In recent years, Online Social Networks (OSNs) have become immensely popular as social interaction services among worldwide Internet users. OSNs facilitate Third-party applications (TPAs) which provide many additional functionalities to users. While providing the extended services TPAs access the users data which would raise serious concerns to user privacy. This is due to the lack of user data protection mechanisms by OSN and none of the present OSN platforms offers satisfactory protection mechanisms to users private data. In this paper, we propose an access control framework called InfoRest to restrict user data to TPA in OSN, considering users privacy preferences and attribute generalization. Further, we propose a relation based access control (ReBAC) policy model and use predicate calculus to represent access conditions. The usability and correctness of the proposed policy model are demonstrated with the help of a logical model developed using answer set programming.