From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Pravin Shelar , Steffen Klassert , "David S. Miller" Subject: [ 046/135] ip_tunnel: Fix a memory corruption in ip_tunnel_xmit Date: Fri, 11 Oct 2013 12:38:47 -0700 Message-Id: <20131011193950.271836427@linuxfoundation.org> In-Reply-To: <20131011193945.181603934@linuxfoundation.org> References: <20131011193945.181603934@linuxfoundation.org> Sender: linux-kernel-owner@vger.kernel.org List-ID: 3.11-stable review patch. If anyone has any objections, please let me know. ------------------ From: Steffen Klassert [ Upstream commit 3e08f4a72f689c6296d336c2aab4bddd60c93ae2 ] 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. Bug was introduced with commit c544193214 ("GRE: Refactor GRE tunneling code.") Cc: Pravin Shelar Signed-off-by: Steffen Klassert Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman --- net/ipv4/ip_tunnel.c | 12 ++++++------ 1 file changed, 6 insertions(+), 6 deletions(-) --- a/net/ipv4/ip_tunnel.c +++ b/net/ipv4/ip_tunnel.c @@ -645,13 +645,13 @@ void ip_tunnel_xmit(struct sk_buff *skb, 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(dev_net(dev), rt, skb,