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 230DDC43603 for ; Wed, 23 Dec 2020 02:25:03 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id F24912222D for ; Wed, 23 Dec 2020 02:25:02 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730337AbgLWCYz (ORCPT ); Tue, 22 Dec 2020 21:24:55 -0500 Received: from mail.kernel.org ([198.145.29.99]:52758 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730320AbgLWCYs (ORCPT ); Tue, 22 Dec 2020 21:24:48 -0500 Received: by mail.kernel.org (Postfix) with ESMTPSA id 2EA502312E; Wed, 23 Dec 2020 02:24:32 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1608690272; bh=we8AE+kHvPYDOLfhQjKJLo+uemooix/TlE2XCdtNzYg=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=sh+qYmsb2WA9J+xtnWa1V+suXCW7/t9pX9vlW75QOvqtGcoJYs2r0I0jLZB/zakkm p50MIq2Ph1pRP225zMKCTB/m34CRYm5cv4BoQzxpVDGkipEvqHNw7h4HdkBzRfRT/y mW9o/2xKo1bTLG74ZU5PWLTpZV3c9aTT/U+aSYmtQOaCTEujcnxG3mpMPwjqaiTk/x kVn3eS81BuDrH+GUFnpIxvCfKCNUmodKAny1hqk541Mar2dmJ0bZig1lXXLFNnDn1g h7GT/AGOLYic9B9qXZLpphBJ9IwSqR/ZM+bK+yu90UKZz8NFWjydBx+g8+3sKkW3vI 7SaclcqEqqh4w== 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 4.9 13/48] net: skb_vlan_untag(): don't reset transport offset if set by GRO layer Date: Tue, 22 Dec 2020 21:23:41 -0500 Message-Id: <20201223022417.2794032-13-sashal@kernel.org> X-Mailer: git-send-email 2.27.0 In-Reply-To: <20201223022417.2794032-1-sashal@kernel.org> References: <20201223022417.2794032-1-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 a4c4234976862..f38ed5b9f5bf7 100644 --- a/net/core/skbuff.c +++ b/net/core/skbuff.c @@ -4607,7 +4607,8 @@ 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