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=-4.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS 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 30305C282C5 for ; Fri, 25 Jan 2019 02:25:48 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 007B0218D0 for ; Fri, 25 Jan 2019 02:25:47 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728696AbfAYCZn (ORCPT ); Thu, 24 Jan 2019 21:25:43 -0500 Received: from shards.monkeyblade.net ([23.128.96.9]:36838 "EHLO shards.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728524AbfAYCZn (ORCPT ); Thu, 24 Jan 2019 21:25:43 -0500 Received: from localhost (unknown [IPv6:2601:601:9f80:35cd::bf5]) (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 7DFFE10888E81; Thu, 24 Jan 2019 18:25:42 -0800 (PST) Date: Thu, 24 Jan 2019 18:25:41 -0800 (PST) Message-Id: <20190124.182541.341610576126108739.davem@davemloft.net> To: lucien.xin@gmail.com Cc: linux-kernel@vger.kernel.org, netdev@vger.kernel.org, linux-sctp@vger.kernel.org, marcelo.leitner@gmail.com, nhorman@tuxdriver.com Subject: Re: [PATCH net] sctp: set flow sport from saddr only when it's 0 From: David Miller In-Reply-To: <91961be2ab833139b1a4b0188ba47c2581b991d4.1548096161.git.lucien.xin@gmail.com> References: <91961be2ab833139b1a4b0188ba47c2581b991d4.1548096161.git.lucien.xin@gmail.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]); Thu, 24 Jan 2019 18:25:42 -0800 (PST) Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org From: Xin Long Date: Tue, 22 Jan 2019 02:42:41 +0800 > Now sctp_transport_pmtu() passes transport->saddr into .get_dst() to set > flow sport from 'saddr'. However, transport->saddr is set only when > transport->dst exists in sctp_transport_route(). > > If sctp_transport_pmtu() is called without transport->saddr set, like > when transport->dst doesn't exists, the flow sport will be set to 0 > from transport->saddr, which will cause a wrong route to be got. > > Commit 6e91b578bf3f ("sctp: re-use sctp_transport_pmtu in > sctp_transport_route") made the issue be triggered more easily > since sctp_transport_pmtu() would be called in sctp_transport_route() > after that. > > In gerneral, fl4->fl4_sport should always be set to > htons(asoc->base.bind_addr.port), unless transport->asoc doesn't exist > in sctp_v4/6_get_dst(), which is the case: > > sctp_ootb_pkt_new() -> > sctp_transport_route() > > For that, we can simply handle it by setting flow sport from saddr only > when it's 0 in sctp_v4/6_get_dst(). > > Fixes: 6e91b578bf3f ("sctp: re-use sctp_transport_pmtu in sctp_transport_route") > Reported-by: Ying Xu > Signed-off-by: Xin Long Applied and queued up for -stable.