From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933713AbdJJT6I (ORCPT ); Tue, 10 Oct 2017 15:58:08 -0400 Received: from mail.linuxfoundation.org ([140.211.169.12]:45700 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933697AbdJJT6F (ORCPT ); Tue, 10 Oct 2017 15:58:05 -0400 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Xin Long , "David S. Miller" Subject: [PATCH 4.9 074/105] ip6_tunnel: update mtu properly for ARPHRD_ETHER tunnel device in tx path Date: Tue, 10 Oct 2017 21:50:45 +0200 Message-Id: <20171010192545.243758089@linuxfoundation.org> X-Mailer: git-send-email 2.14.2 In-Reply-To: <20171010192533.717049376@linuxfoundation.org> References: <20171010192533.717049376@linuxfoundation.org> User-Agent: quilt/0.65 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 4.9-stable review patch. If anyone has any objections, please let me know. ------------------ From: Xin Long [ Upstream commit d41bb33ba33b8f8debe54ed36be6925eb496e354 ] Now when updating mtu in tx path, it doesn't consider ARPHRD_ETHER tunnel device, like ip6gre_tap tunnel, for which it should also subtract ether header to get the correct mtu. Signed-off-by: Xin Long Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman --- net/ipv6/ip6_tunnel.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) --- a/net/ipv6/ip6_tunnel.c +++ b/net/ipv6/ip6_tunnel.c @@ -1042,6 +1042,7 @@ int ip6_tnl_xmit(struct sk_buff *skb, st struct dst_entry *dst = NULL, *ndst = NULL; struct net_device *tdev; int mtu; + unsigned int eth_hlen = t->dev->type == ARPHRD_ETHER ? ETH_HLEN : 0; unsigned int psh_hlen = sizeof(struct ipv6hdr) + t->encap_hlen; unsigned int max_headroom = psh_hlen; bool use_cache = false; @@ -1120,7 +1121,7 @@ route_lookup: t->parms.name); goto tx_err_dst_release; } - mtu = dst_mtu(dst) - psh_hlen - t->tun_hlen; + mtu = dst_mtu(dst) - eth_hlen - psh_hlen - t->tun_hlen; if (encap_limit >= 0) { max_headroom += 8; mtu -= 8; @@ -1129,7 +1130,7 @@ route_lookup: mtu = IPV6_MIN_MTU; if (skb_dst(skb) && !t->parms.collect_md) skb_dst(skb)->ops->update_pmtu(skb_dst(skb), NULL, skb, mtu); - if (skb->len - t->tun_hlen > mtu && !skb_is_gso(skb)) { + if (skb->len - t->tun_hlen - eth_hlen > mtu && !skb_is_gso(skb)) { *pmtu = mtu; err = -EMSGSIZE; goto tx_err_dst_release;