I was asked to disable secure boot in order to install third party drivers on ubuntu 16.04. So I followed the instructions of MOK managemnt to disable secure boot.

But secure boot is still on in bios. It seems that ubuntu has added an exception for itself rather than completely turning it off.

Here is what happens:

1: laptop has win10 and ubuntu16.04 and both are installed in uefi with secure boot on.

2: before grub flashing it shows "booting in insecure mode" and then grub appears.

3: then I boot in win10 & check if secure boot is on using this guide, it shows that it is on.

What is happening here? Is secure boot on or off?

Has ubuntu added an exception for itself in secure boot database?

If ubuntu has added an exception for itself, I would like to know if I can add some more exceptions or remove existing exceptions?

2 Answers 2


sudo mokutil --enable-validation

After restart Mok managment will pop up. There will be an option where you can enable secure boot (just like you disabled after installing Ubuntu).

Manpage of mokutil: http://manpages.ubuntu.com/manpages/xenial/man1/mokutil.1.html

  • Could you explain more? I'm completely lost trying to get a monitor to run and have ended up here, I'm just jumping from island to island without context. I ran this, restarted, did the insane task of trying to figure out which character of my password was in what order with no idea why, and then... nothing is different, and I just have no idea what the hell is going on.
    – Kyle Baker
    Feb 18, 2017 at 5:57

I have never noticed any difference in ubuntu's behaviour with secure boot on or off despite being told to enable and disable it for various reasons.

Secure boot is little more than a marketing concept that adds no real security to Linux systems but does help mitigate some of the boot sector vulnerabilities that have plagued windows in the past.

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