1 files changed, 9 insertions, 2 deletions

diff --git a/net/tipc/bearer.c b/net/tipc/bearer.c
index 975dbeb60ab0..52d74760fb68 100644
--- a/net/tipc/bearer.c
+++ b/net/tipc/bearer.c
@@ -421,6 +421,10 @@ int tipc_enable_l2_media(struct net *net, struct tipc_bearer *b,
         dev = dev_get_by_name(net, driver_name);
         if (!dev)
                 return -ENODEV;
+        if (tipc_mtu_bad(dev, 0)) {
+                dev_put(dev);
+                return -EINVAL;
+        }
 
         /* Associate TIPC bearer with L2 bearer */
         rcu_assign_pointer(b->media_ptr, dev);
@@ -610,8 +614,6 @@ static int tipc_l2_device_event(struct notifier_block *nb, unsigned long evt,
         if (!b)
                 return NOTIFY_DONE;
 
-        b->mtu = dev->mtu;
-
         switch (evt) {
         case NETDEV_CHANGE:
                 if (netif_carrier_ok(dev))
@@ -624,6 +626,11 @@ static int tipc_l2_device_event(struct notifier_block *nb, unsigned long evt,
                 tipc_reset_bearer(net, b);
                 break;
         case NETDEV_CHANGEMTU:
+                if (tipc_mtu_bad(dev, 0)) {
+                        bearer_disable(net, b);
+                        break;
+                }
+                b->mtu = dev->mtu;
                 tipc_reset_bearer(net, b);
                 break;
         case NETDEV_CHANGEADDR: