = crypt_alloc_tfms(cc, cipher_api); 2916 if (ret < 0) { 2917 ti->error = "Error allocating crypto tfm"; 2918 return ret; 2919 } 2920 2921 if (crypt_integrity_aead(cc)) 2922 cc->iv_size = crypto_aead_ivsize(any_tfm_aead(cc)); 2923 else 2924 cc->iv_size = crypto_skcipher_ivsize(any_tfm(cc)); 2925 2926 return 0; 2927 } 2928 2929 static int crypt_ctr_cipher_old(struct dm_target *ti, char *cipher_in, char *key, 2930 char **ivmode, char **ivopts) 2931 { 2932 struct crypt_config *cc = ti->private; 2933 char *tmp, *cipher, *chainmode, *keycount; 2934 char *cipher_api = NULL; 2935 int ret = -EINVAL; 2936 char dummy; 2937 2938 if (strchr(cipher_in, '(') || crypt_integrity_aead(cc)) { 2939 ti->error = "Bad cipher specification"; 2940 return -EINVAL; 2941 } 2942 2943 /* 2944 * Legacy dm-crypt cipher specification 2945 * cipher[:keycount]-mode-iv:ivopts 2946 */ 2947 tmp = cipher_in; 2948 keycount = strsep(&tmp, "-"); 2949 cipher = strsep(&keycount, ":"); 2950 2951 if (!keycount) 2952 cc->tfms_count = 1; 2953 else if (sscanf(keycount, "%u%c", &cc->tfms_count, &dummy) != 1 || 2954 !is_power_of_2(cc->tfms_count)) { 2955 ti->error = "Bad cipher key count specification"; 2956 return -EINVAL; 2957 } 2958 cc->key_parts = cc->tfms_count; 2959 2960 chainmode = strsep(&tmp, "-"); 2961 *ivmode = strsep(&tmp, ":"); 2962 *ivopts = tmp; 2963 2964 /* 2965 * For compatibility with the original dm-crypt mapping format, if 2966 * only the cipher name is supplied, use cbc-plain. 2967 */ 2968 if (!chainmode || (!strcmp(chainmode, "plain") && !*ivmode)) { 2969 chainmode = "cbc"; 2970 *ivmode = "plain"; 2971 } 2972 2973 if (strcmp(chainmode, "ecb") && !*ivmode) { 2974 ti->error = "IV mechanism required"; 2975 return -EINVAL; 2976 } 2977 2978 cipher_api = kmalloc(CRYPTO_MAX_ALG_NAME, GFP_KERNEL); 2979 if (!cipher_api) 2980 goto bad_mem; 2981 2982 if (*ivmode && !strcmp(*ivmode, "essiv")) { 2983 if (!*ivopts) { 2984 ti->error = "Digest algorithm missing for ESSIV mode"; 2985 kfree(cipher_api); 2986 return -EINVAL; 2987 } 2988 ret = snprintf(cipher_api, CRYPTO_MAX_ALG_NAME, 2989 "essiv(%s(%s),%s)", chainmode, cipher, *ivopts); 2990 } else { 2991 ret = snprintf(cipher_api, CRYPTO_MAX_ALG_NAME, 2992 "%s(%s)", chainmode, cipher); 2993 } 2994 if (ret < 0 || ret >= CRYPTO_MAX_ALG_NAME) { 2995 kfree(cipher_api); 2996 goto bad_mem; 2997 } 2998 2999 /* Allocate cipher */ 3000 ret = crypt_alloc_tfms(cc, cipher_api); 3001 if (ret < 0) { 3002 ti->error = "Error allocating crypto tfm"; 3003 kfree(cipher_api); 3004 return ret; 3005 } 3006 kfree(cipher_api); 3007 3008 return 0; 3009 bad_mem: 3010 ti->error = "Cannot allocate cipher strings"; 3011 return -ENOMEM; 3012 } 3013 3014 static int crypt_ctr_cipher(struct dm_target *ti, char *cipher_in, char *key) 3015 { 3016 struct crypt_config *cc = ti->private; 3017 char *ivmode = NULL, *ivopts = NULL; 3018 int ret; 3019 3020 cc->cipher_string = kstrdup(cipher_in, GFP_KERNEL); 3021 if (!cc->cipher_string) { 3022 ti->error = "Cannot allocate cipher strings"; 3023 return -ENOMEM; 3024 } 3025 3026 if (strstarts(cipher_in, "capi:")) 3027 ret = crypt_ctr_cipher_new(ti, cipher_in, key, &ivmode, &ivopts); 3028 else 3029 ret = crypt_ctr_cipher_old(ti, cipher_in, key, &ivmode, &ivopts); 3030 if (ret) 3031 return ret; 3032 3033 /* Initialize IV */ 3034 ret = crypt_ctr_ivmode(ti, ivmode); 3035 if (ret < 0) 3036 return ret; 3037 3038 /* Initialize and set key */ 3039 ret = crypt_set_key(cc, key); 3040 if (ret < 0) { 3041 ti->error = "Error decoding and setting key"; 3042 return ret; 3043 } 3044 3045 /* Allocate IV */ 3046 if (cc->iv_gen_ops && cc->iv_gen_ops->ctr) { 3047 ret = cc->iv_gen_ops->ctr(cc, ti, ivopts); 3048 if (ret < 0) { 3049 ti->error = "Error creating IV"; 3050 return ret; 3051 } 3052 } 3053 3054 /* Initialize IV (set keys for ESSIV etc) */ 3055 if (cc->iv_gen_ops && cc->iv_gen_ops->init) { 3056 ret = cc->iv_gen_ops->init(cc); 3057 if (ret < 0) { 3058 ti->error = "Error initialising IV"; 3059 return ret; 3060 } 3061 } 3062 3063 /* wipe the kernel key payload copy */ 3064 if (cc->key_string) 3065 memset(cc->key, 0, cc->key_size * sizeof(u8)); 3066 3067 return ret; 3068 } 3069 3070 static int crypt_ctr_optional(struct dm_target *ti, unsigned int argc, char **argv) 3071 { 3072 struct crypt_config *cc = ti->private; 3073 struct dm_arg_set as; 3074 static const struct dm_arg _args[] = { 3075 {0, 8, "Invalid number of feature args"}, 3076 }; 3077 unsigned int opt_params, val; 3078 const char *opt_string, *sval; 3079 char dummy; 3080 int ret; 3081 3082 /* Optional parameters */ 3083 as.argc = argc; 3084 as.argv = argv; 3085 3086 ret = dm_read_arg_group(_args, &as, &opt_params, &ti->error); 3087 if (ret) 3088 return ret; 3089 3090 while (opt_params--) { 3091 opt_string = dm_shift_arg(&as); 3092 if (!opt_string) { 3093 ti->error = "Not enough feature arguments"; 3094 return -EINVAL; 3095 } 3096 3097 if (!strcasecmp(opt_string, "allow_discards")) 3098 ti->num_discard_bios = 1; 3099 3100 else if (!strcasecmp(opt_string, "same_cpu_crypt")) 3101 set_bit(DM_CRYPT_SAME_CPU, &cc->flags); 3102 3103 else if (!strcasecmp(opt_string, "submit_from_crypt_cpus")) 3104 set_bit(DM_CRYPT_NO_OFFLOAD, &cc->flags); 3105 else if (!strcasecmp(opt_string, "no_read_workqueue")) 3106 set_bit(DM_CRYPT_NO_READ_WORKQUEUE, &cc->flags); 3107 else if (!strcasecmp(opt_string, "no_write_workqueue")) 3108 set_bit(DM_CRYPT_NO_WRITE_WORKQUEUE, &cc->flags); 3109 else if (sscanf(opt_string, "integrity:%u:", &val) == 1) { 3110 if (val == 0 || val > MAX_TAG_SIZE) { 3111 ti->error = "Invalid integrity arguments"; 3112 return -EINVAL; 3113 } 3114 cc->on_disk_tag_size = val; 3115 sval = strchr(opt_string + strlen("integrity:"), ':') + 1; 3116 if (!strcasecmp(sval, "aead")) { 3117 set_bit(CRYPT_MODE_INTEGRITY_AEAD, &cc->cipher_flags); 3118 } else if (strcasecmp(sval, "none")) { 3119 ti->error = "Unknown integrity profile"; 3120 return -EINVAL; 3121 } 3122 3123 cc->cipher_auth = kstrdup(sval, GFP_KERNEL); 