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=-5.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,UNPARSEABLE_RELAY, URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=ham 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 23941C32753 for ; Wed, 14 Aug 2019 10:19:14 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id E4D392067D for ; Wed, 14 Aug 2019 10:19:13 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726126AbfHNKTN (ORCPT ); Wed, 14 Aug 2019 06:19:13 -0400 Received: from mail.thelounge.net ([91.118.73.15]:25791 "EHLO mail.thelounge.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725800AbfHNKTN (ORCPT ); Wed, 14 Aug 2019 06:19:13 -0400 Received: from srv-rhsoft.rhsoft.net (Authenticated sender: h.reindl@thelounge.net) by mail.thelounge.net (THELOUNGE MTA) with ESMTPSA id 467ltL60M1zXMk; Wed, 14 Aug 2019 12:19:06 +0200 (CEST) Subject: Re: [PATCH AUTOSEL 4.19 04/42] netfilter: conntrack: always store window size un-scaled To: Thomas Jarosch , Sasha Levin Cc: linux-kernel@vger.kernel.org, stable@vger.kernel.org, Florian Westphal , Jakub Jankowski , Jozsef Kadlecsik , Pablo Neira Ayuso , netfilter-devel@vger.kernel.org, coreteam@netfilter.org, netdev@vger.kernel.org References: <20190802132302.13537-1-sashal@kernel.org> <20190802132302.13537-4-sashal@kernel.org> <20190808090209.wb63n6ibii4ivvba@intra2net.com> From: Reindl Harald Openpgp: id=9D2B46CDBC140A36753AE4D733174D5A5892B7B8; url=https://arrakis-tls.thelounge.net/gpg/h.reindl_thelounge.net.pub.txt Organization: the lounge interactive design Message-ID: <41ce587d-dfaa-fe6b-66a8-58ba1a3a2872@thelounge.net> Date: Wed, 14 Aug 2019 12:19:06 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.8.0 MIME-Version: 1.0 In-Reply-To: <20190808090209.wb63n6ibii4ivvba@intra2net.com> Content-Type: text/plain; charset=utf-8 Content-Language: de-CH Content-Transfer-Encoding: 7bit Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org that's still not in 5.2.8 without the exception and "nf_conntrack_tcp_timeout_max_retrans = 60" a vnc-over-ssh session having the VNC view in the background freezes within 60 secods ----------------------------------------------------------------------------------------------- IPV4 TABLE MANGLE (STATEFUL PRE-NAT/FILTER) ----------------------------------------------------------------------------------------------- Chain PREROUTING (policy ACCEPT 100 packets, 9437 bytes) num pkts bytes target prot opt in out source destination 1 6526 3892K ACCEPT all -- * * 0.0.0.0/0 0.0.0.0/0 ctstate RELATED,ESTABLISHED 2 125 6264 ACCEPT all -- lo * 0.0.0.0/0 0.0.0.0/0 3 64 4952 ACCEPT all -- vmnet8 * 0.0.0.0/0 0.0.0.0/0 4 1 40 DROP all -- * * 0.0.0.0/0 0.0.0.0/0 ctstate INVALID -------- Weitergeleitete Nachricht -------- Betreff: [PATCH AUTOSEL 5.2 07/76] netfilter: conntrack: always store window size un-scaled Am 08.08.19 um 11:02 schrieb Thomas Jarosch: > Hello together, > > You wrote on Fri, Aug 02, 2019 at 09:22:24AM -0400: >> From: Florian Westphal >> >> [ Upstream commit 959b69ef57db00cb33e9c4777400ae7183ebddd3 ] >> >> Jakub Jankowski reported following oddity: >> >> After 3 way handshake completes, timeout of new connection is set to >> max_retrans (300s) instead of established (5 days). >> >> shortened excerpt from pcap provided: >> 25.070622 IP (flags [DF], proto TCP (6), length 52) >> 10.8.5.4.1025 > 10.8.1.2.80: Flags [S], seq 11, win 64240, [wscale 8] >> 26.070462 IP (flags [DF], proto TCP (6), length 48) >> 10.8.1.2.80 > 10.8.5.4.1025: Flags [S.], seq 82, ack 12, win 65535, [wscale 3] >> 27.070449 IP (flags [DF], proto TCP (6), length 40) >> 10.8.5.4.1025 > 10.8.1.2.80: Flags [.], ack 83, win 512, length 0 >> >> Turns out the last_win is of u16 type, but we store the scaled value: >> 512 << 8 (== 0x20000) becomes 0 window. >> >> The Fixes tag is not correct, as the bug has existed forever, but >> without that change all that this causes might cause is to mistake a >> window update (to-nonzero-from-zero) for a retransmit. >> >> Fixes: fbcd253d2448b8 ("netfilter: conntrack: lower timeout to RETRANS seconds if window is 0") >> Reported-by: Jakub Jankowski >> Tested-by: Jakub Jankowski >> Signed-off-by: Florian Westphal >> Acked-by: Jozsef Kadlecsik >> Signed-off-by: Pablo Neira Ayuso >> Signed-off-by: Sasha Levin > > Also: > Tested-by: Thomas Jarosch > > ;) > > We've hit the issue with the wrong conntrack timeout at two different sites, > long-lived connections to a SAP server over IPSec VPN were constantly dropping. > > For us this was a regression after updating from kernel 3.14 to 4.19. > Yesterday I've applied the patch to kernel 4.19.57 and the problem is fixed. > > The issue was extra hard to debug as we could just boot the new kernel > for twenty minutes in the evening on these productive systems. > > The stable kernel patch from last Friday came right on time. I was just > about the replay the TCP connection with tcpreplay, so this saved > me from another week of debugging. Thanks everyone!