45.2.6. Enabling or Disabling Enforcement

45.2.6. Enabling or Disabling Enforcement

You can enable and disable SELinux enforcement at runtime or configure it to start in the correct mode at boot time, using the command line or GUI. SELinux can operate in one of three modes: disabled , meaning not enabled in the kernel; permissive , meaning SELinux is running and logging but not controlling permissions; or enforcing , meaning SELinux is running and enforcing policy.

Use the setenforce command to change between permissive and enforcing modes at runtime. Use setenforce 0 to enter permissive mode; use setenforce 1 to enter enforcing mode.

The sestatus command displays the current mode and the mode from the configuration file referenced during boot:

sestatus | grep -i mode
Current mode:           permissive
Mode from config file:  permissive

Note that changing the runtime enforcement does not affect the boot time configuration:

setenforce 1
sestatus | grep -i mode
Current mode:           enforcing
Mode from config file:  permissive

You can also disable enforcing mode for a single daemon. For example, if you are trying to troubleshoot the named daemon and SELinux, you can turn off enforcing for just that daemon.

Use the getsebool command to get the current status of the boolean:

[root@host2a ~]# getsebool named_disable_trans
named_disable_trans --> off

Use the following command to disable enforcing mode for this daemon:

[root@host2a ~]# setsebool named_disable_trans 1

[root@host2a ~]# getsebool named_disable_trans
named_disable_trans --> on

Note

This sets the runtime value only. Use the -P option to make the change persistent across reboots.

Any *_disable_trans booleans that are set to "on" invoke the conditional that prevents the process from transitioning to the domain on execution.

Use the following command to find which of these booleans are set:

getsebool -a | grep disable.*on

httpd_disable_trans=1
mysqld_disable_trans=1
ntpd_disable_trans=1

You can set any number of boolean values using the setsebool command:

setsebool -P httpd_disable_trans=1 mysqld_disable_trans=1 ntpd_disable_trans=1

You can also use togglesebool <boolean_name> to change the value of a specific boolean:

[root@host2a ~]# getsebool httpd_disable_trans
httpd_disable_trans --> off

[root@host2a ~]# togglesebool httpd_disable_trans
httpd_disable_trans: active

You can configure all of these settings using system-config-selinux. The same configuration files are used, so changes appear bidirectionally.

Changing a Runtime Boolean

Use the following procedure to change a runtime boolean using the GUI.

Note

Administrator privileges are required to perform this procedure.

  1. On the System menu, point to Administration and then click Security Level and Firewall to display the Security Level Configuration dialog box.

  2. Click the SELinux tab, and then click Modify SELinux Policy.

  3. In the selection list, click the arrow next to the Name Service entry, and select the Disable SELinux protection for named daemon check box.

  4. Click OK to apply the change. Note that it may take a short time for the policy to be reloaded.

Using the Security Level Configuration dialog box to change a runtime boolean.

Figure 45.1. Using the Security Level Configuration dialog box to change a runtime boolean.


If you want to control these settings with scripts, you can use the setenforce(1), getenforce(1), and selinuxenabled(1) commands.


Note: This documentation is provided {and copyrighted} by Red Hat®, Inc. and is released via the Open Publication License. The copyright holder has added the further requirement that Distribution of substantively modified versions of this document is prohibited without the explicit permission of the copyright holder. The CentOS project redistributes these original works (in their unmodified form) as a reference for CentOS-5 because CentOS-5 is built from publicly available, open source SRPMS. The documentation is unmodified to be compliant with upstream distribution policy. Neither CentOS-5 nor the CentOS Project are in any way affiliated with or sponsored by Red Hat®, Inc.