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>

1 files changed, 2 insertions, 0 deletions

diff --git a/net/ipv6/ip6_gre.c b/net/ipv6/ip6_gre.c
index d3ddd8400354..ecd60733e5e2 100644
--- 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;