Who has control over the rental of a property: the usufructuary or the bare owner?

My husband owned an apartment that he rented out. Since his death I have benefited from the usufruct of this property and my son has the bare ownership. The tenant has informed me that my son has given the latter leave to take over for the benefit of his wife's son. Does he have the right to do so? 

No. When property is the subject to a usufruct, the right to rent belongs to the usufructuary (art. 595, al. 1 C. civ.) and not to the bare owner. He is the only one who can issue leave (Cass. Civ. 3rd, January 26, 2022, n°20-20.223