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=-3.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS 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 B5430C433DF for ; Fri, 22 May 2020 22:48:35 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 8E519204EA for ; Fri, 22 May 2020 22:48:35 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731242AbgEVWsf convert rfc822-to-8bit (ORCPT ); Fri, 22 May 2020 18:48:35 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:46762 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1731029AbgEVWse (ORCPT ); Fri, 22 May 2020 18:48:34 -0400 Received: from shards.monkeyblade.net (shards.monkeyblade.net [IPv6:2620:137:e000::1:9]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id E0A30C061A0E; Fri, 22 May 2020 15:48:34 -0700 (PDT) Received: from localhost (unknown [IPv6:2601:601:9f00:477::3d5]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (Client did not present a certificate) (Authenticated sender: davem-davemloft) by shards.monkeyblade.net (Postfix) with ESMTPSA id 5BD2112744698; Fri, 22 May 2020 15:48:34 -0700 (PDT) Date: Fri, 22 May 2020 15:48:33 -0700 (PDT) Message-Id: <20200522.154833.1534807790311464208.davem@davemloft.net> To: jere.leppanen@nokia.com Cc: linux-sctp@vger.kernel.org, netdev@vger.kernel.org, vyasevich@gmail.com, nhorman@tuxdriver.com, marcelo.leitner@gmail.com, David.Laight@aculab.com Subject: Re: [PATCH net 1/1] sctp: Start shutdown on association restart if in SHUTDOWN-SENT state and socket is closed From: David Miller In-Reply-To: <20200520151531.787414-1-jere.leppanen@nokia.com> References: <20200520151531.787414-1-jere.leppanen@nokia.com> X-Mailer: Mew version 6.8 on Emacs 26.3 Mime-Version: 1.0 Content-Type: Text/Plain; charset=iso-8859-1 Content-Transfer-Encoding: 8BIT X-Greylist: Sender succeeded SMTP AUTH, not delayed by milter-greylist-4.5.12 (shards.monkeyblade.net [149.20.54.216]); Fri, 22 May 2020 15:48:34 -0700 (PDT) Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org From: Jere Leppänen Date: Wed, 20 May 2020 18:15:31 +0300 > Commit bdf6fa52f01b ("sctp: handle association restarts when the > socket is closed.") starts shutdown when an association is restarted, > if in SHUTDOWN-PENDING state and the socket is closed. However, the > rationale stated in that commit applies also when in SHUTDOWN-SENT > state - we don't want to move an association to ESTABLISHED state when > the socket has been closed, because that results in an association > that is unreachable from user space. > > The problem scenario: > > 1. Client crashes and/or restarts. > > 2. Server (using one-to-one socket) calls close(). SHUTDOWN is lost. > > 3. Client reconnects using the same addresses and ports. > > 4. Server's association is restarted. The association and the socket > move to ESTABLISHED state, even though the server process has > closed its descriptor. > > Also, after step 4 when the server process exits, some resources are > leaked in an attempt to release the underlying inet sock structure in > ESTABLISHED state: > > IPv4: Attempt to release TCP socket in state 1 00000000377288c7 > > Fix by acting the same way as in SHUTDOWN-PENDING state. That is, if > an association is restarted in SHUTDOWN-SENT state and the socket is > closed, then start shutdown and don't move the association or the > socket to ESTABLISHED state. > > Fixes: bdf6fa52f01b ("sctp: handle association restarts when the socket is closed.") > Signed-off-by: Jere Leppänen Applied and queued up for -stable, thanks.