Patch "dm crypt: 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 crypt: 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-crypt-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 10:35:57 -0500
Subject: dm crypt: allow unaligned bv_offset
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From: Mikulas Patocka <[email protected]>

commit 0440d5c0ca9744b92a07aeb6df0a9a75db6f4280 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-crypt checks if bv_offset is aligned on page size and these checks fail with slub_debug and XFS.

Fix this bug by removing the bv_offset checks. Switch to checking if bv_len is aligned instead of bv_offset (this check should be sufficient to prevent overruns if a bio with too small bv_len is received).

---
 drivers/md/dm-crypt.c |    4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

@@ -1075,7 +1075,7 @@ static int crypt_convert_block_aead(stru
 	BUG_ON(cc->integrity_iv_size && cc->integrity_iv_size != cc->iv_size);
 
 	/* Reject unexpected unaligned bio. */
-	if (unlikely(bv_in.bv_offset & (cc->sector_size - 1)))
+	if (unlikely(bv_in.bv_len & (cc->sector_size - 1)))
 		return -EIO;
 
 	dmreq = dmreq_of_req(cc, req);

@@ -1168,7 +1168,7 @@ static int crypt_convert_block_skcipher(
 	int r = 0;
 
 	/* Reject unexpected unaligned bio. */
-	if (unlikely(bv_in.bv_offset & (cc->sector_size - 1)))
+	if (unlikely(bv_in.bv_len & (cc->sector_size - 1)))
 		return -EIO;
 
 	dmreq = dmreq_of_req(cc, req);

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