From fec31ce43e3f20a77966065864467e0eb6df2a4a Mon Sep 17 00:00:00 2001
From: bouyer <bouyer@NetBSD.org>
Date: Wed, 19 Nov 2008 18:38:36 +0000
Subject: [PATCH] Check that vnd is not NULL before using it, return ENXIO if
 it is. Avoids a panic when vnconfig -uF is used on a busy vnd.

---
 sys/dev/vnd.c | 12 +++++++++---
 1 file changed, 9 insertions(+), 3 deletions(-)

diff --git a/sys/dev/vnd.c b/sys/dev/vnd.c
index 8ecf9b44a82a..5b45adcd7d22 100644
--- a/sys/dev/vnd.c
+++ b/sys/dev/vnd.c
@@ -1,4 +1,4 @@
-/*	$NetBSD: vnd.c,v 1.188 2008/11/12 12:36:11 ad Exp $	*/
+/*	$NetBSD: vnd.c,v 1.189 2008/11/19 18:38:36 bouyer Exp $	*/
 
 /*-
  * Copyright (c) 1996, 1997, 1998, 2008 The NetBSD Foundation, Inc.
@@ -130,7 +130,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: vnd.c,v 1.188 2008/11/12 12:36:11 ad Exp $");
+__KERNEL_RCSID(0, "$NetBSD: vnd.c,v 1.189 2008/11/19 18:38:36 bouyer Exp $");
 
 #if defined(_KERNEL_OPT)
 #include "fs_nfs.h"
@@ -448,10 +448,16 @@ vndstrategy(struct buf *bp)
 	int unit = vndunit(bp->b_dev);
 	struct vnd_softc *vnd =
 	    device_lookup_private(&vnd_cd, unit);
-	struct disklabel *lp = vnd->sc_dkdev.dk_label;
+	struct disklabel *lp;
 	daddr_t blkno;
 	int s = splbio();
 
+	if (vnd == NULL) {
+		bp->b_error = ENXIO;
+		goto done;
+	}
+	lp = vnd->sc_dkdev.dk_label;
+
 	if ((vnd->sc_flags & VNF_INITED) == 0) {
 		bp->b_error = ENXIO;
 		goto done;