From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-18.8 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 02617C433ED for ; Mon, 12 Apr 2021 09:32:16 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id D0097613A3 for ; Mon, 12 Apr 2021 09:32:15 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S238976AbhDLJc1 (ORCPT ); Mon, 12 Apr 2021 05:32:27 -0400 Received: from mail.kernel.org ([198.145.29.99]:34856 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S239470AbhDLJHS (ORCPT ); Mon, 12 Apr 2021 05:07:18 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 8390B61241; Mon, 12 Apr 2021 09:03:56 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1618218237; bh=FHLjFpiq0SA8ILyN79XAVnMCVDMBdcrFZdA0z1g08gc=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=r7YkTi6kicZ1IdOQmBeHR6WuRBo+eRlnpkoScXaicvGfYZgBiSgzle0JYjU8MkBsh IRqEuy8Fry5yhNOiL7fII6r+0yljjKOUqPjqx9WZVHI2YR48bRSRD7iuS7OR7K9Ji9 5ySaI3kRAzF0oRuutU5cdPx2upYQqSv2AoNycqVw= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Eelco Chaudron , Antoine Tenart , "David S. Miller" , Sasha Levin Subject: [PATCH 5.11 121/210] geneve: do not modify the shared tunnel info when PMTU triggers an ICMP reply Date: Mon, 12 Apr 2021 10:40:26 +0200 Message-Id: <20210412084020.030784878@linuxfoundation.org> X-Mailer: git-send-email 2.31.1 In-Reply-To: <20210412084016.009884719@linuxfoundation.org> References: <20210412084016.009884719@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Antoine Tenart [ Upstream commit 68c1a943ef37bafde5ea2383e8ca224c7169ee31 ] When the interface is part of a bridge or an Open vSwitch port and a packet exceed a PMTU estimate, an ICMP reply is sent to the sender. When using the external mode (collect metadata) the source and destination addresses are reversed, so that Open vSwitch can match the packet against an existing (reverse) flow. But inverting the source and destination addresses in the shared ip_tunnel_info will make following packets of the flow to use a wrong destination address (packets will be tunnelled to itself), if the flow isn't updated. Which happens with Open vSwitch, until the flow times out. Fixes this by uncloning the skb's ip_tunnel_info before inverting its source and destination addresses, so that the modification will only be made for the PTMU packet, not the following ones. Fixes: c1a800e88dbf ("geneve: Support for PMTU discovery on directly bridged links") Tested-by: Eelco Chaudron Reviewed-by: Eelco Chaudron Signed-off-by: Antoine Tenart Signed-off-by: David S. Miller Signed-off-by: Sasha Levin --- drivers/net/geneve.c | 24 ++++++++++++++++++++---- 1 file changed, 20 insertions(+), 4 deletions(-) diff --git a/drivers/net/geneve.c b/drivers/net/geneve.c index 5523f069b9a5..f35b0b83fe85 100644 --- a/drivers/net/geneve.c +++ b/drivers/net/geneve.c @@ -908,8 +908,16 @@ static int geneve_xmit_skb(struct sk_buff *skb, struct net_device *dev, info = skb_tunnel_info(skb); if (info) { - info->key.u.ipv4.dst = fl4.saddr; - info->key.u.ipv4.src = fl4.daddr; + struct ip_tunnel_info *unclone; + + unclone = skb_tunnel_info_unclone(skb); + if (unlikely(!unclone)) { + dst_release(&rt->dst); + return -ENOMEM; + } + + unclone->key.u.ipv4.dst = fl4.saddr; + unclone->key.u.ipv4.src = fl4.daddr; } if (!pskb_may_pull(skb, ETH_HLEN)) { @@ -993,8 +1001,16 @@ static int geneve6_xmit_skb(struct sk_buff *skb, struct net_device *dev, struct ip_tunnel_info *info = skb_tunnel_info(skb); if (info) { - info->key.u.ipv6.dst = fl6.saddr; - info->key.u.ipv6.src = fl6.daddr; + struct ip_tunnel_info *unclone; + + unclone = skb_tunnel_info_unclone(skb); + if (unlikely(!unclone)) { + dst_release(dst); + return -ENOMEM; + } + + unclone->key.u.ipv6.dst = fl6.saddr; + unclone->key.u.ipv6.src = fl6.daddr; } if (!pskb_may_pull(skb, ETH_HLEN)) { -- 2.30.2