releases/3.10.4/gre-fix-a-regression-in-ioctl.patch

From d9b54511307e46a8f144b20af88e9279966725f1 Mon Sep 17 00:00:00 2001
From: Cong Wang <amwang@redhat.com>
Date: Sat, 29 Jun 2013 12:02:59 +0800
Subject: gre: fix a regression in ioctl

From: Cong Wang <amwang@redhat.com>

[ Upstream commit 6c734fb8592f6768170e48e7102cb2f0a1bb9759 ]

When testing GRE tunnel, I got:

 # ip tunnel show
 get tunnel gre0 failed: Invalid argument
 get tunnel gre1 failed: Invalid argument

This is a regression introduced by commit c54419321455631079c7d
("GRE: Refactor GRE tunneling code.") because 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.

After this patch I got:

 # ip tunnel show
 gre0: gre/ip  remote any  local any  ttl inherit  nopmtudisc
 gre1: gre/ip  remote 192.168.122.101  local 192.168.122.45  ttl inherit

Signed-off-by: Cong Wang <amwang@redhat.com>
Cc: Pravin B Shelar <pshelar@nicira.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 net/ipv4/ip_gre.c |    9 +++++----
 1 file changed, 5 insertions(+), 4 deletions(-)

--- a/net/ipv4/ip_gre.c
+++ b/net/ipv4/ip_gre.c
@@ -503,10 +503,11 @@ static int ipgre_tunnel_ioctl(struct net
 
 	if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p)))
 		return -EFAULT;
-	if (p.iph.version != 4 || p.iph.protocol != IPPROTO_GRE ||
-	    p.iph.ihl != 5 || (p.iph.frag_off&htons(~IP_DF)) ||
-	    ((p.i_flags|p.o_flags)&(GRE_VERSION|GRE_ROUTING))) {
-		return -EINVAL;
+	if (cmd == SIOCADDTUNNEL || cmd == SIOCCHGTUNNEL) {
+		if (p.iph.version != 4 || p.iph.protocol != IPPROTO_GRE ||
+		    p.iph.ihl != 5 || (p.iph.frag_off&htons(~IP_DF)) ||
+		    ((p.i_flags|p.o_flags)&(GRE_VERSION|GRE_ROUTING)))
+			return -EINVAL;
 	}
 	p.i_flags = gre_flags_to_tnl_flags(p.i_flags);
 	p.o_flags = gre_flags_to_tnl_flags(p.o_flags);