diff -Nupr src.orig/net/core/dev.c src/net/core/dev.c
--- src.orig/net/core/dev.c	2016-12-15 19:55:39.848000000 +0000
+++ src/net/core/dev.c	2016-12-15 19:56:21.344000000 +0000
@@ -3926,6 +3926,7 @@ ncls:
 		case RX_HANDLER_PASS:
 			break;
 		default:
+			printk("BUG!\n");
 			BUG();
 		}
 	}