BTW. This patch improves dm-verity overflow checking.
Mikulas
---
dm-verity: fix overflow checking
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 <mpatocka@xxxxxxxxxx>
---
drivers/md/dm-verity.c | 8 ++++----
1 file changed, 4 insertions(+), 4 deletions(-)
Index: linux-3.5-fast/drivers/md/dm-verity.c
===================================================================
--- linux-3.5-fast.orig/drivers/md/dm-verity.c 2012-08-08 21:24:00.000000000 +0200
+++ linux-3.5-fast/drivers/md/dm-verity.c 2012-08-08 21:28:06.000000000 +0200
@@ -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) != nul_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;
--
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