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

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

[gregkh]

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 <stable@vger.kernel.org> know about it.


>From 95b1369a9638cfa322ad1c0cde8efbe524059884 Mon Sep 17 00:00:00 2001
From: Mikulas Patocka <mpatocka@redhat.com>
Date: Tue, 7 Nov 2017 10:40:40 -0500
Subject: dm integrity: allow unaligned bv_offset
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

From: Mikulas Patocka <mpatocka@redhat.com>

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.

Fixes: 7eada909bfd7 ("dm: add integrity target")
Reported-by: Bruno Prémont <bonbons@sysophe.eu>
Reviewed-by: Milan Broz <gmazyland@gmail.com>
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

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

--- a/drivers/md/dm-integrity.c
+++ b/drivers/md/dm-integrity.c
@@ -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 mpatocka@redhat.com 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