On Wed, May 19, 2021 at 09:41:24AM +0200, Ard Biesheuvel wrote:
From: Mikulas Patocka <mpatocka@xxxxxxxxxx> commit 4edbe1d7bcffcd6269f3b5eb63f710393ff2ec7a upstream. If there are not any dm devices, we need to zero the "dev" argument in the first structure dm_name_list. However, this can cause out of bounds write, because the "needed" variable is zero and len may be less than eight. Fix this bug by reporting DM_BUFFER_FULL_FLAG if the result buffer is too small to hold the "nl->dev" value. Signed-off-by: Mikulas Patocka <mpatocka@xxxxxxxxxx> Reported-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx> Cc: stable@xxxxxxxxxxxxxxx Signed-off-by: Mike Snitzer <snitzer@xxxxxxxxxx> Signed-off-by: Ard Biesheuvel <ardb@xxxxxxxxxx> --- Please apply to 4.4.y and 4.9.y
We already carry this patch via the backport provided in https://lore.kernel.org/stable/20210513094552.266451-1-nobuhiro1.iwamatsu@xxxxxxxxxxxxx/ -- Thanks, Sasha
