uefi - Why do I get "Required key not available" when install 3rd party kernel modules or after a kernel upgrade? - Ask Ubuntu

this issue happens on uefi systems enabled secure boot.

when try install dkms modules virtualbox, nvidia, or broadcom drivers, not install , required key not available when try modprobe them.

virtualbox complains vboxdrv not loaded.

broadcom wl driver shown in lspci -k kernel module not in use. sudo modprobe wl throws required key not available.

also issue may happen when install kernel modules git sources.

this issue may appear after kernel update disabled wireless adapter, black screen after reboot, etc.

how can fix it?

since ubuntu kernel 4.4.0-20 efi_secure_boot_sig_enforce kernel config has been enabled. prevents loading unsigned third party modules if uefi secure boot enabled.

the easiest way fix issue disable secure boot in uefi (bios) settings.

in cases can uefi settings using grub menu. press esc button on booting, grub menu , select system setup. secure boot option should in "security" or "boot" section of uefi.

you can uefi directly, depends on hardware. read computer manual see how there. may del, or f2 on boot, or else.

an alternative way disable secure boot using mokutil.

since ubuntu kernel build 4.4.0-21.37 can fixed running

sudo apt install mokutil sudo mokutil --disable-validation 

it require create password. password should @ least 8 characters long. after reboot, uefi ask if want change security settings. choose "yes".

then asked enter created password. uefi firmware asks not full password, enter characters of it, 1st, 3rd, etc. careful. people not understand this. did not first attempt either ;-)

update: kernel config enabled in supported ubuntu kernels. ubuntu 16.04, 15.10 , 14.04 affected.