On Wed, 7 Nov 2018, Milan Broz wrote:
> Reference to a device in device-mapper table contains offset in sectors.
>
> If the sector_t is 32bit integer (CONFIG_LBDAF is not set), then
> several device-mapper targets can overflow this offset and validity
> check is then performed on a wrong offset and a wrong table is activated.
>
> See for example (on 32bit without CONFIG_LBDAF) this overflow:
>
> # dmsetup create test --table "0 2048 linear /dev/sdg 4294967297"
> # dmsetup table test
> 0 2048 linear 8:96 1
>
> This patch adds explicit check for overflow if the offset is sector_t type.
>
> Signed-off-by: Milan Broz <gmazyland@xxxxxxxxx>
Reviewed-by: Mikulas Patocka <mpatocka@xxxxxxxxxx>
> ---
> drivers/md/dm-crypt.c | 2 +-
> drivers/md/dm-delay.c | 2 +-
> drivers/md/dm-flakey.c | 2 +-
> drivers/md/dm-linear.c | 2 +-
> drivers/md/dm-raid1.c | 3 ++-
> drivers/md/dm-unstripe.c | 2 +-
> 6 files changed, 7 insertions(+), 6 deletions(-)
>
> diff --git a/drivers/md/dm-crypt.c b/drivers/md/dm-crypt.c
> index 49be7a6a2e81..a41fe7975dc6 100644
> --- a/drivers/md/dm-crypt.c
> +++ b/drivers/md/dm-crypt.c
> @@ -2781,7 +2781,7 @@ static int crypt_ctr(struct dm_target *ti, unsigned int argc, char **argv)
> }
>
> ret = -EINVAL;
> - if (sscanf(argv[4], "%llu%c", &tmpll, &dummy) != 1) {
> + if (sscanf(argv[4], "%llu%c", &tmpll, &dummy) != 1 || tmpll != (sector_t)tmpll) {
> ti->error = "Invalid device sector";
> goto bad;
> }
> diff --git a/drivers/md/dm-delay.c b/drivers/md/dm-delay.c
> index 2fb7bb4304ad..fddffe251bf6 100644
> --- a/drivers/md/dm-delay.c
> +++ b/drivers/md/dm-delay.c
> @@ -141,7 +141,7 @@ static int delay_class_ctr(struct dm_target *ti, struct delay_class *c, char **a
> unsigned long long tmpll;
> char dummy;
>
> - if (sscanf(argv[1], "%llu%c", &tmpll, &dummy) != 1) {
> + if (sscanf(argv[1], "%llu%c", &tmpll, &dummy) != 1 || tmpll != (sector_t)tmpll) {
> ti->error = "Invalid device sector";
> return -EINVAL;
> }
> diff --git a/drivers/md/dm-flakey.c b/drivers/md/dm-flakey.c
> index 3cb97fa4c11d..8261aa8c7fe1 100644
> --- a/drivers/md/dm-flakey.c
> +++ b/drivers/md/dm-flakey.c
> @@ -213,7 +213,7 @@ static int flakey_ctr(struct dm_target *ti, unsigned int argc, char **argv)
> devname = dm_shift_arg(&as);
>
> r = -EINVAL;
> - if (sscanf(dm_shift_arg(&as), "%llu%c", &tmpll, &dummy) != 1) {
> + if (sscanf(dm_shift_arg(&as), "%llu%c", &tmpll, &dummy) != 1 || tmpll != (sector_t)tmpll) {
> ti->error = "Invalid device sector";
> goto bad;
> }
> diff --git a/drivers/md/dm-linear.c b/drivers/md/dm-linear.c
> index 8d7ddee6ac4d..ad980a38fb1e 100644
> --- a/drivers/md/dm-linear.c
> +++ b/drivers/md/dm-linear.c
> @@ -45,7 +45,7 @@ static int linear_ctr(struct dm_target *ti, unsigned int argc, char **argv)
> }
>
> ret = -EINVAL;
> - if (sscanf(argv[1], "%llu%c", &tmp, &dummy) != 1) {
> + if (sscanf(argv[1], "%llu%c", &tmp, &dummy) != 1 || tmp != (sector_t)tmp) {
> ti->error = "Invalid device sector";
> goto bad;
> }
> diff --git a/drivers/md/dm-raid1.c b/drivers/md/dm-raid1.c
> index 79eab1071ec2..5a51151f680d 100644
> --- a/drivers/md/dm-raid1.c
> +++ b/drivers/md/dm-raid1.c
> @@ -943,7 +943,8 @@ static int get_mirror(struct mirror_set *ms, struct dm_target *ti,
> char dummy;
> int ret;
>
> - if (sscanf(argv[1], "%llu%c", &offset, &dummy) != 1) {
> + if (sscanf(argv[1], "%llu%c", &offset, &dummy) != 1 ||
> + offset != (sector_t)offset) {
> ti->error = "Invalid offset";
> return -EINVAL;
> }
> diff --git a/drivers/md/dm-unstripe.c b/drivers/md/dm-unstripe.c
> index 954b7ab4e684..e673dacf6418 100644
> --- a/drivers/md/dm-unstripe.c
> +++ b/drivers/md/dm-unstripe.c
> @@ -78,7 +78,7 @@ static int unstripe_ctr(struct dm_target *ti, unsigned int argc, char **argv)
> goto err;
> }
>
> - if (sscanf(argv[4], "%llu%c", &start, &dummy) != 1) {
> + if (sscanf(argv[4], "%llu%c", &start, &dummy) != 1 || start != (sector_t)start) {
> ti->error = "Invalid striped device offset";
> goto err;
> }
> --
> 2.19.1
>
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