[PATCH 3.13 051/212] ip6_tunnel: fix potential NULL pointer dereference

Kamal Mostafa
2014-06-17T21:42:25Z

From: Susant Sahani <susant@redhat.com>

[ 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: Kamal Mostafa <kamal@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 7881965..41d97be 100644
--- a/net/ipv6/ip6_tunnel.c
+++ b/net/ipv6/ip6_tunnel.c
@@ -1567,7 +1567,7 @@ 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