--- x/drivers/media/usb/em28xx/em28xx-video.c
+++ y/drivers/media/usb/em28xx/em28xx-video.c
@@ -2150,6 +2150,10 @@ static int em28xx_v4l2_open(struct file
 	if (mutex_lock_interruptible(&dev->lock))
 		return -ERESTARTSYS;
 
+	if (dev->v4l2 == NULL) {
+		mutex_unlock(&dev->lock);
+		return -EINVAL;
+	}
 	ret = v4l2_fh_open(filp);
 	if (ret) {
 		dev_err(&dev->intf->dev,
@@ -2898,7 +2902,6 @@ unregister_dev:
 	v4l2_device_unregister(&v4l2->v4l2_dev);
 err:
 	dev->v4l2 = NULL;
-	kref_put(&v4l2->ref, em28xx_free_v4l2);
 	mutex_unlock(&dev->lock);
 	return ret;
 }