SELinux and PostgreSQL: a worthwhile union
When your editor was in Tokyo recently, he had the privilege to talk with KaiGai Kohei at some length about the SE-PgSQL patch set. This work, developed by KaiGai for the last two years or so, integrates SELinux with the PostgreSQL database manager, enabling fine-grained control over access to data stored within a database. The SE-PgSQL patch has struggled to get into the PostgreSQL mainline; it is now preparing for what may well be its last push to be merged. Whether it's successful may, in the end, depend on whether it receives support from potential users.
SELinux works by attaching labels to objects and roles to actors, then enforcing rules describing what sort of access to objects with specific labels is allowed to specific roles. It is a highly flexible system, but also highly complex; even a minimal SELinux policy can involve thousands of rules. The complexity of SELinux has almost certainly inhibited its adoption in the broader Linux community; when SELinux gets in the way of real work, figuring out how to fix it can be a nontrivial task. Over the years, many administrators have concluded, like Ted Ts'o, that "life is too short for SELinux."
