$NetBSD: patch-ac,v 1.1 2009/08/15 06:01:13 snj Exp $

--- net.c.orig	2009-08-14 22:29:07.000000000 -0700
+++ net.c	2009-08-14 22:30:17.000000000 -0700
@@ -91,7 +91,7 @@ client has: sender_server 1, recipient m
 	r=p[8]+(p[9]<<8)+(p[10]<<16)+(p[11]<<24);
 	mem_free(p);
 	if (retval==-1)return -1;
-	if (crc!=crc32(packet,retval-12))return -1;
+	if (retval < 12 || crc!=crc32(packet,retval-12))return -1;
 	if (r!=recipient)return -1;
 	if (sender_server&&s)return -1;
 	return retval-12;