3124 if (!cc->cipher_auth) 3125 return -ENOMEM; 3126 } else if (sscanf(opt_string, "sector_size:%hu%c", &cc->sector_size, &dummy) == 1) { 3127 if (cc->sector_size < (1 << SECTOR_SHIFT) || 3128 cc->sector_size > 4096 || 3129 (cc->sector_size & (cc->sector_size - 1))) { 3130 ti->error = "Invalid feature value for sector_size"; 3131 return -EINVAL; 3132 } 3133 if (ti->len & ((cc->sector_size >> SECTOR_SHIFT) - 1)) { 3134 ti->error = "Device size is not multiple of sector_size feature"; 3135 return -EINVAL; 3136 } 3137 cc->sector_shift = __ffs(cc->sector_size) - SECTOR_SHIFT; 3138 } else if (!strcasecmp(opt_string, "iv_large_sectors")) 3139 set_bit(CRYPT_IV_LARGE_SECTORS, &cc->cipher_flags); 3140 else { 3141 ti->error = "Invalid feature arguments"; 3142 return -EINVAL; 3143 } 3144 } 3145 3146 return 0; 3147 } 3148 3149 #ifdef CONFIG_BLK_DEV_ZONED 3150 static int crypt_report_zones(struct dm_target *ti, 3151 struct dm_report_zones_args *args, unsigned int nr_zones) 3152 { 3153 struct crypt_config *cc = ti->private; 3154 3155 return dm_report_zones(cc->dev->bdev, cc->start, 3156 cc->start + dm_target_offset(ti, args->next_sector), 3157 args, nr_zones); 3158 } 3159 #else 3160 #define crypt_report_zones NULL 3161 #endif 3162 3163 /* 3164 * Construct an encryption mapping: 3165 * <cipher> [<key>|:<key_size>:<user|logon>:<key_description>] <iv_offset> <dev_path> <start> 3166 */ 3167 static int crypt_ctr(struct dm_target *ti, unsigned int argc, char **argv) 3168 { 3169 struct crypt_config *cc; 3170 const char *devname = dm_table_device_name(ti->table); 3171 int key_size; 3172 unsigned int align_mask; 3173 unsigned long long tmpll; 3174 int ret; 3175 size_t iv_size_padding, additional_req_size; 3176 char dummy; 3177 3178 if (argc < 5) { 3179 ti->error = "Not enough arguments"; 3180 return -EINVAL; 3181 } 3182 3183 key_size = get_key_size(&argv[1]); 3184 if (key_size < 0) { 3185 ti->error = "Cannot parse key size"; 3186 return -EINVAL; 3187 } 3188 3189 cc = kzalloc(struct_size(cc, key, key_size), GFP_KERNEL); 3190 if (!cc) { 3191 ti->error = "Cannot allocate encryption context"; 3192 return -ENOMEM; 3193 } 3194 cc->key_size = key_size; 3195 cc->sector_size = (1 << SECTOR_SHIFT); 3196 cc->sector_shift = 0; 3197 3198 ti->private = cc; 3199 3200 spin_lock(&dm_crypt_clients_lock); 3201 dm_crypt_clients_n++; 3202 crypt_calculate_pages_per_client(); 3203 spin_unlock(&dm_crypt_clients_lock); 3204 3205 ret = percpu_counter_init(&cc->n_allocated_pages, 0, GFP_KERNEL); 3206 if (ret < 0) 3207 goto bad; 3208 3209 /* Optional parameters need to be read before cipher constructor */ 3210 if (argc > 5) { 3211 ret = crypt_ctr_optional(ti, argc - 5, &argv[5]); 3212 if (ret) 3213 goto bad; 3214 } 3215 3216 ret = crypt_ctr_cipher(ti, argv[0], argv[1]); 3217 if (ret < 0) 3218 goto bad; 3219 3220 if (crypt_integrity_aead(cc)) { 3221 cc->dmreq_start = sizeof(struct aead_request); 3222 cc->dmreq_start += crypto_aead_reqsize(any_tfm_aead(cc)); 