The list_for_each_entry() loop exits when "entity" is a offset off the list head. In that situation the "entity" pointer doesn't point to a valid uvc_entity struct, so it doesn't make sense to check "entity->id". Since the "entity->id" is a u8 it's plausible that it could be equal to "xqry->unit" by chance. Fixes: c0efd232929c ("V4L/DVB (8145a): USB Video Class driver") Signed-off-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx> --- drivers/media/usb/uvc/uvc_ctrl.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/media/usb/uvc/uvc_ctrl.c b/drivers/media/usb/uvc/uvc_ctrl.c index e399b9fad757..47ab6c315db6 100644 --- a/drivers/media/usb/uvc/uvc_ctrl.c +++ b/drivers/media/usb/uvc/uvc_ctrl.c @@ -1857,7 +1857,7 @@ int uvc_xu_ctrl_query(struct uvc_video_chain *chain, break; } - if (entity->id != xqry->unit) { + if (&entity->chain == &chain->entities) { uvc_trace(UVC_TRACE_CONTROL, "Extension unit %u not found.\n", xqry->unit); return -ENOENT; -- 2.27.0