Merge tag 'for-6.8/dm-fix-3' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm

Pull device mapper fix from Mike Snitzer:

 - Fix DM integrity and verity targets to not use excessive stack when
   they recheck in the error path.

* tag 'for-6.8/dm-fix-3' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm:
  dm-integrity, dm-verity: reduce stack usage for recheck

Author: torvalds

drivers/md/dm-integrity.c

@@ -1691,14 +1691,13 @@ static void integrity_sector_checksum(struct dm_integrity_c *ic, sector_t sector
 	get_random_bytes(result, ic->tag_size);
 }
 
-static void integrity_recheck(struct dm_integrity_io *dio)
+static noinline void integrity_recheck(struct dm_integrity_io *dio, char *checksum)
 {
 	struct bio *bio = dm_bio_from_per_bio_data(dio, sizeof(struct dm_integrity_io));
 	struct dm_integrity_c *ic = dio->ic;
 	struct bvec_iter iter;
 	struct bio_vec bv;
 	sector_t sector, logical_sector, area, offset;
-	char checksum_onstack[max_t(size_t, HASH_MAX_DIGESTSIZE, MAX_TAG_SIZE)];
 	struct page *page;
 	void *buffer;
 
@@ -1734,9 +1733,8 @@ static void integrity_recheck(struct dm_integrity_io *dio)
 				goto free_ret;
 			}
 
-			integrity_sector_checksum(ic, logical_sector, buffer,
-						  checksum_onstack);
-			r = dm_integrity_rw_tag(ic, checksum_onstack, &dio->metadata_block,
+			integrity_sector_checksum(ic, logical_sector, buffer, checksum);
+			r = dm_integrity_rw_tag(ic, checksum, &dio->metadata_block,
 						&dio->metadata_offset, ic->tag_size, TAG_CMP);
 			if (r) {
 				if (r > 0) {
@@ -1851,7 +1849,7 @@ static void integrity_metadata(struct work_struct *w)
 						checksums_ptr - checksums, dio->op == REQ_OP_READ ? TAG_CMP : TAG_WRITE);
 			if (unlikely(r)) {
 				if (r > 0) {
-					integrity_recheck(dio);
+					integrity_recheck(dio, checksums);
 					goto skip_io;
 				}
 				if (likely(checksums != checksums_onstack))

drivers/md/dm-verity-target.c

@@ -491,8 +491,8 @@ static int verity_recheck_copy(struct dm_verity *v, struct dm_verity_io *io,
 	return 0;
 }
 
-static int verity_recheck(struct dm_verity *v, struct dm_verity_io *io,
-			  struct bvec_iter start, sector_t cur_block)
+static noinline int verity_recheck(struct dm_verity *v, struct dm_verity_io *io,
+				   struct bvec_iter start, sector_t cur_block)
 {
 	struct page *page;
 	void *buffer;