The SELinux (Security Enhanced Linux) framework is part of Fedora Core. SELinux limits the actions of both users and programs by enforcing security policies throughout the operating system. Without SELinux, software bugs or configuration changes may render a system more vulnerable. The restrictions imposed by SELinux policies provide extra security against unauthorized access.
Inflexible SELinux policies might inhibit many normal activities on a Fedora system. For this reason, Fedora Core uses targeted policies, which only affect specific network services. These services cannot perform actions that are not part of their normal functions. The targeted policies reduce or eliminate any inconvenience SELinux might cause users. Set the SELinux mode to one of the following:
- Active
Select this mode to use the targeted SELinux policy on your Fedora system. This is the default mode for Fedora installations.
- Warn
Because SELinux is a new technology, this diagnostic mode is provided. In this mode, the system is configured with SELinux, but a breach of security policies only causes an error message to appear. No activities are actually prohibited when SELinux is installed in this mode. You may change the SELinux mode to Active at any time after booting.
- Disabled
If you choose this mode for SELinux, Fedora does not configure the access control system at all. To make SELinux active later, from the main menu, select Desktop->System Settings->Security Level and Firewall.
![[Tip]](./stylesheet-images/tip.png) | Changing the SELinux policy |
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SELinux is unique in that it cannot be bypassed, even by the system administrators. To change the behavior of SELinux after installation, from the main menu, choose Desktop->System Settings->Security Level and Firewall. |