xref: /openbmc/linux/drivers/md/dm-crypt.c (revision 360823a09426347ea8f232b0b0b5156d0aed0302)
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/skcipher.h>
35 #include <crypto/aead.h>
36 #include <crypto/authenc.h>
37 #include <crypto/utils.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 bvec_iter iter_in;
57 	struct bio *bio_out;
58 	struct bvec_iter iter_out;
59 	atomic_t cc_pending;
60 	unsigned int tag_offset;
61 	u64 cc_sector;
62 	union {
63 		struct skcipher_request *req;
64 		struct aead_request *req_aead;
65 	} r;
66 	bool aead_recheck;
67 	bool aead_failed;
68 
69 };
70 
71 /*
72  * per bio private data
73  */
74 struct dm_crypt_io {
75 	struct crypt_config *cc;
76 	struct bio *base_bio;
77 	u8 *integrity_metadata;
78 	bool integrity_metadata_from_pool:1;
79 
80 	struct work_struct work;
81 
82 	struct convert_context ctx;
83 
84 	atomic_t io_pending;
85 	blk_status_t error;
86 	sector_t sector;
87 
88 	struct bvec_iter saved_bi_iter;
89 
90 	struct rb_node rb_node;
91 } CRYPTO_MINALIGN_ATTR;
92 
93 struct dm_crypt_request {
94 	struct convert_context *ctx;
95 	struct scatterlist sg_in[4];
96 	struct scatterlist sg_out[4];
97 	u64 iv_sector;
98 };
99 
100 struct crypt_config;
101 
102 struct crypt_iv_operations {
103 	int (*ctr)(struct crypt_config *cc, struct dm_target *ti,
104 		   const char *opts);
105 	void (*dtr)(struct crypt_config *cc);
106 	int (*init)(struct crypt_config *cc);
107 	int (*wipe)(struct crypt_config *cc);
108 	int (*generator)(struct crypt_config *cc, u8 *iv,
109 			 struct dm_crypt_request *dmreq);
110 	int (*post)(struct crypt_config *cc, u8 *iv,
111 		    struct dm_crypt_request *dmreq);
112 };
113 
114 struct iv_benbi_private {
115 	int shift;
116 };
117 
118 #define LMK_SEED_SIZE 64 /* hash + 0 */
119 struct iv_lmk_private {
120 	struct crypto_shash *hash_tfm;
121 	u8 *seed;
122 };
123 
124 #define TCW_WHITENING_SIZE 16
125 struct iv_tcw_private {
126 	struct crypto_shash *crc32_tfm;
127 	u8 *iv_seed;
128 	u8 *whitening;
129 };
130 
131 #define ELEPHANT_MAX_KEY_SIZE 32
132 struct iv_elephant_private {
133 	struct crypto_skcipher *tfm;
134 };
135 
136 /*
137  * Crypt: maps a linear range of a block device
138  * and encrypts / decrypts at the same time.
139  */
140 enum flags { DM_CRYPT_SUSPENDED, DM_CRYPT_KEY_VALID,
141 	     DM_CRYPT_SAME_CPU, DM_CRYPT_NO_OFFLOAD,
142 	     DM_CRYPT_NO_READ_WORKQUEUE, DM_CRYPT_NO_WRITE_WORKQUEUE,
143 	     DM_CRYPT_WRITE_INLINE };
144 
145 enum cipher_flags {
146 	CRYPT_MODE_INTEGRITY_AEAD,	/* Use authenticated mode for cipher */
147 	CRYPT_IV_LARGE_SECTORS,		/* Calculate IV from sector_size, not 512B sectors */
148 	CRYPT_ENCRYPT_PREPROCESS,	/* Must preprocess data for encryption (elephant) */
149 };
150 
151 /*
152  * The fields in here must be read only after initialization.
153  */
154 struct crypt_config {
155 	struct dm_dev *dev;
156 	sector_t start;
157 
158 	struct percpu_counter n_allocated_pages;
159 
160 	struct workqueue_struct *io_queue;
161 	struct workqueue_struct *crypt_queue;
162 
163 	spinlock_t write_thread_lock;
164 	struct task_struct *write_thread;
165 	struct rb_root write_tree;
166 
167 	char *cipher_string;
168 	char *cipher_auth;
169 	char *key_string;
170 
171 	const struct crypt_iv_operations *iv_gen_ops;
172 	union {
173 		struct iv_benbi_private benbi;
174 		struct iv_lmk_private lmk;
175 		struct iv_tcw_private tcw;
176 		struct iv_elephant_private elephant;
177 	} iv_gen_private;
178 	u64 iv_offset;
179 	unsigned int iv_size;
180 	unsigned short sector_size;
181 	unsigned char sector_shift;
182 
183 	union {
184 		struct crypto_skcipher **tfms;
185 		struct crypto_aead **tfms_aead;
186 	} cipher_tfm;
187 	unsigned int tfms_count;
188 	unsigned long cipher_flags;
189 
190 	/*
191 	 * Layout of each crypto request:
192 	 *
193 	 *   struct skcipher_request
194 	 *      context
195 	 *      padding
196 	 *   struct dm_crypt_request
197 	 *      padding
198 	 *   IV
199 	 *
200 	 * The padding is added so that dm_crypt_request and the IV are
201 	 * correctly aligned.
202 	 */
203 	unsigned int dmreq_start;
204 
205 	unsigned int per_bio_data_size;
206 
207 	unsigned long flags;
208 	unsigned int key_size;
209 	unsigned int key_parts;      /* independent parts in key buffer */
210 	unsigned int key_extra_size; /* additional keys length */
211 	unsigned int key_mac_size;   /* MAC key size for authenc(...) */
212 
213 	unsigned int integrity_tag_size;
214 	unsigned int integrity_iv_size;
215 	unsigned int on_disk_tag_size;
216 
217 	/*
218 	 * pool for per bio private data, crypto requests,
219 	 * encryption requeusts/buffer pages and integrity tags
220 	 */
221 	unsigned int tag_pool_max_sectors;
222 	mempool_t tag_pool;
223 	mempool_t req_pool;
224 	mempool_t page_pool;
225 
226 	struct bio_set bs;
227 	struct mutex bio_alloc_lock;
228 
229 	u8 *authenc_key; /* space for keys in authenc() format (if used) */
230 	u8 key[];
231 };
232 
233 #define MIN_IOS		64
234 #define MAX_TAG_SIZE	480
235 #define POOL_ENTRY_SIZE	512
236 
237 static DEFINE_SPINLOCK(dm_crypt_clients_lock);
238 static unsigned int dm_crypt_clients_n;
239 static volatile unsigned long dm_crypt_pages_per_client;
240 #define DM_CRYPT_MEMORY_PERCENT			2
241 #define DM_CRYPT_MIN_PAGES_PER_CLIENT		(BIO_MAX_VECS * 16)
242 
243 static void crypt_endio(struct bio *clone);
244 static void kcryptd_queue_crypt(struct dm_crypt_io *io);
245 static struct scatterlist *crypt_get_sg_data(struct crypt_config *cc,
246 					     struct scatterlist *sg);
247 
248 static bool crypt_integrity_aead(struct crypt_config *cc);
249 
250 /*
251  * Use this to access cipher attributes that are independent of the key.
252  */
any_tfm(struct crypt_config * cc)253 static struct crypto_skcipher *any_tfm(struct crypt_config *cc)
254 {
255 	return cc->cipher_tfm.tfms[0];
256 }
257 
any_tfm_aead(struct crypt_config * cc)258 static struct crypto_aead *any_tfm_aead(struct crypt_config *cc)
259 {
260 	return cc->cipher_tfm.tfms_aead[0];
261 }
262 
263 /*
264  * Different IV generation algorithms:
265  *
266  * plain: the initial vector is the 32-bit little-endian version of the sector
267  *        number, padded with zeros if necessary.
268  *
269  * plain64: the initial vector is the 64-bit little-endian version of the sector
270  *        number, padded with zeros if necessary.
271  *
272  * plain64be: the initial vector is the 64-bit big-endian version of the sector
273  *        number, padded with zeros if necessary.
274  *
275  * essiv: "encrypted sector|salt initial vector", the sector number is
276  *        encrypted with the bulk cipher using a salt as key. The salt
277  *        should be derived from the bulk cipher's key via hashing.
278  *
279  * benbi: the 64-bit "big-endian 'narrow block'-count", starting at 1
280  *        (needed for LRW-32-AES and possible other narrow block modes)
281  *
282  * null: the initial vector is always zero.  Provides compatibility with
283  *       obsolete loop_fish2 devices.  Do not use for new devices.
284  *
285  * lmk:  Compatible implementation of the block chaining mode used
286  *       by the Loop-AES block device encryption system
287  *       designed by Jari Ruusu. See http://loop-aes.sourceforge.net/
288  *       It operates on full 512 byte sectors and uses CBC
289  *       with an IV derived from the sector number, the data and
290  *       optionally extra IV seed.
291  *       This means that after decryption the first block
292  *       of sector must be tweaked according to decrypted data.
293  *       Loop-AES can use three encryption schemes:
294  *         version 1: is plain aes-cbc mode
295  *         version 2: uses 64 multikey scheme with lmk IV generator
296  *         version 3: the same as version 2 with additional IV seed
297  *                   (it uses 65 keys, last key is used as IV seed)
298  *
299  * tcw:  Compatible implementation of the block chaining mode used
300  *       by the TrueCrypt device encryption system (prior to version 4.1).
301  *       For more info see: https://gitlab.com/cryptsetup/cryptsetup/wikis/TrueCryptOnDiskFormat
302  *       It operates on full 512 byte sectors and uses CBC
303  *       with an IV derived from initial key and the sector number.
304  *       In addition, whitening value is applied on every sector, whitening
305  *       is calculated from initial key, sector number and mixed using CRC32.
306  *       Note that this encryption scheme is vulnerable to watermarking attacks
307  *       and should be used for old compatible containers access only.
308  *
309  * eboiv: Encrypted byte-offset IV (used in Bitlocker in CBC mode)
310  *        The IV is encrypted little-endian byte-offset (with the same key
311  *        and cipher as the volume).
312  *
313  * elephant: The extended version of eboiv with additional Elephant diffuser
314  *           used with Bitlocker CBC mode.
315  *           This mode was used in older Windows systems
316  *           https://download.microsoft.com/download/0/2/3/0238acaf-d3bf-4a6d-b3d6-0a0be4bbb36e/bitlockercipher200608.pdf
317  */
318 
crypt_iv_plain_gen(struct crypt_config * cc,u8 * iv,struct dm_crypt_request * dmreq)319 static int crypt_iv_plain_gen(struct crypt_config *cc, u8 *iv,
320 			      struct dm_crypt_request *dmreq)
321 {
322 	memset(iv, 0, cc->iv_size);
323 	*(__le32 *)iv = cpu_to_le32(dmreq->iv_sector & 0xffffffff);
324 
325 	return 0;
326 }
327 
crypt_iv_plain64_gen(struct crypt_config * cc,u8 * iv,struct dm_crypt_request * dmreq)328 static int crypt_iv_plain64_gen(struct crypt_config *cc, u8 *iv,
329 				struct dm_crypt_request *dmreq)
330 {
331 	memset(iv, 0, cc->iv_size);
332 	*(__le64 *)iv = cpu_to_le64(dmreq->iv_sector);
333 
334 	return 0;
335 }
336 
crypt_iv_plain64be_gen(struct crypt_config * cc,u8 * iv,struct dm_crypt_request * dmreq)337 static int crypt_iv_plain64be_gen(struct crypt_config *cc, u8 *iv,
338 				  struct dm_crypt_request *dmreq)
339 {
340 	memset(iv, 0, cc->iv_size);
341 	/* iv_size is at least of size u64; usually it is 16 bytes */
342 	*(__be64 *)&iv[cc->iv_size - sizeof(u64)] = cpu_to_be64(dmreq->iv_sector);
343 
344 	return 0;
345 }
346 
crypt_iv_essiv_gen(struct crypt_config * cc,u8 * iv,struct dm_crypt_request * dmreq)347 static int crypt_iv_essiv_gen(struct crypt_config *cc, u8 *iv,
348 			      struct dm_crypt_request *dmreq)
349 {
350 	/*
351 	 * ESSIV encryption of the IV is now handled by the crypto API,
352 	 * so just pass the plain sector number here.
353 	 */
354 	memset(iv, 0, cc->iv_size);
355 	*(__le64 *)iv = cpu_to_le64(dmreq->iv_sector);
356 
357 	return 0;
358 }
359 
crypt_iv_benbi_ctr(struct crypt_config * cc,struct dm_target * ti,const char * opts)360 static int crypt_iv_benbi_ctr(struct crypt_config *cc, struct dm_target *ti,
361 			      const char *opts)
362 {
363 	unsigned int bs;
364 	int log;
365 
366 	if (crypt_integrity_aead(cc))
367 		bs = crypto_aead_blocksize(any_tfm_aead(cc));
368 	else
369 		bs = crypto_skcipher_blocksize(any_tfm(cc));
370 	log = ilog2(bs);
371 
372 	/*
373 	 * We need to calculate how far we must shift the sector count
374 	 * to get the cipher block count, we use this shift in _gen.
375 	 */
376 	if (1 << log != bs) {
377 		ti->error = "cypher blocksize is not a power of 2";
378 		return -EINVAL;
379 	}
380 
381 	if (log > 9) {
382 		ti->error = "cypher blocksize is > 512";
383 		return -EINVAL;
384 	}
385 
386 	cc->iv_gen_private.benbi.shift = 9 - log;
387 
388 	return 0;
389 }
390 
crypt_iv_benbi_dtr(struct crypt_config * cc)391 static void crypt_iv_benbi_dtr(struct crypt_config *cc)
392 {
393 }
394 
crypt_iv_benbi_gen(struct crypt_config * cc,u8 * iv,struct dm_crypt_request * dmreq)395 static int crypt_iv_benbi_gen(struct crypt_config *cc, u8 *iv,
396 			      struct dm_crypt_request *dmreq)
397 {
398 	__be64 val;
399 
400 	memset(iv, 0, cc->iv_size - sizeof(u64)); /* rest is cleared below */
401 
402 	val = cpu_to_be64(((u64)dmreq->iv_sector << cc->iv_gen_private.benbi.shift) + 1);
403 	put_unaligned(val, (__be64 *)(iv + cc->iv_size - sizeof(u64)));
404 
405 	return 0;
406 }
407 
crypt_iv_null_gen(struct crypt_config * cc,u8 * iv,struct dm_crypt_request * dmreq)408 static int crypt_iv_null_gen(struct crypt_config *cc, u8 *iv,
409 			     struct dm_crypt_request *dmreq)
410 {
411 	memset(iv, 0, cc->iv_size);
412 
413 	return 0;
414 }
415 
crypt_iv_lmk_dtr(struct crypt_config * cc)416 static void crypt_iv_lmk_dtr(struct crypt_config *cc)
417 {
418 	struct iv_lmk_private *lmk = &cc->iv_gen_private.lmk;
419 
420 	if (lmk->hash_tfm && !IS_ERR(lmk->hash_tfm))
421 		crypto_free_shash(lmk->hash_tfm);
422 	lmk->hash_tfm = NULL;
423 
424 	kfree_sensitive(lmk->seed);
425 	lmk->seed = NULL;
426 }
427 
crypt_iv_lmk_ctr(struct crypt_config * cc,struct dm_target * ti,const char * opts)428 static int crypt_iv_lmk_ctr(struct crypt_config *cc, struct dm_target *ti,
429 			    const char *opts)
430 {
431 	struct iv_lmk_private *lmk = &cc->iv_gen_private.lmk;
432 
433 	if (cc->sector_size != (1 << SECTOR_SHIFT)) {
434 		ti->error = "Unsupported sector size for LMK";
435 		return -EINVAL;
436 	}
437 
438 	lmk->hash_tfm = crypto_alloc_shash("md5", 0,
439 					   CRYPTO_ALG_ALLOCATES_MEMORY);
440 	if (IS_ERR(lmk->hash_tfm)) {
441 		ti->error = "Error initializing LMK hash";
442 		return PTR_ERR(lmk->hash_tfm);
443 	}
444 
445 	/* No seed in LMK version 2 */
446 	if (cc->key_parts == cc->tfms_count) {
447 		lmk->seed = NULL;
448 		return 0;
449 	}
450 
451 	lmk->seed = kzalloc(LMK_SEED_SIZE, GFP_KERNEL);
452 	if (!lmk->seed) {
453 		crypt_iv_lmk_dtr(cc);
454 		ti->error = "Error kmallocing seed storage in LMK";
455 		return -ENOMEM;
456 	}
457 
458 	return 0;
459 }
460 
crypt_iv_lmk_init(struct crypt_config * cc)461 static int crypt_iv_lmk_init(struct crypt_config *cc)
462 {
463 	struct iv_lmk_private *lmk = &cc->iv_gen_private.lmk;
464 	int subkey_size = cc->key_size / cc->key_parts;
465 
466 	/* LMK seed is on the position of LMK_KEYS + 1 key */
467 	if (lmk->seed)
468 		memcpy(lmk->seed, cc->key + (cc->tfms_count * subkey_size),
469 		       crypto_shash_digestsize(lmk->hash_tfm));
470 
471 	return 0;
472 }
473 
crypt_iv_lmk_wipe(struct crypt_config * cc)474 static int crypt_iv_lmk_wipe(struct crypt_config *cc)
475 {
476 	struct iv_lmk_private *lmk = &cc->iv_gen_private.lmk;
477 
478 	if (lmk->seed)
479 		memset(lmk->seed, 0, LMK_SEED_SIZE);
480 
481 	return 0;
482 }
483 
crypt_iv_lmk_one(struct crypt_config * cc,u8 * iv,struct dm_crypt_request * dmreq,u8 * data)484 static int crypt_iv_lmk_one(struct crypt_config *cc, u8 *iv,
485 			    struct dm_crypt_request *dmreq,
486 			    u8 *data)
487 {
488 	struct iv_lmk_private *lmk = &cc->iv_gen_private.lmk;
489 	SHASH_DESC_ON_STACK(desc, lmk->hash_tfm);
490 	struct md5_state md5state;
491 	__le32 buf[4];
492 	int i, r;
493 
494 	desc->tfm = lmk->hash_tfm;
495 
496 	r = crypto_shash_init(desc);
497 	if (r)
498 		return r;
499 
500 	if (lmk->seed) {
501 		r = crypto_shash_update(desc, lmk->seed, LMK_SEED_SIZE);
502 		if (r)
503 			return r;
504 	}
505 
506 	/* Sector is always 512B, block size 16, add data of blocks 1-31 */
507 	r = crypto_shash_update(desc, data + 16, 16 * 31);
508 	if (r)
509 		return r;
510 
511 	/* Sector is cropped to 56 bits here */
512 	buf[0] = cpu_to_le32(dmreq->iv_sector & 0xFFFFFFFF);
513 	buf[1] = cpu_to_le32((((u64)dmreq->iv_sector >> 32) & 0x00FFFFFF) | 0x80000000);
514 	buf[2] = cpu_to_le32(4024);
515 	buf[3] = 0;
516 	r = crypto_shash_update(desc, (u8 *)buf, sizeof(buf));
517 	if (r)
518 		return r;
519 
520 	/* No MD5 padding here */
521 	r = crypto_shash_export(desc, &md5state);
522 	if (r)
523 		return r;
524 
525 	for (i = 0; i < MD5_HASH_WORDS; i++)
526 		__cpu_to_le32s(&md5state.hash[i]);
527 	memcpy(iv, &md5state.hash, cc->iv_size);
528 
529 	return 0;
530 }
531 
crypt_iv_lmk_gen(struct crypt_config * cc,u8 * iv,struct dm_crypt_request * dmreq)532 static int crypt_iv_lmk_gen(struct crypt_config *cc, u8 *iv,
533 			    struct dm_crypt_request *dmreq)
534 {
535 	struct scatterlist *sg;
536 	u8 *src;
537 	int r = 0;
538 
539 	if (bio_data_dir(dmreq->ctx->bio_in) == WRITE) {
540 		sg = crypt_get_sg_data(cc, dmreq->sg_in);
