Patch "dm integrity: allow unaligned bv_offset" has been added to the 4.14-stable tree

This is a note to let you know that I've just added the patch titled

dm integrity: allow unaligned bv_offset

to the 4.14-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
dm-integrity-allow-unaligned-bv_offset.patch
and it can be found in the queue-4.14 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree, please let <[email protected]> know about it.

From: Mikulas Patocka <[email protected]>
Date: Tue, 7 Nov 2017 10:40:40 -0500
Subject: dm integrity: allow unaligned bv_offset
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From: Mikulas Patocka <[email protected]>

commit 95b1369a9638cfa322ad1c0cde8efbe524059884 upstream.

When slub_debug is enabled kmalloc returns unaligned memory. XFS uses this unaligned memory for its buffers (if an unaligned buffer crosses a page, XFS frees it and allocates a full page instead - see the function xfs_buf_allocate_memory).

dm-integrity checks if bv_offset is aligned on page size and this check fail with slub_debug and XFS.

Fix this bug by removing the bv_offset check, leaving only the check for bv_len.

---
 drivers/md/dm-integrity.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

@@ -1376,7 +1376,7 @@ static int dm_integrity_map(struct dm_ta
 		struct bvec_iter iter;
 		struct bio_vec bv;
 		bio_for_each_segment(bv, bio, iter) {
-			if (unlikely((bv.bv_offset | bv.bv_len) & ((ic->sectors_per_block << SECTOR_SHIFT) - 1))) {
+			if (unlikely(bv.bv_len & ((ic->sectors_per_block << SECTOR_SHIFT) - 1))) {
 				DMERR("Bio vector (%u,%u) is not aligned on %u-sector boundary",
 					bv.bv_offset, bv.bv_len, ic->sectors_per_block);
 				return DM_MAPIO_KILL;

Patches currently in stable-queue which might be from [email protected] are

queue-4.14/dm-allocate-struct-mapped_device-with-kvzalloc.patch queue-4.14/dm-integrity-allow-unaligned-bv_offset.patch queue-4.14/dm-crypt-allow-unaligned-bv_offset.patch