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=-3.7 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED 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 4CE24C432C0 for ; Sat, 16 Nov 2019 21:04:25 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 28D5D20729 for ; Sat, 16 Nov 2019 21:04:25 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727727AbfKPVEY (ORCPT ); Sat, 16 Nov 2019 16:04:24 -0500 Received: from shards.monkeyblade.net ([23.128.96.9]:53808 "EHLO shards.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727485AbfKPVEX (ORCPT ); Sat, 16 Nov 2019 16:04:23 -0500 Received: from localhost (unknown [IPv6:2601:601:9f00:1e2::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 426D2151A15FD; Sat, 16 Nov 2019 13:04:23 -0800 (PST) Date: Sat, 16 Nov 2019 13:04:22 -0800 (PST) Message-Id: <20191116.130422.2084572901433723641.davem@davemloft.net> To: kgraul@linux.ibm.com Cc: netdev@vger.kernel.org, linux-s390@vger.kernel.org, heiko.carstens@de.ibm.com, raspl@linux.ibm.com, ubraun@linux.ibm.com Subject: Re: [PATCH net] net/smc: fix fastopen for non-blocking connect() From: David Miller In-Reply-To: <20191115113930.38684-1-kgraul@linux.ibm.com> References: <20191115113930.38684-1-kgraul@linux.ibm.com> X-Mailer: Mew version 6.8 on Emacs 26.1 Mime-Version: 1.0 Content-Type: Text/Plain; charset=us-ascii Content-Transfer-Encoding: 7bit X-Greylist: Sender succeeded SMTP AUTH, not delayed by milter-greylist-4.5.12 (shards.monkeyblade.net [149.20.54.216]); Sat, 16 Nov 2019 13:04:23 -0800 (PST) Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org From: Karsten Graul Date: Fri, 15 Nov 2019 12:39:30 +0100 > From: Ursula Braun > > FASTOPEN does not work with SMC-sockets. Since SMC allows fallback to > TCP native during connection start, the FASTOPEN setsockopts trigger > this fallback, if the SMC-socket is still in state SMC_INIT. > But if a FASTOPEN setsockopt is called after a non-blocking connect(), > this is broken, and fallback does not make sense. > This change complements > commit cd2063604ea6 ("net/smc: avoid fallback in case of non-blocking connect") > and fixes the syzbot reported problem "WARNING in smc_unhash_sk". > > Reported-by: syzbot+8488cc4cf1c9e09b8b86@syzkaller.appspotmail.com > Fixes: e1bbdd570474 ("net/smc: reduce sock_put() for fallback sockets") > Signed-off-by: Ursula Braun > Signed-off-by: Karsten Graul Applied and queued up for -stable, thanks.