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=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_1 autolearn=no 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 4E236C4363A for ; Tue, 20 Oct 2020 15:21:41 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id E719420757 for ; Tue, 20 Oct 2020 15:21:40 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2408668AbgJTPVk (ORCPT ); Tue, 20 Oct 2020 11:21:40 -0400 Received: from correo.us.es ([193.147.175.20]:51618 "EHLO mail.us.es" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2408660AbgJTPVk (ORCPT ); Tue, 20 Oct 2020 11:21:40 -0400 Received: from antivirus1-rhel7.int (unknown [192.168.2.11]) by mail.us.es (Postfix) with ESMTP id 71B421761B1 for ; Tue, 20 Oct 2020 17:21:38 +0200 (CEST) Received: from antivirus1-rhel7.int (localhost [127.0.0.1]) by antivirus1-rhel7.int (Postfix) with ESMTP id 657CAFB37F for ; Tue, 20 Oct 2020 17:21:38 +0200 (CEST) Received: by antivirus1-rhel7.int (Postfix, from userid 99) id 5E2C952AC1; Tue, 20 Oct 2020 17:21:38 +0200 (CEST) Received: from antivirus1-rhel7.int (localhost [127.0.0.1]) by antivirus1-rhel7.int (Postfix) with ESMTP id 37CC2F7327; Tue, 20 Oct 2020 17:21:36 +0200 (CEST) Received: from 192.168.1.97 (192.168.1.97) by antivirus1-rhel7.int (F-Secure/fsigk_smtp/550/antivirus1-rhel7.int); Tue, 20 Oct 2020 17:21:36 +0200 (CEST) X-Virus-Status: clean(F-Secure/fsigk_smtp/550/antivirus1-rhel7.int) Received: from us.es (unknown [90.77.255.23]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) (Authenticated sender: 1984lsi) by entrada.int (Postfix) with ESMTPSA id 123654301DE0; Tue, 20 Oct 2020 17:21:36 +0200 (CEST) Date: Tue, 20 Oct 2020 17:21:35 +0200 X-SMTPAUTHUS: auth mail.us.es From: Pablo Neira Ayuso To: Francesco Ruggeri Cc: linux-kernel@vger.kernel.org, netdev@vger.kernel.org, coreteam@netfilter.org, netfilter-devel@vger.kernel.org, kuba@kernel.org, davem@davemloft.net, fw@strlen.org, kadlec@netfilter.org Subject: Re: [PATCH nf v2] netfilter: conntrack: connection timeout after re-register Message-ID: <20201020152135.GA19913@salvia> References: <20201007193252.7009D95C169C@us180.sjc.aristanetworks.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <20201007193252.7009D95C169C@us180.sjc.aristanetworks.com> User-Agent: Mutt/1.10.1 (2018-07-13) X-Virus-Scanned: ClamAV using ClamSMTP Precedence: bulk List-ID: X-Mailing-List: netfilter-devel@vger.kernel.org On Wed, Oct 07, 2020 at 12:32:52PM -0700, Francesco Ruggeri wrote: > If the first packet conntrack sees after a re-register is an outgoing > keepalive packet with no data (SEG.SEQ = SND.NXT-1), td_end is set to > SND.NXT-1. > When the peer correctly acknowledges SND.NXT, tcp_in_window fails > check III (Upper bound for valid (s)ack: sack <= receiver.td_end) and > returns false, which cascades into nf_conntrack_in setting > skb->_nfct = 0 and in later conntrack iptables rules not matching. > In cases where iptables are dropping packets that do not match > conntrack rules this can result in idle tcp connections to time out. Applied, thanks.