kmf is due to the cluster alias code passing a NULL mbuf to clua_round_robin.

1 panic
  2 trap
  3 _XentMM
  4 rfs_find_fsid
  5 rfs_find_clua
  6 clua_round_robin
  7 clua_register_remote_service_small_rpc
  8 svr_clua_register_remote_service_small_rpc
  9 icssvr_daemon_per_node
