4.20-stable review patch. If anyone has any objections, please let me know.
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From: Mikulas Patocka mpatocka@redhat.com
commit ff0c129d3b5ecb3df7c8f5e2236582bf745b6c5f upstream.
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: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- drivers/md/dm-crypt.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
--- a/drivers/md/dm-crypt.c +++ b/drivers/md/dm-crypt.c @@ -932,7 +932,7 @@ static int dm_crypt_integrity_io_alloc(s 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;