media: uvcvideo: Fix OOB read

If the index provided by the user is bigger than the mask size, we might do
an out of bound read.

CC: stable@kernel.org
Fixes: 40140eda661e ("media: uvcvideo: Implement mask for V4L2_CTRL_TYPE_MENU")
Reported-by: Zubin Mithra <zsm@chromium.org>
Signed-off-by: Ricardo Ribalda <ribalda@chromium.org>
Reviewed-by: Sergey Senozhatsky <senozhatsky@chromium.org>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>

diff --git a/drivers/media/usb/uvc/uvc_ctrl.c b/drivers/media/usb/uvc/uvc_ctrl.c
index 5e9d3da..e59a463 100644 (file)
--- a/drivers/media/usb/uvc/uvc_ctrl.c
+++ b/drivers/media/usb/uvc/uvc_ctrl.c
@@ -1402,6 +1402,9 @@ int uvc_query_v4l2_menu(struct uvc_video_chain *chain,
        query_menu->id = id;
        query_menu->index = index;
 
+       if (index >= BITS_PER_TYPE(mapping->menu_mask))
+               return -EINVAL;
+
        ret = mutex_lock_interruptible(&chain->ctrl_mutex);
        if (ret < 0)
                return -ERESTARTSYS;