media: v4l2-ctrls.c/uvc: zero v4l2_event

BugLink: https://bugs.launchpad.net/bugs/1838116
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@xs4all.nl>
Reported-by: syzbot+4f021cf3697781dbd9fb@syzkaller.appspotmail.com
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Kamal Mostafa <kamal@canonical.com>
Signed-off-by: Khalid Elmously <khalid.elmously@canonical.com>

diff --git a/drivers/media/usb/uvc/uvc_ctrl.c b/drivers/media/usb/uvc/uvc_ctrl.c
index 20397aba6849e01bf4e0d08604e1f48322cabb1f..d92967e2e385309f75eeb2a6e850af9f1154815d 100644 (file)
--- 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 uvc_video_chain *chain,
 
        __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;

diff --git a/drivers/media/v4l2-core/v4l2-ctrls.c b/drivers/media/v4l2-core/v4l2-ctrls.c
index cbb2ef43945fa010366bb95b9fe89912fec1f9dc..7852ddfb5447991b6f12e2e6848423d0e57a9424 100644 (file)
--- 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_ctrl *ctrl)
 
 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;