541 		src = kmap_local_page(sg_page(sg));
542 		r = crypt_iv_lmk_one(cc, iv, dmreq, src + sg->offset);
543 		kunmap_local(src);
544 	} else
545 		memset(iv, 0, cc->iv_size);
546 
547 	return r;
548 }
549 
crypt_iv_lmk_post(struct crypt_config * cc,u8 * iv,struct dm_crypt_request * dmreq)550 static int crypt_iv_lmk_post(struct crypt_config *cc, u8 *iv,
551 			     struct dm_crypt_request *dmreq)
552 {
553 	struct scatterlist *sg;
554 	u8 *dst;
555 	int r;
556 
557 	if (bio_data_dir(dmreq->ctx->bio_in) == WRITE)
558 		return 0;
559 
560 	sg = crypt_get_sg_data(cc, dmreq->sg_out);
561 	dst = kmap_local_page(sg_page(sg));
562 	r = crypt_iv_lmk_one(cc, iv, dmreq, dst + sg->offset);
563 
564 	/* Tweak the first block of plaintext sector */
565 	if (!r)
566 		crypto_xor(dst + sg->offset, iv, cc->iv_size);
567 
568 	kunmap_local(dst);
569 	return r;
570 }
571 
crypt_iv_tcw_dtr(struct crypt_config * cc)572 static void crypt_iv_tcw_dtr(struct crypt_config *cc)
573 {
574 	struct iv_tcw_private *tcw = &cc->iv_gen_private.tcw;
575 
576 	kfree_sensitive(tcw->iv_seed);
577 	tcw->iv_seed = NULL;
578 	kfree_sensitive(tcw->whitening);
579 	tcw->whitening = NULL;
580 
581 	if (tcw->crc32_tfm && !IS_ERR(tcw->crc32_tfm))
582 		crypto_free_shash(tcw->crc32_tfm);
583 	tcw->crc32_tfm = NULL;
584 }
585 
crypt_iv_tcw_ctr(struct crypt_config * cc,struct dm_target * ti,const char * opts)586 static int crypt_iv_tcw_ctr(struct crypt_config *cc, struct dm_target *ti,
587 			    const char *opts)
588 {
589 	struct iv_tcw_private *tcw = &cc->iv_gen_private.tcw;
590 
591 	if (cc->sector_size != (1 << SECTOR_SHIFT)) {
592 		ti->error = "Unsupported sector size for TCW";
593 		return -EINVAL;
594 	}
595 
596 	if (cc->key_size <= (cc->iv_size + TCW_WHITENING_SIZE)) {
597 		ti->error = "Wrong key size for TCW";
598 		return -EINVAL;
599 	}
600 
601 	tcw->crc32_tfm = crypto_alloc_shash("crc32", 0,
602 					    CRYPTO_ALG_ALLOCATES_MEMORY);
603 	if (IS_ERR(tcw->crc32_tfm)) {
604 		ti->error = "Error initializing CRC32 in TCW";
605 		return PTR_ERR(tcw->crc32_tfm);
606 	}
607 
608 	tcw->iv_seed = kzalloc(cc->iv_size, GFP_KERNEL);
609 	tcw->whitening = kzalloc(TCW_WHITENING_SIZE, GFP_KERNEL);
610 	if (!tcw->iv_seed || !tcw->whitening) {
611 		crypt_iv_tcw_dtr(cc);
612 		ti->error = "Error allocating seed storage in TCW";
613 		return -ENOMEM;
614 	}
615 
616 	return 0;
617 }
618 
crypt_iv_tcw_init(struct crypt_config * cc)619 static int crypt_iv_tcw_init(struct crypt_config *cc)
620 {
621 	struct iv_tcw_private *tcw = &cc->iv_gen_private.tcw;
622 	int key_offset = cc->key_size - cc->iv_size - TCW_WHITENING_SIZE;
623 
624 	memcpy(tcw->iv_seed, &cc->key[key_offset], cc->iv_size);
625 	memcpy(tcw->whitening, &cc->key[key_offset + cc->iv_size],
626 	       TCW_WHITENING_SIZE);
627 
628 	return 0;
629 }
630 
crypt_iv_tcw_wipe(struct crypt_config * cc)631 static int crypt_iv_tcw_wipe(struct crypt_config *cc)
632 {
633 	struct iv_tcw_private *tcw = &cc->iv_gen_private.tcw;
634 
635 	memset(tcw->iv_seed, 0, cc->iv_size);
636 	memset(tcw->whitening, 0, TCW_WHITENING_SIZE);
637 
638 	return 0;
639 }
640 
crypt_iv_tcw_whitening(struct crypt_config * cc,struct dm_crypt_request * dmreq,u8 * data)641 static int crypt_iv_tcw_whitening(struct crypt_config *cc,
642 				  struct dm_crypt_request *dmreq,
643 				  u8 *data)
644 {
645 	struct iv_tcw_private *tcw = &cc->iv_gen_private.tcw;
646 	__le64 sector = cpu_to_le64(dmreq->iv_sector);
647 	u8 buf[TCW_WHITENING_SIZE];
648 	SHASH_DESC_ON_STACK(desc, tcw->crc32_tfm);
649 	int i, r;
650 
651 	/* xor whitening with sector number */
652 	crypto_xor_cpy(buf, tcw->whitening, (u8 *)&sector, 8);
653 	crypto_xor_cpy(&buf[8], tcw->whitening + 8, (u8 *)&sector, 8);
654 
655 	/* calculate crc32 for every 32bit part and xor it */
656 	desc->tfm = tcw->crc32_tfm;
657 	for (i = 0; i < 4; i++) {
658 		r = crypto_shash_init(desc);
659 		if (r)
660 			goto out;
661 		r = crypto_shash_update(desc, &buf[i * 4], 4);
662 		if (r)
663 			goto out;
664 		r = crypto_shash_final(desc, &buf[i * 4]);
665 		if (r)
666 			goto out;
667 	}
668 	crypto_xor(&buf[0], &buf[12], 4);
669 	crypto_xor(&buf[4], &buf[8], 4);
670 
671 	/* apply whitening (8 bytes) to whole sector */
672 	for (i = 0; i < ((1 << SECTOR_SHIFT) / 8); i++)
673 		crypto_xor(data + i * 8, buf, 8);
674 out:
675 	memzero_explicit(buf, sizeof(buf));
676 	return r;
677 }
678 
crypt_iv_tcw_gen(struct crypt_config * cc,u8 * iv,struct dm_crypt_request * dmreq)679 static int crypt_iv_tcw_gen(struct crypt_config *cc, u8 *iv,
680 			    struct dm_crypt_request *dmreq)
681 {
682 	struct scatterlist *sg;
683 	struct iv_tcw_private *tcw = &cc->iv_gen_private.tcw;
684 	__le64 sector = cpu_to_le64(dmreq->iv_sector);
685 	u8 *src;
686 	int r = 0;
687 
688 	/* Remove whitening from ciphertext */
689 	if (bio_data_dir(dmreq->ctx->bio_in) != WRITE) {
690 		sg = crypt_get_sg_data(cc, dmreq->sg_in);
691 		src = kmap_local_page(sg_page(sg));
692 		r = crypt_iv_tcw_whitening(cc, dmreq, src + sg->offset);
693 		kunmap_local(src);
694 	}
695 
696 	/* Calculate IV */
697 	crypto_xor_cpy(iv, tcw->iv_seed, (u8 *)&sector, 8);
698 	if (cc->iv_size > 8)
699 		crypto_xor_cpy(&iv[8], tcw->iv_seed + 8, (u8 *)&sector,
700 			       cc->iv_size - 8);
701 
702 	return r;
703 }
704 
crypt_iv_tcw_post(struct crypt_config * cc,u8 * iv,struct dm_crypt_request * dmreq)705 static int crypt_iv_tcw_post(struct crypt_config *cc, u8 *iv,
706 			     struct dm_crypt_request *dmreq)
707 {
708 	struct scatterlist *sg;
709 	u8 *dst;
710 	int r;
711 
712 	if (bio_data_dir(dmreq->ctx->bio_in) != WRITE)
713 		return 0;
714 
715 	/* Apply whitening on ciphertext */
716 	sg = crypt_get_sg_data(cc, dmreq->sg_out);
717 	dst = kmap_local_page(sg_page(sg));
718 	r = crypt_iv_tcw_whitening(cc, dmreq, dst + sg->offset);
719 	kunmap_local(dst);
720 
721 	return r;
722 }
723 
crypt_iv_random_gen(struct crypt_config * cc,u8 * iv,struct dm_crypt_request * dmreq)724 static int crypt_iv_random_gen(struct crypt_config *cc, u8 *iv,
725 				struct dm_crypt_request *dmreq)
726 {
727 	/* Used only for writes, there must be an additional space to store IV */
728 	get_random_bytes(iv, cc->iv_size);
729 	return 0;
730 }
731 
crypt_iv_eboiv_ctr(struct crypt_config * cc,struct dm_target * ti,const char * opts)732 static int crypt_iv_eboiv_ctr(struct crypt_config *cc, struct dm_target *ti,
733 			    const char *opts)
734 {
735 	if (crypt_integrity_aead(cc)) {
736 		ti->error = "AEAD transforms not supported for EBOIV";
737 		return -EINVAL;
738 	}
739 
740 	if (crypto_skcipher_blocksize(any_tfm(cc)) != cc->iv_size) {
741 		ti->error = "Block size of EBOIV cipher does not match IV size of block cipher";
742 		return -EINVAL;
743 	}
744 
745 	return 0;
746 }
747 
crypt_iv_eboiv_gen(struct crypt_config * cc,u8 * iv,struct dm_crypt_request * dmreq)748 static int crypt_iv_eboiv_gen(struct crypt_config *cc, u8 *iv,
749 			    struct dm_crypt_request *dmreq)
750 {
751 	struct crypto_skcipher *tfm = any_tfm(cc);
752 	struct skcipher_request *req;
753 	struct scatterlist src, dst;
754 	DECLARE_CRYPTO_WAIT(wait);
755 	unsigned int reqsize;
756 	int err;
757 	u8 *buf;
758 
759 	reqsize = sizeof(*req) + crypto_skcipher_reqsize(tfm);
760 	reqsize = ALIGN(reqsize, __alignof__(__le64));
761 
762 	req = kmalloc(reqsize + cc->iv_size, GFP_NOIO);
763 	if (!req)
764 		return -ENOMEM;
765 
766 	skcipher_request_set_tfm(req, tfm);
767 
768 	buf = (u8 *)req + reqsize;
769 	memset(buf, 0, cc->iv_size);
770 	*(__le64 *)buf = cpu_to_le64(dmreq->iv_sector * cc->sector_size);
771 
772 	sg_init_one(&src, page_address(ZERO_PAGE(0)), cc->iv_size);
773 	sg_init_one(&dst, iv, cc->iv_size);
774 	skcipher_request_set_crypt(req, &src, &dst, cc->iv_size, buf);
775 	skcipher_request_set_callback(req, 0, crypto_req_done, &wait);
776 	err = crypto_wait_req(crypto_skcipher_encrypt(req), &wait);
777 	kfree_sensitive(req);
778 
779 	return err;
780 }
781 
crypt_iv_elephant_dtr(struct crypt_config * cc)782 static void crypt_iv_elephant_dtr(struct crypt_config *cc)
783 {
784 	struct iv_elephant_private *elephant = &cc->iv_gen_private.elephant;
785 
786 	crypto_free_skcipher(elephant->tfm);
787 	elephant->tfm = NULL;
788 }
789 
crypt_iv_elephant_ctr(struct crypt_config * cc,struct dm_target * ti,const char * opts)790 static int crypt_iv_elephant_ctr(struct crypt_config *cc, struct dm_target *ti,
791 			    const char *opts)
792 {
793 	struct iv_elephant_private *elephant = &cc->iv_gen_private.elephant;
794 	int r;
795 
796 	elephant->tfm = crypto_alloc_skcipher("ecb(aes)", 0,
797 					      CRYPTO_ALG_ALLOCATES_MEMORY);
798 	if (IS_ERR(elephant->tfm)) {
799 		r = PTR_ERR(elephant->tfm);
800 		elephant->tfm = NULL;
801 		return r;
802 	}
803 
804 	r = crypt_iv_eboiv_ctr(cc, ti, NULL);
805 	if (r)
806 		crypt_iv_elephant_dtr(cc);
807 	return r;
808 }
809 
diffuser_disk_to_cpu(u32 * d,size_t n)810 static void diffuser_disk_to_cpu(u32 *d, size_t n)
811 {
812 #ifndef __LITTLE_ENDIAN
813 	int i;
814 
815 	for (i = 0; i < n; i++)
816 		d[i] = le32_to_cpu((__le32)d[i]);
817 #endif
818 }
819 
diffuser_cpu_to_disk(__le32 * d,size_t n)820 static void diffuser_cpu_to_disk(__le32 *d, size_t n)
821 {
822 #ifndef __LITTLE_ENDIAN
823 	int i;
824 
825 	for (i = 0; i < n; i++)
826 		d[i] = cpu_to_le32((u32)d[i]);
827 #endif
828 }
829 
diffuser_a_decrypt(u32 * d,size_t n)830 static void diffuser_a_decrypt(u32 *d, size_t n)
831 {
832 	int i, i1, i2, i3;
833 
834 	for (i = 0; i < 5; i++) {
835 		i1 = 0;
836 		i2 = n - 2;
837 		i3 = n - 5;
838 
839 		while (i1 < (n - 1)) {
840 			d[i1] += d[i2] ^ (d[i3] << 9 | d[i3] >> 23);
841 			i1++; i2++; i3++;
842 
843 			if (i3 >= n)
844 				i3 -= n;
845 
846 			d[i1] += d[i2] ^ d[i3];
847 			i1++; i2++; i3++;
848 
849 			if (i2 >= n)
850 				i2 -= n;
851 
852 			d[i1] += d[i2] ^ (d[i3] << 13 | d[i3] >> 19);
853 			i1++; i2++; i3++;
854 
855 			d[i1] += d[i2] ^ d[i3];
856 			i1++; i2++; i3++;
857 		}
858 	}
859 }
860 
diffuser_a_encrypt(u32 * d,size_t n)861 static void diffuser_a_encrypt(u32 *d, size_t n)
862 {
863 	int i, i1, i2, i3;
864 
865 	for (i = 0; i < 5; i++) {
866 		i1 = n - 1;
867 		i2 = n - 2 - 1;
868 		i3 = n - 5 - 1;
869 
870 		while (i1 > 0) {
871 			d[i1] -= d[i2] ^ d[i3];
872 			i1--; i2--; i3--;
873 
874 			d[i1] -= d[i2] ^ (d[i3] << 13 | d[i3] >> 19);
875 			i1--; i2--; i3--;
876 
877 			if (i2 < 0)
878 				i2 += n;
879 
880 			d[i1] -= d[i2] ^ d[i3];
881 			i1--; i2--; i3--;
882 
883 			if (i3 < 0)
884 				i3 += n;
885 
886 			d[i1] -= d[i2] ^ (d[i3] << 9 | d[i3] >> 23);
887 			i1--; i2--; i3--;
888 		}
889 	}
890 }
891 
diffuser_b_decrypt(u32 * d,size_t n)892 static void diffuser_b_decrypt(u32 *d, size_t n)
893 {
894 	int i, i1, i2, i3;
895 
896 	for (i = 0; i < 3; i++) {
897 		i1 = 0;
898 		i2 = 2;
899 		i3 = 5;
900 
901 		while (i1 < (n - 1)) {
902 			d[i1] += d[i2] ^ d[i3];
903 			i1++; i2++; i3++;
904 
905 			d[i1] += d[i2] ^ (d[i3] << 10 | d[i3] >> 22);
906 			i1++; i2++; i3++;
907 
908 			if (i2 >= n)
909 				i2 -= n;
910 
911 			d[i1] += d[i2] ^ d[i3];
912 			i1++; i2++; i3++;
913 
914 			if (i3 >= n)
915 				i3 -= n;
916 
917 			d[i1] += d[i2] ^ (d[i3] << 25 | d[i3] >> 7);
918 			i1++; i2++; i3++;
919 		}
920 	}
921 }
922 
diffuser_b_encrypt(u32 * d,size_t n)923 static void diffuser_b_encrypt(u32 *d, size_t n)
924 {
925 	int i, i1, i2, i3;
926 
927 	for (i = 0; i < 3; i++) {
928 		i1 = n - 1;
929 		i2 = 2 - 1;
930 		i3 = 5 - 1;
931 
932 		while (i1 > 0) {
933 			d[i1] -= d[i2] ^ (d[i3] << 25 | d[i3] >> 7);
934 			i1--; i2--; i3--;
935 
936 			if (i3 < 0)
937 				i3 += n;
938 
939 			d[i1] -= d[i2] ^ d[i3];
940 			i1--; i2--; i3--;
941 
942 			if (i2 < 0)
943 				i2 += n;
944 
945 			d[i1] -= d[i2] ^ (d[i3] << 10 | d[i3] >> 22);
946 			i1--; i2--; i3--;
947 
948 			d[i1] -= d[i2] ^ d[i3];
949 			i1--; i2--; i3--;
950 		}
951 	}
952 }
953 
crypt_iv_elephant(struct crypt_config * cc,struct dm_crypt_request * dmreq)954 static int crypt_iv_elephant(struct crypt_config *cc, struct dm_crypt_request *dmreq)
955 {
956 	struct iv_elephant_private *elephant = &cc->iv_gen_private.elephant;
957 	u8 *es, *ks, *data, *data2, *data_offset;
958 	struct skcipher_request *req;
959 	struct scatterlist *sg, *sg2, src, dst;
960 	DECLARE_CRYPTO_WAIT(wait);
961 	int i, r;
962 
963 	req = skcipher_request_alloc(elephant->tfm, GFP_NOIO);
964 	es = kzalloc(16, GFP_NOIO); /* Key for AES */
965 	ks = kzalloc(32, GFP_NOIO); /* Elephant sector key */
966 
967 	if (!req || !es || !ks) {
968 		r = -ENOMEM;
969 		goto out;
970 	}
971 
972 	*(__le64 *)es = cpu_to_le64(dmreq->iv_sector * cc->sector_size);
973 
974 	/* E(Ks, e(s)) */
975 	sg_init_one(&src, es, 16);
976 	sg_init_one(&dst, ks, 16);
977 	skcipher_request_set_crypt(req, &src, &dst, 16, NULL);
978 	skcipher_request_set_callback(req, 0, crypto_req_done, &wait);
979 	r = crypto_wait_req(crypto_skcipher_encrypt(req), &wait);
980 	if (r)
981 		goto out;
982 
983 	/* E(Ks, e'(s)) */
984 	es[15] = 0x80;
985 	sg_init_one(&dst, &ks[16], 16);
986 	r = crypto_wait_req(crypto_skcipher_encrypt(req), &wait);
987 	if (r)
988 		goto out;
989 
990 	sg = crypt_get_sg_data(cc, dmreq->sg_out);
991 	data = kmap_local_page(sg_page(sg));
992 	data_offset = data + sg->offset;
993 
994 	/* Cannot modify original bio, copy to sg_out and apply Elephant to it */
995 	if (bio_data_dir(dmreq->ctx->bio_in) == WRITE) {
996 		sg2 = crypt_get_sg_data(cc, dmreq->sg_in);
997 		data2 = kmap_local_page(sg_page(sg2));
998 		memcpy(data_offset, data2 + sg2->offset, cc->sector_size);
999 		kunmap_local(data2);
1000 	}
1001 
1002 	if (bio_data_dir(dmreq->ctx->bio_in) != WRITE) {
1003 		diffuser_disk_to_cpu((u32 *)data_offset, cc->sector_size / sizeof(u32));
1004 		diffuser_b_decrypt((u32 *)data_offset, cc->sector_size / sizeof(u32));
1005 		diffuser_a_decrypt((u32 *)data_offset, cc->sector_size / sizeof(u32));
1006 		diffuser_cpu_to_disk((__le32 *)data_offset, cc->sector_size / sizeof(u32));
1007 	}
1008 
1009 	for (i = 0; i < (cc->sector_size / 32); i++)
1010 		crypto_xor(data_offset + i * 32, ks, 32);
1011 
1012 	if (bio_data_dir(dmreq->ctx->bio_in) == WRITE) {
1013 		diffuser_disk_to_cpu((u32 *)data_offset, cc->sector_size / sizeof(u32));
1014 		diffuser_a_encrypt((u32 *)data_offset, cc->sector_size / sizeof(u32));
1015 		diffuser_b_encrypt((u32 *)data_offset, cc->sector_size / sizeof(u32));
1016 		diffuser_cpu_to_disk((__le32 *)data_offset, cc->sector_size / sizeof(u32));
1017 	}
1018 
1019 	kunmap_local(data);
1020 out:
1021 	kfree_sensitive(ks);
1022 	kfree_sensitive(es);
1023 	skcipher_request_free(req);
1024 	return r;
1025 }
1026 
crypt_iv_elephant_gen(struct crypt_config * cc,u8 * iv,struct dm_crypt_request * dmreq)1027 static int crypt_iv_elephant_gen(struct crypt_config *cc, u8 *iv,
1028 			    struct dm_crypt_request *dmreq)
1029 {
1030 	int r;
1031 
1032 	if (bio_data_dir(dmreq->ctx->bio_in) == WRITE) {
1033 		r = crypt_iv_elephant(cc, dmreq);
1034 		if (r)
1035 			return r;
1036 	}
1037 
1038 	return crypt_iv_eboiv_gen(cc, iv, dmreq);
1039 }
1040 
crypt_iv_elephant_post(struct crypt_config * cc,u8 * iv,struct dm_crypt_request * dmreq)1041 static int crypt_iv_elephant_post(struct crypt_config *cc, u8 *iv,
1042 				  struct dm_crypt_request *dmreq)
1043 {
1044 	if (bio_data_dir(dmreq->ctx->bio_in) != WRITE)
1045 		return crypt_iv_elephant(cc, dmreq);
1046 
1047 	return 0;
1048 }
1049 
crypt_iv_elephant_init(struct crypt_config * cc)1050 static int crypt_iv_elephant_init(struct crypt_config *cc)
1051 {
1052 	struct iv_elephant_private *elephant = &cc->iv_gen_private.elephant;
1053 	int key_offset = cc->key_size - cc->key_extra_size;
1054 
1055 	return crypto_skcipher_setkey(elephant->tfm, &cc->key[key_offset], cc->key_extra_size);
1056 }
1057 
crypt_iv_elephant_wipe(struct crypt_config * cc)1058 static int crypt_iv_elephant_wipe(struct crypt_config *cc)
1059 {
1060 	struct iv_elephant_private *elephant = &cc->iv_gen_private.elephant;
1061 	u8 key[ELEPHANT_MAX_KEY_SIZE];
1062 
1063 	memset(key, 0, cc->key_extra_size);
1064 	return crypto_skcipher_setkey(elephant->tfm, key, cc->key_extra_size);
1065 }
1066 
1067 static const struct crypt_iv_operations crypt_iv_plain_ops = {
1068 	.generator = crypt_iv_plain_gen
1069 };
1070 
1071 static const struct crypt_iv_operations crypt_iv_plain64_ops = {
1072 	.generator = crypt_iv_plain64_gen
1073 };
1074 
1075 static const struct crypt_iv_operations crypt_iv_plain64be_ops = {
1076 	.generator = crypt_iv_plain64be_gen
1077 };
1078 
1079 static const struct crypt_iv_operations crypt_iv_essiv_ops = {
1080 	.generator = crypt_iv_essiv_gen
1081 };
1082 
1083 static const struct crypt_iv_operations crypt_iv_benbi_ops = {
1084 	.ctr	   = crypt_iv_benbi_ctr,
1085 	.dtr	   = crypt_iv_benbi_dtr,
1086 	.generator = crypt_iv_benbi_gen
1087 };
1088 
1089 static const struct crypt_iv_operations crypt_iv_null_ops = {
1090 	.generator = crypt_iv_null_gen
1091 };
1092 
1093 static const struct crypt_iv_operations crypt_iv_lmk_ops = {
1094 	.ctr	   = crypt_iv_lmk_ctr,
1095 	.dtr	   = crypt_iv_lmk_dtr,
1096 	.init	   = crypt_iv_lmk_init,
1097 	.wipe	   = crypt_iv_lmk_wipe,
1098 	.generator = crypt_iv_lmk_gen,
1099 	.post	   = crypt_iv_lmk_post
1100 };
1101 
1102 static const struct crypt_iv_operations crypt_iv_tcw_ops = {
1103 	.ctr	   = crypt_iv_tcw_ctr,
1104 	.dtr	   = crypt_iv_tcw_dtr,
1105 	.init	   = crypt_iv_tcw_init,
1106 	.wipe	   = crypt_iv_tcw_wipe,
1107 	.generator = crypt_iv_tcw_gen,
1108 	.post	   = crypt_iv_tcw_post
1109 };
1110 
1111 static const struct crypt_iv_operations crypt_iv_random_ops = {
1112 	.generator = crypt_iv_random_gen
1113 };
1114 
1115 static const struct crypt_iv_operations crypt_iv_eboiv_ops = {
1116 	.ctr	   = crypt_iv_eboiv_ctr,
1117 	.generator = crypt_iv_eboiv_gen
1118 };
1119 
1120 static const struct crypt_iv_operations crypt_iv_elephant_ops = {
1121 	.ctr	   = crypt_iv_elephant_ctr,
1122 	.dtr	   = crypt_iv_elephant_dtr,
1123 	.init	   = crypt_iv_elephant_init,
1124 	.wipe	   = crypt_iv_elephant_wipe,
1125 	.generator = crypt_iv_elephant_gen,
1126 	.post	   = crypt_iv_elephant_post
1127 };
1128 
1129 /*
1130  * Integrity extensions
1131  */
crypt_integrity_aead(struct crypt_config * cc)1132 static bool crypt_integrity_aead(struct crypt_config *cc)
1133 {
1134 	return test_bit(CRYPT_MODE_INTEGRITY_AEAD, &cc->cipher_flags);
1135 }
1136 
crypt_integrity_hmac(struct crypt_config * cc)1137 static bool crypt_integrity_hmac(struct crypt_config *cc)
1138 {
1139 	return crypt_integrity_aead(cc) && cc->key_mac_size;
1140 }
1141 
1142 /* Get sg containing data */
crypt_get_sg_data(struct crypt_config * cc,struct scatterlist * sg)1143 static struct scatterlist *crypt_get_sg_data(struct crypt_config *cc,
1144 					     struct scatterlist *sg)
1145 {
1146 	if (unlikely(crypt_integrity_aead(cc)))
1147 		return &sg[2];
1148 
1149 	return sg;
1150 }
1151 
dm_crypt_integrity_io_alloc(struct dm_crypt_io * io,struct bio * bio)1152 static int dm_crypt_integrity_io_alloc(struct dm_crypt_io *io, struct bio *bio)
1153 {
1154 	struct bio_integrity_payload *bip;
1155 	unsigned int tag_len;
1156 	int ret;
1157 
1158 	if (!bio_sectors(bio) || !io->cc->on_disk_tag_size)
1159 		return 0;
1160 
1161 	bip = bio_integrity_alloc(bio, GFP_NOIO, 1);
1162 	if (IS_ERR(bip))
1163 		return PTR_ERR(bip);
1164 
1165 	tag_len = io->cc->on_disk_tag_size * (bio_sectors(bio) >> io->cc->sector_shift);
1166 
1167 	bip->bip_iter.bi_sector = io->cc->start + io->sector;
1168 
1169 	ret = bio_integrity_add_page(bio, virt_to_page(io->integrity_metadata),
1170 				     tag_len, offset_in_page(io->integrity_metadata));
1171 	if (unlikely(ret != tag_len))
1172 		return -ENOMEM;
1173 
1174 	return 0;
1175 }
1176 
crypt_integrity_ctr(struct crypt_config * cc,struct dm_target * ti)1177 static int crypt_integrity_ctr(struct crypt_config *cc, struct dm_target *ti)
1178 {
1179 #ifdef CONFIG_BLK_DEV_INTEGRITY
1180 	struct blk_integrity *bi = blk_get_integrity(cc->dev->bdev->bd_disk);
1181 	struct mapped_device *md = dm_table_get_md(ti->table);
1182 
1183 	/* From now we require underlying device with our integrity profile */
1184 	if (!bi || strcasecmp(bi->profile->name, "DM-DIF-EXT-TAG")) {
1185 		ti->error = "Integrity profile not supported.";
1186 		return -EINVAL;
1187 	}
1188 
1189 	if (bi->tag_size != cc->on_disk_tag_size ||
1190 	    bi->tuple_size != cc->on_disk_tag_size) {
1191 		ti->error = "Integrity profile tag size mismatch.";
1192 		return -EINVAL;
1193 	}
1194 	if (1 << bi->interval_exp != cc->sector_size) {
1195 		ti->error = "Integrity profile sector size mismatch.";
1196 		return -EINVAL;
1197 	}
1198 
1199 	if (crypt_integrity_aead(cc)) {
1200 		cc->integrity_tag_size = cc->on_disk_tag_size - cc->integrity_iv_size;
1201 		DMDEBUG("%s: Integrity AEAD, tag size %u, IV size %u.", dm_device_name(md),
1202 		       cc->integrity_tag_size, cc->integrity_iv_size);
1203 
1204 		if (crypto_aead_setauthsize(any_tfm_aead(cc), cc->integrity_tag_size)) {
1205 			ti->error = "Integrity AEAD auth tag size is not supported.";
1206 			return -EINVAL;
1207 		}
1208 	} else if (cc->integrity_iv_size)
1209 		DMDEBUG("%s: Additional per-sector space %u bytes for IV.", dm_device_name(md),
1210 		       cc->integrity_iv_size);
1211 
1212 	if ((cc->integrity_tag_size + cc->integrity_iv_size) != bi->tag_size) {
1213 		ti->error = "Not enough space for integrity tag in the profile.";
1214 		return -EINVAL;
1215 	}
1216 
1217 	return 0;
1218 #else
1219 	ti->error = "Integrity profile not supported.";
1220 	return -EINVAL;
1221 #endif
1222 }
1223 
crypt_convert_init(struct crypt_config * cc,struct convert_context * ctx,struct bio * bio_out,struct bio * bio_in,sector_t sector)1224 static void crypt_convert_init(struct crypt_config *cc,
1225 			       struct convert_context *ctx,
1226 			       struct bio *bio_out, struct bio *bio_in,
1227 			       sector_t sector)
1228 {
1229 	ctx->bio_in = bio_in;
1230 	ctx->bio_out = bio_out;
1231 	if (bio_in)
1232 		ctx->iter_in = bio_in->bi_iter;
1233 	if (bio_out)
1234 		ctx->iter_out = bio_out->bi_iter;
1235 	ctx->cc_sector = sector + cc->iv_offset;
1236 	ctx->tag_offset = 0;
1237 	init_completion(&ctx->restart);
1238 }
1239 
dmreq_of_req(struct crypt_config * cc,void * req)1240 static struct dm_crypt_request *dmreq_of_req(struct crypt_config *cc,
1241 					     void *req)
1242 {
1243 	return (struct dm_crypt_request *)((char *)req + cc->dmreq_start);
1244 }
1245 
req_of_dmreq(struct crypt_config * cc,struct dm_crypt_request * dmreq)1246 static void *req_of_dmreq(struct crypt_config *cc, struct dm_crypt_request *dmreq)
1247 {
1248 	return (void *)((char *)dmreq - cc->dmreq_start);
1249 }
1250 
iv_of_dmreq(struct crypt_config * cc,struct dm_crypt_request * dmreq)1251 static u8 *iv_of_dmreq(struct crypt_config *cc,
1252 		       struct dm_crypt_request *dmreq)
1253 {
1254 	if (crypt_integrity_aead(cc))
1255 		return (u8 *)ALIGN((unsigned long)(dmreq + 1),
1256 			crypto_aead_alignmask(any_tfm_aead(cc)) + 1);
1257 	else
1258 		return (u8 *)ALIGN((unsigned long)(dmreq + 1),
1259 			crypto_skcipher_alignmask(any_tfm(cc)) + 1);
1260 }
1261 
org_iv_of_dmreq(struct crypt_config * cc,struct dm_crypt_request * dmreq)1262 static u8 *org_iv_of_dmreq(struct crypt_config *cc,
1263 		       struct dm_crypt_request *dmreq)
1264 {
1265 	return iv_of_dmreq(cc, dmreq) + cc->iv_size;
1266 }
1267 
org_sector_of_dmreq(struct crypt_config * cc,struct dm_crypt_request * dmreq)1268 static __le64 *org_sector_of_dmreq(struct crypt_config *cc,
1269 		       struct dm_crypt_request *dmreq)
1270 {
1271 	u8 *ptr = iv_of_dmreq(cc, dmreq) + cc->iv_size + cc->iv_size;
1272 
1273 	return (__le64 *) ptr;
1274 }
1275 
org_tag_of_dmreq(struct crypt_config * cc,struct dm_crypt_request * dmreq)1276 static unsigned int *org_tag_of_dmreq(struct crypt_config *cc,
1277 		       struct dm_crypt_request *dmreq)
1278 {
1279 	u8 *ptr = iv_of_dmreq(cc, dmreq) + cc->iv_size +
1280 		  cc->iv_size + sizeof(uint64_t);
1281 
1282 	return (unsigned int *)ptr;
1283 }
1284 
tag_from_dmreq(struct crypt_config * cc,struct dm_crypt_request * dmreq)1285 static void *tag_from_dmreq(struct crypt_config *cc,
1286 				struct dm_crypt_request *dmreq)
1287 {
1288 	struct convert_context *ctx = dmreq->ctx;
1289 	struct dm_crypt_io *io = container_of(ctx, struct dm_crypt_io, ctx);
1290 
1291 	return &io->integrity_metadata[*org_tag_of_dmreq(cc, dmreq) *
1292 		cc->on_disk_tag_size];
1293 }
1294 
iv_tag_from_dmreq(struct crypt_config * cc,struct dm_crypt_request * dmreq)1295 static void *iv_tag_from_dmreq(struct crypt_config *cc,
1296 			       struct dm_crypt_request *dmreq)
1297 {
1298 	return tag_from_dmreq(cc, dmreq) + cc->integrity_tag_size;
1299 }
1300 
crypt_convert_block_aead(struct crypt_config * cc,struct convert_context * ctx,struct aead_request * req,unsigned int tag_offset)1301 static int crypt_convert_block_aead(struct crypt_config *cc,
1302 				     struct convert_context *ctx,
1303 				     struct aead_request *req,
1304 				     unsigned int tag_offset)
1305 {
1306 	struct bio_vec bv_in = bio_iter_iovec(ctx->bio_in, ctx->iter_in);
1307 	struct bio_vec bv_out = bio_iter_iovec(ctx->bio_out, ctx->iter_out);
1308 	struct dm_crypt_request *dmreq;
1309 	u8 *iv, *org_iv, *tag_iv, *tag;
1310 	__le64 *sector;
1311 	int r = 0;
1312 
1313 	BUG_ON(cc->integrity_iv_size && cc->integrity_iv_size != cc->iv_size);
1314 
1315 	/* Reject unexpected unaligned bio. */
1316 	if (unlikely(bv_in.bv_len & (cc->sector_size - 1)))
1317 		return -EIO;
1318 
1319 	dmreq = dmreq_of_req(cc, req);
1320 	dmreq->iv_sector = ctx->cc_sector;
1321 	if (test_bit(CRYPT_IV_LARGE_SECTORS, &cc->cipher_flags))
1322 		dmreq->iv_sector >>= cc->sector_shift;
1323 	dmreq->ctx = ctx;
1324 
1325 	*org_tag_of_dmreq(cc, dmreq) = tag_offset;
1326 
1327 	sector = org_sector_of_dmreq(cc, dmreq);
1328 	*sector = cpu_to_le64(ctx->cc_sector - cc->iv_offset);
1329 
1330 	iv = iv_of_dmreq(cc, dmreq);
1331 	org_iv = org_iv_of_dmreq(cc, dmreq);
1332 	tag = tag_from_dmreq(cc, dmreq);
1333 	tag_iv = iv_tag_from_dmreq(cc, dmreq);
1334 
1335 	/* AEAD request:
1336 	 *  |----- AAD -------|------ DATA -------|-- AUTH TAG --|
1337 	 *  | (authenticated) | (auth+encryption) |              |
1338 	 *  | sector_LE |  IV |  sector in/out    |  tag in/out  |
1339 	 */
1340 	sg_init_table(dmreq->sg_in, 4);
1341 	sg_set_buf(&dmreq->sg_in[0], sector, sizeof(uint64_t));
1342 	sg_set_buf(&dmreq->sg_in[1], org_iv, cc->iv_size);
1343 	sg_set_page(&dmreq->sg_in[2], bv_in.bv_page, cc->sector_size, bv_in.bv_offset);
1344 	sg_set_buf(&dmreq->sg_in[3], tag, cc->integrity_tag_size);
1345 
1346 	sg_init_table(dmreq->sg_out, 4);
1347 	sg_set_buf(&dmreq->sg_out[0], sector, sizeof(uint64_t));
1348 	sg_set_buf(&dmreq->sg_out[1], org_iv, cc->iv_size);
1349 	sg_set_page(&dmreq->sg_out[2], bv_out.bv_page, cc->sector_size, bv_out.bv_offset);
1350 	sg_set_buf(&dmreq->sg_out[3], tag, cc->integrity_tag_size);
1351 
1352 	if (cc->iv_gen_ops) {
1353 		/* For READs use IV stored in integrity metadata */
1354 		if (cc->integrity_iv_size && bio_data_dir(ctx->bio_in) != WRITE) {
1355 			memcpy(org_iv, tag_iv, cc->iv_size);
1356 		} else {
1357 			r = cc->iv_gen_ops->generator(cc, org_iv, dmreq);
1358 			if (r < 0)
1359 				return r;
1360 			/* Store generated IV in integrity metadata */
1361 			if (cc->integrity_iv_size)
1362 				memcpy(tag_iv, org_iv, cc->iv_size);
1363 		}
1364 		/* Working copy of IV, to be modified in crypto API */
1365 		memcpy(iv, org_iv, cc->iv_size);
1366 	}
1367 
1368 	aead_request_set_ad(req, sizeof(uint64_t) + cc->iv_size);
1369 	if (bio_data_dir(ctx->bio_in) == WRITE) {
1370 		aead_request_set_crypt(req, dmreq->sg_in, dmreq->sg_out,
1371 				       cc->sector_size, iv);
1372 		r = crypto_aead_encrypt(req);
1373 		if (cc->integrity_tag_size + cc->integrity_iv_size != cc->on_disk_tag_size)
1374 			memset(tag + cc->integrity_tag_size + cc->integrity_iv_size, 0,
1375 			       cc->on_disk_tag_size - (cc->integrity_tag_size + cc->integrity_iv_size));
1376 	} else {
1377 		aead_request_set_crypt(req, dmreq->sg_in, dmreq->sg_out,
1378 				       cc->sector_size + cc->integrity_tag_size, iv);
1379 		r = crypto_aead_decrypt(req);
1380 	}
1381 
1382 	if (r == -EBADMSG) {
1383 		sector_t s = le64_to_cpu(*sector);
1384 
1385 		ctx->aead_failed = true;
1386 		if (ctx->aead_recheck) {
1387 			DMERR_LIMIT("%pg: INTEGRITY AEAD ERROR, sector %llu",
1388 				    ctx->bio_in->bi_bdev, s);
1389 			dm_audit_log_bio(DM_MSG_PREFIX, "integrity-aead",
1390 					 ctx->bio_in, s, 0);
1391 		}
1392 	}
1393 
1394 	if (!r && cc->iv_gen_ops && cc->iv_gen_ops->post)
1395 		r = cc->iv_gen_ops->post(cc, org_iv, dmreq);
1396 
1397 	bio_advance_iter(ctx->bio_in, &ctx->iter_in, cc->sector_size);
1398 	bio_advance_iter(ctx->bio_out, &ctx->iter_out, cc->sector_size);
1399 
1400 	return r;
1401 }
1402 
crypt_convert_block_skcipher(struct crypt_config * cc,struct convert_context * ctx,struct skcipher_request * req,unsigned int tag_offset)1403 static int crypt_convert_block_skcipher(struct crypt_config *cc,
1404 					struct convert_context *ctx,
1405 					struct skcipher_request *req,
1406 					unsigned int tag_offset)
1407 {
1408 	struct bio_vec bv_in = bio_iter_iovec(ctx->bio_in, ctx->iter_in);
1409 	struct bio_vec bv_out = bio_iter_iovec(ctx->bio_out, ctx->iter_out);
1410 	struct scatterlist *sg_in, *sg_out;
1411 	struct dm_crypt_request *dmreq;
1412 	u8 *iv, *org_iv, *tag_iv;
1413 	__le64 *sector;
1414 	int r = 0;
1415 
1416 	/* Reject unexpected unaligned bio. */
1417 	if (unlikely(bv_in.bv_len & (cc->sector_size - 1)))
1418 		return -EIO;
1419 
1420 	dmreq = dmreq_of_req(cc, req);
1421 	dmreq->iv_sector = ctx->cc_sector;
1422 	if (test_bit(CRYPT_IV_LARGE_SECTORS, &cc->cipher_flags))
1423 		dmreq->iv_sector >>= cc->sector_shift;
1424 	dmreq->ctx = ctx;
1425 
1426 	*org_tag_of_dmreq(cc, dmreq) = tag_offset;
1427 
1428 	iv = iv_of_dmreq(cc, dmreq);
1429 	org_iv = org_iv_of_dmreq(cc, dmreq);
1430 	tag_iv = iv_tag_from_dmreq(cc, dmreq);
1431 
1432 	sector = org_sector_of_dmreq(cc, dmreq);
1433 	*sector = cpu_to_le64(ctx->cc_sector - cc->iv_offset);
1434 
1435 	/* For skcipher we use only the first sg item */
1436 	sg_in  = &dmreq->sg_in[0];
1437 	sg_out = &dmreq->sg_out[0];
1438 
1439 	sg_init_table(sg_in, 1);
1440 	sg_set_page(sg_in, bv_in.bv_page, cc->sector_size, bv_in.bv_offset);
1441 
1442 	sg_init_table(sg_out, 1);
1443 	sg_set_page(sg_out, bv_out.bv_page, cc->sector_size, bv_out.bv_offset);
1444 
1445 	if (cc->iv_gen_ops) {
1446 		/* For READs use IV stored in integrity metadata */
1447 		if (cc->integrity_iv_size && bio_data_dir(ctx->bio_in) != WRITE) {
1448 			memcpy(org_iv, tag_iv, cc->integrity_iv_size);
1449 		} else {
1450 			r = cc->iv_gen_ops->generator(cc, org_iv, dmreq);
1451 			if (r < 0)
1452 				return r;
1453 			/* Data can be already preprocessed in generator */
1454 			if (test_bit(CRYPT_ENCRYPT_PREPROCESS, &cc->cipher_flags))
1455 				sg_in = sg_out;
1456 			/* Store generated IV in integrity metadata */
1457 			if (cc->integrity_iv_size)
1458 				memcpy(tag_iv, org_iv, cc->integrity_iv_size);
1459 		}
1460 		/* Working copy of IV, to be modified in crypto API */
1461 		memcpy(iv, org_iv, cc->iv_size);
1462 	}
1463 
1464 	skcipher_request_set_crypt(req, sg_in, sg_out, cc->sector_size, iv);
1465 
1466 	if (bio_data_dir(ctx->bio_in) == WRITE)
1467 		r = crypto_skcipher_encrypt(req);
1468 	else
1469 		r = crypto_skcipher_decrypt(req);
1470 
1471 	if (!r && cc->iv_gen_ops && cc->iv_gen_ops->post)
1472 		r = cc->iv_gen_ops->post(cc, org_iv, dmreq);
1473 
1474 	bio_advance_iter(ctx->bio_in, &ctx->iter_in, cc->sector_size);
1475 	bio_advance_iter(ctx->bio_out, &ctx->iter_out, cc->sector_size);
1476 
1477 	return r;
1478 }
1479 
1480 static void kcryptd_async_done(void *async_req, int error);
1481 
crypt_alloc_req_skcipher(struct crypt_config * cc,struct convert_context * ctx)1482 static int crypt_alloc_req_skcipher(struct crypt_config *cc,
1483 				     struct convert_context *ctx)
1484 {
1485 	unsigned int key_index = ctx->cc_sector & (cc->tfms_count - 1);
1486 
1487 	if (!ctx->r.req) {
1488 		ctx->r.req = mempool_alloc(&cc->req_pool, in_interrupt() ? GFP_ATOMIC : GFP_NOIO);
1489 		if (!ctx->r.req)
1490 			return -ENOMEM;
1491 	}
1492 
1493 	skcipher_request_set_tfm(ctx->r.req, cc->cipher_tfm.tfms[key_index]);
1494 
1495 	/*
1496 	 * Use REQ_MAY_BACKLOG so a cipher driver internally backlogs
1497 	 * requests if driver request queue is full.
