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 B6D21C4361B for ; Sun, 6 Dec 2020 11:43:11 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 8CE262312F for ; Sun, 6 Dec 2020 11:43:11 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728325AbgLFLmy (ORCPT ); Sun, 6 Dec 2020 06:42:54 -0500 Received: from mail.kernel.org ([198.145.29.99]:41788 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727918AbgLFLmp (ORCPT ); Sun, 6 Dec 2020 06:42:45 -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, Jonathan Morton , Pete Heist , =?UTF-8?q?Toke=20H=C3=B8iland-J=C3=B8rgensen?= , Jakub Kicinski Subject: [PATCH 5.4 21/39] inet_ecn: Fix endianness of checksum update when setting ECT(1) Date: Sun, 6 Dec 2020 12:17:25 +0100 Message-Id: <20201206111555.693217763@linuxfoundation.org> X-Mailer: git-send-email 2.29.2 In-Reply-To: <20201206111554.677764505@linuxfoundation.org> References: <20201206111554.677764505@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: "Toke Høiland-Jørgensen" [ Upstream commit 2867e1eac61016f59b3d730e3f7aa488e186e917 ] When adding support for propagating ECT(1) marking in IP headers it seems I suffered from endianness-confusion in the checksum update calculation: In fact the ECN field is in the *lower* bits of the first 16-bit word of the IP header when calculating in network byte order. This means that the addition performed to update the checksum field was wrong; let's fix that. Fixes: b723748750ec ("tunnel: Propagate ECT(1) when decapsulating as recommended by RFC6040") Reported-by: Jonathan Morton Tested-by: Pete Heist Signed-off-by: Toke Høiland-Jørgensen Link: https://lore.kernel.org/r/20201130183705.17540-1-toke@redhat.com Signed-off-by: Jakub Kicinski Signed-off-by: Greg Kroah-Hartman --- include/net/inet_ecn.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/include/net/inet_ecn.h +++ b/include/net/inet_ecn.h @@ -107,7 +107,7 @@ static inline int IP_ECN_set_ect1(struct if ((iph->tos & INET_ECN_MASK) != INET_ECN_ECT_0) return 0; - check += (__force u16)htons(0x100); + check += (__force u16)htons(0x1); iph->check = (__force __sum16)(check + (check>=0xFFFF)); iph->tos ^= INET_ECN_MASK;