[CentOS] Login failure with Secure Boot

Tue Sep 22 10:01:04 UTC 2020
isdtor <isdtor at gmail.com>

Hi all,

I have a laptop in UEFI mode running CentOS 8.2. All works fine but when I enable Secure Boot, login via gdm is no longer possible. Console login is ok.

I found some related discussions over on Ubuntu forums, suggesting that this could be related to 3rd-party kernel modules, such as nvidia. This laptop has only Intel builtin graphics, and every single module installed is part of the CentOS distribution.

This is from a file /tmp/xses-.XXXXXX (random 6-char string)

xrdb: Can't open display ''
xmodmap: unable to open display ''
Failed to import environment: Process org.freedesktop.systemd1 exited with status 1
/usr/bin/xmbind: Can't open display
Unable to init server: Could not connect: Connection refused

Something is different in the way Xorg is started. In this situation, the first part of the Xorg log file (under ~/.local) is a dump of X command line options.

use: X [:<display>] [options]
-a # ...
-ac ...