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SELinux: Flip a Boolean That Survives Reboot

MediumRHCSA Prep10-15 min
The brief

A web app on this RHEL box is being blocked by SELinux, and the denial is captured in /root/case/avc.log (your brief, /root/case/brief.txt, says what the app is trying to do). The policy already supports this access behind a boolean. Diagnose the denial with audit2why, find the ONE boolean that allows exactly this access, and turn it on persistently so the fix survives a reboot. Least privilege counts: don't switch on any other boolean, including catch-alls like httpd_unified or httpd_can_network_connect. This lab machine's kernel has SELinux disabled, so nothing is enforced live; grading reads the persistent SELinux policy store, which is what an enforcing box loads at boot.

What you'll do
  • Diagnose an AVC denial with audit2why
  • Pick the narrowest boolean that allows it
  • Set the boolean persistently, not runtime-only

Hands-on lab: you work on a real Linux box in your browser, graded on the machine's actual state.