rocker: handle non-bridge master change

Master change notifications may occur other than when joining or
leaving a bridge, for example when being added to or removed from
a bond or Open vSwitch.

Previously in those cases rocker_port_bridge_leave() was called
which results in a null-pointer dereference as rocker_port->bridge_dev
is NULL because there is no bridge device.

This patch makes provision for doing nothing in such cases.

Fixes: 6c7079450071f ("rocker: implement L2 bridge offloading")
Acked-by: Jiri Pirko <jiri@resnulli.us>
Acked-by: Scott Feldman <sfeldma@gmail.com>
Signed-off-by: Simon Horman <simon.horman@netronome.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/drivers/net/ethernet/rocker/rocker.c b/drivers/net/ethernet/rocker/rocker.c
index 9fb6948e14c64ef424c032811364aaefc608d4cb..5cecec282aba8b471b60b91af594ba6374edcda7 100644 (file)
--- a/drivers/net/ethernet/rocker/rocker.c
+++ b/drivers/net/ethernet/rocker/rocker.c
@@ -4468,10 +4468,16 @@ static int rocker_port_master_changed(struct net_device *dev)
        struct net_device *master = netdev_master_upper_dev_get(dev);
        int err = 0;
 
+       /* There are currently three cases handled here:
+        * 1. Joining a bridge
+        * 2. Leaving a previously joined bridge
+        * 3. Other, e.g. being added to or removed from a bond or openvswitch,
+        *    in which case nothing is done
+        */
        if (master && master->rtnl_link_ops &&
            !strcmp(master->rtnl_link_ops->kind, "bridge"))
                err = rocker_port_bridge_join(rocker_port, master);
-       else
+       else if (rocker_port_is_bridged(rocker_port))
                err = rocker_port_bridge_leave(rocker_port);
 
        return err;