From: Susant Sahani <susant@redhat.com>
Date: Fri, 9 May 2014 18:41:32 +0000 (+0530)
Subject: ip6_tunnel: fix potential NULL pointer dereference
X-Git-Tag: v3.12.21~6
X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=166c6b578bc07449529aa40ba524c694c2fd1623;p=thirdparty%2Fkernel%2Fstable.git

ip6_tunnel: fix potential NULL pointer dereference

[ Upstream commit c8965932a2e3b70197ec02c6741c29460279e2a8 ]

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@redhat.com>
Acked-by: Thomas Graf <tgraf@suug.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
---

diff --git a/net/ipv6/ip6_tunnel.c b/net/ipv6/ip6_tunnel.c
index c1e11b5d6ccc0..aac89c3c6af4c 100644
--- a/net/ipv6/ip6_tunnel.c
+++ b/net/ipv6/ip6_tunnel.c
@@ -1549,7 +1549,7 @@ 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]);