1498 	 */
1499 	skcipher_request_set_callback(ctx->r.req,
1500 	    CRYPTO_TFM_REQ_MAY_BACKLOG,
1501 	    kcryptd_async_done, dmreq_of_req(cc, ctx->r.req));
1502 
1503 	return 0;
1504 }
1505 
crypt_alloc_req_aead(struct crypt_config * cc,struct convert_context * ctx)1506 static int crypt_alloc_req_aead(struct crypt_config *cc,
1507 				 struct convert_context *ctx)
1508 {
1509 	if (!ctx->r.req_aead) {
1510 		ctx->r.req_aead = mempool_alloc(&cc->req_pool, in_interrupt() ? GFP_ATOMIC : GFP_NOIO);
1511 		if (!ctx->r.req_aead)
1512 			return -ENOMEM;
1513 	}
1514 
1515 	aead_request_set_tfm(ctx->r.req_aead, cc->cipher_tfm.tfms_aead[0]);
1516 
1517 	/*
1518 	 * Use REQ_MAY_BACKLOG so a cipher driver internally backlogs
1519 	 * requests if driver request queue is full.
1520 	 */
1521 	aead_request_set_callback(ctx->r.req_aead,
1522 	    CRYPTO_TFM_REQ_MAY_BACKLOG,
1523 	    kcryptd_async_done, dmreq_of_req(cc, ctx->r.req_aead));
1524 
1525 	return 0;
1526 }
1527 
crypt_alloc_req(struct crypt_config * cc,struct convert_context * ctx)1528 static int crypt_alloc_req(struct crypt_config *cc,
1529 			    struct convert_context *ctx)
1530 {
1531 	if (crypt_integrity_aead(cc))
1532 		return crypt_alloc_req_aead(cc, ctx);
1533 	else
1534 		return crypt_alloc_req_skcipher(cc, ctx);
1535 }
1536 
crypt_free_req_skcipher(struct crypt_config * cc,struct skcipher_request * req,struct bio * base_bio)1537 static void crypt_free_req_skcipher(struct crypt_config *cc,
1538 				    struct skcipher_request *req, struct bio *base_bio)
1539 {
1540 	struct dm_crypt_io *io = dm_per_bio_data(base_bio, cc->per_bio_data_size);
1541 
1542 	if ((struct skcipher_request *)(io + 1) != req)
1543 		mempool_free(req, &cc->req_pool);
1544 }
1545 
crypt_free_req_aead(struct crypt_config * cc,struct aead_request * req,struct bio * base_bio)1546 static void crypt_free_req_aead(struct crypt_config *cc,
1547 				struct aead_request *req, struct bio *base_bio)
1548 {
1549 	struct dm_crypt_io *io = dm_per_bio_data(base_bio, cc->per_bio_data_size);
1550 
1551 	if ((struct aead_request *)(io + 1) != req)
1552 		mempool_free(req, &cc->req_pool);
1553 }
1554 
crypt_free_req(struct crypt_config * cc,void * req,struct bio * base_bio)1555 static void crypt_free_req(struct crypt_config *cc, void *req, struct bio *base_bio)
1556 {
1557 	if (crypt_integrity_aead(cc))
1558 		crypt_free_req_aead(cc, req, base_bio);
1559 	else
1560 		crypt_free_req_skcipher(cc, req, base_bio);
1561 }
1562 
1563 /*
1564  * Encrypt / decrypt data from one bio to another one (can be the same one)
1565  */
crypt_convert(struct crypt_config * cc,struct convert_context * ctx,bool atomic,bool reset_pending)1566 static blk_status_t crypt_convert(struct crypt_config *cc,
1567 			 struct convert_context *ctx, bool atomic, bool reset_pending)
1568 {
1569 	unsigned int sector_step = cc->sector_size >> SECTOR_SHIFT;
1570 	int r;
1571 
1572 	/*
1573 	 * if reset_pending is set we are dealing with the bio for the first time,
1574 	 * else we're continuing to work on the previous bio, so don't mess with
1575 	 * the cc_pending counter
1576 	 */
1577 	if (reset_pending)
1578 		atomic_set(&ctx->cc_pending, 1);
1579 
1580 	while (ctx->iter_in.bi_size && ctx->iter_out.bi_size) {
1581 
1582 		r = crypt_alloc_req(cc, ctx);
1583 		if (r) {
1584 			complete(&ctx->restart);
1585 			return BLK_STS_DEV_RESOURCE;
1586 		}
1587 
1588 		atomic_inc(&ctx->cc_pending);
1589 
1590 		if (crypt_integrity_aead(cc))
1591 			r = crypt_convert_block_aead(cc, ctx, ctx->r.req_aead, ctx->tag_offset);
1592 		else
1593 			r = crypt_convert_block_skcipher(cc, ctx, ctx->r.req, ctx->tag_offset);
1594 
1595 		switch (r) {
1596 		/*
1597 		 * The request was queued by a crypto driver
1598 		 * but the driver request queue is full, let's wait.
1599 		 */
1600 		case -EBUSY:
1601 			if (in_interrupt()) {
1602 				if (try_wait_for_completion(&ctx->restart)) {
1603 					/*
1604 					 * we don't have to block to wait for completion,
1605 					 * so proceed
1606 					 */
1607 				} else {
1608 					/*
1609 					 * we can't wait for completion without blocking
1610 					 * exit and continue processing in a workqueue
1611 					 */
1612 					ctx->r.req = NULL;
1613 					ctx->tag_offset++;
1614 					ctx->cc_sector += sector_step;
1615 					return BLK_STS_DEV_RESOURCE;
1616 				}
1617 			} else {
1618 				wait_for_completion(&ctx->restart);
1619 			}
1620 			reinit_completion(&ctx->restart);
1621 			fallthrough;
1622 		/*
1623 		 * The request is queued and processed asynchronously,
1624 		 * completion function kcryptd_async_done() will be called.
1625 		 */
1626 		case -EINPROGRESS:
1627 			ctx->r.req = NULL;
1628 			ctx->tag_offset++;
1629 			ctx->cc_sector += sector_step;
1630 			continue;
1631 		/*
1632 		 * The request was already processed (synchronously).
1633 		 */
1634 		case 0:
1635 			atomic_dec(&ctx->cc_pending);
1636 			ctx->cc_sector += sector_step;
1637 			ctx->tag_offset++;
1638 			if (!atomic)
1639 				cond_resched();
1640 			continue;
1641 		/*
1642 		 * There was a data integrity error.
1643 		 */
1644 		case -EBADMSG:
1645 			atomic_dec(&ctx->cc_pending);
1646 			return BLK_STS_PROTECTION;
1647 		/*
1648 		 * There was an error while processing the request.
1649 		 */
1650 		default:
1651 			atomic_dec(&ctx->cc_pending);
1652 			return BLK_STS_IOERR;
1653 		}
1654 	}
1655 
1656 	return 0;
1657 }
1658 
1659 static void crypt_free_buffer_pages(struct crypt_config *cc, struct bio *clone);
1660 
1661 /*
1662  * Generate a new unfragmented bio with the given size
1663  * This should never violate the device limitations (but only because
1664  * max_segment_size is being constrained to PAGE_SIZE).
1665  *
1666  * This function may be called concurrently. If we allocate from the mempool
1667  * concurrently, there is a possibility of deadlock. For example, if we have
1668  * mempool of 256 pages, two processes, each wanting 256, pages allocate from
1669  * the mempool concurrently, it may deadlock in a situation where both processes
1670  * have allocated 128 pages and the mempool is exhausted.
1671  *
1672  * In order to avoid this scenario we allocate the pages under a mutex.
1673  *
1674  * In order to not degrade performance with excessive locking, we try
1675  * non-blocking allocations without a mutex first but on failure we fallback
1676  * to blocking allocations with a mutex.
1677  *
1678  * In order to reduce allocation overhead, we try to allocate compound pages in
1679  * the first pass. If they are not available, we fall back to the mempool.
1680  */
crypt_alloc_buffer(struct dm_crypt_io * io,unsigned int size)1681 static struct bio *crypt_alloc_buffer(struct dm_crypt_io *io, unsigned int size)
1682 {
1683 	struct crypt_config *cc = io->cc;
1684 	struct bio *clone;
1685 	unsigned int nr_iovecs = (size + PAGE_SIZE - 1) >> PAGE_SHIFT;
1686 	gfp_t gfp_mask = GFP_NOWAIT | __GFP_HIGHMEM;
1687 	unsigned int remaining_size;
1688 	unsigned int order = MAX_ORDER;
1689 
1690 retry:
1691 	if (unlikely(gfp_mask & __GFP_DIRECT_RECLAIM))
1692 		mutex_lock(&cc->bio_alloc_lock);
1693 
1694 	clone = bio_alloc_bioset(cc->dev->bdev, nr_iovecs, io->base_bio->bi_opf,
1695 				 GFP_NOIO, &cc->bs);
1696 	clone->bi_private = io;
1697 	clone->bi_end_io = crypt_endio;
1698 
1699 	remaining_size = size;
1700 
1701 	while (remaining_size) {
1702 		struct page *pages;
1703 		unsigned size_to_add;
1704 		unsigned remaining_order = __fls((remaining_size + PAGE_SIZE - 1) >> PAGE_SHIFT);
1705 		order = min(order, remaining_order);
1706 
1707 		while (order > 0) {
1708 			if (unlikely(percpu_counter_read_positive(&cc->n_allocated_pages) +
1709 					(1 << order) > dm_crypt_pages_per_client))
1710 				goto decrease_order;
1711 			pages = alloc_pages(gfp_mask
1712 				| __GFP_NOMEMALLOC | __GFP_NORETRY | __GFP_NOWARN | __GFP_COMP,
1713 				order);
1714 			if (likely(pages != NULL)) {
1715 				percpu_counter_add(&cc->n_allocated_pages, 1 << order);
1716 				goto have_pages;
1717 			}
1718 decrease_order:
1719 			order--;
1720 		}
1721 
1722 		pages = mempool_alloc(&cc->page_pool, gfp_mask);
1723 		if (!pages) {
1724 			crypt_free_buffer_pages(cc, clone);
1725 			bio_put(clone);
1726 			gfp_mask |= __GFP_DIRECT_RECLAIM;
1727 			order = 0;
1728 			goto retry;
1729 		}
1730 
1731 have_pages:
1732 		size_to_add = min((unsigned)PAGE_SIZE << order, remaining_size);
1733 		__bio_add_page(clone, pages, size_to_add, 0);
1734 		remaining_size -= size_to_add;
1735 	}
1736 
1737 	/* Allocate space for integrity tags */
1738 	if (dm_crypt_integrity_io_alloc(io, clone)) {
1739 		crypt_free_buffer_pages(cc, clone);
1740 		bio_put(clone);
1741 		clone = NULL;
1742 	}
1743 
1744 	if (unlikely(gfp_mask & __GFP_DIRECT_RECLAIM))
1745 		mutex_unlock(&cc->bio_alloc_lock);
1746 
1747 	return clone;
1748 }
1749 
crypt_free_buffer_pages(struct crypt_config * cc,struct bio * clone)1750 static void crypt_free_buffer_pages(struct crypt_config *cc, struct bio *clone)
1751 {
1752 	struct folio_iter fi;
1753 
1754 	if (clone->bi_vcnt > 0) { /* bio_for_each_folio_all crashes with an empty bio */
1755 		bio_for_each_folio_all(fi, clone) {
1756 			if (folio_test_large(fi.folio)) {
1757 				percpu_counter_sub(&cc->n_allocated_pages,
1758 						1 << folio_order(fi.folio));
1759 				folio_put(fi.folio);
1760 			} else {
1761 				mempool_free(&fi.folio->page, &cc->page_pool);
1762 			}
1763 		}
1764 	}
1765 }
1766 
crypt_io_init(struct dm_crypt_io * io,struct crypt_config * cc,struct bio * bio,sector_t sector)1767 static void crypt_io_init(struct dm_crypt_io *io, struct crypt_config *cc,
1768 			  struct bio *bio, sector_t sector)
1769 {
1770 	io->cc = cc;
1771 	io->base_bio = bio;
1772 	io->sector = sector;
1773 	io->error = 0;
1774 	io->ctx.aead_recheck = false;
1775 	io->ctx.aead_failed = false;
1776 	io->ctx.r.req = NULL;
1777 	io->integrity_metadata = NULL;
1778 	io->integrity_metadata_from_pool = false;
1779 	atomic_set(&io->io_pending, 0);
1780 }
1781 
crypt_inc_pending(struct dm_crypt_io * io)1782 static void crypt_inc_pending(struct dm_crypt_io *io)
1783 {
1784 	atomic_inc(&io->io_pending);
1785 }
1786 
1787 static void kcryptd_queue_read(struct dm_crypt_io *io);
1788 
1789 /*
1790  * One of the bios was finished. Check for completion of
1791  * the whole request and correctly clean up the buffer.
1792  */
crypt_dec_pending(struct dm_crypt_io * io)1793 static void crypt_dec_pending(struct dm_crypt_io *io)
1794 {
1795 	struct crypt_config *cc = io->cc;
1796 	struct bio *base_bio = io->base_bio;
1797 	blk_status_t error = io->error;
1798 
1799 	if (!atomic_dec_and_test(&io->io_pending))
1800 		return;
1801 
1802 	if (likely(!io->ctx.aead_recheck) && unlikely(io->ctx.aead_failed) &&
1803 	    cc->on_disk_tag_size && bio_data_dir(base_bio) == READ) {
1804 		io->ctx.aead_recheck = true;
1805 		io->ctx.aead_failed = false;
1806 		io->error = 0;
1807 		kcryptd_queue_read(io);
1808 		return;
1809 	}
1810 
1811 	if (io->ctx.r.req)
1812 		crypt_free_req(cc, io->ctx.r.req, base_bio);
1813 
1814 	if (unlikely(io->integrity_metadata_from_pool))
1815 		mempool_free(io->integrity_metadata, &io->cc->tag_pool);
1816 	else
1817 		kfree(io->integrity_metadata);
1818 
1819 	base_bio->bi_status = error;
1820 
1821 	bio_endio(base_bio);
1822 }
1823 
1824 /*
1825  * kcryptd/kcryptd_io:
1826  *
1827  * Needed because it would be very unwise to do decryption in an
1828  * interrupt context.
1829  *
1830  * kcryptd performs the actual encryption or decryption.
1831  *
1832  * kcryptd_io performs the IO submission.
1833  *
1834  * They must be separated as otherwise the final stages could be
1835  * starved by new requests which can block in the first stages due
1836  * to memory allocation.
1837  *
1838  * The work is done per CPU global for all dm-crypt instances.
1839  * They should not depend on each other and do not block.
1840  */
crypt_endio(struct bio * clone)1841 static void crypt_endio(struct bio *clone)
1842 {
1843 	struct dm_crypt_io *io = clone->bi_private;
1844 	struct crypt_config *cc = io->cc;
1845 	unsigned int rw = bio_data_dir(clone);
1846 	blk_status_t error = clone->bi_status;
1847 
1848 	if (io->ctx.aead_recheck && !error) {
1849 		kcryptd_queue_crypt(io);
1850 		return;
1851 	}
1852 
1853 	/*
1854 	 * free the processed pages
1855 	 */
1856 	if (rw == WRITE || io->ctx.aead_recheck)
1857 		crypt_free_buffer_pages(cc, clone);
1858 
1859 	bio_put(clone);
1860 
1861 	if (rw == READ && !error) {
1862 		kcryptd_queue_crypt(io);
1863 		return;
1864 	}
1865 
1866 	if (unlikely(error))
1867 		io->error = error;
1868 
1869 	crypt_dec_pending(io);
1870 }
1871 
1872 #define CRYPT_MAP_READ_GFP GFP_NOWAIT
1873 
kcryptd_io_read(struct dm_crypt_io * io,gfp_t gfp)1874 static int kcryptd_io_read(struct dm_crypt_io *io, gfp_t gfp)
1875 {
1876 	struct crypt_config *cc = io->cc;
1877 	struct bio *clone;
1878 
1879 	if (io->ctx.aead_recheck) {
1880 		if (!(gfp & __GFP_DIRECT_RECLAIM))
1881 			return 1;
1882 		crypt_inc_pending(io);
1883 		clone = crypt_alloc_buffer(io, io->base_bio->bi_iter.bi_size);
1884 		if (unlikely(!clone)) {
1885 			crypt_dec_pending(io);
1886 			return 1;
1887 		}
1888 		clone->bi_iter.bi_sector = cc->start + io->sector;
1889 		crypt_convert_init(cc, &io->ctx, clone, clone, io->sector);
1890 		io->saved_bi_iter = clone->bi_iter;
1891 		dm_submit_bio_remap(io->base_bio, clone);
1892 		return 0;
1893 	}
1894 
1895 	/*
1896 	 * We need the original biovec array in order to decrypt the whole bio
1897 	 * data *afterwards* -- thanks to immutable biovecs we don't need to
1898 	 * worry about the block layer modifying the biovec array; so leverage
1899 	 * bio_alloc_clone().
