What is the ruling on endowing an undivided property (musha') if part of it is valid and part invalid, and is it permissible for the endower to revoke his endowment?

Your father's endowment of what you own, without your permission, is an unauthorized act. It becomes effective with your approval, and if you do not approve, you have the right to reclaim your property. However, if it was done with your permission or authorization, you do not have the right to revoke the endowment. Your father does not have the right to revoke what he has endowed from his share, and the endowment of jointly owned property is permissible according to the majority of jurists.