From 15d16124c27c4ef7f603e2c4c45f95cceec5d782 Mon Sep 17 00:00:00 2001
From: kib <kib@FreeBSD.org>
Date: Tue, 6 Jul 2010 18:20:49 +0000
Subject: [PATCH] In revoke(), verify that VCHR vnode indeed belongs to devfs.

Found and tested by:	pho
MFC after:	1 week
---
 sys/kern/vfs_syscalls.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/sys/kern/vfs_syscalls.c b/sys/kern/vfs_syscalls.c
index ab0627d7bf22..4fd9dfa0e8f5 100644
--- a/sys/kern/vfs_syscalls.c
+++ b/sys/kern/vfs_syscalls.c
@@ -4215,7 +4215,7 @@ revoke(td, uap)
 	vfslocked = NDHASGIANT(&nd);
 	vp = nd.ni_vp;
 	NDFREE(&nd, NDF_ONLY_PNBUF);
-	if (vp->v_type != VCHR) {
+	if (vp->v_type != VCHR || vp->v_rdev == NULL) {
 		error = EINVAL;
 		goto out;
 	}