compiz crashed with SIGSEGV in unity::UnityScreen::compizDamageNux() from unity::UnityScreen::preparePaint()

[Alexander Langanke]

Was watching a fullscreen video on youtube.

ProblemType: Crash
DistroRelease: Ubuntu 13.04
Package: unity 6.12.0daily12.12.05-0ubuntu1
ProcVersionSignature: Ubuntu 3.7.0-7.15-generic 3.7.0
Uname: Linux 3.7.0-7-generic x86_64
NonfreeKernelModules: nvidia
ApportVersion: 2.8-0ubuntu1
Architecture: amd64
Date: Wed Jan 9 11:49:41 2013
Disassembly: => 0xffffffffffffffe8: Cannot access memory at address 0xffffffffffffffe8
ExecutablePath: /usr/bin/compiz
InstallationDate: Installed on 2012-06-12 (210 days ago)
InstallationMedia: Ubuntu 12.04 LTS "Precise Pangolin" - Release amd64 (20120425)
MarkForUpload: True
ProcCmdline: compiz
SegvAnalysis:
 Segfault happened at: 0xffffffffffffffe8: Cannot access memory at address 0xffffffffffffffe8
 PC (0xffffffffffffffe8) not located in a known VMA region (needed executable region)!
SegvReason: executing unknown VMA
Signal: 11
SourcePackage: unity
StacktraceTop:
 ?? ()
 unity::UnityScreen::compizDamageNux(CompRegion const&) () from /usr/lib/compiz/libunityshell.so
 unity::UnityScreen::preparePaint(int) () from /usr/lib/compiz/libunityshell.so
 CompositeScreen::preparePaint(int) () from /usr/lib/compiz/libcomposite.so
 CompositeScreen::handlePaintTimeout() () from /usr/lib/compiz/libcomposite.so
Title: compiz crashed with SIGSEGV in unity::UnityScreen::compizDamageNux()
UpgradeStatus: Upgraded to raring on 2012-12-21 (18 days ago)
UserGroups: adm cdrom dip lpadmin plugdev sambashare sudo
XsessionErrors:
 gnome-session[2064]: WARNING: Failed to start app: Unable to start application: Failed to execute child process "owncloud" (No such file or directory)
 gnome-session[2064]: WARNING: Could not launch application 'evolution-alarm-notify.desktop': Unable to start application: Failed to execute child process "/usr/lib/evolution/3.6/evolution-alarm-notify" (No such file or directory)
 gnome-session[2064]: WARNING: Application 'compiz.desktop' killed by signal 11
 gnome-session[2064]: WARNING: App 'compiz.desktop' respawning too quickly
 gnome-session[2064]: CRITICAL: We failed, but the fail whale is dead. Sorry....

[Apport retracing service (apport)]

StacktraceTop:
 ?? ()
 unity::UnityScreen::compizDamageNux (this=this@entry=0xe37e60, damage=...) at /build/buildd/unity-6.12.0daily12.12.05/plugins/unityshell/src/unityshell.cpp:1435
 unity::UnityScreen::preparePaint (this=0xe37e60, ms=16) at /build/buildd/unity-6.12.0daily12.12.05/plugins/unityshell/src/unityshell.cpp:1318
 CompositeScreen::preparePaint (this=0xa78ea0, msSinceLastPaint=<optimized out>) at /build/buildd/compiz-0.9.9~daily12.12.05/plugins/composite/src/screen.cpp:897
 CompositeScreen::handlePaintTimeout (this=0xa78ea0) at /build/buildd/compiz-0.9.9~daily12.12.05/plugins/composite/src/screen.cpp:802

[Daniel van Vugt (vanvugt)]

Reviewing Unity r2956 at unityshell.cpp:1435 I find:

  QuicklistManager* qm = QuicklistManager::Default();
  if (qm)
  {
    QuicklistView* view = qm->Current();

    if (view)
    {
      nux::Geometry const& geo = view->GetAbsoluteGeometry(); <============
      CompRegion quicklist_region(geo.x, geo.y, geo.width, geo.height);

      if (damage.intersects(quicklist_region))
        view->QueueDraw();
    }
  }

Looks like view is a stale pointer (and not null either).

[Launchpad Janitor (janitor)]

Status changed to 'Confirmed' because the bug affects multiple users.

[Stephen M. Webb (bregma)]

The code in at the root of this problem was modified to fix another bug in such a way that this bug will not occur, and the code already merged. Marking as Fix Released appropriately.

If the problem reoccurs, please open a new bug.

[Stephen M. Webb (bregma)]

The code in at the root of this problem was modified to fix another bug in such a way that this bug will not occur, and the code already released into Ubuntu. Marking as Fix Released appropriately.

If the problem reoccurs, please open a new bug.

[Stephen M. Webb (bregma)]

Fix Released in Unity Unity 7.0.0 "R series".