CentOS Stream 10 – Common Problem 227 – Diagnosis and Fix

📖 ~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

httpd fails to start when configured on a non-standard port due to SELinux port type mismatch.

Environment & Reproduction

Seen after moving Apache to ports such as 8443 or 9090 without updating SELinux port labels.

Root Cause Analysis

http_port_t does not include the new port, so the targeted policy denies the bind operation.

Quick Triage

Inspect /var/log/audit/audit.log for AVC denials referencing name_bind and the chosen port.

Step-by-Step Diagnosis

Run: sudo ausearch -m AVC -ts recent | audit2why; sudo semanage port -l | grep http_port_t.

Solution – Primary Fix

Run: sudo semanage port -a -t http_port_t -p tcp 8443; sudo systemctl restart httpd.

Solution – Alternative Approaches

Use a custom policy module from audit2allow when multiple ports or protocols are required.

Verification & Acceptance Criteria

httpd listens on the new port and no further AVC denials appear during startup.

Rollback Plan

Remove the port mapping with semanage port -d and revert httpd.conf Listen directives.

Prevention & Hardening

Keep an approved port label list and add SELinux port changes to provisioning automation.

Related Errors & Cross-Refs

Often combined with firewalld zone errors and missing http_port_t labels on similar services.

Related tutorial: View the step-by-step tutorial for centos-stream-10.

View all centos-stream-10 tutorials on the Tutorials Hub →

Browse all common problems & solutions on the Tutorials Hub.

References & Further Reading

Red Hat SELinux User and Administrator guide and semanage(8) man page.