netdev - [PATCH v2] net: gre: use icmp_hdr() to get inner ip header

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [thread-next>] [day] [month] [year] [list]

Message-ID: <52E728D7.70506@cn.fujitsu.com>
Date:	Tue, 28 Jan 2014 11:49:43 +0800
From:	Duan Jiong <duanj.fnst@...fujitsu.com>
To:	David Miller <davem@...emloft.net>
CC:	Daniel Borkmann <dborkman@...hat.com>, netdev@...r.kernel.org,
	Pravin Shelar <pshelar@...ira.com>
Subject: [PATCH v2] net: gre: use icmp_hdr() to get inner ip header


When dealing with icmp messages, the skb->data points the
ip header that triggered the sending of the icmp message.

In gre_cisco_err(), the parse_gre_header() is called, and the
iptunnel_pull_header() is called to pull the skb at the end of
the parse_gre_header(), so the skb->data doesn't point the
inner ip header.

Unfortunately, the ipgre_err still needs those ip addresses in
inner ip header to look up tunnel by ip_tunnel_lookup().

So just use icmp_hdr() to get inner ip header instead of skb->data.

Signed-off-by: Duan Jiong <duanj.fnst@...fujitsu.com>
---

v2: use icmp_hdr() instead of conditional pulling of headers

 net/ipv4/ip_gre.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/net/ipv4/ip_gre.c b/net/ipv4/ip_gre.c
index e7a92fd..ec4f762 100644
--- a/net/ipv4/ip_gre.c
+++ b/net/ipv4/ip_gre.c
@@ -178,7 +178,7 @@ static int ipgre_err(struct sk_buff *skb, u32 info,
 	else
 		itn = net_generic(net, ipgre_net_id);
 
-	iph = (const struct iphdr *)skb->data;
+	iph = (const struct iphdr *)(icmp_hdr(skb) + 1);
 	t = ip_tunnel_lookup(itn, skb->dev->ifindex, tpi->flags,
 			     iph->daddr, iph->saddr, tpi->key);
 
-- 
1.8.3.1
--
To unsubscribe from this list: send the line "unsubscribe netdev" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html