| From | Greg Kroah-Hartman <> | Subject | [ 04/52] dm verity: fix overflow check | Date | Thu, 4 Oct 2012 14:20:55 -0700 |
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3.4-stable review patch. If anyone has any objections, please let me know.
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From: Mikulas Patocka <mpatocka@redhat.com>
commit 1d55f6bcc0331d744cd5b56c4ee79e3809438161 upstream.
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> Signed-off-by: Alasdair G Kergon <agk@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
--- drivers/md/dm-verity.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-)
--- a/drivers/md/dm-verity.c +++ b/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;
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