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, Daniel Petre , Eric Dumazet , "David S. Miller" Subject: [ 55/95] ip_tunnel: fix kernel panic with icmp_dest_unreach Date: Tue, 25 Jun 2013 11:32:42 -0700 Message-Id: <20130625182159.856000678@linuxfoundation.org> In-Reply-To: <20130625182153.605455184@linuxfoundation.org> References: <20130625182153.605455184@linuxfoundation.org> Sender: linux-kernel-owner@vger.kernel.org List-ID: 3.9-stable review patch. If anyone has any objections, please let me know. ------------------ From: Eric Dumazet [ Upstream commit a622260254ee481747cceaaa8609985b29a31565 ] Daniel Petre reported crashes in icmp_dst_unreach() with following call graph: Daniel found a similar problem mentioned in http://lkml.indiana.edu/hypermail/linux/kernel/1007.0/00961.html And indeed this is the root cause : skb->cb[] contains data fooling IP stack. We must clear IPCB in ip_tunnel_xmit() sooner in case dst_link_failure() is called. Or else skb->cb[] might contain garbage from GSO segmentation layer. A similar fix was tested on linux-3.9, but gre code was refactored in linux-3.10. I'll send patches for stable kernels as well. Many thanks to Daniel for providing reports, patches and testing ! Reported-by: Daniel Petre Signed-off-by: Eric Dumazet Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman --- net/ipv4/ip_gre.c | 2 +- net/ipv4/ipip.c | 2 +- 2 files changed, 2 insertions(+), 2 deletions(-) --- a/net/ipv4/ip_gre.c +++ b/net/ipv4/ip_gre.c @@ -804,6 +804,7 @@ static netdev_tx_t ipgre_tunnel_xmit(str tiph = &tunnel->parms.iph; } + memset(&(IPCB(skb)->opt), 0, sizeof(IPCB(skb)->opt)); if ((dst = tiph->daddr) == 0) { /* NBMA tunnel */ @@ -952,7 +953,6 @@ static netdev_tx_t ipgre_tunnel_xmit(str skb_push(skb, gre_hlen); skb_reset_network_header(skb); skb_set_transport_header(skb, sizeof(*iph)); - memset(&(IPCB(skb)->opt), 0, sizeof(IPCB(skb)->opt)); IPCB(skb)->flags &= ~(IPSKB_XFRM_TUNNEL_SIZE | IPSKB_XFRM_TRANSFORMED | IPSKB_REROUTED); skb_dst_drop(skb); --- a/net/ipv4/ipip.c +++ b/net/ipv4/ipip.c @@ -491,6 +491,7 @@ static netdev_tx_t ipip_tunnel_xmit(stru if (tos & 1) tos = old_iph->tos; + memset(&(IPCB(skb)->opt), 0, sizeof(IPCB(skb)->opt)); if (!dst) { /* NBMA tunnel */ if ((rt = skb_rtable(skb)) == NULL) { @@ -573,7 +574,6 @@ static netdev_tx_t ipip_tunnel_xmit(stru skb->transport_header = skb->network_header; skb_push(skb, sizeof(struct iphdr)); skb_reset_network_header(skb); - memset(&(IPCB(skb)->opt), 0, sizeof(IPCB(skb)->opt)); IPCB(skb)->flags &= ~(IPSKB_XFRM_TUNNEL_SIZE | IPSKB_XFRM_TRANSFORMED | IPSKB_REROUTED); skb_dst_drop(skb);