4.9-stable review patch. If anyone has any objections, please let me know. ------------------ From: Mauro Carvalho Chehab <mchehab@xxxxxxxxxxxxxxxx> commit ea72fbf588ac9c017224dcdaa2019ff52ca56fee upstream. As warned by smatch: drivers/media/v4l2-core/v4l2-compat-ioctl32.c:879 put_v4l2_ext_controls32() warn: check for integer overflow 'count' The access_ok() logic should check for too big arrays too. Cc: stable@xxxxxxxxxxxxxxx Signed-off-by: Mauro Carvalho Chehab <mchehab@xxxxxxxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/media/v4l2-core/v4l2-compat-ioctl32.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/drivers/media/v4l2-core/v4l2-compat-ioctl32.c +++ b/drivers/media/v4l2-core/v4l2-compat-ioctl32.c @@ -864,7 +864,7 @@ static int put_v4l2_ext_controls32(struc get_user(kcontrols, &kp->controls)) return -EFAULT; - if (!count) + if (!count || count > (U32_MAX/sizeof(*ucontrols))) return 0; if (get_user(p, &up->controls)) return -EFAULT;