3223 align_mask = crypto_aead_alignmask(any_tfm_aead(cc)); 3224 } else { 3225 cc->dmreq_start = sizeof(struct skcipher_request); 3226 cc->dmreq_start += crypto_skcipher_reqsize(any_tfm(cc)); 3227 align_mask = crypto_skcipher_alignmask(any_tfm(cc)); 3228 } 3229 cc->dmreq_start = ALIGN(cc->dmreq_start, __alignof__(struct dm_crypt_request)); 3230 3231 if (align_mask < CRYPTO_MINALIGN) { 3232 /* Allocate the padding exactly */ 3233 iv_size_padding = -(cc->dmreq_start + sizeof(struct dm_crypt_request)) 3234 & align_mask; 3235 } else { 3236 /* 3237 * If the cipher requires greater alignment than kmalloc 3238 * alignment, we don't know the exact position of the 3239 * initialization vector. We must assume worst case. 3240 */ 3241 iv_size_padding = align_mask; 3242 } 3243 3244 /* ...| IV + padding | original IV | original sec. number | bio tag offset | */ 3245 additional_req_size = sizeof(struct dm_crypt_request) + 3246 iv_size_padding + cc->iv_size + 3247 cc->iv_size + 3248 sizeof(uint64_t) + 3249 sizeof(unsigned int); 3250 3251 ret = mempool_init_kmalloc_pool(&cc->req_pool, MIN_IOS, cc->dmreq_start + additional_req_size); 3252 if (ret) { 3253 ti->error = "Cannot allocate crypt request mempool"; 3254 goto bad; 3255 } 3256 3257 cc->per_bio_data_size = ti->per_io_data_size = 3258 ALIGN(sizeof(struct dm_crypt_io) + cc->dmreq_start + additional_req_size, 3259 ARCH_DMA_MINALIGN); 3260 3261 ret = mempool_init(&cc->page_pool, BIO_MAX_VECS, crypt_page_alloc, crypt_page_free, cc); 3262 if (ret) { 3263 ti->error = "Cannot allocate page mempool"; 3264 goto bad; 3265 } 3266 3267 ret = bioset_init(&cc->bs, MIN_IOS, 0, BIOSET_NEED_BVECS); 3268 if (ret) { 3269 ti->error = "Cannot allocate crypt bioset"; 3270 goto bad; 3271 } 3272 3273 mutex_init(&cc->bio_alloc_lock); 3274 3275 ret = -EINVAL; 3276 if ((sscanf(argv[2], "%llu%c", &tmpll, &dummy) != 1) || 3277 (tmpll & ((cc->sector_size >> SECTOR_SHIFT) - 1))) { 3278 ti->error = "Invalid iv_offset sector"; 3279 goto bad; 3280 } 3281 cc->iv_offset = tmpll; 3282 3283 ret = dm_get_device(ti, argv[3], dm_table_get_mode(ti->table), &cc->dev); 3284 if (ret) { 3285 ti->error = "Device lookup failed"; 3286 goto bad; 3287 } 3288 3289 ret = -EINVAL; 3290 if (sscanf(argv[4], "%llu%c", &tmpll, &dummy) != 1 || tmpll != (sector_t)tmpll) { 3291 ti->error = "Invalid device sector"; 3292 goto bad; 3293 } 3294 cc->start = tmpll; 3295 3296 if (bdev_is_zoned(cc->dev->bdev)) { 3297 /* 3298 * For zoned block devices, we need to preserve the issuer write 3299 * ordering. To do so, disable write workqueues and force inline 3300 * encryption completion. 3301 */ 3302 set_bit(DM_CRYPT_NO_WRITE_WORKQUEUE, &cc->flags); 3303 set_bit(DM_CRYPT_WRITE_INLINE, &cc->flags); 3304 3305 /* 3306 * All zone append writes to a zone of a zoned block device will 3307 * have the same BIO sector, the start of the zone. When the 3308 * cypher IV mode uses sector values, all data targeting a 3309 * zone will be encrypted using the first sector numbers of the 3310 * zone. This will not result in write errors but will 3311 * cause most reads to fail as reads will use the sector values 3312 * for the actual data locations, resulting in IV mismatch. 