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=-7.0 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE, SPF_PASS autolearn=no 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 7E06FC433E0 for ; Mon, 3 Aug 2020 22:30:27 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 9B5EC206D7 for ; Mon, 3 Aug 2020 22:30:27 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727979AbgHCWa0 (ORCPT ); Mon, 3 Aug 2020 18:30:26 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:50812 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726356AbgHCWa0 (ORCPT ); Mon, 3 Aug 2020 18:30:26 -0400 Received: from shards.monkeyblade.net (shards.monkeyblade.net [IPv6:2620:137:e000::1:9]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 3C521C06174A for ; Mon, 3 Aug 2020 15:30:26 -0700 (PDT) Received: from localhost (unknown [IPv6:2601:601:9f00:477::3d5]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (Client did not present a certificate) (Authenticated sender: davem-davemloft) by shards.monkeyblade.net (Postfix) with ESMTPSA id 4138012773034; Mon, 3 Aug 2020 15:13:40 -0700 (PDT) Date: Mon, 03 Aug 2020 15:30:24 -0700 (PDT) Message-Id: <20200803.153024.29144597725572653.davem@davemloft.net> To: lorenzo@kernel.org Cc: netdev@vger.kernel.org, lorenzo.bianconi@redhat.com, tom@herbertland.com Subject: Re: [PATCH net] net: gre: recompute gre csum for sctp over gre tunnels From: David Miller In-Reply-To: <6722d2c4fe1b9b376a277b3f35cdf3eb3345874e.1596218124.git.lorenzo@kernel.org> References: <6722d2c4fe1b9b376a277b3f35cdf3eb3345874e.1596218124.git.lorenzo@kernel.org> X-Mailer: Mew version 6.8 on Emacs 26.3 Mime-Version: 1.0 Content-Type: Text/Plain; charset=us-ascii Content-Transfer-Encoding: 7bit X-Greylist: Sender succeeded SMTP AUTH, not delayed by milter-greylist-4.5.12 (shards.monkeyblade.net [149.20.54.216]); Mon, 03 Aug 2020 15:13:40 -0700 (PDT) Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org From: Lorenzo Bianconi Date: Fri, 31 Jul 2020 20:12:05 +0200 > The GRE tunnel can be used to transport traffic that does not rely on a > Internet checksum (e.g. SCTP). The issue can be triggered creating a GRE > or GRETAP tunnel and transmitting SCTP traffic ontop of it where CRC > offload has been disabled. In order to fix the issue we need to > recompute the GRE csum in gre_gso_segment() not relying on the inner > checksum. > The issue is still present when we have the CRC offload enabled. > In this case we need to disable the CRC offload if we require GRE > checksum since otherwise skb_checksum() will report a wrong value. > > Fixes: 4749c09c37030 ("gre: Call gso_make_checksum") > Signed-off-by: Lorenzo Bianconi Applied with Fixes: tag corrected and queued up for -stable. Thanks.