lec: Use rtnl lock/unlock when updating MTU

The LECS response contains the MTU that should be used.  Correctly
synchronize with other layers when updating.

Signed-off-by: Chas Williams - CONTRACTOR <chas@cmf.nrl.navy.mil>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 2 insertions, 0 deletions

diff --git a/net/atm/lec.c b/net/atm/lec.c
index e4853b50cf40..4b98f897044a 100644
--- a/net/atm/lec.c
+++ b/net/atm/lec.c
@@ -410,9 +410,11 @@ static int lec_atm_send(struct atm_vcc *vcc, struct sk_buff *skb)
                 priv->lane2_ops = NULL;
                 if (priv->lane_version > 1)
                         priv->lane2_ops = &lane2_ops;
+                rtnl_lock();
                 if (dev_set_mtu(dev, mesg->content.config.mtu))
                         pr_info("%s: change_mtu to %d failed\n",
                                 dev->name, mesg->content.config.mtu);
+                rtnl_unlock();
                 priv->is_proxy = mesg->content.config.is_proxy;
                 break;
         case l_flush_tran_id: