From patchwork Fri Mar 5 12:20:43 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg Kroah-Hartman X-Patchwork-Id: 395051 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=-23.8 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER, INCLUDES_PATCH, MAILING_LIST_MULTI, MENTIONS_GIT_HOSTING, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT 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 D64A0C43331 for ; Fri, 5 Mar 2021 12:29:31 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id BDC5D6502E for ; Fri, 5 Mar 2021 12:29:31 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232013AbhCEM3C (ORCPT ); Fri, 5 Mar 2021 07:29:02 -0500 Received: from mail.kernel.org ([198.145.29.99]:37604 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232051AbhCEM2k (ORCPT ); Fri, 5 Mar 2021 07:28:40 -0500 Received: by mail.kernel.org (Postfix) with ESMTPSA id 786816502E; Fri, 5 Mar 2021 12:28:39 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1614947320; bh=GjKNN1+d7+ftKqoKBaGmEIZRKBdFr9E7KXZOSOCqDkw=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=ajFvTMVi00cRd7Fc0rBHYonyB3F9rj27Z55/Skdn1tamnROd/BYotLBGsGGBsN0KM KKWBKYT2RE6qjgMMFdlTV3zDDL9L+kssKjzdi41Q19nlyolXAsiOcQ5c1o08N07ZeF C5HzVFA2t3eNaf0rm8pmLkSerP7CIHhFJKHjtZE0= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, "Dr. David Alan Gilbert" , Mat Martineau , Paolo Abeni , Jakub Kicinski Subject: [PATCH 5.10 024/102] mptcp: do not wakeup listener for MPJ subflows Date: Fri, 5 Mar 2021 13:20:43 +0100 Message-Id: <20210305120904.473118256@linuxfoundation.org> X-Mailer: git-send-email 2.30.1 In-Reply-To: <20210305120903.276489876@linuxfoundation.org> References: <20210305120903.276489876@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Paolo Abeni commit 52557dbc7538ecceb27ef2206719a47a8039a335 upstream. MPJ subflows are not exposed as fds to user spaces. As such, incoming MPJ subflows are removed from the accept queue by tcp_check_req()/tcp_get_cookie_sock(). Later tcp_child_process() invokes subflow_data_ready() on the parent socket regardless of the subflow kind, leading to poll wakeups even if the later accept will block. Address the issue by double-checking the queue state before waking the user-space. Closes: https://github.com/multipath-tcp/mptcp_net-next/issues/164 Reported-by: Dr. David Alan Gilbert Fixes: f296234c98a8 ("mptcp: Add handling of incoming MP_JOIN requests") Reviewed-by: Mat Martineau Signed-off-by: Paolo Abeni Signed-off-by: Jakub Kicinski Signed-off-by: Greg Kroah-Hartman --- net/mptcp/subflow.c | 6 ++++++ 1 file changed, 6 insertions(+) --- a/net/mptcp/subflow.c +++ b/net/mptcp/subflow.c @@ -981,6 +981,12 @@ static void subflow_data_ready(struct so msk = mptcp_sk(parent); if (state & TCPF_LISTEN) { + /* MPJ subflow are removed from accept queue before reaching here, + * avoid stray wakeups + */ + if (reqsk_queue_empty(&inet_csk(sk)->icsk_accept_queue)) + return; + set_bit(MPTCP_DATA_READY, &msk->flags); parent->sk_data_ready(parent); return;