Bug#801869: nvidia-graphics-drivers: setting /dev/nvidia* to root:video 0660 breaks gdm3, sddm, ...

[Andreas Beckmann]

Source: nvidia-graphics-drivers
Version: 304.125-1
Severity: serious
Tags: jessie sid stretch experimental help
Control: affects -1 + gdm3 sddm

Setting the permissions on /dev/nvidia* properly (i.e. root:video 0660)
breaks display managers that use acceleration (e.g. gdm3, sddm).

A workaround is to put the dm's user into the video group
(e.g. adduser Debian-gdm video).

For local users logging into X a session-based membership in the video
group is handled automatically via some consolekit magic (in
nvidia-kernel-common).

This bug went unnoticed for a long time due to wrong permissions
(root:root 0666) being applied by the udev module autoload (see #801598).


Andreas