1900 	 */
1901 	clone = bio_alloc_clone(cc->dev->bdev, io->base_bio, gfp, &cc->bs);
1902 	if (!clone)
1903 		return 1;
1904 	clone->bi_private = io;
1905 	clone->bi_end_io = crypt_endio;
1906 
1907 	crypt_inc_pending(io);
1908 
1909 	clone->bi_iter.bi_sector = cc->start + io->sector;
1910 
1911 	if (dm_crypt_integrity_io_alloc(io, clone)) {
1912 		crypt_dec_pending(io);
1913 		bio_put(clone);
1914 		return 1;
1915 	}
1916 
1917 	dm_submit_bio_remap(io->base_bio, clone);
1918 	return 0;
1919 }
1920 
kcryptd_io_read_work(struct work_struct * work)1921 static void kcryptd_io_read_work(struct work_struct *work)
1922 {
1923 	struct dm_crypt_io *io = container_of(work, struct dm_crypt_io, work);
1924 
1925 	crypt_inc_pending(io);
1926 	if (kcryptd_io_read(io, GFP_NOIO))
1927 		io->error = BLK_STS_RESOURCE;
1928 	crypt_dec_pending(io);
1929 }
1930 
kcryptd_queue_read(struct dm_crypt_io * io)1931 static void kcryptd_queue_read(struct dm_crypt_io *io)
1932 {
1933 	struct crypt_config *cc = io->cc;
1934 
1935 	INIT_WORK(&io->work, kcryptd_io_read_work);
1936 	queue_work(cc->io_queue, &io->work);
1937 }
1938 
kcryptd_io_write(struct dm_crypt_io * io)1939 static void kcryptd_io_write(struct dm_crypt_io *io)
1940 {
1941 	struct bio *clone = io->ctx.bio_out;
1942 
1943 	dm_submit_bio_remap(io->base_bio, clone);
1944 }
1945 
1946 #define crypt_io_from_node(node) rb_entry((node), struct dm_crypt_io, rb_node)
1947 
dmcrypt_write(void * data)1948 static int dmcrypt_write(void *data)
1949 {
1950 	struct crypt_config *cc = data;
1951 	struct dm_crypt_io *io;
1952 
1953 	while (1) {
1954 		struct rb_root write_tree;
1955 		struct blk_plug plug;
1956 
1957 		spin_lock_irq(&cc->write_thread_lock);
1958 continue_locked:
1959 
1960 		if (!RB_EMPTY_ROOT(&cc->write_tree))
1961 			goto pop_from_list;
1962 
1963 		set_current_state(TASK_INTERRUPTIBLE);
1964 
1965 		spin_unlock_irq(&cc->write_thread_lock);
1966 
1967 		if (unlikely(kthread_should_stop())) {
1968 			set_current_state(TASK_RUNNING);
1969 			break;
1970 		}
1971 
1972 		schedule();
1973 
1974 		set_current_state(TASK_RUNNING);
1975 		spin_lock_irq(&cc->write_thread_lock);
1976 		goto continue_locked;
1977 
1978 pop_from_list:
1979 		write_tree = cc->write_tree;
1980 		cc->write_tree = RB_ROOT;
1981 		spin_unlock_irq(&cc->write_thread_lock);
1982 
1983 		BUG_ON(rb_parent(write_tree.rb_node));
1984 
1985 		/*
1986 		 * Note: we cannot walk the tree here with rb_next because
1987 		 * the structures may be freed when kcryptd_io_write is called.
1988 		 */
1989 		blk_start_plug(&plug);
1990 		do {
1991 			io = crypt_io_from_node(rb_first(&write_tree));
1992 			rb_erase(&io->rb_node, &write_tree);
1993 			kcryptd_io_write(io);
1994 			cond_resched();
1995 		} while (!RB_EMPTY_ROOT(&write_tree));
1996 		blk_finish_plug(&plug);
1997 	}
1998 	return 0;
1999 }
2000 
kcryptd_crypt_write_io_submit(struct dm_crypt_io * io,int async)2001 static void kcryptd_crypt_write_io_submit(struct dm_crypt_io *io, int async)
2002 {
2003 	struct bio *clone = io->ctx.bio_out;
2004 	struct crypt_config *cc = io->cc;
2005 	unsigned long flags;
2006 	sector_t sector;
2007 	struct rb_node **rbp, *parent;
2008 
2009 	if (unlikely(io->error)) {
2010 		crypt_free_buffer_pages(cc, clone);
2011 		bio_put(clone);
2012 		crypt_dec_pending(io);
2013 		return;
2014 	}
2015 
2016 	/* crypt_convert should have filled the clone bio */
2017 	BUG_ON(io->ctx.iter_out.bi_size);
2018 
2019 	clone->bi_iter.bi_sector = cc->start + io->sector;
2020 
2021 	if ((likely(!async) && test_bit(DM_CRYPT_NO_OFFLOAD, &cc->flags)) ||
2022 	    test_bit(DM_CRYPT_NO_WRITE_WORKQUEUE, &cc->flags)) {
2023 		dm_submit_bio_remap(io->base_bio, clone);
2024 		return;
2025 	}
2026 
2027 	spin_lock_irqsave(&cc->write_thread_lock, flags);
2028 	if (RB_EMPTY_ROOT(&cc->write_tree))
2029 		wake_up_process(cc->write_thread);
2030 	rbp = &cc->write_tree.rb_node;
2031 	parent = NULL;
2032 	sector = io->sector;
2033 	while (*rbp) {
2034 		parent = *rbp;
2035 		if (sector < crypt_io_from_node(parent)->sector)
2036 			rbp = &(*rbp)->rb_left;
2037 		else
2038 			rbp = &(*rbp)->rb_right;
2039 	}
2040 	rb_link_node(&io->rb_node, parent, rbp);
2041 	rb_insert_color(&io->rb_node, &cc->write_tree);
2042 	spin_unlock_irqrestore(&cc->write_thread_lock, flags);
2043 }
2044 
kcryptd_crypt_write_inline(struct crypt_config * cc,struct convert_context * ctx)2045 static bool kcryptd_crypt_write_inline(struct crypt_config *cc,
2046 				       struct convert_context *ctx)
2047 
2048 {
2049 	if (!test_bit(DM_CRYPT_WRITE_INLINE, &cc->flags))
2050 		return false;
2051 
2052 	/*
2053 	 * Note: zone append writes (REQ_OP_ZONE_APPEND) do not have ordering
2054 	 * constraints so they do not need to be issued inline by
2055 	 * kcryptd_crypt_write_convert().
2056 	 */
2057 	switch (bio_op(ctx->bio_in)) {
2058 	case REQ_OP_WRITE:
2059 	case REQ_OP_WRITE_ZEROES:
2060 		return true;
2061 	default:
2062 		return false;
2063 	}
2064 }
2065 
kcryptd_crypt_write_continue(struct work_struct * work)2066 static void kcryptd_crypt_write_continue(struct work_struct *work)
2067 {
2068 	struct dm_crypt_io *io = container_of(work, struct dm_crypt_io, work);
2069 	struct crypt_config *cc = io->cc;
2070 	struct convert_context *ctx = &io->ctx;
2071 	int crypt_finished;
2072 	blk_status_t r;
2073 
2074 	wait_for_completion(&ctx->restart);
2075 	reinit_completion(&ctx->restart);
2076 
2077 	r = crypt_convert(cc, &io->ctx, true, false);
2078 	if (r)
2079 		io->error = r;
2080 	crypt_finished = atomic_dec_and_test(&ctx->cc_pending);
2081 	if (!crypt_finished && kcryptd_crypt_write_inline(cc, ctx)) {
2082 		/* Wait for completion signaled by kcryptd_async_done() */
2083 		wait_for_completion(&ctx->restart);
2084 		crypt_finished = 1;
2085 	}
2086 
2087 	/* Encryption was already finished, submit io now */
2088 	if (crypt_finished)
2089 		kcryptd_crypt_write_io_submit(io, 0);
2090 
2091 	crypt_dec_pending(io);
2092 }
2093 
kcryptd_crypt_write_convert(struct dm_crypt_io * io)2094 static void kcryptd_crypt_write_convert(struct dm_crypt_io *io)
2095 {
2096 	struct crypt_config *cc = io->cc;
2097 	struct convert_context *ctx = &io->ctx;
2098 	struct bio *clone;
2099 	int crypt_finished;
2100 	blk_status_t r;
2101 
2102 	/*
2103 	 * Prevent io from disappearing until this function completes.
2104 	 */
2105 	crypt_inc_pending(io);
2106 	crypt_convert_init(cc, ctx, NULL, io->base_bio, io->sector);
2107 
2108 	clone = crypt_alloc_buffer(io, io->base_bio->bi_iter.bi_size);
2109 	if (unlikely(!clone)) {
2110 		io->error = BLK_STS_IOERR;
2111 		goto dec;
2112 	}
2113 
2114 	io->ctx.bio_out = clone;
2115 	io->ctx.iter_out = clone->bi_iter;
2116 
2117 	if (crypt_integrity_aead(cc)) {
2118 		bio_copy_data(clone, io->base_bio);
2119 		io->ctx.bio_in = clone;
2120 		io->ctx.iter_in = clone->bi_iter;
2121 	}
2122 
2123 	crypt_inc_pending(io);
2124 	r = crypt_convert(cc, ctx,
2125 			  test_bit(DM_CRYPT_NO_WRITE_WORKQUEUE, &cc->flags), true);
2126 	/*
2127 	 * Crypto API backlogged the request, because its queue was full
2128 	 * and we're in softirq context, so continue from a workqueue
2129 	 * (TODO: is it actually possible to be in softirq in the write path?)
2130 	 */
2131 	if (r == BLK_STS_DEV_RESOURCE) {
2132 		INIT_WORK(&io->work, kcryptd_crypt_write_continue);
2133 		queue_work(cc->crypt_queue, &io->work);
2134 		return;
2135 	}
2136 	if (r)
2137 		io->error = r;
2138 	crypt_finished = atomic_dec_and_test(&ctx->cc_pending);
2139 	if (!crypt_finished && kcryptd_crypt_write_inline(cc, ctx)) {
2140 		/* Wait for completion signaled by kcryptd_async_done() */
2141 		wait_for_completion(&ctx->restart);
2142 		crypt_finished = 1;
2143 	}
2144 
2145 	/* Encryption was already finished, submit io now */
2146 	if (crypt_finished)
2147 		kcryptd_crypt_write_io_submit(io, 0);
2148 
2149 dec:
2150 	crypt_dec_pending(io);
2151 }
2152 
kcryptd_crypt_read_done(struct dm_crypt_io * io)2153 static void kcryptd_crypt_read_done(struct dm_crypt_io *io)
2154 {
2155 	if (io->ctx.aead_recheck) {
2156 		if (!io->error) {
2157 			io->ctx.bio_in->bi_iter = io->saved_bi_iter;
2158 			bio_copy_data(io->base_bio, io->ctx.bio_in);
2159 		}
2160 		crypt_free_buffer_pages(io->cc, io->ctx.bio_in);
2161 		bio_put(io->ctx.bio_in);
2162 	}
2163 	crypt_dec_pending(io);
2164 }
2165 
kcryptd_crypt_read_continue(struct work_struct * work)2166 static void kcryptd_crypt_read_continue(struct work_struct *work)
2167 {
2168 	struct dm_crypt_io *io = container_of(work, struct dm_crypt_io, work);
2169 	struct crypt_config *cc = io->cc;
2170 	blk_status_t r;
2171 
2172 	wait_for_completion(&io->ctx.restart);
2173 	reinit_completion(&io->ctx.restart);
2174 
2175 	r = crypt_convert(cc, &io->ctx, true, false);
2176 	if (r)
2177 		io->error = r;
2178 
2179 	if (atomic_dec_and_test(&io->ctx.cc_pending))
2180 		kcryptd_crypt_read_done(io);
2181 
2182 	crypt_dec_pending(io);
2183 }
2184 
kcryptd_crypt_read_convert(struct dm_crypt_io * io)2185 static void kcryptd_crypt_read_convert(struct dm_crypt_io *io)
2186 {
2187 	struct crypt_config *cc = io->cc;
2188 	blk_status_t r;
2189 
2190 	crypt_inc_pending(io);
2191 
2192 	if (io->ctx.aead_recheck) {
2193 		io->ctx.cc_sector = io->sector + cc->iv_offset;
2194 		r = crypt_convert(cc, &io->ctx,
2195 				  test_bit(DM_CRYPT_NO_READ_WORKQUEUE, &cc->flags), true);
2196 	} else {
2197 		crypt_convert_init(cc, &io->ctx, io->base_bio, io->base_bio,
2198 				   io->sector);
2199 
2200 		r = crypt_convert(cc, &io->ctx,
2201 				  test_bit(DM_CRYPT_NO_READ_WORKQUEUE, &cc->flags), true);
2202 	}
2203 	/*
2204 	 * Crypto API backlogged the request, because its queue was full
2205 	 * and we're in softirq context, so continue from a workqueue
2206 	 */
2207 	if (r == BLK_STS_DEV_RESOURCE) {
2208 		INIT_WORK(&io->work, kcryptd_crypt_read_continue);
2209 		queue_work(cc->crypt_queue, &io->work);
2210 		return;
2211 	}
2212 	if (r)
2213 		io->error = r;
2214 
2215 	if (atomic_dec_and_test(&io->ctx.cc_pending))
2216 		kcryptd_crypt_read_done(io);
2217 
2218 	crypt_dec_pending(io);
2219 }
2220 
kcryptd_async_done(void * data,int error)2221 static void kcryptd_async_done(void *data, int error)
2222 {
2223 	struct dm_crypt_request *dmreq = data;
2224 	struct convert_context *ctx = dmreq->ctx;
2225 	struct dm_crypt_io *io = container_of(ctx, struct dm_crypt_io, ctx);
2226 	struct crypt_config *cc = io->cc;
2227 
2228 	/*
2229 	 * A request from crypto driver backlog is going to be processed now,
2230 	 * finish the completion and continue in crypt_convert().
2231 	 * (Callback will be called for the second time for this request.)
2232 	 */
2233 	if (error == -EINPROGRESS) {
2234 		complete(&ctx->restart);
2235 		return;
2236 	}
2237 
2238 	if (!error && cc->iv_gen_ops && cc->iv_gen_ops->post)
2239 		error = cc->iv_gen_ops->post(cc, org_iv_of_dmreq(cc, dmreq), dmreq);
2240 
2241 	if (error == -EBADMSG) {
2242 		sector_t s = le64_to_cpu(*org_sector_of_dmreq(cc, dmreq));
2243 
2244 		ctx->aead_failed = true;
2245 		if (ctx->aead_recheck) {
2246 			DMERR_LIMIT("%pg: INTEGRITY AEAD ERROR, sector %llu",
2247 				    ctx->bio_in->bi_bdev, s);
2248 			dm_audit_log_bio(DM_MSG_PREFIX, "integrity-aead",
2249 					 ctx->bio_in, s, 0);
2250 		}
2251 		io->error = BLK_STS_PROTECTION;
2252 	} else if (error < 0)
2253 		io->error = BLK_STS_IOERR;
2254 
2255 	crypt_free_req(cc, req_of_dmreq(cc, dmreq), io->base_bio);
2256 
2257 	if (!atomic_dec_and_test(&ctx->cc_pending))
2258 		return;
2259 
2260 	/*
2261 	 * The request is fully completed: for inline writes, let
2262 	 * kcryptd_crypt_write_convert() do the IO submission.
2263 	 */
2264 	if (bio_data_dir(io->base_bio) == READ) {
2265 		kcryptd_crypt_read_done(io);
2266 		return;
2267 	}
2268 
2269 	if (kcryptd_crypt_write_inline(cc, ctx)) {
2270 		complete(&ctx->restart);
2271 		return;
2272 	}
2273 
2274 	kcryptd_crypt_write_io_submit(io, 1);
2275 }
2276 
kcryptd_crypt(struct work_struct * work)2277 static void kcryptd_crypt(struct work_struct *work)
2278 {
2279 	struct dm_crypt_io *io = container_of(work, struct dm_crypt_io, work);
2280 
2281 	if (bio_data_dir(io->base_bio) == READ)
2282 		kcryptd_crypt_read_convert(io);
2283 	else
2284 		kcryptd_crypt_write_convert(io);
2285 }
2286 
kcryptd_queue_crypt(struct dm_crypt_io * io)2287 static void kcryptd_queue_crypt(struct dm_crypt_io *io)
2288 {
2289 	struct crypt_config *cc = io->cc;
2290 
2291 	if ((bio_data_dir(io->base_bio) == READ && test_bit(DM_CRYPT_NO_READ_WORKQUEUE, &cc->flags)) ||
2292 	    (bio_data_dir(io->base_bio) == WRITE && test_bit(DM_CRYPT_NO_WRITE_WORKQUEUE, &cc->flags))) {
2293 		/*
2294 		 * in_hardirq(): Crypto API's skcipher_walk_first() refuses to work in hard IRQ context.
2295 		 * irqs_disabled(): the kernel may run some IO completion from the idle thread, but
2296 		 * it is being executed with irqs disabled.
2297 		 */
2298 		if (!(in_hardirq() || irqs_disabled())) {
2299 			kcryptd_crypt(&io->work);
2300 			return;
2301 		}
2302 	}
2303 
2304 	INIT_WORK(&io->work, kcryptd_crypt);
2305 	queue_work(cc->crypt_queue, &io->work);
2306 }
2307 
crypt_free_tfms_aead(struct crypt_config * cc)2308 static void crypt_free_tfms_aead(struct crypt_config *cc)
2309 {
2310 	if (!cc->cipher_tfm.tfms_aead)
2311 		return;
2312 
2313 	if (cc->cipher_tfm.tfms_aead[0] && !IS_ERR(cc->cipher_tfm.tfms_aead[0])) {
2314 		crypto_free_aead(cc->cipher_tfm.tfms_aead[0]);
2315 		cc->cipher_tfm.tfms_aead[0] = NULL;
2316 	}
2317 
2318 	kfree(cc->cipher_tfm.tfms_aead);
2319 	cc->cipher_tfm.tfms_aead = NULL;
2320 }
2321 
crypt_free_tfms_skcipher(struct crypt_config * cc)2322 static void crypt_free_tfms_skcipher(struct crypt_config *cc)
2323 {
2324 	unsigned int i;
2325 
2326 	if (!cc->cipher_tfm.tfms)
2327 		return;
2328 
2329 	for (i = 0; i < cc->tfms_count; i++)
2330 		if (cc->cipher_tfm.tfms[i] && !IS_ERR(cc->cipher_tfm.tfms[i])) {
2331 			crypto_free_skcipher(cc->cipher_tfm.tfms[i]);
2332 			cc->cipher_tfm.tfms[i] = NULL;
2333 		}
2334 
2335 	kfree(cc->cipher_tfm.tfms);
2336 	cc->cipher_tfm.tfms = NULL;
2337 }
2338 
crypt_free_tfms(struct crypt_config * cc)2339 static void crypt_free_tfms(struct crypt_config *cc)
2340 {
2341 	if (crypt_integrity_aead(cc))
2342 		crypt_free_tfms_aead(cc);
2343 	else
2344 		crypt_free_tfms_skcipher(cc);
2345 }
2346 
crypt_alloc_tfms_skcipher(struct crypt_config * cc,char * ciphermode)2347 static int crypt_alloc_tfms_skcipher(struct crypt_config *cc, char *ciphermode)
2348 {
2349 	unsigned int i;
2350 	int err;
2351 
2352 	cc->cipher_tfm.tfms = kcalloc(cc->tfms_count,
2353 				      sizeof(struct crypto_skcipher *),
2354 				      GFP_KERNEL);
2355 	if (!cc->cipher_tfm.tfms)
2356 		return -ENOMEM;
2357 
2358 	for (i = 0; i < cc->tfms_count; i++) {
2359 		cc->cipher_tfm.tfms[i] = crypto_alloc_skcipher(ciphermode, 0,
2360 						CRYPTO_ALG_ALLOCATES_MEMORY);
2361 		if (IS_ERR(cc->cipher_tfm.tfms[i])) {
2362 			err = PTR_ERR(cc->cipher_tfm.tfms[i]);
2363 			crypt_free_tfms(cc);
2364 			return err;
2365 		}
2366 	}
2367 
2368 	/*
2369 	 * dm-crypt performance can vary greatly depending on which crypto
2370 	 * algorithm implementation is used.  Help people debug performance
2371 	 * problems by logging the ->cra_driver_name.
