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=-10.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,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 38C8FC33CAF for ; Thu, 16 Jan 2020 18:36:57 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 0F6B62073A for ; Thu, 16 Jan 2020 18:36:57 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1579199817; bh=3BOj0VQFcmveERWLpa/tuFBG9tDDPouv+gFGtCBGxDI=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=zo70uFipiDUDXNz9gDX1RJIHExsq21uccUEG4xQHwleBMH4++gkp4pawkX5ExnCbG FiJ5hkn/p9QCTZAjuh2Oi9sHbObCF5J9Qam6dj3Ixl7lEGR3rRtTv8j/LtpYbzlwlJ xICmVUx76pqCWSagHzlmpGh4Pcl8yrzYuoKlwQVY= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2436866AbgAPSg4 (ORCPT ); Thu, 16 Jan 2020 13:36:56 -0500 Received: from mail.kernel.org ([198.145.29.99]:56760 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2390616AbgAPRM5 (ORCPT ); Thu, 16 Jan 2020 12:12:57 -0500 Received: from sasha-vm.mshome.net (c-73-47-72-35.hsd1.nh.comcast.net [73.47.72.35]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 3DF5420684; Thu, 16 Jan 2020 17:12:56 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1579194777; bh=3BOj0VQFcmveERWLpa/tuFBG9tDDPouv+gFGtCBGxDI=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=wyETtSTQUpajkOfKLHtz9ixoxz01qDjHk+svPTJ+MR0jX2NUMMncjubZoQ8o02gAM E3Uw9V3AlE6qTJQkAs2QDzEzZiu0A9NsrPrgpGOBimgJQPujJ1Tw5AfSj+ZNRvUCBi MQ8QAgg0F0m3mQecNr5jGBUqtL9WtnCiLAQUahwE= From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Karsten Graul , Ursula Braun , Jakub Kicinski , Sasha Levin , linux-s390@vger.kernel.org, netdev@vger.kernel.org Subject: [PATCH AUTOSEL 4.19 594/671] net/smc: receive pending data after RCV_SHUTDOWN Date: Thu, 16 Jan 2020 12:03:52 -0500 Message-Id: <20200116170509.12787-331-sashal@kernel.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20200116170509.12787-1-sashal@kernel.org> References: <20200116170509.12787-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Karsten Graul [ Upstream commit 107529e31a87acd475ff6a0f82745821b8f70fec ] smc_rx_recvmsg() first checks if data is available, and then if RCV_SHUTDOWN is set. There is a race when smc_cdc_msg_recv_action() runs in between these 2 checks, receives data and sets RCV_SHUTDOWN. In that case smc_rx_recvmsg() would return from receive without to process the available data. Fix that with a final check for data available if RCV_SHUTDOWN is set. Move the check for data into a function and call it twice. And use the existing helper smc_rx_data_available(). Fixes: 952310ccf2d8 ("smc: receive data from RMBE") Reviewed-by: Ursula Braun Signed-off-by: Karsten Graul Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin --- net/smc/smc_rx.c | 25 ++++++++++++++++++++----- 1 file changed, 20 insertions(+), 5 deletions(-) diff --git a/net/smc/smc_rx.c b/net/smc/smc_rx.c index 1ee5fdbf8284..36340912df48 100644 --- a/net/smc/smc_rx.c +++ b/net/smc/smc_rx.c @@ -262,6 +262,18 @@ static int smc_rx_recv_urg(struct smc_sock *smc, struct msghdr *msg, int len, return -EAGAIN; } +static bool smc_rx_recvmsg_data_available(struct smc_sock *smc) +{ + struct smc_connection *conn = &smc->conn; + + if (smc_rx_data_available(conn)) + return true; + else if (conn->urg_state == SMC_URG_VALID) + /* we received a single urgent Byte - skip */ + smc_rx_update_cons(smc, 0); + return false; +} + /* smc_rx_recvmsg - receive data from RMBE * @msg: copy data to receive buffer * @pipe: copy data to pipe if set - indicates splice() call @@ -303,15 +315,18 @@ int smc_rx_recvmsg(struct smc_sock *smc, struct msghdr *msg, if (read_done >= target || (pipe && read_done)) break; - if (atomic_read(&conn->bytes_to_rcv)) + if (smc_rx_recvmsg_data_available(smc)) goto copy; - else if (conn->urg_state == SMC_URG_VALID) - /* we received a single urgent Byte - skip */ - smc_rx_update_cons(smc, 0); if (sk->sk_shutdown & RCV_SHUTDOWN || - conn->local_tx_ctrl.conn_state_flags.peer_conn_abort) + conn->local_tx_ctrl.conn_state_flags.peer_conn_abort) { + /* smc_cdc_msg_recv_action() could have run after + * above smc_rx_recvmsg_data_available() + */ + if (smc_rx_recvmsg_data_available(smc)) + goto copy; break; + } if (read_done) { if (sk->sk_err || -- 2.20.1