Bug#802769: xinit: startx failed if started after su - <user> from a autologged root (getty@.service)

[Laurent Bigonville <bigon@debian.org>]

On Fri, 23 Oct 2015 12:51:50 +0200 Walter <wstemb@gmail.com> wrote:
> Dear Maintainer,

Hi,

> After the apt-get upgrade which changed the xinit from 1.3.4-1 to 1.3.4-3
> the before functioning system stops to work with the following error in
> exec startx:
>
> Fatal server error:
> (EE) xf86OpenConsole: Cannot open virtual console 1 (Permission denied)
>
> The invocation of the startx is:
>
> 1. The system autologs the root user using getty@.service ( via
> ExecStart=-/sbin/agetty -a root %I $TERM )
> 2. the root user starts the <user> via su - <user>
> 3. the user's .bash_profile contains the exec startx ...
> (but is the same if you start it manually)
>
> The ls -al /dev/tty give:
> crw------- 1 root tty 4, 1 Jan 1 01:11 /dev/tty1
>
> if you chown <user> or chmod 666 /dev/tty1, the startx displays the
> graphical screen, but the mouse is not moving the cursor.
>
> If you autostart the <user> directly from getty@.service, all is 
working as
> expected,
>
> ls -al /dev/tty1
> crw------- 1 <user> tty 4, 1 Jan 1 01:11 /dev/tty1
>
> I filled this bug report because is the upgrade that broke the 
functioning
> system (twice, on two systems build on same image), nothing other changed
> in the meantime except upgrade.

Since the version 2:1.17.2-2 of the xserver, it tries to run as non-root 
using logind features. But this is only working if you are opening the 
current vt.

For the time being, if you want to run the xserver on a different vt, 
you either first need to login on the vt before starting the xserver, or 
the xserver needs to run as root.

To achieve this, you need to install the xserver-xorg-legacy package and 
configure the Xwrapper.config config file (see Xwrapper.config(5) manpage)

Other solution would be to use the socket activation, but this is not 
yet enabled in debian see bug #803254

Cheers,

Laurent Bigonville