WARNING regarding 4.3.x kernel

[Cristian Sava]

On Thu, 2016-01-21 at 11:55 +0100, thibaut noah wrote:
> Did you report it? seems like someone forgot to check the pointer
> before accessing it.
Not yet. Further investigation is needed.
What I've done now in virtual environment:
1-Install F23 server, default, no options.
2-Update, reboot
3-Install minimal X:
  dnf groupinstall base-x
  dnf install xterm xorg-x11-xbitmaps xorg-x11-fonts-ISO8859-15-75dpi
xorg-x11-fonts-ISO8859-15-100dpi xorg-x11-fonts-misc
  dnf install xorg-x11-xdm xorg-x11-xsm xorg-x11-xkb-extras xorg-x11-
xfs xorg-x11-xfs-utils xorg-x11-twm
4-Install VM environment:
  dnf install qemu qemu-common qemu-guest-agent qemu-img qemu-kvm qemu-
kvm-tools qemu-user qemu-system-x86
  dnf install libvirt virt-manager virt-install
5-Switch to graphical and the error is there:
  su -c virt-manager
6-Reboot and add very basic gnome:
  dnf install gnome-desktop3 gnome-commander gnome-abrt gnome-disk-
utility gnome-menus gnome-shell gnome-shell-extension-common gnome-
terminal gnome-themes-standard gnome-tweak-tool
7-reboot, switch to graphical:
 a) Still error in xterm: su -c virt-manager
 b) Surprise: the VM icon works as expected!
Same result on a phisical machine with the difference that trying to
switch back to multi-user freezes the box.
Anyone else want to test it?

> 2016-01-21 9:12 GMT+01:00 Cristian Sava <csava at central.ucv.ro>:
> > I have a F23 server with minimal working X (no desktop).
> > All was working well with kernel-4.2.x
> > With kernel-4.3.x I get (in xterm):
> > 
> > [a53 at s ~]$ su -c virt-manager
> > Password: 
> > [a53 at s ~]$ No protocol specified
> > Unable to init server: Could not connect: Connection refused
> > (virt-manager:54862): Gtk-CRITICAL **: gtk_settings_get_for_screen:
> > assertion 'GDK_IS_SCREEN (screen)' failed
> > [a53 at s ~]$ 
> > 
> > journalctl gives:
> > 
> > kernel: virt-manager[8896]: segfault at 0 ip 00007f612fce78a9 sp
> > 00007ffe5a45e580 error 4 in libgtk-
> > 3.so.0.1800.6[7f612fa2d000+710000]
> > kernel: BUG: unable to handle kernel NULL pointer dereference at
> > 0000000000000060
> > 
> > Searching the web I discovered that during years this error shows
> > up
> > from time to time across different distributions (including
> > Fedora).
> > This time it seems to be kernel related and does not show up with
> > Gnome.
> > 
> > C.S
> >