[PATCH 4.14 18/41] media: v4l2-ctrls.c/uvc: zero v4l2_event

From: Greg Kroah-Hartman
Date: Tue Mar 26 2019 - 02:35:13 EST


4.14-stable review patch. If anyone has any objections, please let me know.

------------------

From: Hans Verkuil <hverkuil@xxxxxxxxx>

commit f45f3f753b0a3d739acda8e311b4f744d82dc52a upstream.

Control events can leak kernel memory since they do not fully zero the
event. The same code is present in both v4l2-ctrls.c and uvc_ctrl.c, so
fix both.

It appears that all other event code is properly zeroing the structure,
it's these two places.

Signed-off-by: Hans Verkuil <hverkuil-cisco@xxxxxxxxx>
Reported-by: syzbot+4f021cf3697781dbd9fb@xxxxxxxxxxxxxxxxxxxxxxxxx
Reviewed-by: Laurent Pinchart <laurent.pinchart@xxxxxxxxxxxxxxxx>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
drivers/media/usb/uvc/uvc_ctrl.c | 2 +-
drivers/media/v4l2-core/v4l2-ctrls.c | 2 +-
2 files changed, 2 insertions(+), 2 deletions(-)

--- a/drivers/media/usb/uvc/uvc_ctrl.c
+++ b/drivers/media/usb/uvc/uvc_ctrl.c
@@ -1203,7 +1203,7 @@ static void uvc_ctrl_fill_event(struct u

__uvc_query_v4l2_ctrl(chain, ctrl, mapping, &v4l2_ctrl);

- memset(ev->reserved, 0, sizeof(ev->reserved));
+ memset(ev, 0, sizeof(*ev));
ev->type = V4L2_EVENT_CTRL;
ev->id = v4l2_ctrl.id;
ev->u.ctrl.value = value;
--- a/drivers/media/v4l2-core/v4l2-ctrls.c
+++ b/drivers/media/v4l2-core/v4l2-ctrls.c
@@ -1239,7 +1239,7 @@ static u32 user_flags(const struct v4l2_

static void fill_event(struct v4l2_event *ev, struct v4l2_ctrl *ctrl, u32 changes)
{
- memset(ev->reserved, 0, sizeof(ev->reserved));
+ memset(ev, 0, sizeof(*ev));
ev->type = V4L2_EVENT_CTRL;
ev->id = ctrl->id;
ev->u.ctrl.changes = changes;