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=-16.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,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 F369CC4361B for ; Sun, 6 Dec 2020 11:44:11 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id BD70E23122 for ; Sun, 6 Dec 2020 11:44:11 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729249AbgLFLnz (ORCPT ); Sun, 6 Dec 2020 06:43:55 -0500 Received: from mail.kernel.org ([198.145.29.99]:42898 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729215AbgLFLnr (ORCPT ); Sun, 6 Dec 2020 06:43:47 -0500 From: Greg Kroah-Hartman Authentication-Results: mail.kernel.org; dkim=permerror (bad message/signature format) To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Vadim Fedorenko , Jakub Kicinski Subject: [PATCH 5.9 06/46] net/tls: missing received data after fast remote close Date: Sun, 6 Dec 2020 12:17:14 +0100 Message-Id: <20201206111556.757320563@linuxfoundation.org> X-Mailer: git-send-email 2.29.2 In-Reply-To: <20201206111556.455533723@linuxfoundation.org> References: <20201206111556.455533723@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Vadim Fedorenko [ Upstream commit 20ffc7adf53a5fd3d19751fbff7895bcca66686e ] In case when tcp socket received FIN after some data and the parser haven't started before reading data caller will receive an empty buffer. This behavior differs from plain TCP socket and leads to special treating in user-space. The flow that triggers the race is simple. Server sends small amount of data right after the connection is configured to use TLS and closes the connection. In this case receiver sees TLS Handshake data, configures TLS socket right after Change Cipher Spec record. While the configuration is in process, TCP socket receives small Application Data record, Encrypted Alert record and FIN packet. So the TCP socket changes sk_shutdown to RCV_SHUTDOWN and sk_flag with SK_DONE bit set. The received data is not parsed upon arrival and is never sent to user-space. Patch unpauses parser directly if we have unparsed data in tcp receive queue. Fixes: fcf4793e278e ("tls: check RCV_SHUTDOWN in tls_wait_data") Signed-off-by: Vadim Fedorenko Link: https://lore.kernel.org/r/1605801588-12236-1-git-send-email-vfedorenko@novek.ru Signed-off-by: Jakub Kicinski Signed-off-by: Greg Kroah-Hartman --- net/tls/tls_sw.c | 6 ++++++ 1 file changed, 6 insertions(+) --- a/net/tls/tls_sw.c +++ b/net/tls/tls_sw.c @@ -1295,6 +1295,12 @@ static struct sk_buff *tls_wait_data(str return NULL; } + if (!skb_queue_empty(&sk->sk_receive_queue)) { + __strp_unpause(&ctx->strp); + if (ctx->recv_pkt) + return ctx->recv_pkt; + } + if (sk->sk_shutdown & RCV_SHUTDOWN) return NULL;