From: Mikulas Patocka Overflow checking in dm-verity was not sufficient. It would check overflow if sector_t was smaller than long long but not if sector_t and long long have the same size. This patch implements proper overflow checking. Signed-off-by: Mikulas Patocka Signed-off-by: Alasdair G Kergon --- drivers/md/dm-verity.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) Index: linux/drivers/md/dm-verity.c =================================================================== --- linux.orig/drivers/md/dm-verity.c +++ linux/drivers/md/dm-verity.c @@ -718,8 +718,8 @@ static int verity_ctr(struct dm_target * v->hash_dev_block_bits = ffs(num) - 1; if (sscanf(argv[5], "%llu%c", &num_ll, &dummy) != 1 || - num_ll << (v->data_dev_block_bits - SECTOR_SHIFT) != - (sector_t)num_ll << (v->data_dev_block_bits - SECTOR_SHIFT)) { + (sector_t)(num_ll << (v->data_dev_block_bits - SECTOR_SHIFT)) + >> (v->data_dev_block_bits - SECTOR_SHIFT) != num_ll) { ti->error = "Invalid data blocks"; r = -EINVAL; goto bad; @@ -733,8 +733,8 @@ static int verity_ctr(struct dm_target * } if (sscanf(argv[6], "%llu%c", &num_ll, &dummy) != 1 || - num_ll << (v->hash_dev_block_bits - SECTOR_SHIFT) != - (sector_t)num_ll << (v->hash_dev_block_bits - SECTOR_SHIFT)) { + (sector_t)(num_ll << (v->hash_dev_block_bits - SECTOR_SHIFT)) + >> (v->hash_dev_block_bits - SECTOR_SHIFT) != num_ll) { ti->error = "Invalid hash start"; r = -EINVAL; goto bad;