SELinux

General

• ls -Z
• audit2allow and audit2why
• If Linux audit daemon (see below) is turned on, SELinux problems should be written to file /var/log/audit/audit.log
• CentOS6 SELinux troubleshooting
  • "SELinux decisions, such as allowing or disallowing access, are cached. This cache is known as the Access Vector Cache (AVC). Denial messages are logged when SELinux denies access. These denials are also known as "AVC denials""
• CentOS7 SELinux troubleshooting

semanage

• SELinux Policy Management tool
• semanage fcontext -a -t httpd_sys_content_t "/var/www/lgorders/admin(/.*)?

restorecon

• restore file(s) default SELinux security contexts.
• passively check whether the file contexts are all set as specified by the active policy
• restorecon -Rv .
  • -n is dry-run (passive-check)

1. When you cp files from one location to another, they keep their original context
2. If you scp (from another machine?) directly into place, they get the context corresponding to the receiving location.
3. Every time you copy (cp) new/modified files into /var/www/lgorders you’ll have to run sudo restorecon -R /var/www/lgorders to allow httpd to use them.

Linux audit daemon

• man auditd
• /etc/audit/auditd.conf
• service auditd status
• dumps infos to /var/log/audit/audit.log
• aureport -a
• ausearch -m avc -ts recent - denials from the last 10 minutes