nVidia kernel module: key rejected

Situation

On a Dell Precision 7520 running Debian, I found myself switching between UEFI / secure boot and legacy BIOS boot, and having trouble restoring the right boot settings after reenabling secure boot.

The first problem was to identify the correct file to boot from: EFI/debian/shimx64.efi.

Kernel module load issue

After disabling secure boot and then reenabling it again, kernel modules not loading despite updating nvidia-driver and kernel-image

solution: reenroll MOK (Machine Owner Key):

• mokutil --import /var/lib/dkms/mok.pub (set an import password)
• mokutil --list-new
• reboot into MOK management => provide import password => key reenrolled
• modules loding :thumsbup:

Debian documentation: Secure Boot