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=-14.5 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS,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 B3A59C433E9 for ; Thu, 14 Jan 2021 19:22:49 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 7934B23B5D for ; Thu, 14 Jan 2021 19:22:49 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730024AbhANTWh (ORCPT ); Thu, 14 Jan 2021 14:22:37 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:43688 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729921AbhANTWg (ORCPT ); Thu, 14 Jan 2021 14:22:36 -0500 Received: from mail-wm1-x334.google.com (mail-wm1-x334.google.com [IPv6:2a00:1450:4864:20::334]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id BC07CC061757 for ; Thu, 14 Jan 2021 11:21:55 -0800 (PST) Received: by mail-wm1-x334.google.com with SMTP id v184so1471977wma.1 for ; Thu, 14 Jan 2021 11:21:55 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=subject:to:cc:references:from:message-id:date:user-agent :mime-version:in-reply-to:content-language:content-transfer-encoding; bh=yoBKqmxECo5TZjsaPrlrADanJOS8g5VDMzzQPzlMK2k=; b=WcRwmSASeF1C62I+RmvsgYoUAVU8m0aQnCXTsiArgucO7t2ukRqT4lt0lrdjt/fE/N psZFDOqpUdy77btPEd8Ewii/MCAr4irtWNq4KI5PhtsKOcYjr6AZ6AAWmiUba0bvbLsp plZtlatodNuL+HXLVutV/yAGAbmvub4K5VsHZDV8kF5FddDjmPIhPHBJeXp9TNwmFoyg BUfZTJw3FhMZ3+2pRuOqlCH2F8amfkIv4FAMlF9jAn7GiA/8gYkSIf5fCO4LPqWAZ/xU vCr/6pkyAx/7X+UuDB1h3lBfbewFqXMOM4phK5rAd/XweK9ekXDr5Ej15M2b3UMNBCMj PKbg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:subject:to:cc:references:from:message-id:date :user-agent:mime-version:in-reply-to:content-language :content-transfer-encoding; bh=yoBKqmxECo5TZjsaPrlrADanJOS8g5VDMzzQPzlMK2k=; b=rNQmY17N/TViJTHsw+eBifXzFjTKFejlDUNIN2ADoNoKbYz2dMcDc5ZCVtbw5v3oSj 2wpfpUOCl5o9MTqoeIq/8A1XmsELdPN0S+Xc5zamgcazClqsWXLMicURzGK0qsG4dXFx Y+odY23pyVPHPVL2qVPBMMTVh+kVj+Qem9U4f8qptBoLX7C7ADLj71c0BpThu2tulgai 6Bkg2BxxC7KZGoNRCA8BceVL0AJCYvbutHm65BWhzfhUvkRv9yy3tBAM9CBoIoIINsg2 KWDGh8EPYGMnf5zX5HJLDlnYaZeOB6Fa/KrxxkooG7BwyPMeMrIkfvPNchI1z0sLM2UE W1Pw== X-Gm-Message-State: AOAM531olKYUipPG+6Ok/OoSqty//xCcxkfnKUiaeWfDiKcwriMNBkZe q7Jymg4Gh+cmYuvD8ASohKlY/k7Fjk0= X-Google-Smtp-Source: ABdhPJwe/FiAs5+FQyBSSMMGDzWyObAR0oJ7ZOWsNtChU1x1N0hrCtgnuAUkcM+2MhvotVERC3v1hw== X-Received: by 2002:a1c:3286:: with SMTP id y128mr5298896wmy.104.1610652114541; Thu, 14 Jan 2021 11:21:54 -0800 (PST) Received: from [192.168.1.101] ([37.166.145.83]) by smtp.gmail.com with ESMTPSA id q7sm4927667wmq.0.2021.01.14.11.21.51 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Thu, 14 Jan 2021 11:21:53 -0800 (PST) Subject: Re: [PATCH net] mptcp: fix locking in mptcp_disconnect() To: Paolo Abeni , netdev@vger.kernel.org Cc: mptcp@lists.01.org, "David S. Miller" , Jakub Kicinski , Eric Dumazet References: From: Eric Dumazet Message-ID: <9cf07f1b-c013-adfc-15b4-58902095cf07@gmail.com> Date: Thu, 14 Jan 2021 20:21:48 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.6.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org On 1/14/21 4:37 PM, Paolo Abeni wrote: > tcp_disconnect() expects the caller acquires the sock lock, > but mptcp_disconnect() is not doing that. Add the missing > required lock. > > Reported-by: Eric Dumazet > Fixes: 76e2a55d1625 ("mptcp: better msk-level shutdown.") > Signed-off-by: Paolo Abeni > --- > net/mptcp/protocol.c | 9 +++++++-- > 1 file changed, 7 insertions(+), 2 deletions(-) > > diff --git a/net/mptcp/protocol.c b/net/mptcp/protocol.c > index 81faeff8f3bb..f998a077c7dd 100644 > --- a/net/mptcp/protocol.c > +++ b/net/mptcp/protocol.c > @@ -2646,8 +2646,13 @@ static int mptcp_disconnect(struct sock *sk, int flags) > struct mptcp_sock *msk = mptcp_sk(sk); > > __mptcp_flush_join_list(msk); > - mptcp_for_each_subflow(msk, subflow) > - tcp_disconnect(mptcp_subflow_tcp_sock(subflow), flags); > + mptcp_for_each_subflow(msk, subflow) { > + struct sock *ssk = mptcp_subflow_tcp_sock(subflow); > + > + lock_sock(ssk); > + tcp_disconnect(ssk, flags); > + release_sock(ssk); > + } Reviewed-by: Eric Dumazet Note that for loops like this one, calling non blocking functions, you could use lock_sock_fast() (Probably does not matter in slow path)