Ubuntu 24.04 LTS – Common Problem 022 – 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

Third-party kernel modules fail to load when Secure Boot is enabled.

Environment & Reproduction

Ubuntu 24.04 with Secure Boot on and DKMS modules such as NVIDIA or VirtualBox.

Root Cause Analysis

Module signature key not enrolled in MOK database or signature became invalid after rebuild.

Quick Triage

Check Secure Boot status with mokutil –sb-state and module load errors in dmesg.

Step-by-Step Diagnosis

Verify signer details with modinfo and inspect kernel logs for Lockdown or verification failures.

Solution – Primary Fix

Generate/enroll MOK key, rebuild/sign affected modules, reboot, and complete MOK enrollment in firmware UI.

Solution – Alternative Approaches

Disable Secure Boot temporarily where policy allows, then restore after proper signing workflow is in place.

Verification & Acceptance Criteria

Module loads successfully with Secure Boot enabled and no signature errors in logs.

Rollback Plan

Revert to previous signed module package or temporarily disable problematic module autoload.

Prevention & Hardening

Integrate module signing into DKMS build pipeline and store keys securely with rotation policy.

Related Errors & Cross-Refs

Required key not available, module verification failed, Lockdown: loading of unsigned module denied.

Related tutorial: View the step-by-step tutorial for Ubuntu 24.04 LTS.

View all Ubuntu 24.04 LTS tutorials on the Tutorials Hub →

Browse all common problems & solutions on the Tutorials Hub.

References & Further Reading

Ubuntu Secure Boot docs, shim/MOK manuals, and kernel module signing documentation.