[media] uvcvideo: Return -ERANGE when userspace sets an unsupported menu entry

Instead of passing the value down to the device and getting an error
back (or worse, crashing the firmware), return -ERANGE when the
requested menu entry is not supported.

Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

1 files changed, 17 insertions, 0 deletions

diff --git a/drivers/media/video/uvc/uvc_ctrl.c b/drivers/media/video/uvc/uvc_ctrl.c
index 0dc2a9f7ca51..a4db26fa2f53 100644
--- a/drivers/media/video/uvc/uvc_ctrl.c
+++ b/drivers/media/video/uvc/uvc_ctrl.c
@@ -1221,6 +1221,23 @@ int uvc_ctrl_set(struct uvc_video_chain *chain,
                 if (xctrl->value < 0 || xctrl->value >= mapping->menu_count)
                         return -ERANGE;
                 value = mapping->menu_info[xctrl->value].value;
+
+                /* Valid menu indices are reported by the GET_RES request for
+                 * UVC controls that support it.
+                 */
+                if (ctrl->info.flags & UVC_CTRL_FLAG_GET_RES) {
+                        if (!ctrl->cached) {
+                                ret = uvc_ctrl_populate_cache(chain, ctrl);
+                                if (ret < 0)
+                                        return ret;
+                        }
+
+                        step = mapping->get(mapping, UVC_GET_RES,
+                                        uvc_ctrl_data(ctrl, UVC_CTRL_DATA_RES));
+                        if (!(step & value))
+                                return -ERANGE;
+                }
+
                 break;
 
         default: