3.3. Confined non-administrator roles in SELinux

In SELinux, confined non-administrator roles grant specific sets of privileges and permissions for performing specific tasks to the Linux users assigned to them. By assigning separate confined non-administrator roles, you can assign specific privileges to individual users. This is useful in scenarios with multiple users who each have a different level of authorizations.

You can also customize the permissions of SELinux roles by changing the related SELinux booleans on your system. To see the SELinux booleans and their current state, use the semanage boolean -l command as root. You can get more detailed descriptions if you install the selinux-policy-devel package.

# semanage boolean -l
SELinux boolean                State  Default Description
…
xguest_connect_network         (on   ,   on)  Allow xguest users to configure Network Manager and connect to apache ports
xguest_exec_content            (on   ,   on)  Allow xguest to exec content
…

Linux users in the user_t, guest_t, and xguest_t domains can only run set user ID (setuid) applications if SELinux policy permits it (for example, passwd). These users cannot run the setuid applications su and sudo, and therefore cannot use these applications to become root.

By default, Linux users in the staff_t, user_t, guest_t, and xguest_t domains can execute applications in their home directories and /tmp. Applications inherit the permissions of the user that executed them.

To prevent guest_t, and xguest_t users from executing applications in directories in which they have write access, set the guest_exec_content and xguest_exec_content booleans to off.

SELinux has the following confined non-administrator roles, each with specific privileges and limitations: