Has my ex any rights to my son even he is not from Canada and is just on a Workpomit?

Yes... he is the other parent...

His work status, or birth place have nothing to do with his rights as a father.

He has all the same rights of a parent, his nationality, work status, immigration status has no effect on his legal rights to custody, to visitation and other child care rights.

The child is not only "your" son, but his son also, he can file in court for full custody, joint custody, visitation and so on, just like any father can.

As the others have noted, he certainly has the same rights as any father. But not being a citizen, especially on a work permit, may make it harder for him to enforce those rights.

As the others have noted, he certainly has the same rights as any father. But not being a citizen, especially on a work permit, may make it harder for him to enforce those rights.

As I understand the OP's question, he does have a work permit, and is in Canada (where OP and the child also live, I assume). The possible difficulty in enforcement is not really related to his citizenship status or whether he has a work permit; but rather it is related to his possible financial inability to retain an attorney. Also, Canada is a big place. If he is in Nova Scotia, and the OP is in the Yukon, for example, that would make his task daunting, of course.

I don't think we know other important details, including whether he was married to OP (The term "ex" is ambiguous), whether he has been adjudicated the father, and whether there is any child custody/ visitation order in place.