From 3b7b514f44bff05d26a6499c4d4fac2a83938e6e Mon Sep 17 00:00:00 2001
From: Cong Wang <amwang@redhat.com>
Date: Tue, 2 Jul 2013 14:49:34 +0800
Subject: [PATCH] ipip: fix a regression in ioctl

This is a regression introduced by
commit fd58156e456d9f68fe0448 (IPIP: Use ip-tunneling code.)

Similar to GRE tunnel, previously we only check the parameters
for SIOCADDTUNNEL and SIOCCHGTUNNEL, after that commit, the
check is moved for all commands.

So, just check for SIOCADDTUNNEL and SIOCCHGTUNNEL.

Also, the check for i_key, o_key etc. is suspicious too,
which did not exist before, reset them before passing
to ip_tunnel_ioctl().

Cc: Pravin B Shelar <pshelar@nicira.com>
Cc: "David S. Miller" <davem@davemloft.net>
Signed-off-by: Cong Wang <amwang@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
---
 net/ipv4/ipip.c | 12 +++++++-----
 1 file changed, 7 insertions(+), 5 deletions(-)

diff --git a/net/ipv4/ipip.c b/net/ipv4/ipip.c
index e6905fbda2a2..51fc2a1dcdd3 100644
--- a/net/ipv4/ipip.c
+++ b/net/ipv4/ipip.c
@@ -244,11 +244,13 @@ ipip_tunnel_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd)
 	if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p)))
 		return -EFAULT;
 
-	if (p.iph.version != 4 || p.iph.protocol != IPPROTO_IPIP ||
-			p.iph.ihl != 5 || (p.iph.frag_off&htons(~IP_DF)))
-		return -EINVAL;
-	if (p.i_key || p.o_key || p.i_flags || p.o_flags)
-		return -EINVAL;
+	if (cmd == SIOCADDTUNNEL || cmd == SIOCCHGTUNNEL) {
+		if (p.iph.version != 4 || p.iph.protocol != IPPROTO_IPIP ||
+		    p.iph.ihl != 5 || (p.iph.frag_off&htons(~IP_DF)))
+			return -EINVAL;
+	}
+
+	p.i_key = p.o_key = p.i_flags = p.o_flags = 0;
 	if (p.iph.ttl)
 		p.iph.frag_off |= htons(IP_DF);