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=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 CC2C2C43603 for ; Wed, 23 Dec 2020 02:41:11 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id B7A6B225AB for ; Wed, 23 Dec 2020 02:41:11 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730025AbgLWCXe (ORCPT ); Tue, 22 Dec 2020 21:23:34 -0500 Received: from mail.kernel.org ([198.145.29.99]:52234 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730011AbgLWCXb (ORCPT ); Tue, 22 Dec 2020 21:23:31 -0500 Received: by mail.kernel.org (Postfix) with ESMTPSA id 70A6C225AC; Wed, 23 Dec 2020 02:23:13 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1608690194; bh=+UTwsuGRzzZhpz0EhL6quu0QIDzAmdWzEoKDyc32D14=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=PrpOy1/RugdnUlindMTyKBrm8xW5fWLGJ2AU0fc7rzfaG4VQoznYDHZMviUl/EFw3 0Rswct0pI7bVv+VYA+7U91TNBo6rux2pVNCyZyl1+zwCCRwGW7ilvho8Jl6zcT2fP7 H9MF0ahHtyj5T9MbbdBPLuyQEwdg7u9fM7bVtrv94J7v3/rUnud2d143RpDkrQEK3U gdLqGbVp/YmkFL5IxgFoADKwAT30nesSbEVJKJGsDGkmKc9LMmPAeJ+S08VnPWYKX0 d6WhTkmIT0+rMYtw1eQttnnDvdjf+OLuscdzWRTZHtU/FFAzWGukxXQF0w37aZZ02n /to7QiadvgS5Q== 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 4.14 17/66] net: skb_vlan_untag(): don't reset transport offset if set by GRO layer Date: Tue, 22 Dec 2020 21:22:03 -0500 Message-Id: <20201223022253.2793452-17-sashal@kernel.org> X-Mailer: git-send-email 2.27.0 In-Reply-To: <20201223022253.2793452-1-sashal@kernel.org> References: <20201223022253.2793452-1-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: netdev@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 c4f412526dfeb..9ab02babfcebc 100644 --- a/net/core/skbuff.c +++ b/net/core/skbuff.c @@ -5069,7 +5069,8 @@ 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