[sf-lug] (forw) Re: Problems with Ubuntu 17.10 (18.04) using kernels before 4.13.0-21

[Rick Moen]

Quoting Ken Shaffer (kenshaffer80 at gmail.com):

> As of noon 12/24, the ISOs still have not been fixed.

_Part_ of your point about the intel-spi driver being present, hence
capable of writing to the Intel Serial Peripheral Interface bus, is well
taken.  Let's discuss that:

> Lenovo (not an identified model in the bug) and have not noticed any
> problems. Canonical's "fix" seems to be just to remove the intel-spi module
> from the 4.13.0-21 kernel build,  Rick's fix below would work for an update
> from 17.04 to 17.10 if done before the reboot to the 17.10 system.
> Although the blacklist will prevent loading the module at boot, it doesn't
> prevent any later insertion of the module, so getting rid of the module
> seems safer.

It prevents any autoloading of the module resulting from the hardware
autorecognition process.  That's what the blacklist keyword means.   No,
it doesn't prevent you for going to the commnd line and typing:

$ sudo su -
# modprobe intel-spi
# exit
$

But that would be manually acting to shoot yourself in the foot.  You
should not be going around randomly loading into your running kernel
modules you don't have any use for, and why _would_ you?

But you've highlighted a possible concern.  It's possible that module 
intel-spi is present not merely in Ubuntu 17.10's _installed_ kernel but
also in its _installer_ kernel, hence could enable the installation
system to write garbage to the target system's Serial Peripheral
Interface bus, thereby overwriting BIOS data.  To deal with _that_
possibility, you would want to manually tell the booting _installer_
kernel to avoid autoloading intel-spi, too.

Enter your bootloader's options, find the kernel line, and add the
following parameter

  modprobe.blacklist=intel-spi

Then boot.  This ensures that even the _installer_ system will not
decide to load that driver on account of hardware autoprobing.

https://wiki.archlinux.org/index.php/kernel_modules#Using_kernel_command_line