From 00a2f9f8be6f5a2b32b0cfa4ac2dacaa16b53520 Mon Sep 17 00:00:00 2001
From: maxv <maxv@NetBSD.org>
Date: Mon, 9 Apr 2018 11:35:22 +0000
Subject: [PATCH] Add KASSERT. The input point expects struct ether_header to
 be there.

Now, I'm wondering whether it can be triggered by L2 encapsulation
protocols - they may not provide a contiguous area.
---
 sys/net/if_ethersubr.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/sys/net/if_ethersubr.c b/sys/net/if_ethersubr.c
index 0077021352d7..88d3e82e33d0 100644
--- a/sys/net/if_ethersubr.c
+++ b/sys/net/if_ethersubr.c
@@ -1,4 +1,4 @@
-/*	$NetBSD: if_ethersubr.c,v 1.261 2018/04/09 11:05:59 maxv Exp $	*/
+/*	$NetBSD: if_ethersubr.c,v 1.262 2018/04/09 11:35:22 maxv Exp $	*/
 
 /*
  * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
@@ -61,7 +61,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: if_ethersubr.c,v 1.261 2018/04/09 11:05:59 maxv Exp $");
+__KERNEL_RCSID(0, "$NetBSD: if_ethersubr.c,v 1.262 2018/04/09 11:35:22 maxv Exp $");
 
 #ifdef _KERNEL_OPT
 #include "opt_inet.h"
@@ -588,6 +588,7 @@ ether_input(struct ifnet *ifp, struct mbuf *m)
 
 	KASSERT(!cpu_intr_p());
 	KASSERT((m->m_flags & M_PKTHDR) != 0);
+	KASSERT(m->m_len >= sizeof(*eh));
 
 	if ((ifp->if_flags & IFF_UP) == 0) {
 		m_freem(m);