CentOS Stream 10 – Common Problem 093 – 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

pam_faillock locks out service accounts on CentOS Stream 10 disrupts services and slows incident response until the root cause is resolved.

Environment & Reproduction

Service account locked out repeatedly because faillock counts failed sudo attempts.

faillock --user 
cat /etc/security/faillock.conf

Root Cause Analysis

Misalignment between auth configuration and CentOS Stream 10 defaults causes the failure path described above.

Quick Triage

Confirm package state, service status, and recent changes before deeper diagnostics.

systemctl status
rpm -qa | grep -i 
journalctl -p err -b --no-pager | tail -100

Step-by-Step Diagnosis

Capture detailed logs, configuration deltas, and runtime state to isolate the failing component.

faillock --user 
grep faillock /etc/pam.d/system-auth /etc/pam.d/password-auth
journalctl -t sudo -n 100

Solution – Primary Fix

Apply the targeted configuration change and restart the relevant services to restore expected behavior.

sudo faillock --user  --reset
sudo authselect select sssd with-faillock --force
sudo sed -i 's/^# deny =.*/deny = 10/' /etc/security/faillock.conf

Solution – Alternative Approaches

Exempt automation accounts via even_deny_root no_magic_root tuning.

Verification & Acceptance Criteria

Validate the fix with deterministic checks and ensure no regressions in dependent services.

faillock --user 
sudo -u  id

Rollback Plan

Revert configuration and restart services to return to the previous known-good state.

authselect select minimal --force
faillock --user  --reset

Prevention & Hardening

Whitelist robotic accounts and monitor faillock counters.

Related Errors & Cross-Refs

Related: faillock, authselect, PAM stack; see also adjacent topics in the CentOS Stream 10 common problems series.

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

CentOS Stream documentation, Red Hat upstream guides, and CentOS Stream 10 release notes covering this subsystem.