Bug#806256: libpam-systemd: log out from a TTY and your X input devices get lost!

[Francesco Poli]

Control: found -1 systemd/237-4


On Wed, 7 Mar 2018 23:55:06 +0100 Michael Biebl wrote:

> Am 25.11.2015 um 22:20 schrieb Francesco Poli (wintermute):
> > Package: libpam-systemd
> > Version: 228-2
> > Severity: normal
> > 
> > Hello,
> > I noticed a weird bug that is possibly caused by libpam-systemd.
> > 
> > Steps to reproduce (on a box with systemd as PID 1 process):
> > 
> >   0) login on TTY1 (virtual terminal 1) as a regular user
> > 
> >   1) start an X session with
> > 
> >      $ startx
> > 
> >   2) press [Ctrl+Alt+F2], in order to switch to TTY2
> > 
> >   3) login on TTY2 as the same user
> > 
> >   4) logout by pressing [Ctrl+D] on the empty command prompt
> > 
> >   5) awkwardly the screen goes automatically back to the X session
> >      (rather than showing a fresh new TTY2 login prompt)
> > 
> >   6) even more awkwardly, any keyboard and mouse input is ignored
> >      except for [Ctrl+Alt+F1], which however causes the screen to
> >      go blank and immediately enter sleep mode
> > 
> >   7) the only way out seems to be a poweroff command, issued by
> >      pressing the power button (which is handled by acpid)
> > 
> > I didn't try to SSH into the box and take a look at the system...
> > 
> > 
> > I suspect that this bug is caused by libpam-systemd, since starting
> > an X session on a box with systemd as PID 1 process, but without
> > libpam-systemd installed, causes the same inability to use X input
> > devices.
> > 
> > I noticed this bug some days ago with libpam-systemd/227-2: I waited
> > for version 228-2 to migrate to testing, before reporting the bug.
> > After reproducing the same exact misbehavior with libpam-systemd/228-2,
> > I decided that it is time to report it.
> > 
> > Could you please investigate this bug and fix it and/or forward it
> > upstream, as appropriate?
> 
> As the original bug reporter, can you still reproduce the issue, and if
> so, could you share your ~/.bash_logout file.

Hello Michael,
thanks for following up on this bug report.

I have just reproduced the bug on an up-to-date Debian testing box,
with a slight difference.

Steps to reproduce are now (on a box with systemd as PID 1
process):

  0) login on TTY1 (virtual terminal 1) as a regular user

  1) start an X session with

     $ startx

  2) press [Ctrl+Alt+F2], in order to switch to TTY2

  3) login on TTY2 as the same user

  4) logout by pressing [Ctrl+D] on the empty command prompt

  5) awkwardly the screen goes automatically back to the X session
     (rather than showing a fresh new TTY2 login prompt)

  6) even more awkwardly, any keyboard and mouse input is ignored
     except for [Ctrl+Alt+F1], which however causes the X server
     to crash

  7) the screen shows the TTY1 bash with the latest error messages
     from the crashed X server and a prompt ready to accept new
     commands


My ~/.bash_logout is attached, but it's nothing special: it should be
identical to the one provided by the bash package in /etc/skel/

I am also attaching the Xorg.0.log produced by the crashed X server.

I hope this additional information will help to pinpoint the issue...

Bye.



-- 
 http://www.inventati.org/frx/
 There's not a second to spare! To the laboratory!
..................................................... Francesco Poli .
 GnuPG key fpr == CA01 1147 9CD2 EFDF FB82  3925 3E1C 27E1 1F69 BFFE
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