From b712e9ec66540408c4ec9da326c2aa98eb120208 Mon Sep 17 00:00:00 2001
From: Brian Feldman <green@FreeBSD.org>
Date: Fri, 9 Jan 2004 02:03:24 +0000
Subject: [PATCH] Also, don't crash in the netgraph disconnect node if the
 interface is detached from the other direction.

---
 sys/netgraph/ng_ether.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/sys/netgraph/ng_ether.c b/sys/netgraph/ng_ether.c
index b741b07faf4..db8e9412d3a 100644
--- a/sys/netgraph/ng_ether.c
+++ b/sys/netgraph/ng_ether.c
@@ -628,7 +628,8 @@ ng_ether_disconnect(hook_p hook)
 
 	if (hook == priv->upper) {
 		priv->upper = NULL;
-		priv->ifp->if_hwassist = priv->hwassist;  /* restore h/w csum */
+		if (priv->ifp != NULL)		/* restore h/w csum */
+			priv->ifp->if_hwassist = priv->hwassist;
 	} else if (hook == priv->lower) {
 		priv->lower = NULL;
 		priv->lowerOrphan = 0;