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=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,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 EF8C2C433DF for ; Thu, 20 Aug 2020 11:22:27 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id C8FEF2078D for ; Thu, 20 Aug 2020 11:22:27 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1597922547; bh=0ZrsPUjG0hdVMilu3PldGC8BakCU6TEwpGp5jBD+8ro=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=kgNLgFcHFIKLUfBly4Nvwj9HEOwiLbQz5AyaM1s16f4tRhz9HN0hWhOa2S9mggWUF 6QHkXDhk2M292+4aMrnWyJ5twlNdcqZKfOPT6OBOycjAo4QzIDr39PDyP+0N2RqYV4 Rr0g3yHObN91S4b67eUts4EPnurr75tRe5cFII+0= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730032AbgHTLWZ (ORCPT ); Thu, 20 Aug 2020 07:22:25 -0400 Received: from mail.kernel.org ([198.145.29.99]:37970 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730494AbgHTKHa (ORCPT ); Thu, 20 Aug 2020 06:07:30 -0400 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (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 A9A652173E; Thu, 20 Aug 2020 10:07:29 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1597918050; bh=0ZrsPUjG0hdVMilu3PldGC8BakCU6TEwpGp5jBD+8ro=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=NqjFTAh/Wrwc9Pt4ei206QWCf0c3h9XOny8WMoImGMie0Wf96HiGEaJdxrY6uzKJc yrsUF4+2GWlIh0CePTrBYVz2LWgKBWOwosHQCSGgk3naW8MhpJsMqNCHvpGMSp2q14 e/dbzRvmHCsh1ybb8RdJRHKPoPzugdqL9oGERoSY= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Lorenzo Bianconi , Marcelo Ricardo Leitner , "David S. Miller" Subject: [PATCH 4.14 036/228] net: gre: recompute gre csum for sctp over gre tunnels Date: Thu, 20 Aug 2020 11:20:11 +0200 Message-Id: <20200820091609.341714819@linuxfoundation.org> X-Mailer: git-send-email 2.28.0 In-Reply-To: <20200820091607.532711107@linuxfoundation.org> References: <20200820091607.532711107@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: Lorenzo Bianconi [ Upstream commit 622e32b7d4a6492cf5c1f759ef833f817418f7b3 ] 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: 90017accff61 ("sctp: Add GSO support") Signed-off-by: Lorenzo Bianconi Reviewed-by: Marcelo Ricardo Leitner Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman --- net/ipv4/gre_offload.c | 13 +++++++++++-- 1 file changed, 11 insertions(+), 2 deletions(-) --- a/net/ipv4/gre_offload.c +++ b/net/ipv4/gre_offload.c @@ -19,12 +19,12 @@ static struct sk_buff *gre_gso_segment(s netdev_features_t features) { int tnl_hlen = skb_inner_mac_header(skb) - skb_transport_header(skb); + bool need_csum, need_recompute_csum, gso_partial; struct sk_buff *segs = ERR_PTR(-EINVAL); u16 mac_offset = skb->mac_header; __be16 protocol = skb->protocol; u16 mac_len = skb->mac_len; int gre_offset, outer_hlen; - bool need_csum, gso_partial; if (!skb->encapsulation) goto out; @@ -45,6 +45,7 @@ static struct sk_buff *gre_gso_segment(s skb->protocol = skb->inner_protocol; need_csum = !!(skb_shinfo(skb)->gso_type & SKB_GSO_GRE_CSUM); + need_recompute_csum = skb->csum_not_inet; skb->encap_hdr_csum = need_csum; features &= skb->dev->hw_enc_features; @@ -102,7 +103,15 @@ static struct sk_buff *gre_gso_segment(s } *(pcsum + 1) = 0; - *pcsum = gso_make_checksum(skb, 0); + if (need_recompute_csum && !skb_is_gso(skb)) { + __wsum csum; + + csum = skb_checksum(skb, gre_offset, + skb->len - gre_offset, 0); + *pcsum = csum_fold(csum); + } else { + *pcsum = gso_make_checksum(skb, 0); + } } while ((skb = skb->next)); out: return segs;