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=-9.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT 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 5E407C32771 for ; Fri, 24 Jan 2020 11:35:28 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 357D0206D4 for ; Fri, 24 Jan 2020 11:35:28 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1579865728; bh=t60YEIkTPM+weChxBuQ9RL7zky9tW+NV2nEWVLpqr8o=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=1l9yjAvUxq8YRX7HXtvBrjuFdc0aYQhxv7DhcY4ftiNQOXjwNdhdq8ZTT6baG+6I9 7uu+oqvBqoshVvnOi4Annep073RcsuhOYtiAE+gCMoAhgs6Ow5byIzblTl7SKoeZwk wMwyJFmTPHGQqQ/E3RySA/IhikyZBYNi6LdIKYnc= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2404805AbgAXLfM (ORCPT ); Fri, 24 Jan 2020 06:35:12 -0500 Received: from mail.kernel.org ([198.145.29.99]:55094 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2404795AbgAXLfG (ORCPT ); Fri, 24 Jan 2020 06:35:06 -0500 Received: from localhost (ip-213-127-102-57.ip.prioritytelecom.net [213.127.102.57]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 936DB222D9; Fri, 24 Jan 2020 11:35:04 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1579865705; bh=t60YEIkTPM+weChxBuQ9RL7zky9tW+NV2nEWVLpqr8o=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=LciA+VKWQRN+78uX5BzQizNJdJd8ZWpd3ugvQ00HOnGu+2Ci/tRAvCRfr83wxOcsh 4TwypCYuJmPiPPczrt60ZXGrbyxHwS90tly5GTwKa4JnCNRaSUTrDm1jjTpyoQv0a3 xY/peEnLHVo0TLUoD1b4JpwuAFgFCWPeWNk6jp40= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Ursula Braun , Karsten Graul , Jakub Kicinski , Sasha Levin Subject: [PATCH 4.19 603/639] net/smc: receive pending data after RCV_SHUTDOWN Date: Fri, 24 Jan 2020 10:32:53 +0100 Message-Id: <20200124093204.933660026@linuxfoundation.org> X-Mailer: git-send-email 2.25.0 In-Reply-To: <20200124093047.008739095@linuxfoundation.org> References: <20200124093047.008739095@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 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 1ee5fdbf8284e..36340912df48a 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