gre: information leak in ip6_tnl_ioctl()

There is a one byte hole between p->hop_limit and p->flowinfo where
stack memory is leaked to the user.  This was introduced in c12b395a46
"gre: Support GRE over IPv6".

Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>

1 files changed, 2 insertions, 0 deletions

diff --git a/net/ipv6/ip6_tunnel.c b/net/ipv6/ip6_tunnel.c
index 33d2a0e6712d..cb7e2ded6f08 100644
--- a/net/ipv6/ip6_tunnel.c
+++ b/net/ipv6/ip6_tunnel.c
@@ -1312,6 +1312,8 @@ ip6_tnl_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd)
                         }
                         ip6_tnl_parm_from_user(&p1, &p);
                         t = ip6_tnl_locate(net, &p1, 0);
+                } else {
+                        memset(&p, 0, sizeof(p));
                 }
                 if (t == NULL)
                         t = netdev_priv(dev);