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=-6.0 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY, 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 72404C282C7 for ; Tue, 29 Jan 2019 11:58:36 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 3FD8620882 for ; Tue, 29 Jan 2019 11:58:36 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1548763116; bh=jgNwobwcjuBaBKgm/XiNIytbEiXvDmy8fmeVvY7bxz8=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=iJBj2r0zulSThO+tTvM/4GSZqJfRSTRk3PIqW6R5Le884C1Ntt7xflcb5chZsumCv 7iZzvNKIlhkS3ySimBQTW3MM/jAWA23Ix2KlktgX0OYcdv5WNaSy/pv6c70S61LYKf PQjXSovtH8kNNIw5rc+eYfrlJqIjUG/G54phrMmw= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731288AbfA2L6e (ORCPT ); Tue, 29 Jan 2019 06:58:34 -0500 Received: from mail.kernel.org ([198.145.29.99]:38824 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730337AbfA2LsB (ORCPT ); Tue, 29 Jan 2019 06:48:01 -0500 Received: from localhost (5356596B.cm-6-7b.dynamic.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 135B02086C; Tue, 29 Jan 2019 11:47:59 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1548762480; bh=jgNwobwcjuBaBKgm/XiNIytbEiXvDmy8fmeVvY7bxz8=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=orOMEhiYZW3g3SMAdY+U3nK2paWGsj++/A0HEEoiJ/wzxZvn6+3bUIutez631udc9 uovKRDwtE8nAO6U+VRZcxFZhcuLzW/m+urZEeVFq+5p7au6AB+X92KjQsx3hbr24G/ OkGg3tkFiHurT2A1XV937K1kLdOlD9jJcoJo8Wmg= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, bridge@lists.linux-foundation.org, Nkolay Aleksandrov , Roopa Prabhu , Stephen Hemminger , Yunjian Wang , "David S. Miller" Subject: [PATCH 4.14 02/68] net: bridge: Fix ethernet header pointer before check skb forwardable Date: Tue, 29 Jan 2019 12:35:24 +0100 Message-Id: <20190129113131.910742749@linuxfoundation.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20190129113131.751891514@linuxfoundation.org> References: <20190129113131.751891514@linuxfoundation.org> User-Agent: quilt/0.65 X-stable: review X-Patchwork-Hint: ignore 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 4.14-stable review patch. If anyone has any objections, please let me know. ------------------ From: Yunjian Wang [ Upstream commit 28c1382fa28f2e2d9d0d6f25ae879b5af2ecbd03 ] The skb header should be set to ethernet header before using is_skb_forwardable. Because the ethernet header length has been considered in is_skb_forwardable(including dev->hard_header_len length). To reproduce the issue: 1, add 2 ports on linux bridge br using following commands: $ brctl addbr br $ brctl addif br eth0 $ brctl addif br eth1 2, the MTU of eth0 and eth1 is 1500 3, send a packet(Data 1480, UDP 8, IP 20, Ethernet 14, VLAN 4) from eth0 to eth1 So the expect result is packet larger than 1500 cannot pass through eth0 and eth1. But currently, the packet passes through success, it means eth1's MTU limit doesn't take effect. Fixes: f6367b4660dd ("bridge: use is_skb_forwardable in forward path") Cc: bridge@lists.linux-foundation.org Cc: Nkolay Aleksandrov Cc: Roopa Prabhu Cc: Stephen Hemminger Signed-off-by: Yunjian Wang Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman --- net/bridge/br_forward.c | 9 ++++----- 1 file changed, 4 insertions(+), 5 deletions(-) --- a/net/bridge/br_forward.c +++ b/net/bridge/br_forward.c @@ -35,10 +35,10 @@ static inline int should_deliver(const s int br_dev_queue_push_xmit(struct net *net, struct sock *sk, struct sk_buff *skb) { + skb_push(skb, ETH_HLEN); if (!is_skb_forwardable(skb->dev, skb)) goto drop; - skb_push(skb, ETH_HLEN); br_drop_fake_rtable(skb); if (skb->ip_summed == CHECKSUM_PARTIAL && @@ -96,12 +96,11 @@ static void __br_forward(const struct ne net = dev_net(indev); } else { if (unlikely(netpoll_tx_running(to->br->dev))) { - if (!is_skb_forwardable(skb->dev, skb)) { + skb_push(skb, ETH_HLEN); + if (!is_skb_forwardable(skb->dev, skb)) kfree_skb(skb); - } else { - skb_push(skb, ETH_HLEN); + else br_netpoll_send_skb(to, skb); - } return; } br_hook = NF_BR_LOCAL_OUT;