From 30545786bb310c0a754b406402d8a07de1fb7fae Mon Sep 17 00:00:00 2001
From: Edward Tomasz Napierala <trasz@FreeBSD.org>
Date: Sun, 19 Feb 2017 16:08:58 +0000
Subject: [PATCH] Make mdconfig(8) not segfault when the kernel returns garbage
 data.

MFC after:	2 weeks
Sponsored by:	DARPA, AFRL
---
 sbin/mdconfig/mdconfig.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/sbin/mdconfig/mdconfig.c b/sbin/mdconfig/mdconfig.c
index e86ffdc4e96..f1c013c8b9f 100644
--- a/sbin/mdconfig/mdconfig.c
+++ b/sbin/mdconfig/mdconfig.c
@@ -452,8 +452,8 @@ md_list(const char *units, int opt, const char *fflag)
 			}
 			gc = &pp->lg_config;
 			type = geom_config_get(gc, "type");
-			if (strcmp(type, "vnode") == 0 ||
-			    strcmp(type, "preload") == 0) {
+			if (type != NULL && (strcmp(type, "vnode") == 0 ||
+			    strcmp(type, "preload") == 0)) {
 				file = geom_config_get(gc, "file");
 				if (fflag != NULL &&
 				    strcmp(fflag, file) != 0)