2372 	 */
2373 	DMDEBUG_LIMIT("%s using implementation \"%s\"", ciphermode,
2374 	       crypto_skcipher_alg(any_tfm(cc))->base.cra_driver_name);
2375 	return 0;
2376 }
2377 
crypt_alloc_tfms_aead(struct crypt_config * cc,char * ciphermode)2378 static int crypt_alloc_tfms_aead(struct crypt_config *cc, char *ciphermode)
2379 {
2380 	int err;
2381 
2382 	cc->cipher_tfm.tfms = kmalloc(sizeof(struct crypto_aead *), GFP_KERNEL);
2383 	if (!cc->cipher_tfm.tfms)
2384 		return -ENOMEM;
2385 
2386 	cc->cipher_tfm.tfms_aead[0] = crypto_alloc_aead(ciphermode, 0,
2387 						CRYPTO_ALG_ALLOCATES_MEMORY);
2388 	if (IS_ERR(cc->cipher_tfm.tfms_aead[0])) {
2389 		err = PTR_ERR(cc->cipher_tfm.tfms_aead[0]);
2390 		crypt_free_tfms(cc);
2391 		return err;
2392 	}
2393 
2394 	DMDEBUG_LIMIT("%s using implementation \"%s\"", ciphermode,
2395 	       crypto_aead_alg(any_tfm_aead(cc))->base.cra_driver_name);
2396 	return 0;
2397 }
2398 
crypt_alloc_tfms(struct crypt_config * cc,char * ciphermode)2399 static int crypt_alloc_tfms(struct crypt_config *cc, char *ciphermode)
2400 {
2401 	if (crypt_integrity_aead(cc))
2402 		return crypt_alloc_tfms_aead(cc, ciphermode);
2403 	else
2404 		return crypt_alloc_tfms_skcipher(cc, ciphermode);
2405 }
2406 
crypt_subkey_size(struct crypt_config * cc)2407 static unsigned int crypt_subkey_size(struct crypt_config *cc)
2408 {
2409 	return (cc->key_size - cc->key_extra_size) >> ilog2(cc->tfms_count);
2410 }
2411 
crypt_authenckey_size(struct crypt_config * cc)2412 static unsigned int crypt_authenckey_size(struct crypt_config *cc)
2413 {
2414 	return crypt_subkey_size(cc) + RTA_SPACE(sizeof(struct crypto_authenc_key_param));
2415 }
2416 
2417 /*
2418  * If AEAD is composed like authenc(hmac(sha256),xts(aes)),
2419  * the key must be for some reason in special format.
2420  * This funcion converts cc->key to this special format.
2421  */
crypt_copy_authenckey(char * p,const void * key,unsigned int enckeylen,unsigned int authkeylen)2422 static void crypt_copy_authenckey(char *p, const void *key,
2423 				  unsigned int enckeylen, unsigned int authkeylen)
2424 {
2425 	struct crypto_authenc_key_param *param;
2426 	struct rtattr *rta;
2427 
2428 	rta = (struct rtattr *)p;
2429 	param = RTA_DATA(rta);
2430 	param->enckeylen = cpu_to_be32(enckeylen);
2431 	rta->rta_len = RTA_LENGTH(sizeof(*param));
2432 	rta->rta_type = CRYPTO_AUTHENC_KEYA_PARAM;
2433 	p += RTA_SPACE(sizeof(*param));
2434 	memcpy(p, key + enckeylen, authkeylen);
2435 	p += authkeylen;
2436 	memcpy(p, key, enckeylen);
2437 }
2438 
crypt_setkey(struct crypt_config * cc)2439 static int crypt_setkey(struct crypt_config *cc)
2440 {
2441 	unsigned int subkey_size;
2442 	int err = 0, i, r;
2443 
2444 	/* Ignore extra keys (which are used for IV etc) */
2445 	subkey_size = crypt_subkey_size(cc);
2446 
2447 	if (crypt_integrity_hmac(cc)) {
2448 		if (subkey_size < cc->key_mac_size)
2449 			return -EINVAL;
2450 
2451 		crypt_copy_authenckey(cc->authenc_key, cc->key,
2452 				      subkey_size - cc->key_mac_size,
2453 				      cc->key_mac_size);
2454 	}
2455 
2456 	for (i = 0; i < cc->tfms_count; i++) {
2457 		if (crypt_integrity_hmac(cc))
2458 			r = crypto_aead_setkey(cc->cipher_tfm.tfms_aead[i],
2459 				cc->authenc_key, crypt_authenckey_size(cc));
2460 		else if (crypt_integrity_aead(cc))
2461 			r = crypto_aead_setkey(cc->cipher_tfm.tfms_aead[i],
2462 					       cc->key + (i * subkey_size),
2463 					       subkey_size);
2464 		else
2465 			r = crypto_skcipher_setkey(cc->cipher_tfm.tfms[i],
2466 						   cc->key + (i * subkey_size),
2467 						   subkey_size);
2468 		if (r)
2469 			err = r;
2470 	}
2471 
2472 	if (crypt_integrity_hmac(cc))
2473 		memzero_explicit(cc->authenc_key, crypt_authenckey_size(cc));
2474 
2475 	return err;
2476 }
2477 
2478 #ifdef CONFIG_KEYS
2479 
contains_whitespace(const char * str)2480 static bool contains_whitespace(const char *str)
2481 {
2482 	while (*str)
2483 		if (isspace(*str++))
2484 			return true;
2485 	return false;
2486 }
2487 
set_key_user(struct crypt_config * cc,struct key * key)2488 static int set_key_user(struct crypt_config *cc, struct key *key)
2489 {
2490 	const struct user_key_payload *ukp;
2491 
2492 	ukp = user_key_payload_locked(key);
2493 	if (!ukp)
2494 		return -EKEYREVOKED;
2495 
2496 	if (cc->key_size != ukp->datalen)
2497 		return -EINVAL;
2498 
2499 	memcpy(cc->key, ukp->data, cc->key_size);
2500 
2501 	return 0;
2502 }
2503 
set_key_encrypted(struct crypt_config * cc,struct key * key)2504 static int set_key_encrypted(struct crypt_config *cc, struct key *key)
2505 {
2506 	const struct encrypted_key_payload *ekp;
2507 
2508 	ekp = key->payload.data[0];
2509 	if (!ekp)
2510 		return -EKEYREVOKED;
2511 
2512 	if (cc->key_size != ekp->decrypted_datalen)
2513 		return -EINVAL;
2514 
2515 	memcpy(cc->key, ekp->decrypted_data, cc->key_size);
2516 
2517 	return 0;
2518 }
2519 
set_key_trusted(struct crypt_config * cc,struct key * key)2520 static int set_key_trusted(struct crypt_config *cc, struct key *key)
2521 {
2522 	const struct trusted_key_payload *tkp;
2523 
2524 	tkp = key->payload.data[0];
2525 	if (!tkp)
2526 		return -EKEYREVOKED;
2527 
2528 	if (cc->key_size != tkp->key_len)
2529 		return -EINVAL;
2530 
2531 	memcpy(cc->key, tkp->key, cc->key_size);
2532 
2533 	return 0;
2534 }
2535 
crypt_set_keyring_key(struct crypt_config * cc,const char * key_string)2536 static int crypt_set_keyring_key(struct crypt_config *cc, const char *key_string)
2537 {
2538 	char *new_key_string, *key_desc;
2539 	int ret;
2540 	struct key_type *type;
2541 	struct key *key;
2542 	int (*set_key)(struct crypt_config *cc, struct key *key);
2543 
2544 	/*
2545 	 * Reject key_string with whitespace. dm core currently lacks code for
2546 	 * proper whitespace escaping in arguments on DM_TABLE_STATUS path.
2547 	 */
2548 	if (contains_whitespace(key_string)) {
2549 		DMERR("whitespace chars not allowed in key string");
2550 		return -EINVAL;
2551 	}
2552 
2553 	/* look for next ':' separating key_type from key_description */
2554 	key_desc = strchr(key_string, ':');
2555 	if (!key_desc || key_desc == key_string || !strlen(key_desc + 1))
2556 		return -EINVAL;
2557 
2558 	if (!strncmp(key_string, "logon:", key_desc - key_string + 1)) {
2559 		type = &key_type_logon;
2560 		set_key = set_key_user;
2561 	} else if (!strncmp(key_string, "user:", key_desc - key_string + 1)) {
2562 		type = &key_type_user;
2563 		set_key = set_key_user;
2564 	} else if (IS_ENABLED(CONFIG_ENCRYPTED_KEYS) &&
2565 		   !strncmp(key_string, "encrypted:", key_desc - key_string + 1)) {
2566 		type = &key_type_encrypted;
2567 		set_key = set_key_encrypted;
2568 	} else if (IS_ENABLED(CONFIG_TRUSTED_KEYS) &&
2569 		   !strncmp(key_string, "trusted:", key_desc - key_string + 1)) {
2570 		type = &key_type_trusted;
2571 		set_key = set_key_trusted;
2572 	} else {
2573 		return -EINVAL;
2574 	}
2575 
2576 	new_key_string = kstrdup(key_string, GFP_KERNEL);
2577 	if (!new_key_string)
2578 		return -ENOMEM;
2579 
2580 	key = request_key(type, key_desc + 1, NULL);
2581 	if (IS_ERR(key)) {
2582 		kfree_sensitive(new_key_string);
2583 		return PTR_ERR(key);
2584 	}
2585 
2586 	down_read(&key->sem);
2587 
2588 	ret = set_key(cc, key);
2589 	if (ret < 0) {
2590 		up_read(&key->sem);
2591 		key_put(key);
2592 		kfree_sensitive(new_key_string);
2593 		return ret;
2594 	}
2595 
2596 	up_read(&key->sem);
2597 	key_put(key);
2598 
2599 	/* clear the flag since following operations may invalidate previously valid key */
2600 	clear_bit(DM_CRYPT_KEY_VALID, &cc->flags);
2601 
2602 	ret = crypt_setkey(cc);
2603 
2604 	if (!ret) {
2605 		set_bit(DM_CRYPT_KEY_VALID, &cc->flags);
2606 		kfree_sensitive(cc->key_string);
2607 		cc->key_string = new_key_string;
2608 	} else
2609 		kfree_sensitive(new_key_string);
2610 
2611 	return ret;
2612 }
2613 
get_key_size(char ** key_string)2614 static int get_key_size(char **key_string)
2615 {
2616 	char *colon, dummy;
2617 	int ret;
2618 
2619 	if (*key_string[0] != ':')
2620 		return strlen(*key_string) >> 1;
2621 
2622 	/* look for next ':' in key string */
2623 	colon = strpbrk(*key_string + 1, ":");
2624 	if (!colon)
2625 		return -EINVAL;
2626 
2627 	if (sscanf(*key_string + 1, "%u%c", &ret, &dummy) != 2 || dummy != ':')
2628 		return -EINVAL;
2629 
2630 	*key_string = colon;
2631 
2632 	/* remaining key string should be :<logon|user>:<key_desc> */
2633 
2634 	return ret;
2635 }
2636 
2637 #else
2638 
crypt_set_keyring_key(struct crypt_config * cc,const char * key_string)2639 static int crypt_set_keyring_key(struct crypt_config *cc, const char *key_string)
2640 {
2641 	return -EINVAL;
2642 }
2643 
get_key_size(char ** key_string)2644 static int get_key_size(char **key_string)
2645 {
2646 	return (*key_string[0] == ':') ? -EINVAL : (int)(strlen(*key_string) >> 1);
2647 }
2648 
2649 #endif /* CONFIG_KEYS */
2650 
crypt_set_key(struct crypt_config * cc,char * key)2651 static int crypt_set_key(struct crypt_config *cc, char *key)
2652 {
2653 	int r = -EINVAL;
2654 	int key_string_len = strlen(key);
2655 
2656 	/* Hyphen (which gives a key_size of zero) means there is no key. */
2657 	if (!cc->key_size && strcmp(key, "-"))
2658 		goto out;
2659 
2660 	/* ':' means the key is in kernel keyring, short-circuit normal key processing */
2661 	if (key[0] == ':') {
2662 		r = crypt_set_keyring_key(cc, key + 1);
2663 		goto out;
2664 	}
2665 
2666 	/* clear the flag since following operations may invalidate previously valid key */
2667 	clear_bit(DM_CRYPT_KEY_VALID, &cc->flags);
2668 
2669 	/* wipe references to any kernel keyring key */
2670 	kfree_sensitive(cc->key_string);
2671 	cc->key_string = NULL;
2672 
2673 	/* Decode key from its hex representation. */
2674 	if (cc->key_size && hex2bin(cc->key, key, cc->key_size) < 0)
2675 		goto out;
2676 
2677 	r = crypt_setkey(cc);
2678 	if (!r)
2679 		set_bit(DM_CRYPT_KEY_VALID, &cc->flags);
2680 
2681 out:
2682 	/* Hex key string not needed after here, so wipe it. */
2683 	memset(key, '0', key_string_len);
2684 
2685 	return r;
2686 }
2687 
crypt_wipe_key(struct crypt_config * cc)2688 static int crypt_wipe_key(struct crypt_config *cc)
2689 {
2690 	int r;
2691 
2692 	clear_bit(DM_CRYPT_KEY_VALID, &cc->flags);
2693 	get_random_bytes(&cc->key, cc->key_size);
2694 
2695 	/* Wipe IV private keys */
2696 	if (cc->iv_gen_ops && cc->iv_gen_ops->wipe) {
2697 		r = cc->iv_gen_ops->wipe(cc);
2698 		if (r)
2699 			return r;
2700 	}
2701 
2702 	kfree_sensitive(cc->key_string);
2703 	cc->key_string = NULL;
2704 	r = crypt_setkey(cc);
2705 	memset(&cc->key, 0, cc->key_size * sizeof(u8));
2706 
2707 	return r;
2708 }
2709 
crypt_calculate_pages_per_client(void)2710 static void crypt_calculate_pages_per_client(void)
2711 {
2712 	unsigned long pages = (totalram_pages() - totalhigh_pages()) * DM_CRYPT_MEMORY_PERCENT / 100;
2713 
2714 	if (!dm_crypt_clients_n)
2715 		return;
2716 
2717 	pages /= dm_crypt_clients_n;
2718 	if (pages < DM_CRYPT_MIN_PAGES_PER_CLIENT)
2719 		pages = DM_CRYPT_MIN_PAGES_PER_CLIENT;
2720 	dm_crypt_pages_per_client = pages;
2721 }
2722 
crypt_page_alloc(gfp_t gfp_mask,void * pool_data)2723 static void *crypt_page_alloc(gfp_t gfp_mask, void *pool_data)
2724 {
2725 	struct crypt_config *cc = pool_data;
2726 	struct page *page;
2727 
2728 	/*
2729 	 * Note, percpu_counter_read_positive() may over (and under) estimate
2730 	 * the current usage by at most (batch - 1) * num_online_cpus() pages,
2731 	 * but avoids potential spinlock contention of an exact result.
2732 	 */
2733 	if (unlikely(percpu_counter_read_positive(&cc->n_allocated_pages) >= dm_crypt_pages_per_client) &&
2734 	    likely(gfp_mask & __GFP_NORETRY))
2735 		return NULL;
2736 
2737 	page = alloc_page(gfp_mask);
2738 	if (likely(page != NULL))
2739 		percpu_counter_add(&cc->n_allocated_pages, 1);
2740 
2741 	return page;
2742 }
2743 
crypt_page_free(void * page,void * pool_data)2744 static void crypt_page_free(void *page, void *pool_data)
2745 {
2746 	struct crypt_config *cc = pool_data;
2747 
2748 	__free_page(page);
2749 	percpu_counter_sub(&cc->n_allocated_pages, 1);
2750 }
2751 
crypt_dtr(struct dm_target * ti)2752 static void crypt_dtr(struct dm_target *ti)
2753 {
2754 	struct crypt_config *cc = ti->private;
2755 
2756 	ti->private = NULL;
2757 
2758 	if (!cc)
2759 		return;
2760 
2761 	if (cc->write_thread)
2762 		kthread_stop(cc->write_thread);
2763 
2764 	if (cc->io_queue)
2765 		destroy_workqueue(cc->io_queue);
2766 	if (cc->crypt_queue)
2767 		destroy_workqueue(cc->crypt_queue);
2768 
2769 	crypt_free_tfms(cc);
2770 
2771 	bioset_exit(&cc->bs);
2772 
2773 	mempool_exit(&cc->page_pool);
2774 	mempool_exit(&cc->req_pool);
2775 	mempool_exit(&cc->tag_pool);
2776 
2777 	WARN_ON(percpu_counter_sum(&cc->n_allocated_pages) != 0);
2778 	percpu_counter_destroy(&cc->n_allocated_pages);
2779 
2780 	if (cc->iv_gen_ops && cc->iv_gen_ops->dtr)
2781 		cc->iv_gen_ops->dtr(cc);
2782 
2783 	if (cc->dev)
2784 		dm_put_device(ti, cc->dev);
2785 
2786 	kfree_sensitive(cc->cipher_string);
2787 	kfree_sensitive(cc->key_string);
2788 	kfree_sensitive(cc->cipher_auth);
2789 	kfree_sensitive(cc->authenc_key);
2790 
2791 	mutex_destroy(&cc->bio_alloc_lock);
2792 
2793 	/* Must zero key material before freeing */
2794 	kfree_sensitive(cc);
2795 
2796 	spin_lock(&dm_crypt_clients_lock);
2797 	WARN_ON(!dm_crypt_clients_n);
2798 	dm_crypt_clients_n--;
2799 	crypt_calculate_pages_per_client();
2800 	spin_unlock(&dm_crypt_clients_lock);
2801 
2802 	dm_audit_log_dtr(DM_MSG_PREFIX, ti, 1);
2803 }
2804 
crypt_ctr_ivmode(struct dm_target * ti,const char * ivmode)2805 static int crypt_ctr_ivmode(struct dm_target *ti, const char *ivmode)
2806 {
2807 	struct crypt_config *cc = ti->private;
2808 
2809 	if (crypt_integrity_aead(cc))
2810 		cc->iv_size = crypto_aead_ivsize(any_tfm_aead(cc));
2811 	else
2812 		cc->iv_size = crypto_skcipher_ivsize(any_tfm(cc));
2813 
2814 	if (cc->iv_size)
2815 		/* at least a 64 bit sector number should fit in our buffer */
2816 		cc->iv_size = max(cc->iv_size,
2817 				  (unsigned int)(sizeof(u64) / sizeof(u8)));
2818 	else if (ivmode) {
2819 		DMWARN("Selected cipher does not support IVs");
2820 		ivmode = NULL;
2821 	}
2822 
2823 	/* Choose ivmode, see comments at iv code. */
2824 	if (ivmode == NULL)
2825 		cc->iv_gen_ops = NULL;
2826 	else if (strcmp(ivmode, "plain") == 0)
2827 		cc->iv_gen_ops = &crypt_iv_plain_ops;
2828 	else if (strcmp(ivmode, "plain64") == 0)
2829 		cc->iv_gen_ops = &crypt_iv_plain64_ops;
2830 	else if (strcmp(ivmode, "plain64be") == 0)
2831 		cc->iv_gen_ops = &crypt_iv_plain64be_ops;
2832 	else if (strcmp(ivmode, "essiv") == 0)
2833 		cc->iv_gen_ops = &crypt_iv_essiv_ops;
2834 	else if (strcmp(ivmode, "benbi") == 0)
2835 		cc->iv_gen_ops = &crypt_iv_benbi_ops;
2836 	else if (strcmp(ivmode, "null") == 0)
2837 		cc->iv_gen_ops = &crypt_iv_null_ops;
2838 	else if (strcmp(ivmode, "eboiv") == 0)
2839 		cc->iv_gen_ops = &crypt_iv_eboiv_ops;
2840 	else if (strcmp(ivmode, "elephant") == 0) {
2841 		cc->iv_gen_ops = &crypt_iv_elephant_ops;
2842 		cc->key_parts = 2;
2843 		cc->key_extra_size = cc->key_size / 2;
2844 		if (cc->key_extra_size > ELEPHANT_MAX_KEY_SIZE)
2845 			return -EINVAL;
2846 		set_bit(CRYPT_ENCRYPT_PREPROCESS, &cc->cipher_flags);
2847 	} else if (strcmp(ivmode, "lmk") == 0) {
2848 		cc->iv_gen_ops = &crypt_iv_lmk_ops;
2849 		/*
2850 		 * Version 2 and 3 is recognised according
2851 		 * to length of provided multi-key string.
2852 		 * If present (version 3), last key is used as IV seed.
2853 		 * All keys (including IV seed) are always the same size.
2854 		 */
2855 		if (cc->key_size % cc->key_parts) {
2856 			cc->key_parts++;
2857 			cc->key_extra_size = cc->key_size / cc->key_parts;
2858 		}
2859 	} else if (strcmp(ivmode, "tcw") == 0) {
2860 		cc->iv_gen_ops = &crypt_iv_tcw_ops;
2861 		cc->key_parts += 2; /* IV + whitening */
2862 		cc->key_extra_size = cc->iv_size + TCW_WHITENING_SIZE;
2863 	} else if (strcmp(ivmode, "random") == 0) {
2864 		cc->iv_gen_ops = &crypt_iv_random_ops;
2865 		/* Need storage space in integrity fields. */
2866 		cc->integrity_iv_size = cc->iv_size;
2867 	} else {
2868 		ti->error = "Invalid IV mode";
2869 		return -EINVAL;
2870 	}
2871 
2872 	return 0;
2873 }
2874 
2875 /*
2876  * Workaround to parse HMAC algorithm from AEAD crypto API spec.
2877  * The HMAC is needed to calculate tag size (HMAC digest size).
2878  * This should be probably done by crypto-api calls (once available...)
2879  */
crypt_ctr_auth_cipher(struct crypt_config * cc,char * cipher_api)2880 static int crypt_ctr_auth_cipher(struct crypt_config *cc, char *cipher_api)
2881 {
2882 	char *start, *end, *mac_alg = NULL;
2883 	struct crypto_ahash *mac;
2884 
2885 	if (!strstarts(cipher_api, "authenc("))
2886 		return 0;
2887 
2888 	start = strchr(cipher_api, '(');
2889 	end = strchr(cipher_api, ',');
2890 	if (!start || !end || ++start > end)
2891 		return -EINVAL;
2892 
2893 	mac_alg = kzalloc(end - start + 1, GFP_KERNEL);
2894 	if (!mac_alg)
2895 		return -ENOMEM;
2896 	strncpy(mac_alg, start, end - start);
2897 
2898 	mac = crypto_alloc_ahash(mac_alg, 0, CRYPTO_ALG_ALLOCATES_MEMORY);
2899 	kfree(mac_alg);
2900 
2901 	if (IS_ERR(mac))
2902 		return PTR_ERR(mac);
2903 
2904 	cc->key_mac_size = crypto_ahash_digestsize(mac);
2905 	crypto_free_ahash(mac);
2906 
2907 	cc->authenc_key = kmalloc(crypt_authenckey_size(cc), GFP_KERNEL);
2908 	if (!cc->authenc_key)
2909 		return -ENOMEM;
2910 
2911 	return 0;
2912 }
2913 
crypt_ctr_cipher_new(struct dm_target * ti,char * cipher_in,char * key,char ** ivmode,char ** ivopts)2914 static int crypt_ctr_cipher_new(struct dm_target *ti, char *cipher_in, char *key,
2915 				char **ivmode, char **ivopts)
2916 {
2917 	struct crypt_config *cc = ti->private;
2918 	char *tmp, *cipher_api, buf[CRYPTO_MAX_ALG_NAME];
2919 	int ret = -EINVAL;
2920 
2921 	cc->tfms_count = 1;
2922 
2923 	/*
2924 	 * New format (capi: prefix)
2925 	 * capi:cipher_api_spec-iv:ivopts
2926 	 */
2927 	tmp = &cipher_in[strlen("capi:")];
2928 
2929 	/* Separate IV options if present, it can contain another '-' in hash name */
2930 	*ivopts = strrchr(tmp, ':');
2931 	if (*ivopts) {
2932 		**ivopts = '\0';
2933 		(*ivopts)++;
2934 	}
2935 	/* Parse IV mode */
2936 	*ivmode = strrchr(tmp, '-');
2937 	if (*ivmode) {
2938 		**ivmode = '\0';
2939 		(*ivmode)++;
2940 	}
2941 	/* The rest is crypto API spec */
2942 	cipher_api = tmp;
2943 
2944 	/* Alloc AEAD, can be used only in new format. */
2945 	if (crypt_integrity_aead(cc)) {
2946 		ret = crypt_ctr_auth_cipher(cc, cipher_api);
2947 		if (ret < 0) {
2948 			ti->error = "Invalid AEAD cipher spec";
2949 			return ret;
2950 		}
2951 	}
2952 
2953 	if (*ivmode && !strcmp(*ivmode, "lmk"))
2954 		cc->tfms_count = 64;
2955 
2956 	if (*ivmode && !strcmp(*ivmode, "essiv")) {
2957 		if (!*ivopts) {
2958 			ti->error = "Digest algorithm missing for ESSIV mode";
2959 			return -EINVAL;
2960 		}
2961 		ret = snprintf(buf, CRYPTO_MAX_ALG_NAME, "essiv(%s,%s)",
2962 			       cipher_api, *ivopts);
2963 		if (ret < 0 || ret >= CRYPTO_MAX_ALG_NAME) {
2964 			ti->error = "Cannot allocate cipher string";
2965 			return -ENOMEM;
2966 		}
2967 		cipher_api = buf;
2968 	}
2969 
2970 	cc->key_parts = cc->tfms_count;
2971 
2972 	/* Allocate cipher */
2973 	ret = crypt_alloc_tfms(cc, cipher_api);
2974 	if (ret < 0) {
2975 		ti->error = "Error allocating crypto tfm";
2976 		return ret;
2977 	}
2978 
2979 	if (crypt_integrity_aead(cc))
2980 		cc->iv_size = crypto_aead_ivsize(any_tfm_aead(cc));
2981 	else
2982 		cc->iv_size = crypto_skcipher_ivsize(any_tfm(cc));
2983 
2984 	return 0;
2985 }
2986 
crypt_ctr_cipher_old(struct dm_target * ti,char * cipher_in,char * key,char ** ivmode,char ** ivopts)2987 static int crypt_ctr_cipher_old(struct dm_target *ti, char *cipher_in, char *key,
2988 				char **ivmode, char **ivopts)
2989 {
2990 	struct crypt_config *cc = ti->private;
2991 	char *tmp, *cipher, *chainmode, *keycount;
2992 	char *cipher_api = NULL;
2993 	int ret = -EINVAL;
2994 	char dummy;
2995 
2996 	if (strchr(cipher_in, '(') || crypt_integrity_aead(cc)) {
2997 		ti->error = "Bad cipher specification";
2998 		return -EINVAL;
2999 	}
3000 
3001 	/*
3002 	 * Legacy dm-crypt cipher specification
3003 	 * cipher[:keycount]-mode-iv:ivopts
3004 	 */
3005 	tmp = cipher_in;
3006 	keycount = strsep(&tmp, "-");
3007 	cipher = strsep(&keycount, ":");
3008 
3009 	if (!keycount)
3010 		cc->tfms_count = 1;
3011 	else if (sscanf(keycount, "%u%c", &cc->tfms_count, &dummy) != 1 ||
3012 		 !is_power_of_2(cc->tfms_count)) {
3013 		ti->error = "Bad cipher key count specification";
3014 		return -EINVAL;
3015 	}
3016 	cc->key_parts = cc->tfms_count;
3017 
3018 	chainmode = strsep(&tmp, "-");
3019 	*ivmode = strsep(&tmp, ":");
3020 	*ivopts = tmp;
3021 
3022 	/*
3023 	 * For compatibility with the original dm-crypt mapping format, if
3024 	 * only the cipher name is supplied, use cbc-plain.
3025 	 */
3026 	if (!chainmode || (!strcmp(chainmode, "plain") && !*ivmode)) {
3027 		chainmode = "cbc";
3028 		*ivmode = "plain";
3029 	}
3030 
3031 	if (strcmp(chainmode, "ecb") && !*ivmode) {
3032 		ti->error = "IV mechanism required";
3033 		return -EINVAL;
3034 	}
3035 
3036 	cipher_api = kmalloc(CRYPTO_MAX_ALG_NAME, GFP_KERNEL);
3037 	if (!cipher_api)
3038 		goto bad_mem;
3039 
3040 	if (*ivmode && !strcmp(*ivmode, "essiv")) {
3041 		if (!*ivopts) {
3042 			ti->error = "Digest algorithm missing for ESSIV mode";
3043 			kfree(cipher_api);
3044 			return -EINVAL;
3045 		}
3046 		ret = snprintf(cipher_api, CRYPTO_MAX_ALG_NAME,
3047 			       "essiv(%s(%s),%s)", chainmode, cipher, *ivopts);
3048 	} else {
3049 		ret = snprintf(cipher_api, CRYPTO_MAX_ALG_NAME,
3050 			       "%s(%s)", chainmode, cipher);
3051 	}
3052 	if (ret < 0 || ret >= CRYPTO_MAX_ALG_NAME) {
3053 		kfree(cipher_api);
3054 		goto bad_mem;
3055 	}
3056 
3057 	/* Allocate cipher */
3058 	ret = crypt_alloc_tfms(cc, cipher_api);
3059 	if (ret < 0) {
3060 		ti->error = "Error allocating crypto tfm";
3061 		kfree(cipher_api);
3062 		return ret;
3063 	}
3064 	kfree(cipher_api);
3065 
3066 	return 0;
3067 bad_mem:
3068 	ti->error = "Cannot allocate cipher strings";
3069 	return -ENOMEM;
3070 }
3071 
crypt_ctr_cipher(struct dm_target * ti,char * cipher_in,char * key)3072 static int crypt_ctr_cipher(struct dm_target *ti, char *cipher_in, char *key)
3073 {
3074 	struct crypt_config *cc = ti->private;
3075 	char *ivmode = NULL, *ivopts = NULL;
3076 	int ret;
3077 
3078 	cc->cipher_string = kstrdup(cipher_in, GFP_KERNEL);
3079 	if (!cc->cipher_string) {
3080 		ti->error = "Cannot allocate cipher strings";
3081 		return -ENOMEM;
3082 	}
3083 
3084 	if (strstarts(cipher_in, "capi:"))
3085 		ret = crypt_ctr_cipher_new(ti, cipher_in, key, &ivmode, &ivopts);
3086 	else
3087 		ret = crypt_ctr_cipher_old(ti, cipher_in, key, &ivmode, &ivopts);
3088 	if (ret)
3089 		return ret;
3090 
3091 	/* Initialize IV */
3092 	ret = crypt_ctr_ivmode(ti, ivmode);
3093 	if (ret < 0)
3094 		return ret;
3095 
3096 	/* Initialize and set key */
3097 	ret = crypt_set_key(cc, key);
3098 	if (ret < 0) {
3099 		ti->error = "Error decoding and setting key";
3100 		return ret;
3101 	}
3102 
3103 	/* Allocate IV */
3104 	if (cc->iv_gen_ops && cc->iv_gen_ops->ctr) {
3105 		ret = cc->iv_gen_ops->ctr(cc, ti, ivopts);
3106 		if (ret < 0) {
3107 			ti->error = "Error creating IV";
3108 			return ret;
3109 		}
3110 	}
3111 
3112 	/* Initialize IV (set keys for ESSIV etc) */
3113 	if (cc->iv_gen_ops && cc->iv_gen_ops->init) {
3114 		ret = cc->iv_gen_ops->init(cc);
3115 		if (ret < 0) {
3116 			ti->error = "Error initialising IV";
3117 			return ret;
3118 		}
3119 	}
3120 
3121 	/* wipe the kernel key payload copy */
3122 	if (cc->key_string)
3123 		memset(cc->key, 0, cc->key_size * sizeof(u8));
3124 
3125 	return ret;
3126 }
3127 
crypt_ctr_optional(struct dm_target * ti,unsigned int argc,char ** argv)3128 static int crypt_ctr_optional(struct dm_target *ti, unsigned int argc, char **argv)
3129 {
3130 	struct crypt_config *cc = ti->private;
3131 	struct dm_arg_set as;
3132 	static const struct dm_arg _args[] = {
3133 		{0, 8, "Invalid number of feature args"},
3134 	};
3135 	unsigned int opt_params, val;
3136 	const char *opt_string, *sval;
3137 	char dummy;
3138 	int ret;
3139 
3140 	/* Optional parameters */
3141 	as.argc = argc;
3142 	as.argv = argv;
3143 
3144 	ret = dm_read_arg_group(_args, &as, &opt_params, &ti->error);
3145 	if (ret)
3146 		return ret;
3147 
3148 	while (opt_params--) {
3149 		opt_string = dm_shift_arg(&as);
3150 		if (!opt_string) {
3151 			ti->error = "Not enough feature arguments";
3152 			return -EINVAL;
3153 		}
3154 
3155 		if (!strcasecmp(opt_string, "allow_discards"))
3156 			ti->num_discard_bios = 1;
3157 
3158 		else if (!strcasecmp(opt_string, "same_cpu_crypt"))
3159 			set_bit(DM_CRYPT_SAME_CPU, &cc->flags);
3160 
3161 		else if (!strcasecmp(opt_string, "submit_from_crypt_cpus"))
3162 			set_bit(DM_CRYPT_NO_OFFLOAD, &cc->flags);
3163 		else if (!strcasecmp(opt_string, "no_read_workqueue"))
3164 			set_bit(DM_CRYPT_NO_READ_WORKQUEUE, &cc->flags);
3165 		else if (!strcasecmp(opt_string, "no_write_workqueue"))
3166 			set_bit(DM_CRYPT_NO_WRITE_WORKQUEUE, &cc->flags);
3167 		else if (sscanf(opt_string, "integrity:%u:", &val) == 1) {
3168 			if (val == 0 || val > MAX_TAG_SIZE) {
3169 				ti->error = "Invalid integrity arguments";
3170 				return -EINVAL;
3171 			}
3172 			cc->on_disk_tag_size = val;
3173 			sval = strchr(opt_string + strlen("integrity:"), ':') + 1;
3174 			if (!strcasecmp(sval, "aead")) {
3175 				set_bit(CRYPT_MODE_INTEGRITY_AEAD, &cc->cipher_flags);
3176 			} else if (strcasecmp(sval, "none")) {
3177 				ti->error = "Unknown integrity profile";
3178 				return -EINVAL;
3179 			}
3180 
3181 			cc->cipher_auth = kstrdup(sval, GFP_KERNEL);
3182 			if (!cc->cipher_auth)
3183 				return -ENOMEM;
3184 		} else if (sscanf(opt_string, "sector_size:%hu%c", &cc->sector_size, &dummy) == 1) {
3185 			if (cc->sector_size < (1 << SECTOR_SHIFT) ||
3186 			    cc->sector_size > 4096 ||
3187 			    (cc->sector_size & (cc->sector_size - 1))) {
3188 				ti->error = "Invalid feature value for sector_size";
3189 				return -EINVAL;
3190 			}
3191 			if (ti->len & ((cc->sector_size >> SECTOR_SHIFT) - 1)) {
3192 				ti->error = "Device size is not multiple of sector_size feature";
3193 				return -EINVAL;
3194 			}
3195 			cc->sector_shift = __ffs(cc->sector_size) - SECTOR_SHIFT;
3196 		} else if (!strcasecmp(opt_string, "iv_large_sectors"))
3197 			set_bit(CRYPT_IV_LARGE_SECTORS, &cc->cipher_flags);
3198 		else {
3199 			ti->error = "Invalid feature arguments";
3200 			return -EINVAL;
3201 		}
3202 	}
3203 
3204 	return 0;
3205 }
3206 
3207 #ifdef CONFIG_BLK_DEV_ZONED
crypt_report_zones(struct dm_target * ti,struct dm_report_zones_args * args,unsigned int nr_zones)3208 static int crypt_report_zones(struct dm_target *ti,
3209 		struct dm_report_zones_args *args, unsigned int nr_zones)
3210 {
3211 	struct crypt_config *cc = ti->private;
3212 
3213 	return dm_report_zones(cc->dev->bdev, cc->start,
3214 			cc->start + dm_target_offset(ti, args->next_sector),
3215 			args, nr_zones);
3216 }
3217 #else
3218 #define crypt_report_zones NULL
3219 #endif
3220 
3221 /*
3222  * Construct an encryption mapping:
3223  * <cipher> [<key>|:<key_size>:<user|logon>:<key_description>] <iv_offset> <dev_path> <start>
3224  */
crypt_ctr(struct dm_target * ti,unsigned int argc,char ** argv)3225 static int crypt_ctr(struct dm_target *ti, unsigned int argc, char **argv)
3226 {
3227 	struct crypt_config *cc;
3228 	const char *devname = dm_table_device_name(ti->table);
3229 	int key_size;
3230 	unsigned int align_mask;
3231 	unsigned long long tmpll;
3232 	int ret;
3233 	size_t iv_size_padding, additional_req_size;
3234 	char dummy;
3235 
3236 	if (argc < 5) {
3237 		ti->error = "Not enough arguments";
3238 		return -EINVAL;
3239 	}
3240 
3241 	key_size = get_key_size(&argv[1]);
3242 	if (key_size < 0) {
3243 		ti->error = "Cannot parse key size";
3244 		return -EINVAL;
3245 	}
3246 
3247 	cc = kzalloc(struct_size(cc, key, key_size), GFP_KERNEL);
3248 	if (!cc) {
3249 		ti->error = "Cannot allocate encryption context";
3250 		return -ENOMEM;
3251 	}
3252 	cc->key_size = key_size;
3253 	cc->sector_size = (1 << SECTOR_SHIFT);
3254 	cc->sector_shift = 0;
3255 
3256 	ti->private = cc;
3257 
3258 	spin_lock(&dm_crypt_clients_lock);
3259 	dm_crypt_clients_n++;
3260 	crypt_calculate_pages_per_client();
3261 	spin_unlock(&dm_crypt_clients_lock);
3262 
3263 	ret = percpu_counter_init(&cc->n_allocated_pages, 0, GFP_KERNEL);
3264 	if (ret < 0)
3265 		goto bad;
3266 
3267 	/* Optional parameters need to be read before cipher constructor */
3268 	if (argc > 5) {
3269 		ret = crypt_ctr_optional(ti, argc - 5, &argv[5]);
3270 		if (ret)
3271 			goto bad;
3272 	}
3273 
3274 	ret = crypt_ctr_cipher(ti, argv[0], argv[1]);
3275 	if (ret < 0)
3276 		goto bad;
3277 
3278 	if (crypt_integrity_aead(cc)) {
3279 		cc->dmreq_start = sizeof(struct aead_request);
3280 		cc->dmreq_start += crypto_aead_reqsize(any_tfm_aead(cc));
3281 		align_mask = crypto_aead_alignmask(any_tfm_aead(cc));
3282 	} else {
3283 		cc->dmreq_start = sizeof(struct skcipher_request);
3284 		cc->dmreq_start += crypto_skcipher_reqsize(any_tfm(cc));
3285 		align_mask = crypto_skcipher_alignmask(any_tfm(cc));
3286 	}
3287 	cc->dmreq_start = ALIGN(cc->dmreq_start, __alignof__(struct dm_crypt_request));
3288 
3289 	if (align_mask < CRYPTO_MINALIGN) {
3290 		/* Allocate the padding exactly */
3291 		iv_size_padding = -(cc->dmreq_start + sizeof(struct dm_crypt_request))
3292 				& align_mask;
3293 	} else {
3294 		/*
3295 		 * If the cipher requires greater alignment than kmalloc
3296 		 * alignment, we don't know the exact position of the
3297 		 * initialization vector. We must assume worst case.
