The productivity of this construction needs to be investigated in order to establish its status as a true passive. The verb + du form may be better analyzed as an adjective. Such forms appear prenominally. Intransitive verbs appear in this pseudo-passive construction (as in Example 6).
Source: Smith 1974-5: 4970
Source: Smith 1974-5: 4290
Source: Smith 1974-5: 5146
Source: Smith 1974-5: 3569