dm crypt: don't decrease device limits

commit bc9e9cf0401f18e33b78d4c8a518661b8346baf7 upstream.

dm-crypt should only increase device limits, it should not decrease them.

This fixes a bug where the user could creates a crypt device with 1024
sector size on the top of scsi device that had 4096 logical block size.
The limit 4096 would be lost and the user could incorrectly send
1024-I/Os to the crypt device.

Cc: stable@vger.kernel.org
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>

diff --git a/drivers/md/dm-crypt.c b/drivers/md/dm-crypt.c
index f575110454b6a2dd7df499e07fe15141184a7d06..c60d29d09687d73368e0490d096736c8d1456c5a 100644 (file)
--- a/drivers/md/dm-crypt.c
+++ b/drivers/md/dm-crypt.c
@@ -3072,11 +3072,11 @@ static void crypt_io_hints(struct dm_target *ti, struct queue_limits *limits)
         */
        limits->max_segment_size = PAGE_SIZE;
 
-       if (cc->sector_size != (1 << SECTOR_SHIFT)) {
-               limits->logical_block_size = cc->sector_size;
-               limits->physical_block_size = cc->sector_size;
-               blk_limits_io_min(limits, cc->sector_size);
-       }
+       limits->logical_block_size =
+               max_t(unsigned short, limits->logical_block_size, cc->sector_size);
+       limits->physical_block_size =
+               max_t(unsigned, limits->physical_block_size, cc->sector_size);
+       limits->io_min = max_t(unsigned, limits->io_min, cc->sector_size);
 }
 
 static struct target_type crypt_target = {