Halakhah su Levitico 25:45

Also, if an Israelite has intercourse with a Canaanite slave woman - that is, a woman from the [other] nations who was purchased by an Israelite - behold the offspring from her is a Canaanite slave for all purposes (Yevamot 22a), and even if she is the slave of that Israelite that had intercourse with her. Similarly, [in the case of a free man] from the nations that had intercourse with a Canaanite slave woman of ours, the child is a Canaanite slave - as it it stated (Leviticus 25:45), "that they begot in your land." However [in the case of] one of our slaves that has intercourse with a [free woman] from the nations, the child is not a slave - as a slave has no [paternity]. And so [too,] a resident alien - that is, one that has accepted not to worship idolatry and he is living in our land - who sold himself to an Israelite, behold his status is that of a Canaanite slave. And they, may their memory be blessed, said regarding a Canaanite slave (Yevamot 48b) that his master takes care of him up to twelve months; if he wants to deny and abandon idolatry, get circumcised and immerse for the sake of slavery and accept the commandments that Jewish women are obligated, it is good. But if not, it is forbidden for us to hold him in our homes longer than twelve months. Rather we sell him immediately. And [it is] about those slaves that were circumcised and immersed for the sake of slavery that we were commanded to work them forever.