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=-19.0 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,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 09EE8C43603 for ; Wed, 23 Dec 2020 02:48:57 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id DD273225AA for ; Wed, 23 Dec 2020 02:48:56 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731069AbgLWCsj (ORCPT ); Tue, 22 Dec 2020 21:48:39 -0500 Received: from mail.kernel.org ([198.145.29.99]:51198 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729563AbgLWCWJ (ORCPT ); Tue, 22 Dec 2020 21:22:09 -0500 Received: by mail.kernel.org (Postfix) with ESMTPSA id 2F9C12222D; Wed, 23 Dec 2020 02:21:28 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1608690088; bh=q5lnLKhN6/PAD3aGTO5DXqsgsw59pUGaN75CuoZMLZA=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=JH+ykgISKHXySb14PVeGm2VL4dbN59O6jsEiWNpOL3oIJziZ9OvhyhVDfU6d7d49X /vcjY/2eyCqpehye0Qhdiyys0WHZuYW68NeNZmOA+rjzT0DR2DaiAAZcHTOVfp6DmP zfHr8WE1NhxSrSm5f61laYZgxIr9lj2+bfrItXXN8uS0Vlq+I1A3MsOcTtUSSRyvAs J0Bvkhnia2schKNbZyxOtkYCyjYboXf6yUlMmw44BJdj/fIsqvlBeYPvupU7Gir4cc 4QXvfEofOrLvM+D5aVFOHYeu1RiCkPdmJs7MLG/3C/4yWZZuacFP/CLbIFVCIlmCWI Ckwaes6gH5Flg== From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Alexander Lobakin , Jakub Kicinski , Sasha Levin , netdev@vger.kernel.org Subject: [PATCH AUTOSEL 4.19 20/87] net: skb_vlan_untag(): don't reset transport offset if set by GRO layer Date: Tue, 22 Dec 2020 21:19:56 -0500 Message-Id: <20201223022103.2792705-20-sashal@kernel.org> X-Mailer: git-send-email 2.27.0 In-Reply-To: <20201223022103.2792705-1-sashal@kernel.org> References: <20201223022103.2792705-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Alexander Lobakin [ Upstream commit 8be33ecfc1ffd2da20cc29e957e4cb6eb99310cb ] Similar to commit fda55eca5a33f ("net: introduce skb_transport_header_was_set()"), avoid resetting transport offsets that were already set by GRO layer. This not only mirrors the behavior of __netif_receive_skb_core(), but also makes sense when it comes to UDP GSO fraglists forwarding: transport offset of such skbs is set only once by GRO receive callback and remains untouched and correct up to the xmitting driver in 1:1 case, but becomes junk after untagging in ingress VLAN case and breaks UDP GSO offload. This does not happen after this change, and all types of forwarding of UDP GSO fraglists work as expected. Since v1 [1]: - keep the code 1:1 with __netif_receive_skb_core() (Jakub). [1] https://lore.kernel.org/netdev/zYurwsZRN7BkqSoikWQLVqHyxz18h4LhHU4NFa2Vw@cp4-web-038.plabs.ch Signed-off-by: Alexander Lobakin Link: https://lore.kernel.org/r/7JgIkgEztzt0W6ZtC9V9Cnk5qfkrUFYcpN871syCi8@cp4-web-040.plabs.ch Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin --- net/core/skbuff.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/net/core/skbuff.c b/net/core/skbuff.c index b5d9c9b2c7028..57fdf450fd6fe 100644 --- a/net/core/skbuff.c +++ b/net/core/skbuff.c @@ -5144,7 +5144,8 @@ struct sk_buff *skb_vlan_untag(struct sk_buff *skb) goto err_free; skb_reset_network_header(skb); - skb_reset_transport_header(skb); + if (!skb_transport_header_was_set(skb)) + skb_reset_transport_header(skb); skb_reset_mac_len(skb); return skb; -- 2.27.0