Removing the mutex_lock/unlock around clear_bit allowed device_unregister() to race with v4l2_open(). The device can be unregistered between the video_devdata() and video_get() calls. Revert the patch to fix the problem. This reverts commit dd0daf2a6fb6bec436a3ef68bd585ea09a2a54b7. Signed-off-by: Laurent Pinchart <laurent.pinchart@xxxxxxxxxxxxxxxx> --- drivers/media/video/v4l2-dev.c | 2 ++ 1 files changed, 2 insertions(+), 0 deletions(-) diff --git a/drivers/media/video/v4l2-dev.c b/drivers/media/video/v4l2-dev.c index 03f7f46..f777da6 100644 --- a/drivers/media/video/v4l2-dev.c +++ b/drivers/media/video/v4l2-dev.c @@ -596,7 +596,9 @@ void video_unregister_device(struct video_device *vdev) if (!vdev || !video_is_registered(vdev)) return; + mutex_lock(&videodev_lock); clear_bit(V4L2_FL_REGISTERED, &vdev->flags); + mutex_unlock(&videodev_lock); device_unregister(&vdev->dev); } EXPORT_SYMBOL(video_unregister_device); -- 1.7.2.2 -- To unsubscribe from this list: send the line "unsubscribe linux-media" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
