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 <mpatocka@redhat.com>
Cc: stable@vger.kernel.org
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
diff --git a/drivers/md/dm-verity.c b/drivers/md/dm-verity.c
index 254d192..892ae27 100644
--- a/drivers/md/dm-verity.c
+++ b/drivers/md/dm-verity.c
@@ -718,8 +718,8 @@
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 @@
}
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;