macvtap: check minor when unregistering
macvtap_device_event(NETDEV_UNREGISTER) should check vlan->minor to
determine if it is being invoked in the context of a macvtap_newlink
that failed, for example in this code sequence:
macvtap_newlink
macvlan_common_newlink
register_netdevice
call_netdevice_notifiers(NETDEV_REGISTER, dev)
macvtap_device_event(NETDEV_REGISTER)
<fail here, vlan->minor = 0>
rollback_registered(dev);
rollback_registered_many
call_netdevice_notifiers(NETDEV_UNREGISTER, dev);
macvtap_device_event(NETDEV_UNREGISTER)
<nothing to clean up here>
Signed-off-by: Francesco Ruggeri <fruggeri@arista.com>
Acked-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/macvtap.c b/drivers/net/macvtap.c
index 95394ed..74cb15a 100644
--- a/drivers/net/macvtap.c
+++ b/drivers/net/macvtap.c
@@ -1303,6 +1303,9 @@
}
break;
case NETDEV_UNREGISTER:
+ /* vlan->minor == 0 if NETDEV_REGISTER above failed */
+ if (vlan->minor == 0)
+ break;
devt = MKDEV(MAJOR(macvtap_major), vlan->minor);
device_destroy(macvtap_class, devt);
macvtap_free_minor(vlan);