Commit 8b8f8037 authored by Hou Tao's avatar Hou Tao Committed by Mikulas Patocka
Browse files

dm-crypt: track tag_offset in convert_context 



dm-crypt uses tag_offset to index the integrity metadata for each crypt
sector. When the initial crypt_convert() returns BLK_STS_DEV_RESOURCE,
dm-crypt will try to continue the crypt/decrypt procedure in a kworker.
However, it resets tag_offset as zero instead of using the tag_offset
related with current sector. It may return unexpected data when using
random IV or return unexpected integrity related error.

Fix the problem by tracking tag_offset in per-IO convert_context.
Therefore, when the crypt/decrypt procedure continues in a kworker, it
could use the next tag_offset saved in convert_context.

Fixes: 8abec36d ("dm crypt: do not wait for backlogged crypto request completion in softirq")
Cc: stable@vger.kernel.org
Signed-off-by: default avatarHou Tao <houtao1@huawei.com>
Signed-off-by: default avatarMikulas Patocka <mpatocka@redhat.com>
parent 996c451d

drivers/md/dm-crypt.c

+7 −6
Original line number Diff line number Diff line
@@ -59,6 +59,7 @@ struct convert_context { 
	struct bio *bio_out;

	struct bvec_iter iter_out;

	atomic_t cc_pending;

	unsigned int tag_offset;

	u64 cc_sector;

	union {

		struct skcipher_request *req;
@@ -1256,6 +1257,7 @@ static void crypt_convert_init(struct crypt_config *cc, 
	if (bio_out)

		ctx->iter_out = bio_out->bi_iter;

	ctx->cc_sector = sector + cc->iv_offset;

	ctx->tag_offset = 0;

	init_completion(&ctx->restart);

}
@@ -1588,7 +1590,6 @@ static void crypt_free_req(struct crypt_config *cc, void *req, struct bio *base_ 
static blk_status_t crypt_convert(struct crypt_config *cc,

			 struct convert_context *ctx, bool atomic, bool reset_pending)

{

	unsigned int tag_offset = 0;

	unsigned int sector_step = cc->sector_size >> SECTOR_SHIFT;

	int r;
@@ -1611,9 +1612,9 @@ static blk_status_t crypt_convert(struct crypt_config *cc, 
		atomic_inc(&ctx->cc_pending);



		if (crypt_integrity_aead(cc))

			r = crypt_convert_block_aead(cc, ctx, ctx->r.req_aead, tag_offset);

			r = crypt_convert_block_aead(cc, ctx, ctx->r.req_aead, ctx->tag_offset);

		else

			r = crypt_convert_block_skcipher(cc, ctx, ctx->r.req, tag_offset);

			r = crypt_convert_block_skcipher(cc, ctx, ctx->r.req, ctx->tag_offset);



		switch (r) {

		/*
@@ -1633,8 +1634,8 @@ static blk_status_t crypt_convert(struct crypt_config *cc, 
					 * exit and continue processing in a workqueue

					 */

					ctx->r.req = NULL;

					ctx->tag_offset++;

					ctx->cc_sector += sector_step;

					tag_offset++;

					return BLK_STS_DEV_RESOURCE;

				}

			} else {
@@ -1648,8 +1649,8 @@ static blk_status_t crypt_convert(struct crypt_config *cc, 
		 */

		case -EINPROGRESS:

			ctx->r.req = NULL;

			ctx->tag_offset++;

			ctx->cc_sector += sector_step;

			tag_offset++;

			continue;

		/*

		 * The request was already processed (synchronously).
@@ -1657,7 +1658,7 @@ static blk_status_t crypt_convert(struct crypt_config *cc, 
		case 0:

			atomic_dec(&ctx->cc_pending);

			ctx->cc_sector += sector_step;

			tag_offset++;

			ctx->tag_offset++;

			if (!atomic)

				cond_resched();

			continue;