Comment # 27
on bug 93199
from Jani Nikula
Based on an IRC chat with Joonas and Dave, looks like this is indeed kernel
lockdown on UEFI secure boot doing its magic. The kernel lockdown patches
haven't been merged upstream, so you should not be able to reproduce this on
kernel.org upstream kernels. Please file your bugs against your distro if this
remains an issue for you.
See e.g. https://mjg59.dreamwidth.org/50577.html for background.
Sorry it took us so long to get this; we're obviously not running non-upstream
kernels with lockdown enabled.