[PATCH 5.15 37/83] media: v4l2-compat-ioctl32.c: zero buffer passed to v4l2_compat_get_array_args()

Greg Kroah-Hartman
2022-10-03T07:35:40Z

From: Hans Verkuil <hverkuil-cisco@xs4all.nl>

commit 4e768c8e34e639cff66a0f175bc4aebf472e4305 upstream.

The v4l2_compat_get_array_args() function can leave uninitialized memory in the
buffer it is passed. So zero it before copying array elements from userspace
into the buffer.

Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Reported-by: syzbot+ff18193ff05f3f87f226@syzkaller.appspotmail.com
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
drivers/media/v4l2-core/v4l2-compat-ioctl32.c | 2 ++
1 file changed, 2 insertions(+)

--- a/drivers/media/v4l2-core/v4l2-compat-ioctl32.c
+++ b/drivers/media/v4l2-core/v4l2-compat-ioctl32.c
@@ -1033,6 +1033,8 @@ int v4l2_compat_get_array_args(struct fi
{
int err = 0;

+ memset(mbuf, 0, array_size);
+
switch (cmd) {
case VIDIOC_G_FMT32:
case VIDIOC_S_FMT32: