Ubuntu 26.04 LTS – Secure Boot blocks DKMS module loading – Fix & Prevention

📖 ~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

After reboot, third-party kernel modules fail to load, causing missing drivers or broken virtualization/network features.

Environment & Reproduction

Common with NVIDIA, VirtualBox, or custom DKMS modules on Secure Boot-enabled systems.

mokutil --sb-state
dkms status
modprobe 

Root Cause Analysis

Unsigned or improperly signed DKMS modules are rejected by Secure Boot policy.

Quick Triage

Inspect kernel logs for signature and lockdown messages.

journalctl -k -n 120 --no-pager | grep -Ei 'secure|lockdown|signature|module'
modinfo 

Step-by-Step Diagnosis

Validate DKMS build output and key enrollment status.

sudo dkms autoinstall
sudo tail -n 120 /var/lib/dkms//*/build/make.log
mokutil --list-enrolled

Solution – Primary Fix

Sign module with MOK-compatible key and enroll it through firmware workflow.

sudo update-secureboot-policy --new-key
sudo dkms autoinstall
sudo update-initramfs -u
echo 'Reboot and complete MOK enrollment in firmware prompt'

Solution – Alternative Approaches

Use Ubuntu repository-signed driver packages where available to avoid custom signing overhead.

sudo ubuntu-drivers devices
sudo ubuntu-drivers autoinstall

Verification & Acceptance Criteria

Module loads without signature errors and dependent service is operational.

sudo modprobe 
lsmod | grep 
journalctl -k -n 60 --no-pager

Rollback Plan

Remove newly installed module package if instability appears.

sudo apt purge -y 
sudo update-initramfs -u
sudo reboot

Prevention & Hardening

Standardize module signing process for all kernel updates in Secure Boot environments.

Automate patch management and compliance across your fleet with our DevOps services.

dkms status
mokutil --sb-state
uname -r

Related Errors & Cross-Refs

Related to missing headers, failed DKMS compilation, and post-upgrade driver mismatch.

Related tutorial: View the step-by-step tutorial for Ubuntu 26.04 LTS.

View all Ubuntu 26.04 LTS tutorials on the Tutorials Hub →

Browse all common problems & solutions on the Tutorials Hub.

References & Further Reading

Ubuntu Secure Boot, DKMS, and signed-driver deployment documentation.