Secureboot + Ubuntu + VirtualBox Signing kernel modules

Motivation

minikube start

was throwing errors like the following

  minikube start
😄  minikube v1.18.1 on Ubuntu 21.04
✨  Automatically selected the virtualbox driver
👍  Starting control plane node minikube in cluster minikube
🔥  Creating virtualbox VM (CPUs=2, Memory=2900MB, Disk=20000MB) ...
🤦  StartHost failed, but will try again: creating host: create: precreate: We support Virtualbox starting with version 5. Your VirtualBox install is "WARNING: The vboxdrv kernel module is not loaded. Either there is no module\n         available for the current kernel (5.11.0-16-generic) or it failed to\n         load. Please recompile the kernel module and install it by\n\n           sudo /sbin/vboxconfig\n\n         You will not be able to start VMs until this problem is fixed.\n6.1.22r144080". Please upgrade at https://www.virtualbox.org
🔥  Creating virtualbox VM (CPUs=2, Memory=2900MB, Disk=20000MB) ...
😿  Failed to start virtualbox VM. Running "minikube delete" may fix it: creating host: create: precreate: We support Virtualbox starting with version 5. Your VirtualBox install is "WARNING: The vboxdrv kernel module is not loaded. Either there is no module\n         available for the current kernel (5.11.0-16-generic) or it failed to\n         load. Please recompile the kernel module and install it by\n\n           sudo /sbin/vboxconfig\n\n         You will not be able to start VMs until this problem is fixed.\n6.1.22r144080". Please upgrade at https://www.virtualbox.org
❗  Startup with virtualbox driver failed, trying with alternate driver ssh: Failed to start host: creating host: create: precreate: We support Virtualbox starting with version 5. Your VirtualBox install is "WARNING: The vboxdrv kernel module is not loaded. Either there is no module\n         available for the current kernel (5.11.0-16-generic) or it failed to\n         load. Please recompile the kernel module and install it by\n\n           sudo /sbin/vboxconfig\n\n         You will not be able to start VMs until this problem is fixed.\n6.1.22r144080". Please upgrade at https://www.virtualbox.org
💀  Removed all traces of the "minikube" cluster.

❌  Exiting due to MK_USAGE: No IP address provided. Try specifying --ssh-ip-address, or see https://minikube.sigs.k8s.io/docs/drivers/ssh/

Resolution

Had to check multiple resources to make this a working solution. Quoting all the original resources

Install the virtualbox manually

sudo apt-get update
sudo apt-get install virtualbox-6.1

Sign the modules for secureboot

sudo -i
mkdir /root/module-signing
cd /root/module-signing
openssl req -new -x509 -newkey rsa:2048 -keyout MOK.priv -outform DER -out MOK.der -nodes -days 36500 -subj "/CN=Descriptive common name/"

mokutil --import /root/module-signing/MOK.der
# Input a simple password

Restart the machine

During the boot when prompted choose Enroll MOK
You will see the keys that were created and signed and choose Continue
Reboot

Create a bash script to sign the kernel modules

sudo -i
touch /root/module-signing/sign-vbox-modules
vi /root/module-signing/sign-vbox-modules

Paste the following in to the script file (hit i to be in insert mode)

#!/bin/bash

for modfile in $(dirname $(modinfo -n vboxdrv))/*.ko; do
  echo "Signing $modfile"
  /usr/src/linux-headers-$(uname -r)/scripts/sign-file sha256 \
                                /root/module-signing/MOK.priv \
                                /root/module-signing/MOK.der "$modfile"
done

Then hit ESC + wq to save and quit the file

Execute the script after updating the permissions

chmod 700 /root/module-signing/sign-vbox-modules
/root/module-signing/sign-vbox-modules

Sample output should look like the following

#  /root/module-signing/sign-vbox-modules
Signing /lib/modules/5.11.0-16-generic/updates/dkms/vboxdrv.ko
Signing /lib/modules/5.11.0-16-generic/updates/dkms/vboxnetadp.ko
Signing /lib/modules/5.11.0-16-generic/updates/dkms/vboxnetflt.ko

Start Virtualbox

modprobe vboxdrv

Check

minikube start

should now work as expected and start the local cluster

$  minikube start
😄  minikube v1.18.1 on Ubuntu 21.04
✨  Automatically selected the virtualbox driver. Other choices: none, ssh
👍  Starting control plane node minikube in cluster minikube
🔥  Creating virtualbox VM (CPUs=2, Memory=2900MB, Disk=20000MB) ...
🐳  Preparing Kubernetes v1.20.2 on Docker 20.10.3 ...
    ▪ Generating certificates and keys ...
    ▪ Booting up control plane ...
    ▪ Configuring RBAC rules ...
🔎  Verifying Kubernetes components...
    ▪ Using image gcr.io/k8s-minikube/storage-provisioner:v4
🌟  Enabled addons: storage-provisioner, default-storageclass
🏄  Done! kubectl is now configured to use "minikube" cluster and "default" namespace by default