diff -Nupr src.orig/net/core/dev.c src/net/core/dev.c
--- src.orig/net/core/dev.c	2020-09-03 11:48:30.763726955 -0400
+++ src/net/core/dev.c	2020-09-03 11:49:21.514885728 -0400
@@ -4327,6 +4327,7 @@ skip_classify:
 		case RX_HANDLER_PASS:
 			break;
 		default:
+			printk("BUG!\n");
 			BUG();
 		}
 	}