3298 		 */
3299 		iv_size_padding = align_mask;
3300 	}
3301 
3302 	/*  ...| IV + padding | original IV | original sec. number | bio tag offset | */
3303 	additional_req_size = sizeof(struct dm_crypt_request) +
3304 		iv_size_padding + cc->iv_size +
3305 		cc->iv_size +
3306 		sizeof(uint64_t) +
3307 		sizeof(unsigned int);
3308 
3309 	ret = mempool_init_kmalloc_pool(&cc->req_pool, MIN_IOS, cc->dmreq_start + additional_req_size);
3310 	if (ret) {
3311 		ti->error = "Cannot allocate crypt request mempool";
3312 		goto bad;
3313 	}
3314 
3315 	cc->per_bio_data_size = ti->per_io_data_size =
3316 		ALIGN(sizeof(struct dm_crypt_io) + cc->dmreq_start + additional_req_size,
3317 		      ARCH_DMA_MINALIGN);
3318 
3319 	ret = mempool_init(&cc->page_pool, BIO_MAX_VECS, crypt_page_alloc, crypt_page_free, cc);
3320 	if (ret) {
3321 		ti->error = "Cannot allocate page mempool";
3322 		goto bad;
3323 	}
3324 
3325 	ret = bioset_init(&cc->bs, MIN_IOS, 0, BIOSET_NEED_BVECS);
3326 	if (ret) {
3327 		ti->error = "Cannot allocate crypt bioset";
3328 		goto bad;
3329 	}
3330 
3331 	mutex_init(&cc->bio_alloc_lock);
3332 
3333 	ret = -EINVAL;
3334 	if ((sscanf(argv[2], "%llu%c", &tmpll, &dummy) != 1) ||
3335 	    (tmpll & ((cc->sector_size >> SECTOR_SHIFT) - 1))) {
3336 		ti->error = "Invalid iv_offset sector";
3337 		goto bad;
3338 	}
3339 	cc->iv_offset = tmpll;
3340 
3341 	ret = dm_get_device(ti, argv[3], dm_table_get_mode(ti->table), &cc->dev);
3342 	if (ret) {
3343 		ti->error = "Device lookup failed";
3344 		goto bad;
3345 	}
3346 
3347 	ret = -EINVAL;
3348 	if (sscanf(argv[4], "%llu%c", &tmpll, &dummy) != 1 || tmpll != (sector_t)tmpll) {
3349 		ti->error = "Invalid device sector";
3350 		goto bad;
3351 	}
3352 	cc->start = tmpll;
3353 
3354 	if (bdev_is_zoned(cc->dev->bdev)) {
3355 		/*
3356 		 * For zoned block devices, we need to preserve the issuer write
3357 		 * ordering. To do so, disable write workqueues and force inline
3358 		 * encryption completion.
3359 		 */
3360 		set_bit(DM_CRYPT_NO_WRITE_WORKQUEUE, &cc->flags);
3361 		set_bit(DM_CRYPT_WRITE_INLINE, &cc->flags);
3362 
3363 		/*
3364 		 * All zone append writes to a zone of a zoned block device will
3365 		 * have the same BIO sector, the start of the zone. When the
3366 		 * cypher IV mode uses sector values, all data targeting a
3367 		 * zone will be encrypted using the first sector numbers of the
3368 		 * zone. This will not result in write errors but will
3369 		 * cause most reads to fail as reads will use the sector values
3370 		 * for the actual data locations, resulting in IV mismatch.
3371 		 * To avoid this problem, ask DM core to emulate zone append
3372 		 * operations with regular writes.
3373 		 */
3374 		DMDEBUG("Zone append operations will be emulated");
3375 		ti->emulate_zone_append = true;
3376 	}
3377 
3378 	if (crypt_integrity_aead(cc) || cc->integrity_iv_size) {
3379 		ret = crypt_integrity_ctr(cc, ti);
3380 		if (ret)
3381 			goto bad;
3382 
3383 		cc->tag_pool_max_sectors = POOL_ENTRY_SIZE / cc->on_disk_tag_size;
3384 		if (!cc->tag_pool_max_sectors)
3385 			cc->tag_pool_max_sectors = 1;
3386 
3387 		ret = mempool_init_kmalloc_pool(&cc->tag_pool, MIN_IOS,
3388 			cc->tag_pool_max_sectors * cc->on_disk_tag_size);
3389 		if (ret) {
3390 			ti->error = "Cannot allocate integrity tags mempool";
3391 			goto bad;
3392 		}
3393 
3394 		cc->tag_pool_max_sectors <<= cc->sector_shift;
3395 	}
3396 
3397 	ret = -ENOMEM;
3398 	cc->io_queue = alloc_workqueue("kcryptd_io/%s", WQ_MEM_RECLAIM, 1, devname);
3399 	if (!cc->io_queue) {
3400 		ti->error = "Couldn't create kcryptd io queue";
3401 		goto bad;
3402 	}
3403 
3404 	if (test_bit(DM_CRYPT_SAME_CPU, &cc->flags))
3405 		cc->crypt_queue = alloc_workqueue("kcryptd/%s", WQ_CPU_INTENSIVE | WQ_MEM_RECLAIM,
3406 						  1, devname);
3407 	else
3408 		cc->crypt_queue = alloc_workqueue("kcryptd/%s",
3409 						  WQ_CPU_INTENSIVE | WQ_MEM_RECLAIM | WQ_UNBOUND,
3410 						  num_online_cpus(), devname);
3411 	if (!cc->crypt_queue) {
3412 		ti->error = "Couldn't create kcryptd queue";
3413 		goto bad;
3414 	}
3415 
3416 	spin_lock_init(&cc->write_thread_lock);
3417 	cc->write_tree = RB_ROOT;
3418 
3419 	cc->write_thread = kthread_run(dmcrypt_write, cc, "dmcrypt_write/%s", devname);
3420 	if (IS_ERR(cc->write_thread)) {
3421 		ret = PTR_ERR(cc->write_thread);
3422 		cc->write_thread = NULL;
3423 		ti->error = "Couldn't spawn write thread";
3424 		goto bad;
3425 	}
3426 
3427 	ti->num_flush_bios = 1;
3428 	ti->limit_swap_bios = true;
3429 	ti->accounts_remapped_io = true;
3430 
3431 	dm_audit_log_ctr(DM_MSG_PREFIX, ti, 1);
3432 	return 0;
3433 
3434 bad:
3435 	dm_audit_log_ctr(DM_MSG_PREFIX, ti, 0);
3436 	crypt_dtr(ti);
3437 	return ret;
3438 }
3439 
crypt_map(struct dm_target * ti,struct bio * bio)3440 static int crypt_map(struct dm_target *ti, struct bio *bio)
3441 {
3442 	struct dm_crypt_io *io;
3443 	struct crypt_config *cc = ti->private;
3444 
3445 	/*
3446 	 * If bio is REQ_PREFLUSH or REQ_OP_DISCARD, just bypass crypt queues.
3447 	 * - for REQ_PREFLUSH device-mapper core ensures that no IO is in-flight
3448 	 * - for REQ_OP_DISCARD caller must use flush if IO ordering matters
3449 	 */
3450 	if (unlikely(bio->bi_opf & REQ_PREFLUSH ||
3451 	    bio_op(bio) == REQ_OP_DISCARD)) {
3452 		bio_set_dev(bio, cc->dev->bdev);
3453 		if (bio_sectors(bio))
3454 			bio->bi_iter.bi_sector = cc->start +
3455 				dm_target_offset(ti, bio->bi_iter.bi_sector);
3456 		return DM_MAPIO_REMAPPED;
3457 	}
3458 
3459 	/*
3460 	 * Check if bio is too large, split as needed.
3461 	 */
3462 	if (unlikely(bio->bi_iter.bi_size > (BIO_MAX_VECS << PAGE_SHIFT)) &&
3463 	    (bio_data_dir(bio) == WRITE || cc->on_disk_tag_size))
3464 		dm_accept_partial_bio(bio, ((BIO_MAX_VECS << PAGE_SHIFT) >> SECTOR_SHIFT));
3465 
3466 	/*
3467 	 * Ensure that bio is a multiple of internal sector encryption size
3468 	 * and is aligned to this size as defined in IO hints.
3469 	 */
3470 	if (unlikely((bio->bi_iter.bi_sector & ((cc->sector_size >> SECTOR_SHIFT) - 1)) != 0))
3471 		return DM_MAPIO_KILL;
3472 
3473 	if (unlikely(bio->bi_iter.bi_size & (cc->sector_size - 1)))
3474 		return DM_MAPIO_KILL;
3475 
3476 	io = dm_per_bio_data(bio, cc->per_bio_data_size);
3477 	crypt_io_init(io, cc, bio, dm_target_offset(ti, bio->bi_iter.bi_sector));
3478 
3479 	if (cc->on_disk_tag_size) {
3480 		unsigned int tag_len = cc->on_disk_tag_size * (bio_sectors(bio) >> cc->sector_shift);
3481 
3482 		if (unlikely(tag_len > KMALLOC_MAX_SIZE))
3483 			io->integrity_metadata = NULL;
3484 		else
3485 			io->integrity_metadata = kmalloc(tag_len, GFP_NOIO | __GFP_NORETRY | __GFP_NOMEMALLOC | __GFP_NOWARN);
3486 
3487 		if (unlikely(!io->integrity_metadata)) {
3488 			if (bio_sectors(bio) > cc->tag_pool_max_sectors)
3489 				dm_accept_partial_bio(bio, cc->tag_pool_max_sectors);
3490 			io->integrity_metadata = mempool_alloc(&cc->tag_pool, GFP_NOIO);
3491 			io->integrity_metadata_from_pool = true;
3492 		}
3493 	}
3494 
3495 	if (crypt_integrity_aead(cc))
3496 		io->ctx.r.req_aead = (struct aead_request *)(io + 1);
3497 	else
3498 		io->ctx.r.req = (struct skcipher_request *)(io + 1);
3499 
3500 	if (bio_data_dir(io->base_bio) == READ) {
3501 		if (kcryptd_io_read(io, CRYPT_MAP_READ_GFP))
3502 			kcryptd_queue_read(io);
3503 	} else
3504 		kcryptd_queue_crypt(io);
3505 
3506 	return DM_MAPIO_SUBMITTED;
3507 }
3508 
hex2asc(unsigned char c)3509 static char hex2asc(unsigned char c)
3510 {
3511 	return c + '0' + ((unsigned int)(9 - c) >> 4 & 0x27);
3512 }
3513 
crypt_status(struct dm_target * ti,status_type_t type,unsigned int status_flags,char * result,unsigned int maxlen)3514 static void crypt_status(struct dm_target *ti, status_type_t type,
3515 			 unsigned int status_flags, char *result, unsigned int maxlen)
3516 {
3517 	struct crypt_config *cc = ti->private;
3518 	unsigned int i, sz = 0;
3519 	int num_feature_args = 0;
3520 
3521 	switch (type) {
3522 	case STATUSTYPE_INFO:
3523 		result[0] = '\0';
3524 		break;
3525 
3526 	case STATUSTYPE_TABLE:
3527 		DMEMIT("%s ", cc->cipher_string);
3528 
3529 		if (cc->key_size > 0) {
3530 			if (cc->key_string)
3531 				DMEMIT(":%u:%s", cc->key_size, cc->key_string);
3532 			else {
3533 				for (i = 0; i < cc->key_size; i++) {
3534 					DMEMIT("%c%c", hex2asc(cc->key[i] >> 4),
3535 					       hex2asc(cc->key[i] & 0xf));
3536 				}
3537 			}
3538 		} else
3539 			DMEMIT("-");
3540 
3541 		DMEMIT(" %llu %s %llu", (unsigned long long)cc->iv_offset,
3542 				cc->dev->name, (unsigned long long)cc->start);
3543 
3544 		num_feature_args += !!ti->num_discard_bios;
3545 		num_feature_args += test_bit(DM_CRYPT_SAME_CPU, &cc->flags);
3546 		num_feature_args += test_bit(DM_CRYPT_NO_OFFLOAD, &cc->flags);
3547 		num_feature_args += test_bit(DM_CRYPT_NO_READ_WORKQUEUE, &cc->flags);
3548 		num_feature_args += test_bit(DM_CRYPT_NO_WRITE_WORKQUEUE, &cc->flags);
3549 		num_feature_args += cc->sector_size != (1 << SECTOR_SHIFT);
3550 		num_feature_args += test_bit(CRYPT_IV_LARGE_SECTORS, &cc->cipher_flags);
3551 		if (cc->on_disk_tag_size)
3552 			num_feature_args++;
3553 		if (num_feature_args) {
3554 			DMEMIT(" %d", num_feature_args);
3555 			if (ti->num_discard_bios)
3556 				DMEMIT(" allow_discards");
3557 			if (test_bit(DM_CRYPT_SAME_CPU, &cc->flags))
3558 				DMEMIT(" same_cpu_crypt");
3559 			if (test_bit(DM_CRYPT_NO_OFFLOAD, &cc->flags))
3560 				DMEMIT(" submit_from_crypt_cpus");
3561 			if (test_bit(DM_CRYPT_NO_READ_WORKQUEUE, &cc->flags))
3562 				DMEMIT(" no_read_workqueue");
3563 			if (test_bit(DM_CRYPT_NO_WRITE_WORKQUEUE, &cc->flags))
3564 				DMEMIT(" no_write_workqueue");
3565 			if (cc->on_disk_tag_size)
3566 				DMEMIT(" integrity:%u:%s", cc->on_disk_tag_size, cc->cipher_auth);
3567 			if (cc->sector_size != (1 << SECTOR_SHIFT))
3568 				DMEMIT(" sector_size:%d", cc->sector_size);
3569 			if (test_bit(CRYPT_IV_LARGE_SECTORS, &cc->cipher_flags))
3570 				DMEMIT(" iv_large_sectors");
3571 		}
3572 		break;
3573 
3574 	case STATUSTYPE_IMA:
3575 		DMEMIT_TARGET_NAME_VERSION(ti->type);
3576 		DMEMIT(",allow_discards=%c", ti->num_discard_bios ? 'y' : 'n');
3577 		DMEMIT(",same_cpu_crypt=%c", test_bit(DM_CRYPT_SAME_CPU, &cc->flags) ? 'y' : 'n');
3578 		DMEMIT(",submit_from_crypt_cpus=%c", test_bit(DM_CRYPT_NO_OFFLOAD, &cc->flags) ?
3579 		       'y' : 'n');
3580 		DMEMIT(",no_read_workqueue=%c", test_bit(DM_CRYPT_NO_READ_WORKQUEUE, &cc->flags) ?
3581 		       'y' : 'n');
3582 		DMEMIT(",no_write_workqueue=%c", test_bit(DM_CRYPT_NO_WRITE_WORKQUEUE, &cc->flags) ?
3583 		       'y' : 'n');
3584 		DMEMIT(",iv_large_sectors=%c", test_bit(CRYPT_IV_LARGE_SECTORS, &cc->cipher_flags) ?
3585 		       'y' : 'n');
3586 
3587 		if (cc->on_disk_tag_size)
3588 			DMEMIT(",integrity_tag_size=%u,cipher_auth=%s",
3589 			       cc->on_disk_tag_size, cc->cipher_auth);
3590 		if (cc->sector_size != (1 << SECTOR_SHIFT))
3591 			DMEMIT(",sector_size=%d", cc->sector_size);
3592 		if (cc->cipher_string)
3593 			DMEMIT(",cipher_string=%s", cc->cipher_string);
3594 
3595 		DMEMIT(",key_size=%u", cc->key_size);
3596 		DMEMIT(",key_parts=%u", cc->key_parts);
3597 		DMEMIT(",key_extra_size=%u", cc->key_extra_size);
3598 		DMEMIT(",key_mac_size=%u", cc->key_mac_size);
3599 		DMEMIT(";");
3600 		break;
3601 	}
3602 }
3603 
crypt_postsuspend(struct dm_target * ti)3604 static void crypt_postsuspend(struct dm_target *ti)
3605 {
3606 	struct crypt_config *cc = ti->private;
3607 
3608 	set_bit(DM_CRYPT_SUSPENDED, &cc->flags);
3609 }
3610 
crypt_preresume(struct dm_target * ti)3611 static int crypt_preresume(struct dm_target *ti)
3612 {
3613 	struct crypt_config *cc = ti->private;
3614 
3615 	if (!test_bit(DM_CRYPT_KEY_VALID, &cc->flags)) {
3616 		DMERR("aborting resume - crypt key is not set.");
3617 		return -EAGAIN;
3618 	}
3619 
3620 	return 0;
3621 }
3622 
crypt_resume(struct dm_target * ti)3623 static void crypt_resume(struct dm_target *ti)
3624 {
3625 	struct crypt_config *cc = ti->private;
3626 
3627 	clear_bit(DM_CRYPT_SUSPENDED, &cc->flags);
3628 }
3629 
3630 /* Message interface
3631  *	key set <key>
3632  *	key wipe
3633  */
crypt_message(struct dm_target * ti,unsigned int argc,char ** argv,char * result,unsigned int maxlen)3634 static int crypt_message(struct dm_target *ti, unsigned int argc, char **argv,
3635 			 char *result, unsigned int maxlen)
3636 {
3637 	struct crypt_config *cc = ti->private;
3638 	int key_size, ret = -EINVAL;
3639 
3640 	if (argc < 2)
3641 		goto error;
3642 
3643 	if (!strcasecmp(argv[0], "key")) {
3644 		if (!test_bit(DM_CRYPT_SUSPENDED, &cc->flags)) {
3645 			DMWARN("not suspended during key manipulation.");
3646 			return -EINVAL;
3647 		}
3648 		if (argc == 3 && !strcasecmp(argv[1], "set")) {
3649 			/* The key size may not be changed. */
3650 			key_size = get_key_size(&argv[2]);
3651 			if (key_size < 0 || cc->key_size != key_size) {
3652 				memset(argv[2], '0', strlen(argv[2]));
3653 				return -EINVAL;
3654 			}
3655 
3656 			ret = crypt_set_key(cc, argv[2]);
3657 			if (ret)
3658 				return ret;
3659 			if (cc->iv_gen_ops && cc->iv_gen_ops->init)
3660 				ret = cc->iv_gen_ops->init(cc);
3661 			/* wipe the kernel key payload copy */
3662 			if (cc->key_string)
3663 				memset(cc->key, 0, cc->key_size * sizeof(u8));
3664 			return ret;
3665 		}
3666 		if (argc == 2 && !strcasecmp(argv[1], "wipe"))
3667 			return crypt_wipe_key(cc);
3668 	}
3669 
3670 error:
3671 	DMWARN("unrecognised message received.");
3672 	return -EINVAL;
3673 }
3674 
crypt_iterate_devices(struct dm_target * ti,iterate_devices_callout_fn fn,void * data)3675 static int crypt_iterate_devices(struct dm_target *ti,
3676 				 iterate_devices_callout_fn fn, void *data)
3677 {
3678 	struct crypt_config *cc = ti->private;
3679 
3680 	return fn(ti, cc->dev, cc->start, ti->len, data);
3681 }
3682 
crypt_io_hints(struct dm_target * ti,struct queue_limits * limits)3683 static void crypt_io_hints(struct dm_target *ti, struct queue_limits *limits)
3684 {
3685 	struct crypt_config *cc = ti->private;
3686 
3687 	/*
3688 	 * Unfortunate constraint that is required to avoid the potential
3689 	 * for exceeding underlying device's max_segments limits -- due to
3690 	 * crypt_alloc_buffer() possibly allocating pages for the encryption
3691 	 * bio that are not as physically contiguous as the original bio.
3692 	 */
3693 	limits->max_segment_size = PAGE_SIZE;
3694 
3695 	limits->logical_block_size =
3696 		max_t(unsigned int, limits->logical_block_size, cc->sector_size);
3697 	limits->physical_block_size =
3698 		max_t(unsigned int, limits->physical_block_size, cc->sector_size);
3699 	limits->io_min = max_t(unsigned int, limits->io_min, cc->sector_size);
3700 	limits->dma_alignment = limits->logical_block_size - 1;
3701 }
3702 
3703 static struct target_type crypt_target = {
3704 	.name   = "crypt",
3705 	.version = {1, 24, 0},
3706 	.module = THIS_MODULE,
3707 	.ctr    = crypt_ctr,
3708 	.dtr    = crypt_dtr,
3709 	.features = DM_TARGET_ZONED_HM,
3710 	.report_zones = crypt_report_zones,
3711 	.map    = crypt_map,
3712 	.status = crypt_status,
3713 	.postsuspend = crypt_postsuspend,
3714 	.preresume = crypt_preresume,
3715 	.resume = crypt_resume,
3716 	.message = crypt_message,
3717 	.iterate_devices = crypt_iterate_devices,
3718 	.io_hints = crypt_io_hints,
3719 };
3720 module_dm(crypt);
3721 
3722 MODULE_AUTHOR("Jana Saout <jana@saout.de>");
3723 MODULE_DESCRIPTION(DM_NAME " target for transparent encryption / decryption");
3724 MODULE_LICENSE("GPL");
3725