ipv6,gre: do not leak info to user-space

[ Upstream commit 5dbd5068430b8bd1c19387d46d6c1a88b261257f ]

There is a hole in struct ip6_tnl_parm2, so we have to
zero the struct on stack before copying it to user-space.

Cc: David S. Miller <davem@davemloft.net>
Signed-off-by: Cong Wang <amwang@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/net/ipv6/ip6_gre.c b/net/ipv6/ip6_gre.c
index e4efffe2522e0173a6ec96100f6cac3d34a61d1e..95d13c76d316fc5ebdb0181df22ece9255e6efd2 100644 (file)
--- a/net/ipv6/ip6_gre.c
+++ b/net/ipv6/ip6_gre.c
@@ -1135,6 +1135,7 @@ static int ip6gre_tunnel_ioctl(struct net_device *dev,
                }
                if (t == NULL)
                        t = netdev_priv(dev);
+               memset(&p, 0, sizeof(p));
                ip6gre_tnl_parm_to_user(&p, &t->parms);
                if (copy_to_user(ifr->ifr_ifru.ifru_data, &p, sizeof(p)))
                        err = -EFAULT;
@@ -1182,6 +1183,7 @@ static int ip6gre_tunnel_ioctl(struct net_device *dev,
                if (t) {
                        err = 0;
 
+                       memset(&p, 0, sizeof(p));
                        ip6gre_tnl_parm_to_user(&p, &t->parms);
                        if (copy_to_user(ifr->ifr_ifru.ifru_data, &p, sizeof(p)))
                                err = -EFAULT;