Selinux

Internal

• Linux 7 Security

How to Find Out Whether SELinux is Enabled

getenforce

If SELinux is enabled, the command will return "Enforcing".

Configuration

Install Management and Troubleshooting Tools

yum provides /usr/sbin/semanage
yum provides sealert

yum -y install policycoreutils-python
yum -y install setroubleshoot-server

Troubleshooting

Get the SELinux Security Context

ls -lZ <dir>

Diagnosing and Fixing SELinux Problems

If you have a suspicion that SELinux may be at the root of your problems, run:

sealert -a /var/log/audit/audit.log

You may get an output similar to the following one, which helps diagnose the problem:

[...]
SELinux is preventing /usr/sbin/httpd from write access on the file manager.node.nodes.lock.
[...]

Then use audit2allow to parse the audit logs and generate the SELinux policy to allow a denied operation.

grep httpd /var/log/audit/audit.log | audit2allow

The result is similar to:

#============= httpd_t ==============
allow httpd_t httpd_log_t:file write;

Then change the directory SELinux security context:

chcon -t httpd_sys_script_rw_t /var/log/httpd

Permission Denied when Trying to Write in a Directory

TODO, rationalize the following content: Media_Wiki_Installation#Fails_to_upload_images_with_.27Fatal_exception_of_type_.22MWException.22.27.