Quoting Tony Godshall (togo@of.net):
Oh, wow. Writing to BIOS is serious stuff.
So serious that, on Intel-based systems with Intel SPI (Serial Peripheral Interface) firmware such as those discussed at the links provided, it could brick the motherboard unfixably. (EFI-based systems could likewise get knackered by OS software writing to the EFI system partition, but that's not what's at issue in today's hapless Ubuntu cockup.)
About the SPI problem: Some recent Intel CPUs like Baytrail and Braswell have held BIOS and other platform-specific data in writeable flash memory, dubbed 'the SPI serial flash'. Recent Ubuntu installation kernels have included a kernel driver called intel-spi, making it possible to read and write the SPI serial flash. That driver seems, on present evidence, not ready for prime time, causing BIOS data corruption as reported.
Including the driver in an installation kernel at all is a particularly stupid blunder, as there was no legitimate purpose for it there, and the risks should have been obvious -- as Canonical, Ltd. are now learning.
(Hey, my collection of .signature files is up to #490. Time to update http://linuxmafia.com/pub/humour/sigs-rickmoen.html .)