Based on my reading of the following website to which I have provided a link, I would say that there is a passive voice in ASL. This discussion occurred on http://aslpah.com: A journal for American Sign Language students and teachers:
Much of your confusion (and that of others) has to do with the fact that you can use either a subject or object as your “topic” in a sentence.
If you use the subject as your topic, you are using “active voice.”
Example: The boy threw the ball. (BOY THROW BALL)
If you use the object as your topic your are using “passive voice.”
Example: The ball was thrown by the boy. (BALL? BOY THROW).
Note that the active voice: BOY THROW BALL is definitely SUBJECT-VERB-OBJECT word order.
The passive voice is: OBJECT-SUBJECT-VERB word order.
Both of those can be considered TOPIC COMMENT:
Topic: BOY Comment: THROW BALL (active voice)
Topic: BALL Comment: BOY THROW (passive voice)
In the passive voice sentence the “ball” which is actually the object is being used as the topic, and the comment is that it “was thrown by the boy.”
So, you can see that the topic can be either a subject or an object.
A “topic” is simply that to which a comment is referring. A topic is what you are talking about.
from
http://aslpah.com/main/archives/49aug07.htm