Canon law is concerned with discipline. Infallibility has to do with faith and morals. So of it self, canon law is not infallible. However, insofar as canon law deals with matters that the Church considers infallible, then such content is infallible. Whether the content of canon law is infallible or not, Catholics are obliged to obey it because it is an expression of the authority the Church has received from Christ, Himself.
My concern in my first answer was with the fact that the use of only wheat bread for the Eucharist does not originate in canon law. It comes to us from Scripture. The Church cannot change that. Scripture is infallible. So here we have a case of the content of canon law being infallible.
Fr. Vincent Serpa, O.P.