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

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>

diff --git a/net/ipv6/ip6_gre.c b/net/ipv6/ip6_gre.c
index d3ddd840035450570d634fb22002496a447d5d34..ecd60733e5e24afdb28a52c95686fec28e2e4d73 100644 (file)
--- a/net/ipv6/ip6_gre.c
+++ b/net/ipv6/ip6_gre.c
@@ -1081,6 +1081,7 @@ 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;
@@ -1128,6 +1129,7 @@ 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;