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Virtualbox 1.6.4 segfault when displayed via ssh/X11forward

Posted: 21. Aug 2008, 09:27
by jwoithe
During my testing of Virtualbox 1.6.4 (binary edition) I have noticed a problem when connecting to the virtualbox host via ssh with X11 forwarding active. Let's say machine "Ahost" is where I'm sitting and "Bhost" is the machine with virtualbox installed. On Ahost I do
ssh -Y Bhost
which gets me a prompt on Bhost. DISPLAY is set to "localhost:11.0" which is the proxy set up by ssh.

I then start Virtualbox which runs as expected. I select the desired VM and "start" it. At this point it *might* run - if not, the VM status becomes "Aborted" and dmesg reports
VirtualBox[23317]: segfault at 0 ip 00000000 sp bfb37bac error 4 in VirtualBox[8048000+20f000]
If the VM starts then everything runs apparently without trouble until I do a shutdown/poweroff of the VM. The guest OS shuts down normally and the window disappears, but the VM status is again reported as "Aborted". This time dmesg reports
VirtualBox[23511]: segfault at b28db1c8 ip b5d67440 sp bfdd21d0 error 4 in libSDL-1.2.so.0.11.2[b5d4f000+66000]
None of these segfaults occur if I run Virtualbox directly from an xsession running on Bhost (DISPLAY set to ":0.0"). However, curiously enough if I do
xhost +
ssh Bhost
on Ahost, and then do
export DISPLAY=Ahost:0.0
Virtualbox
in the resulting shell running on Bhost the segfaults do not occur and everything seems to perform as expected. Finally, doing
ssh -Y Bhost
*on Bhost* and then running "Virtualbox" gives rise to the problems.

So in other words, it is not the remote display itself which causes the problem, but simply the act of displaying on an X display created by ssh's X11 forwarding feature.

Has anyone else seen this? Are there any known fixes?

Both Ahost and Bhost are running Slackware 12.1 with a 2.6.26 kernel.

Regards
jonathan

Posted: 21. Aug 2008, 13:07
by TerryE
use the ticket search trick discussed in the Forum Posting Guide and if you get no luck then raise a new ticket (see the Forum FAQ for how to do this).

Posted: 22. Aug 2008, 04:57
by jwoithe
Thanks for the suggestion. FYI I tried the google/search approach yesterday to no avail which is why I tried the forums. Maybe I'm just trying the wrong search terms.

In any case, there doesn't appear to be another ticket along these lines so I have created one. It's ticket number 2001.

Regards
jonathan