From mboxrd@z Thu Jan 1 00:00:00 1970 From: Steffen Klassert Subject: Re: BUG: MARK in OUTPUT + ip_tunnel causes kernel panic Date: Wed, 25 Sep 2013 10:59:47 +0200 Message-ID: <20130925085947.GY7660@secunet.com> References: Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: netdev@vger.kernel.org To: Konstantin Kuzov Return-path: Received: from a.mx.secunet.com ([195.81.216.161]:53475 "EHLO a.mx.secunet.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751267Ab3IYI7u (ORCPT ); Wed, 25 Sep 2013 04:59:50 -0400 Content-Disposition: inline In-Reply-To: Sender: netdev-owner@vger.kernel.org List-ID: On Wed, Sep 25, 2013 at 08:31:52AM +0000, Konstantin Kuzov wrote: > Kristian Evensen gmail.com> writes: > > > When trying to tunnel traffic originating from the same machine as the > > tunnel endpoint, I am experiencing kernel panics for some types of > > traffic (ICMP and UDP). TCP seems not to be affected by this, at least > > I have not been able to trigger the panic. > > > > I have one tunnel (without an IP address) and use policy routing to > > steer some traffic through the tunnels. > [...] > > An interesting thing is that I have seen different kernel panics being > > triggered. The other one I have seen has RIP pointing to > > e1000_xmit_frame() and the message "protocol 0800 is buggy". However, > > the one I have posted is by far the most common. > I'm experiencing the same issue on two different machines. It happens on any > kernel starting from 3.10 when ip_tunnel/ip_tunnel_core were introduced. > Can you please try the patch below? I've posted the same patch already to netdev in the morning. Subject: [PATCH net 1/2] ip_tunnel: Fix a memory corruption in ip_tunnel_xmit We might extend the used aera of a skb beyond the total headroom when we install the ipip header. Fix this by calling skb_cow_head() unconditionally. Signed-off-by: Steffen Klassert --- net/ipv4/ip_tunnel.c | 12 ++++++------ 1 file changed, 6 insertions(+), 6 deletions(-) diff --git a/net/ipv4/ip_tunnel.c b/net/ipv4/ip_tunnel.c index ac9fabe..b8ce640 100644 --- a/net/ipv4/ip_tunnel.c +++ b/net/ipv4/ip_tunnel.c @@ -641,13 +641,13 @@ void ip_tunnel_xmit(struct sk_buff *skb, struct net_device *dev, max_headroom = LL_RESERVED_SPACE(rt->dst.dev) + sizeof(struct iphdr) + rt->dst.header_len; - if (max_headroom > dev->needed_headroom) { + if (max_headroom > dev->needed_headroom) dev->needed_headroom = max_headroom; - if (skb_cow_head(skb, dev->needed_headroom)) { - dev->stats.tx_dropped++; - dev_kfree_skb(skb); - return; - } + + if (skb_cow_head(skb, dev->needed_headroom)) { + dev->stats.tx_dropped++; + dev_kfree_skb(skb); + return; } err = iptunnel_xmit(rt, skb, fl4.saddr, fl4.daddr, protocol, -- 1.7.9.5