From: Mikulas Patocka Date: Wed, 26 Sep 2012 22:45:48 +0000 (+0100) Subject: dm verity: fix overflow check X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=1d55f6bcc0331d744cd5b56c4ee79e3809438161;p=GitHub%2Fmt8127%2Fandroid_kernel_alcatel_ttab.git dm verity: fix overflow check This patch fixes sector_t overflow checking in dm-verity. Without this patch, the code checks for overflow only if sector_t is smaller than long long, not if sector_t and long long have the same size. Signed-off-by: Mikulas Patocka Cc: stable@vger.kernel.org Signed-off-by: Alasdair G Kergon --- diff --git a/drivers/md/dm-verity.c b/drivers/md/dm-verity.c index 254d19268ad2..892ae2766aa6 100644 --- a/drivers/md/dm-verity.c +++ b/drivers/md/dm-verity.c @@ -718,8 +718,8 @@ static int verity_ctr(struct dm_target *ti, unsigned argc, char **argv) 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 *ti, unsigned argc, char **argv) } 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;