[3.11.y.z extended stable] Patch "ip6_tunnel: fix potential NULL pointer dereference" has been added to staging queue

[Luis Henriques]

This is a note to let you know that I have just added a patch titled

    ip6_tunnel: fix potential NULL pointer dereference

to the linux-3.11.y-queue branch of the 3.11.y.z extended stable tree 
which can be found at:

 http://kernel.ubuntu.com/git?p=ubuntu/linux.git;a=shortlog;h=refs/heads/linux-3.11.y-queue

If you, or anyone else, feels it should not be added to this tree, please 
reply to this email.

For more information about the 3.11.y.z tree, see
https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable

Thanks.
-Luis

------

>From 88b126f8c79dbc3cca959f50e5507ac30404606f Mon Sep 17 00:00:00 2001
From: Susant Sahani <susant at redhat.com>
Date: Sat, 10 May 2014 00:11:32 +0530
Subject: ip6_tunnel: fix potential NULL pointer dereference

commit c8965932a2e3b70197ec02c6741c29460279e2a8 upstream.

The function ip6_tnl_validate assumes that the rtnl
attribute IFLA_IPTUN_PROTO always be filled . If this
attribute is not filled by  the userspace application
kernel get crashed with NULL pointer dereference. This
patch fixes the potential kernel crash when
IFLA_IPTUN_PROTO is missing .

Signed-off-by: Susant Sahani <susant at redhat.com>
Acked-by: Thomas Graf <tgraf at suug.ch>
Signed-off-by: David S. Miller <davem at davemloft.net>
Signed-off-by: Luis Henriques <luis.henriques at canonical.com>
---
 net/ipv6/ip6_tunnel.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/net/ipv6/ip6_tunnel.c b/net/ipv6/ip6_tunnel.c
index 7839b9d5319e..bdbbadcfb4e1 100644
--- a/net/ipv6/ip6_tunnel.c
+++ b/net/ipv6/ip6_tunnel.c
@@ -1537,7 +1537,7 @@ static int ip6_tnl_validate(struct nlattr *tb[], struct nlattr *data[])
 {
 	u8 proto;

-	if (!data)
+	if (!data || !data[IFLA_IPTUN_PROTO])
 		return 0;

 	proto = nla_get_u8(data[IFLA_IPTUN_PROTO]);
--
1.9.1