[PATCH 4.9 162/329] ip6_tunnel: fix IFLA_MTU ignored on NEWLINK

From: Greg Kroah-Hartman
Date: Mon May 28 2018 - 06:33:38 EST


4.9-stable review patch. If anyone has any objections, please let me know.

------------------

From: Xin Long <lucien.xin@xxxxxxxxx>

[ Upstream commit a6aa80446234ec0ad38eecdb8efc59e91daae565 ]

Commit 128bb975dc3c ("ip6_gre: init dev->mtu and dev->hard_header_len
correctly") fixed IFLA_MTU ignored on NEWLINK for ip6_gre. The same
mtu fix is also needed for ip6_tunnel.

Note that dev->hard_header_len setting for ip6_tunnel works fine,
no need to fix it.

Reported-by: Jianlin Shi <jishi@xxxxxxxxxx>
Signed-off-by: Xin Long <lucien.xin@xxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <alexander.levin@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
net/ipv6/ip6_tunnel.c | 12 ++++++++----
1 file changed, 8 insertions(+), 4 deletions(-)

--- a/net/ipv6/ip6_tunnel.c
+++ b/net/ipv6/ip6_tunnel.c
@@ -1972,14 +1972,14 @@ static int ip6_tnl_newlink(struct net *s
{
struct net *net = dev_net(dev);
struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id);
- struct ip6_tnl *nt, *t;
struct ip_tunnel_encap ipencap;
+ struct ip6_tnl *nt, *t;
+ int err;

nt = netdev_priv(dev);

if (ip6_tnl_netlink_encap_parms(data, &ipencap)) {
- int err = ip6_tnl_encap_setup(nt, &ipencap);
-
+ err = ip6_tnl_encap_setup(nt, &ipencap);
if (err < 0)
return err;
}
@@ -1995,7 +1995,11 @@ static int ip6_tnl_newlink(struct net *s
return -EEXIST;
}

- return ip6_tnl_create2(dev);
+ err = ip6_tnl_create2(dev);
+ if (!err && tb[IFLA_MTU])
+ ip6_tnl_change_mtu(dev, nla_get_u32(tb[IFLA_MTU]));
+
+ return err;
}

static int ip6_tnl_changelink(struct net_device *dev, struct nlattr *tb[],