System hard freezes when running vncviewer

[Ryan Lynch]

I am running Kubuntu 12.04 on a Lenovo X220 with integrated Intel graphics and a Core i5 processor, 8 GB of RAM.

After upgrading to 12.04 my system has experience a hard freeze on 3 occasions while running xtight vncviewer. This has occurred while connected to 2 different tightvnc servers on other machines. vncviewer works for a while but then the system freezes.

I am not sure where to find more detailed debugging information since the system hard freezes and I can't use anything. I can move the mouse but no windows respond, I can't switch to a virtual terminal (no response when using Ctrl+Alt+F1), I can't restart X (no response when using Ctrl+Alt+Backspace) and I can't reboot using Ctrl+Alt+Delete. This only started after upgrading to 12.04, so I don't think it is a problem with tightvnc itself. I'm happy to try to provide more information if given directions. Thanks very much.

Description: Ubuntu 12.04 LTS
Release: 12.04

tightvncviewer:
  Installed: 1.3.9-6.2ubuntu2
  Candidate: 1.3.9-6.2ubuntu2
  Version table:
 *** 1.3.9-6.2ubuntu2 0
        500 http://ca.archive.ubuntu.com/ubuntu/ precise/universe amd64 Packages
        100 /var/lib/dpkg/status

ProblemType: Bug
DistroRelease: Ubuntu 12.04
Package: xorg 1:7.6+12ubuntu1
ProcVersionSignature: Ubuntu 3.2.0-24.37-generic 3.2.14
Uname: Linux 3.2.0-24-generic x86_64
ApportVersion: 2.0.1-0ubuntu7
Architecture: amd64
Date: Fri May 4 09:25:25 2012
InstallationMedia: Kubuntu 11.10 "Oneiric Ocelot" - Release amd64 (20111012)
ProcEnviron:
 LANGUAGE=en_US
 TERM=xterm
 PATH=(custom, user)
 LANG=en_US.UTF-8
 SHELL=/bin/bash
SourcePackage: xorg
Symptom: display
UpgradeStatus: Upgraded to precise on 2012-05-02 (2 days ago)

[penalvch (penalvch)]

Ryan Lynch, thank you for reporting this and helping make Ubuntu better. However, your crash report is missing. Please follow these instructions to have apport report a new bug about your crash that can be dealt with by the automatic retracer. First, execute at a terminal:
cd /var/crash && sudo rm * ; sudo apt-get update && sudo apt-get -y upgrade && sudo service apport start force_start=1

If you are running the Ubuntu Stable Release you might need to enable apport in /etc/default/apport and restart.

Now reproduce the crash, then open your file manager, navigate to your /var/crash directory and open the crash report you wish to submit.
If this fails you will have to open a terminal and file your report with 'ubuntu-bug /var/crash/_my_crash_report.crash' where _my_crash_report.crash is the crash you would like to report. If you get an error that you aren't allowed to access this report you will have to file it with 'sudo ubuntu-bug /var/crash/_my_crash_report.crash'. If you run the command against the crash report and a window pops up asking you to report this, but then never opens a new report, you would be affected by https://bugs.launchpad.net/ubuntu/+source/apport/+bug/994921 . In order to WORKAROUND this, one would need to open the following file via a command line:
sudo nano /etc/apport/crashdb.conf

and comment out the line:
'problem_types': ['Bug', 'Package'],

by changing it to:
# 'problem_types': ['Bug', 'Package'],

Save, close, and try to file the crash report again via:
ubuntu-bug /var/crash/_my_crash_report.crash

I'm closing this bug report since the process outlined above will automatically open a new bug report which can then dealt with more efficiently.

Please feel free to subscribe me to this new report.

Also, please do not attach your crash report manually to this report and reopen it.

Thank you for your understanding.

Helpful bug reporting tips:
https://wiki.ubuntu.com/ReportingBugs