Fix a boundary condition that caused failure for certain device sizes The problem is reported at http://code.google.com/p/cryptsetup/issues/detail?id=160 For certain device sizes the number of hashes at a specific level was calculated incorrectly. It happens for example for a device with data and metadata block size 4096 that has 16385 blocks and algorithm sha256. This patch fixes it. The same bug exists in the veritysetup tool, so you must use fixed veritysetup too if you want to use devices that are affected by this boundary condition. Cc: stable@xxxxxxxxxx # 3.4+ Signed-off-by: Mikulas Patocka <mpatocka@xxxxxxxxxx> --- drivers/md/dm-verity.c | 5 ++--- 1 file changed, 2 insertions(+), 3 deletions(-) Index: linux-3.9.8-fast/drivers/md/dm-verity.c =================================================================== --- linux-3.9.8-fast.orig/drivers/md/dm-verity.c 2013-06-28 00:58:12.000000000 +0200 +++ linux-3.9.8-fast/drivers/md/dm-verity.c 2013-06-28 02:01:32.000000000 +0200 @@ -831,9 +831,8 @@ static int verity_ctr(struct dm_target * for (i = v->levels - 1; i >= 0; i--) { sector_t s; v->hash_level_block[i] = hash_position; - s = verity_position_at_level(v, v->data_blocks, i); - s = (s >> v->hash_per_block_bits) + - !!(s & ((1 << v->hash_per_block_bits) - 1)); + s = (v->data_blocks + ((sector_t)1 << ((i + 1) * v->hash_per_block_bits)) - 1) + >> ((i + 1) * v->hash_per_block_bits); if (hash_position + s < hash_position) { ti->error = "Hash device offset overflow"; r = -E2BIG; -- dm-devel mailing list dm-devel@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/dm-devel