3313 * To avoid this problem, ask DM core to emulate zone append 3314 * operations with regular writes. 3315 */ 3316 DMDEBUG("Zone append operations will be emulated"); 3317 ti->emulate_zone_append = true; 3318 } 3319 3320 if (crypt_integrity_aead(cc) || cc->integrity_iv_size) { 3321 ret = crypt_integrity_ctr(cc, ti); 3322 if (ret) 3323 goto bad; 3324 3325 cc->tag_pool_max_sectors = POOL_ENTRY_SIZE / cc->on_disk_tag_size; 3326 if (!cc->tag_pool_max_sectors) 3327 cc->tag_pool_max_sectors = 1; 3328 3329 ret = mempool_init_kmalloc_pool(&cc->tag_pool, MIN_IOS, 3330 cc->tag_pool_max_sectors * cc->on_disk_tag_size); 3331 if (ret) { 3332 ti->error = "Cannot allocate integrity tags mempool"; 3333 goto bad; 3334 } 3335 3336 cc->tag_pool_max_sectors <<= cc->sector_shift; 3337 } 3338 3339 ret = -ENOMEM; 3340 cc->io_queue = alloc_workqueue("kcryptd_io/%s", WQ_MEM_RECLAIM, 1, devname); 3341 if (!cc->io_queue) { 3342 ti->error = "Couldn't create kcryptd io queue"; 3343 goto bad; 3344 } 3345 3346 if (test_bit(DM_CRYPT_SAME_CPU, &cc->flags)) 3347 cc->crypt_queue = alloc_workqueue("kcryptd/%s", WQ_CPU_INTENSIVE | WQ_MEM_RECLAIM, 3348 1, devname); 3349 else 3350 cc->crypt_queue = alloc_workqueue("kcryptd/%s", 3351 WQ_CPU_INTENSIVE | WQ_MEM_RECLAIM | WQ_UNBOUND, 3352 num_online_cpus(), devname); 3353 if (!cc->crypt_queue) { 3354 ti->error = "Couldn't create kcryptd queue"; 3355 goto bad; 3356 } 3357 3358 spin_lock_init(&cc->write_thread_lock); 3359 cc->write_tree = RB_ROOT; 3360 3361 cc->write_thread = kthread_run(dmcrypt_write, cc, "dmcrypt_write/%s", devname); 3362 if (IS_ERR(cc->write_thread)) { 3363 ret = PTR_ERR(cc->write_thread); 3364 cc->write_thread = NULL; 3365 ti->error = "Couldn't spawn write thread"; 3366 goto bad; 3367 } 3368 3369 ti->num_flush_bios = 1; 3370 ti->limit_swap_bios = true; 3371 ti->accounts_remapped_io = true; 3372 3373 dm_audit_log_ctr(DM_MSG_PREFIX, ti, 1); 3374 return 0; 3375 3376 bad: 3377 dm_audit_log_ctr(DM_MSG_PREFIX, ti, 0); 3378 crypt_dtr(ti); 3379 return ret; 3380 } 3381 3382 static int crypt_map(struct dm_target *ti, struct bio *bio) 3383 { 3384 struct dm_crypt_io *io; 3385 struct crypt_config *cc = ti->private; 3386 3387 /* 3388 * If bio is REQ_PREFLUSH or REQ_OP_DISCARD, just bypass crypt queues. 3389 * - for REQ_PREFLUSH device-mapper core ensures that no IO is in-flight 3390 * - for REQ_OP_DISCARD caller must use flush if IO ordering matters 3391 */ 3392 if (unlikely(bio->bi_opf & REQ_PREFLUSH || 3393 bio_op(bio) == REQ_OP_DISCARD)) { 3394 bio_set_dev(bio, cc->dev->bdev); 3395 if (bio_sectors(bio)) 3396 bio->bi_iter.bi_sector = cc->start + 3397 dm_target_offset(ti, bio->bi_iter.bi_sector); 3398 return DM_MAPIO_REMAPPED; 3399 } 3400 3401 /* 3402 * Check if bio is too large, split as needed. 3403 */ 3404 if (unlikely(bio->bi_iter.bi_size > (BIO_MAX_VECS << PAGE_SHIFT)) && 3405 (bio_data_dir(bio) == WRITE || cc->on_disk_tag_size)) 3406 dm_accept_partial_bio(bio, ((BIO_MAX_VECS << PAGE_SHIFT) >> SECTOR_SHIFT)); 3407 3408 /* 3409 * Ensure that bio is a multiple of internal sector encryption size 3410 * and is aligned to this size as defined in IO hints. 3411 */ 3412 if (unlikely((bio->bi_iter.bi_sector & ((cc->sector_size >> SECTOR_SHIFT) - 1)) != 0)) 3413 return DM_MAPIO_KILL; 3414 3415 if (unlikely(bio->bi_iter.bi_size & (cc->sector_size - 1))) 3416 return DM_MAPIO_KILL; 3417 3418 io = dm_per_bio_data(bio, cc->per_bio_data_size); 3419 crypt_io_init(io, cc, bio, dm_target_offset(ti, bio->bi_iter.bi_sector)); 3420 3421 if (cc->on_disk_tag_size) { 3422 unsigned int tag_len = cc->on_disk_tag_size * (bio_sectors(bio) >> cc->sector_shift); 3423 3424 if (unlikely(tag_len > KMALLOC_MAX_SIZE)) 3425 io->integrity_metadata = NULL; 3426 else 3427 io->integrity_metadata = kmalloc(tag_len, GFP_NOIO | __GFP_NORETRY | __GFP_NOMEMALLOC | __GFP_NOWARN); 3428 3429 if (unlikely(!io->integrity_metadata)) { 3430 if (bio_sectors(bio) > cc->tag_pool_max_sectors) 3431 dm_accept_partial_bio(bio, cc->tag_pool_max_sectors); 3432 io->integrity_metadata = mempool_alloc(&cc->tag_pool, GFP_NOIO); 3433 io->integrity_metadata_from_pool = true; 3434 } 3435 } 3436 3437 if (crypt_integrity_aead(cc)) 3438 io->ctx.r.req_aead = (struct aead_request *)(io + 1); 3439 else 3440 io->ctx.r.req = (struct skcipher_request *)(io + 1); 3441 3442 if (bio_data_dir(io->base_bio) == READ) { 3443 if (kcryptd_io_read(io, CRYPT_MAP_READ_GFP)) 3444 kcryptd_queue_read(io); 3445 } else 3446 kcryptd_queue_crypt(io); 3447 3448 return DM_MAPIO_SUBMITTED; 3449 } 3450 3451 static char hex2asc(unsigned char c) 3452 { 3453 return c + '0' + ((unsigned int)(9 - c) >> 4 & 0x27); 3454 } 3455 3456 static void crypt_status(struct dm_target *ti, status_type_t type, 3457 unsigned int status_flags, char *result, unsigned int maxlen) 3458 { 3459 struct crypt_config *cc = ti->private; 3460 unsigned int i, sz = 0; 3461 int num_feature_args = 0; 3462 3463 switch (type) { 3464 case STATUSTYPE_INFO: 3465 result[0] = '\0'; 3466 break; 3467 3468 case STATUSTYPE_TABLE: 3469 DMEMIT("%s ", cc->cipher_string); 3470 3471 if (cc->key_size > 0) { 3472 if (cc->key_string) 3473 DMEMIT(":%u:%s", cc->key_size, cc->key_string); 3474 else { 3475 for (i = 0; i < cc->key_size; i++) { 3476 DMEMIT("%c%c", hex2asc(cc->key[i] >> 4), 3477 hex2asc(cc->key[i] & 0xf)); 3478 } 3479 } 3480 } else 3481 DMEMIT("-"); 3482 3483 DMEMIT(" %llu %s %llu", (unsigned long long)cc->iv_offset, 3484 cc->dev->name, (unsigned long long)cc->start); 3485 3486 num_feature_args += !!ti->num_discard_bios; 3487 num_feature_args += test_bit(DM_CRYPT_SAME_CPU, &cc->flags); 3488 num_feature_args += test_bit(DM_CRYPT_NO_OFFLOAD, &cc->flags); 3489 num_feature_args += test_bit(DM_CRYPT_NO_READ_WORKQUEUE, &cc->flags); 3490 num_feature_args += test_bit(DM_CRYPT_NO_WRITE_WORKQUEUE, &cc->flags); 3491 num_feature_args += cc->sector_size != (1 << SECTOR_SHIFT); 3492 num_feature_args += test_bit(CRYPT_IV_LARGE_SECTORS, &cc->cipher_flags); 3493 if (cc->on_disk_tag_size) 3494 num_feature_args++; 3495 if (num_feature_args) { 3496 DMEMIT(" %d", num_feature_args); 3497 if (ti->num_discard_bios) 3498 DMEMIT(" allow_discards"); 3499 if (test_bit(DM_CRYPT_SAME_CPU, &cc->flags)) 3500 DMEMIT(" same_cpu_crypt"); 3501 if (test_bit(DM_CRYPT_NO_OFFLOAD, &cc->flags)) 3502 DMEMIT(" submit_from_crypt_cpus"); 3503 if (test_bit(DM_CRYPT_NO_READ_WORKQUEUE, &cc->flags)) 3504 DMEMIT(" no_read_workqueue"); 3505 if (test_bit(DM_CRYPT_NO_WRITE_WORKQUEUE, &cc->flags)) 3506 DMEMIT(" no_write_workqueue"); 3507 if (cc->on_disk_tag_size) 3508 DMEMIT(" integrity:%u:%s", cc->on_disk_tag_size, cc->cipher_auth); 3509 if (cc->sector_size != (1 << SECTOR_SHIFT)) 3510 DMEMIT(" sector_size:%d", cc->sector_size); 3511 if (test_bit(CRYPT_IV_LARGE_SECTORS, &cc->cipher_flags)) 3512 DMEMIT(" iv_large_sectors"); 3513 } 3514 break; 3515 3516 case STATUSTYPE_IMA: 3517 DMEMIT_TARGET_NAME_VERSION(ti->type); 3518 DMEMIT(",allow_discards=%c", ti->num_discard_bios ? 'y' : 'n'); 3519 DMEMIT(",same_cpu_crypt=%c", test_bit(DM_CRYPT_SAME_CPU, &cc->flags) ? 'y' : 'n'); 3520 DMEMIT(",submit_from_crypt_cpus=%c", test_bit(DM_CRYPT_NO_OFFLOAD, &cc->flags) ? 3521 'y' : 'n'); 3522 DMEMIT(",no_read_workqueue=%c", test_bit(DM_CRYPT_NO_READ_WORKQUEUE, &cc->flags) ? 3523 'y' : 'n'); 3524 DMEMIT(",no_write_workqueue=%c", test_bit(DM_CRYPT_NO_WRITE_WORKQUEUE, &cc->flags) ? 3525 'y' : 'n'); 3526 DMEMIT(",iv_large_sectors=%c", test_bit(CRYPT_IV_LARGE_SECTORS, &cc->cipher_flags) ? 3527 'y' : 'n'); 3528 3529 if (cc->on_disk_tag_size) 3530 DMEMIT(",integrity_tag_size=%u,cipher_auth=%s", 3531 cc->on_disk_tag_size, cc->cipher_auth); 3532 if (cc->sector_size != (1 << SECTOR_SHIFT)) 3533 DMEMIT(",sector_size=%d", cc->sector_size); 3534 if (cc->cipher_string) 3535 DMEMIT(",cipher_string=%s", cc->cipher_string); 3536 3537 DMEMIT(",key_size=%u", cc->key_size); 3538 DMEMIT(",key_parts=%u", cc->key_parts); 3539 DMEMIT(",key_extra_size=%u", cc->key_extra_size); 3540 DMEMIT(",key_mac_size=%u", cc->key_mac_size); 3541 DMEMIT(";"); 3542 break; 3543 } 3544 } 3545 3546 static void crypt_postsuspend(struct dm_target *ti) 3547 { 3548 struct crypt_config *cc = ti->private; 3549 3550 set_bit(DM_CRYPT_SUSPENDED, &cc->flags); 3551 } 3552 3553 static int crypt_preresume(struct dm_target *ti) 3554 { 3555 struct crypt_config *cc = ti->private; 3556 3557 if (!test_bit(DM_CRYPT_KEY_VALID, &cc->flags)) { 3558 DMERR("aborting resume - crypt key is not set."); 3559 return -EAGAIN; 3560 } 3561 3562 return 0; 3563 } 3564 3565 static void crypt_resume(struct dm_target *ti) 3566 { 3567 struct crypt_config *cc = ti->private; 3568 3569 clear_bit(DM_CRYPT_SUSPENDED, &cc->flags); 3570 } 3571 3572 /* Message interface 3573 * key set <key> 3574 * key wipe 3575 */ 3576 static