From ff0c129d3b5ecb3df7c8f5e2236582bf745b6c5f Mon Sep 17 00:00:00 2001
From: Mikulas Patocka <mpatocka@redhat.com>
Date: Fri, 8 Feb 2019 10:52:07 -0500
Subject: [PATCH] dm crypt: don't overallocate the integrity tag space
Git-commit: ff0c129d3b5ecb3df7c8f5e2236582bf745b6c5f
Patch-mainline: v5.0-rc7
References: git fixes
bio_sectors() returns the value in the units of 512-byte sectors (no
matter what the real sector size of the device). dm-crypt multiplies
bio_sectors() by on_disk_tag_size to calculate the space allocated for
integrity tags. If dm-crypt is running with sector size larger than
512b, it allocates more data than is needed.
Device Mapper trims the extra space when passing the bio to
dm-integrity, so this bug didn't result in any visible misbehavior.
But it must be fixed to avoid wasteful memory allocation for the block
integrity payload.
Fixes: ef43aa38063a6 ("dm crypt: add cryptographic data integrity protection (authenticated encryption)")
Cc: stable@vger.kernel.org # 4.12+
Reported-by: Milan Broz <mbroz@redhat.com>
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Coly Li <colyli@suse.de>
---
drivers/md/dm-crypt.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/md/dm-crypt.c b/drivers/md/dm-crypt.c
index 47d4e0d30bf0..dd538e6b2748 100644
--- a/drivers/md/dm-crypt.c
+++ b/drivers/md/dm-crypt.c
@@ -932,7 +932,7 @@ static int dm_crypt_integrity_io_alloc(struct dm_crypt_io *io, struct bio *bio)
if (IS_ERR(bip))
return PTR_ERR(bip);
- tag_len = io->cc->on_disk_tag_size * bio_sectors(bio);
+ tag_len = io->cc->on_disk_tag_size * (bio_sectors(bio) >> io->cc->sector_shift);
bip->bip_iter.bi_size = tag_len;
bip->bip_iter.bi_sector = io->cc->start + io->sector;
--
2.16.4