ubi: Check for too small LEB size in VTBL code

If the LEB size is smaller than a volume table record we cannot
have volumes.
In this case abort attaching.

Cc: Chenyuan Yang <cy54@illinois.edu>
Cc: stable@vger.kernel.org
Fixes: 801c135ce73d ("UBI: Unsorted Block Images")
Reported-by: Chenyuan Yang <cy54@illinois.edu>
Closes: https://lore.kernel.org/linux-mtd/1433EB7A-FC89-47D6-8F47-23BE41B263B3@illinois.edu/
Signed-off-by: Richard Weinberger <richard@nod.at>
Reviewed-by: Zhihao Cheng <chengzhihao1@huawei.com>

diff --git a/drivers/mtd/ubi/vtbl.c b/drivers/mtd/ubi/vtbl.c
index f700f0e..6e5489e 100644 (file)
--- a/drivers/mtd/ubi/vtbl.c
+++ b/drivers/mtd/ubi/vtbl.c
@@ -791,6 +791,12 @@ int ubi_read_volume_table(struct ubi_device *ubi, struct ubi_attach_info *ai)
         * The number of supported volumes is limited by the eraseblock size
         * and by the UBI_MAX_VOLUMES constant.
         */
+
+       if (ubi->leb_size < UBI_VTBL_RECORD_SIZE) {
+               ubi_err(ubi, "LEB size too small for a volume record");
+               return -EINVAL;
+       }
+
        ubi->vtbl_slots = ubi->leb_size / UBI_VTBL_RECORD_SIZE;
        if (ubi->vtbl_slots > UBI_MAX_VOLUMES)
                ubi->vtbl_slots = UBI_MAX_VOLUMES;