From patchwork Mon Mar 8 09:00:04 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Davide Caratti X-Patchwork-Id: 12121807 X-Patchwork-Delegate: kuba@kernel.org 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=-16.0 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,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED 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 21A4EC433E6 for ; Mon, 8 Mar 2021 09:01:04 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id D6ECB65132 for ; Mon, 8 Mar 2021 09:01:03 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229829AbhCHJAc (ORCPT ); Mon, 8 Mar 2021 04:00:32 -0500 Received: from us-smtp-delivery-124.mimecast.com ([63.128.21.124]:43025 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229737AbhCHJA2 (ORCPT ); Mon, 8 Mar 2021 04:00:28 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1615194028; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding; bh=vrWUpIGtgFZn7irbq7MRye/8EbAlu1J6dvDk6oFAR6E=; b=DWdCHv646jwsyeg7T0XM6aRZ7aiJKA+BNUYc0WJFhAy2wBh8WOWNbsUO2lSNN5ZhFnAgZK fpnXjlNdggMyLzKDz4ky2Fz4/0jeWbXlk3h2/6hG4AS1MxzSTV8V7nU/rwZN9ZdC3D9hql DZ9d8kgkekZ3TeevC9/gw9hEzql6Doo= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-502-ybqmKa0dPRmKm9IE5XZdmQ-1; Mon, 08 Mar 2021 04:00:23 -0500 X-MC-Unique: ybqmKa0dPRmKm9IE5XZdmQ-1 Received: from smtp.corp.redhat.com (int-mx08.intmail.prod.int.phx2.redhat.com [10.5.11.23]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 02AD857; Mon, 8 Mar 2021 09:00:22 +0000 (UTC) Received: from computer-6.station (unknown [10.40.192.32]) by smtp.corp.redhat.com (Postfix) with ESMTP id 3738A19D7C; Mon, 8 Mar 2021 09:00:20 +0000 (UTC) From: Davide Caratti To: netdev@vger.kernel.org, "David S. Miller" , Jakub Kicinski Cc: Matthieu Baerts , stable@vger.kernel.org, mptcp@lists.01.org Subject: [PATCH net] mptcp: fix length of ADD_ADDR with port sub-option Date: Mon, 8 Mar 2021 10:00:04 +0100 Message-Id: <66b3a2eec724af07ffdb04fefc6c7d50b85f296b.1615191605.git.dcaratti@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.84 on 10.5.11.23 Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org X-Patchwork-Delegate: kuba@kernel.org in current Linux, MPTCP peers advertising endpoints with port numbers use a sub-option length that wrongly accounts for the trailing TCP NOP. Also, receivers will only process incoming ADD_ADDR with port having such wrong sub-option length. Fix this, making ADD_ADDR compliant to RFC8684 ยง3.4.1. this can be verified running tcpdump on the kselftests artifacts: unpatched kernel: [root@bottarga mptcp]# tcpdump -tnnr unpatched.pcap | grep add-addr reading from file unpatched.pcap, link-type LINUX_SLL (Linux cooked v1), snapshot length 65535 IP 10.0.1.1.10000 > 10.0.1.2.53078: Flags [.], ack 101, win 509, options [nop,nop,TS val 214459678 ecr 521312851,mptcp add-addr v1 id 1 a00:201:2774:2d88:7436:85c3:17fd:101], length 0 IP 10.0.1.2.53078 > 10.0.1.1.10000: Flags [.], ack 101, win 502, options [nop,nop,TS val 521312852 ecr 214459678,mptcp add-addr[bad opt]] patched kernel: [root@bottarga mptcp]# tcpdump -tnnr patched.pcap | grep add-addr reading from file patched.pcap, link-type LINUX_SLL (Linux cooked v1), snapshot length 65535 IP 10.0.1.1.10000 > 10.0.1.2.38178: Flags [.], ack 101, win 509, options [nop,nop,TS val 3728873902 ecr 2732713192,mptcp add-addr v1 id 1 10.0.2.1:10100 hmac 0xbccdfcbe59292a1f,nop,nop], length 0 IP 10.0.1.2.38178 > 10.0.1.1.10000: Flags [.], ack 101, win 502, options [nop,nop,TS val 2732713195 ecr 3728873902,mptcp add-addr v1-echo id 1 10.0.2.1:10100,nop,nop], length 0 Fixes: 22fb85ffaefb ("mptcp: add port support for ADD_ADDR suboption writing") CC: stable@vger.kernel.org # 5.11+ Reviewed-by: Mat Martineau Acked-and-tested-by: Geliang Tang Signed-off-by: Davide Caratti --- net/mptcp/protocol.h | 14 ++++++++------ 1 file changed, 8 insertions(+), 6 deletions(-) diff --git a/net/mptcp/protocol.h b/net/mptcp/protocol.h index 91827d949766..e21a5bc36cf0 100644 --- a/net/mptcp/protocol.h +++ b/net/mptcp/protocol.h @@ -52,14 +52,15 @@ #define TCPOLEN_MPTCP_DSS_MAP64 14 #define TCPOLEN_MPTCP_DSS_CHECKSUM 2 #define TCPOLEN_MPTCP_ADD_ADDR 16 -#define TCPOLEN_MPTCP_ADD_ADDR_PORT 20 +#define TCPOLEN_MPTCP_ADD_ADDR_PORT 18 #define TCPOLEN_MPTCP_ADD_ADDR_BASE 8 -#define TCPOLEN_MPTCP_ADD_ADDR_BASE_PORT 12 +#define TCPOLEN_MPTCP_ADD_ADDR_BASE_PORT 10 #define TCPOLEN_MPTCP_ADD_ADDR6 28 -#define TCPOLEN_MPTCP_ADD_ADDR6_PORT 32 +#define TCPOLEN_MPTCP_ADD_ADDR6_PORT 30 #define TCPOLEN_MPTCP_ADD_ADDR6_BASE 20 -#define TCPOLEN_MPTCP_ADD_ADDR6_BASE_PORT 24 -#define TCPOLEN_MPTCP_PORT_LEN 4 +#define TCPOLEN_MPTCP_ADD_ADDR6_BASE_PORT 22 +#define TCPOLEN_MPTCP_PORT_LEN 2 +#define TCPOLEN_MPTCP_PORT_ALIGN 2 #define TCPOLEN_MPTCP_RM_ADDR_BASE 4 #define TCPOLEN_MPTCP_PRIO 3 #define TCPOLEN_MPTCP_PRIO_ALIGN 4 @@ -701,8 +702,9 @@ static inline unsigned int mptcp_add_addr_len(int family, bool echo, bool port) len = TCPOLEN_MPTCP_ADD_ADDR6_BASE; if (!echo) len += MPTCPOPT_THMAC_LEN; + /* account for 2 trailing 'nop' options */ if (port) - len += TCPOLEN_MPTCP_PORT_LEN; + len += TCPOLEN_MPTCP_PORT_LEN + TCPOLEN_MPTCP_PORT_ALIGN; return len; }