int crypt_message(struct dm_target *ti, unsigned int argc, char **argv, 3577 char *result, unsigned int maxlen) 3578 { 3579 struct crypt_config *cc = ti->private; 3580 int key_size, ret = -EINVAL; 3581 3582 if (argc < 2) 3583 goto error; 3584 3585 if (!strcasecmp(argv[0], "key")) { 3586 if (!test_bit(DM_CRYPT_SUSPENDED, &cc->flags)) { 3587 DMWARN("not suspended during key manipulation."); 3588 return -EINVAL; 3589 } 3590 if (argc == 3 && !strcasecmp(argv[1], "set")) { 3591 /* The key size may not be changed. */ 3592 key_size = get_key_size(&argv[2]); 3593 if (key_size < 0 || cc->key_size != key_size) { 3594 memset(argv[2], '0', strlen(argv[2])); 3595 return -EINVAL; 3596 } 3597 3598 ret = crypt_set_key(cc, argv[2]); 3599 if (ret) 3600 return ret; 3601 if (cc->iv_gen_ops && cc->iv_gen_ops->init) 3602 ret = cc->iv_gen_ops->init(cc); 3603 /* wipe the kernel key payload copy */ 3604 if (cc->key_string) 3605 memset(cc->key, 0, cc->key_size * sizeof(u8)); 3606 return ret; 3607 } 3608 if (argc == 2 && !strcasecmp(argv[1], "wipe")) 3609 return crypt_wipe_key(cc); 3610 } 3611 3612 error: 3613 DMWARN("unrecognised message received."); 3614 return -EINVAL; 3615 } 3616 3617 static int crypt_iterate_devices(struct dm_target *ti, 3618 iterate_devices_callout_fn fn, void *data) 3619 { 3620 struct crypt_config *cc = ti->private; 3621 3622 return fn(ti, cc->dev, cc->start, ti->len, data); 3623 } 3624 3625 static void crypt_io_hints(struct dm_target *ti, struct queue_limits *limits) 3626 { 3627 struct crypt_config *cc = ti->private; 3628 3629 /* 3630 * Unfortunate constraint that is required to avoid the potential 3631 * for exceeding underlying device's max_segments limits -- due to 3632 * crypt_alloc_buffer() possibly allocating pages for the encryption 3633 * bio that are not as physically contiguous as the original bio. 3634 */ 3635 limits->max_segment_size = PAGE_SIZE; 3636 3637 limits->logical_block_size = 3638 max_t(unsigned int, limits->logical_block_size, cc->sector_size); 3639 limits->physical_block_size = 3640 max_t(unsigned int, limits->physical_block_size, cc->sector_size); 3641 limits->io_min = max_t(unsigned int, limits->io_min, cc->sector_size); 3642 limits->dma_alignment = limits->logical_block_size - 1; 3643 } 3644 3645 static struct target_type crypt_target = { 3646 .name = "crypt", 3647 .version = {1, 24, 0}, 3648 .module = THIS_MODULE, 3649 .ctr = crypt_ctr, 3650 .dtr = crypt_dtr, 3651 .features = DM_TARGET_ZONED_HM, 3652 .report_zones = crypt_report_zones, 3653 .map = crypt_map, 3654 .status = crypt_status, 3655 .postsuspend = crypt_postsuspend, 3656 .preresume = crypt_preresume, 3657 .resume = crypt_resume, 3658 .message = crypt_message, 3659 .iterate_devices = crypt_iterate_devices, 3660 .io_hints = crypt_io_hints, 3661 }; 3662 module_dm(crypt); 3663 3664 MODULE_AUTHOR("Jana Saout <jana@saout.de>"); 3665 MODULE_DESCRIPTION(DM_NAME " target for transparent encryption / decryption"); 3666 MODULE_LICENSE("GPL"); 3667