From patchwork Thu Jul 25 16:40:17 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Haishuang Yan X-Patchwork-Id: 1137017 X-Patchwork-Delegate: davem@davemloft.net Return-Path: X-Original-To: patchwork-incoming-netdev@ozlabs.org Delivered-To: patchwork-incoming-netdev@ozlabs.org Authentication-Results: ozlabs.org; spf=none (mailfrom) smtp.mailfrom=vger.kernel.org (client-ip=209.132.180.67; helo=vger.kernel.org; envelope-from=netdev-owner@vger.kernel.org; receiver=) Authentication-Results: ozlabs.org; dmarc=none (p=none dis=none) header.from=cmss.chinamobile.com Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id 45vdJ66X55z9sMr for ; Fri, 26 Jul 2019 02:40:54 +1000 (AEST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729506AbfGYQkq (ORCPT ); Thu, 25 Jul 2019 12:40:46 -0400 Received: from cmccmta3.chinamobile.com ([221.176.66.81]:2359 "EHLO cmccmta3.chinamobile.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727957AbfGYQkq (ORCPT ); Thu, 25 Jul 2019 12:40:46 -0400 Received: from spf.mail.chinamobile.com (unknown[172.16.121.17]) by rmmx-syy-dmz-app10-12010 (RichMail) with SMTP id 2eea5d39db803aa-2e984; Fri, 26 Jul 2019 00:40:32 +0800 (CST) X-RM-TRANSID: 2eea5d39db803aa-2e984 X-RM-TagInfo: emlType=0 X-RM-SPAM-FLAG: 00000000 Received: from localhost (unknown[223.105.0.241]) by rmsmtp-syy-appsvr09-12009 (RichMail) with SMTP id 2ee95d39db7fe7d-57bd5; Fri, 26 Jul 2019 00:40:32 +0800 (CST) X-RM-TRANSID: 2ee95d39db7fe7d-57bd5 From: Haishuang Yan To: "David S. Miller" , Alexey Kuznetsov Cc: netdev@vger.kernel.org, linux-kernel@vger.kernel.org, Haishuang Yan Subject: [PATCH] ip6_tunnel: fix possible use-after-free on xmit Date: Fri, 26 Jul 2019 00:40:17 +0800 Message-Id: <1564072817-13240-1-git-send-email-yanhaishuang@cmss.chinamobile.com> X-Mailer: git-send-email 1.8.3.1 Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org ip4ip6/ip6ip6 tunnels run iptunnel_handle_offloads on xmit which can cause a possible use-after-free accessing iph/ipv6h pointer since the packet will be 'uncloned' running pskb_expand_head if it is a cloned gso skb. Fixes: 0e9a709560db ("ip6_tunnel, ip6_gre: fix setting of DSCP on encapsulated packets") Signed-off-by: Haishuang Yan --- net/ipv6/ip6_tunnel.c | 6 ++---- 1 file changed, 2 insertions(+), 4 deletions(-) diff --git a/net/ipv6/ip6_tunnel.c b/net/ipv6/ip6_tunnel.c index 3134fbb..754a484 100644 --- a/net/ipv6/ip6_tunnel.c +++ b/net/ipv6/ip6_tunnel.c @@ -1278,12 +1278,11 @@ int ip6_tnl_xmit(struct sk_buff *skb, struct net_device *dev, __u8 dsfield, } fl6.flowi6_uid = sock_net_uid(dev_net(dev), NULL); + dsfield = INET_ECN_encapsulate(dsfield, ipv4_get_dsfield(iph)); if (iptunnel_handle_offloads(skb, SKB_GSO_IPXIP6)) return -1; - dsfield = INET_ECN_encapsulate(dsfield, ipv4_get_dsfield(iph)); - skb_set_inner_ipproto(skb, IPPROTO_IPIP); err = ip6_tnl_xmit(skb, dev, dsfield, &fl6, encap_limit, &mtu, @@ -1367,12 +1366,11 @@ int ip6_tnl_xmit(struct sk_buff *skb, struct net_device *dev, __u8 dsfield, } fl6.flowi6_uid = sock_net_uid(dev_net(dev), NULL); + dsfield = INET_ECN_encapsulate(dsfield, ipv6_get_dsfield(ipv6h)); if (iptunnel_handle_offloads(skb, SKB_GSO_IPXIP6)) return -1; - dsfield = INET_ECN_encapsulate(dsfield, ipv6_get_dsfield(ipv6h)); - skb_set_inner_ipproto(skb, IPPROTO_IPV6); err = ip6_tnl_xmit(skb, dev, dsfield, &fl6, encap_limit, &mtu,