SELinux Denials Breaking Web Application Access – RHEL 8 Post 030

📖 ~1 min read

Table of contents

1. Symptom & Impact
2. Environment & Reproduction
3. Root Cause Analysis
4. Quick Triage
5. Step-by-Step Diagnosis
6. Solution – Primary Fix
7. Solution – Alternative Approaches
8. Verification & Acceptance Criteria
9. Rollback Plan
10. Prevention & Hardening
11. Related Errors & Cross-Refs
12. References & Further Reading

Symptom & Impact

Application returns permission errors while file permissions look correct, creating prolonged service disruption.

Environment & Reproduction

After moving web content, mounting new volumes, changing ports, or deploying custom binaries under httpd.

Root Cause Analysis

Incorrect SELinux context, blocked boolean, non-standard port type, or policy gap for custom behavior.

Quick Triage

Run `getenforce`, inspect contexts with `ls -Z`, and confirm service status via `systemctl status httpd`.

Step-by-Step Diagnosis

Use `ausearch -m avc -ts recent`, `sealert -a /var/log/audit/audit.log`, and `semanage port -l | grep http`.

Solution – Primary Fix

AVC entries map to actionable context or boolean fixes, and no new denials appear after remediation.

Solution – Alternative Approaches

Apply correct labels with `restorecon`, set required booleans using `setsebool -P`, and map custom ports with `semanage`.

Verification & Acceptance Criteria

Retest endpoint and verify `journalctl -u httpd` plus audit logs are clean of fresh AVC denials.

Rollback Plan

Revert recent boolean or policy module changes if unexpected access broadening occurs.

Prevention & Hardening

Keep SELinux enforcing, standardize file contexts in deployment scripts, and review AVC alerts continuously.

Related Errors & Cross-Refs

`restorecon -RFv /var/www && setsebool -P httpd_can_network_connect on`

Related tutorial: View the step-by-step tutorial for rhel-8.

View all rhel-8 tutorials on the Tutorials Hub →

Browse all common problems & solutions on the Tutorials Hub.

References & Further Reading

RHEL 8 SELinux administration guide, `man semanage`, and Red Hat KB on AVC troubleshooting.