From 207bd73af718bfad9260482cfb2b9af9679ca424 Mon Sep 17 00:00:00 2001
From: yasuoka <yasuoka@openbsd.org>
Date: Fri, 26 Jul 2024 15:45:31 +0000
Subject: [PATCH] In pipex_l2tp_input(), check if ipsecflowinfo is not changed
 instead of updating it blindly.

ok mvs
---
 sys/net/pipex.c | 10 ++++++++--
 1 file changed, 8 insertions(+), 2 deletions(-)

diff --git a/sys/net/pipex.c b/sys/net/pipex.c
index ba3038ed07b..c1bb5a86bcf 100644
--- a/sys/net/pipex.c
+++ b/sys/net/pipex.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: pipex.c,v 1.154 2024/06/07 13:43:21 jsg Exp $ */
+/*	$OpenBSD: pipex.c,v 1.155 2024/07/26 15:45:31 yasuoka Exp $ */
 
 /*-
  * Copyright (c) 2009 Internet Initiative Japan Inc.
@@ -2031,7 +2031,13 @@ pipex_l2tp_input(struct mbuf *m0, int off0, struct pipex_session *session,
 	mtx_enter(&session->pxs_mtx);
 
 	l2tp_session = &session->proto.l2tp;
-	l2tp_session->ipsecflowinfo = ipsecflowinfo;
+	if (l2tp_session->ipsecflowinfo != ipsecflowinfo) {
+		pipex_session_log(session, LOG_DEBUG,
+		    "received message is %s",
+		    (ipsecflowinfo != 0)? "from invalid ipsec flow" :
+		    "without ipsec");
+		goto drop;
+	}
 
 	m_copydata(m0, off0, sizeof(flags), &flags);
 
-- 
2.20.1