Kubuntu kernel updates - bad shim - must load kernel first

[waggers1]

Kubuntu 23.04

For all kernels since 6.2.0-24 I get an error message about bad shim signature and I'm not using any custom kernels. if I disable Secure boot, they all work fine.

Ok, I've obviously broken something along the way. Any clues on how to fix this issue or do I need to do a clean install of 23.10 This may have been caused by a bios upgrade but I'm just guessing there.

[TinyTim]

Do you have a Nvidia GPU?

[waggers1]

Do you have a Nvidia GPU?

I'm gunna say Yes to that one.

I know that their Linux drivers are iffy as Wayland works rather poorly but i didn't think it would affect the kernel loading.

[TinyTim]

I'm gunna say Yes to that one.

I know that their Linux drivers are iffy as Wayland works rather poorly but i didn't think it would affect the kernel loading.

I am just at the beginning stages of learning about new kernels needing new "shim" from Nvidia so the driver can attach correctly. What I did until Nvidia can improve their shim process is.... entered the terminal command.

I have two Nvidia machines with new kernels that was having Nvidia "shim" problems, I Edited the GRUB, so it would boot up on the last kernel I booted on every time. (You might purge/remove that problem kernel, but I had problems with a different machine that would not let me remove the new kernel and use the old kernel, So this is the way I kept doing it.)

sudo nano etc/default/grub
and I added these lines to the end
GRUB_SAVEDEFAULT=true
GRUB_DEFAULT=saved

sudo update-grub
reboot system

Then in terminal
uname -r
to get the kernel version " 6.2.0-34-generic "
then I gave the command to not upgrade the kernel
sudo apt-mark hold " kernel version here "

Now this is what I personally chose to do until Nvidia can either make it open source, or streamline their process or whatever it is they do. Please note, there are more experienced people on here that know a lot more than I do. I would patiently wait for their input.