Application: kwin (4.6.2 (4.6.2))
KDE Platform Version: 4.6.2 (4.6.2)
Qt Version: 4.7.2
Operating System: Linux 2.6.38-8-generic x86_64
Distribution: Ubuntu 11.04

-- Information about the crash:
- What I was doing when the application crashed:
unlocking screen.
screen saver: flux(gl)

- Unusual behavior I noticed:

unlock password window didnt appear fully, only the input box where one can type in password.

probably not related anomaly: when kde starts, desktop appears on top of other windows.
choosing another desktop mode and reverting back again restores normal behavior.

The crash can be reproduced some of the time.

-- Backtrace:
Application: KWin (kwin), signal: Segmentation fault
[Current thread is 1 (Thread 0x7fb582d7d7a0 (LWP 3915))]

Thread 3 (Thread 0x7fb567879700 (LWP 3921)):
#0  0x00007fb5825c4143 in select () at ../sysdeps/unix/syscall-template.S:82
#1  0x00007fb57e9a232c in qt_safe_select (nfds=18, fdread=0x37cf3c0, fdwrite=0x37cf658, fdexcept=0x37cf8f0, orig_timeout=<value optimized out>) at kernel/qcore_unix.cpp:82
#2  0x00007fb57e9a73d0 in QEventDispatcherUNIXPrivate::doSelect (this=0x37cf200, flags=..., timeout=0x0) at kernel/qeventdispatcher_unix.cpp:219
#3  0x00007fb57e9a804a in QEventDispatcherUNIX::processEvents (this=0x3545ba0, flags=...) at kernel/qeventdispatcher_unix.cpp:919
#4  0x00007fb57e979882 in QEventLoop::processEvents (this=<value optimized out>, flags=...) at kernel/qeventloop.cpp:149
#5  0x00007fb57e979abc in QEventLoop::exec (this=0x7fb567878db0, flags=...) at kernel/qeventloop.cpp:201
#6  0x00007fb57e890924 in QThread::exec (this=<value optimized out>) at thread/qthread.cpp:492
#7  0x00007fb57e95bc2f in QInotifyFileSystemWatcherEngine::run (this=0x37ce440) at io/qfilesystemwatcher_inotify.cpp:248
#8  0x00007fb57e893175 in QThreadPrivate::start (arg=0x37ce440) at thread/qthread_unix.cpp:320
#9  0x00007fb578f86d8c in start_thread (arg=0x7fb567879700) at pthread_create.c:304
#10 0x00007fb5825cc04d in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:112
#11 0x0000000000000000 in ?? ()

Thread 2 (Thread 0x7fb567078700 (LWP 3922)):
#0  pthread_cond_wait@@GLIBC_2.3.2 () at ../nptl/sysdeps/unix/sysv/linux/x86_64/pthread_cond_wait.S:162
#1  0x00007fb58142b2a2 in QTWTF::TCMalloc_PageHeap::scavengerThread (this=0x7fb581744180) at ../3rdparty/javascriptcore/JavaScriptCore/wtf/FastMalloc.cpp:2359
#2  0x00007fb58142b2d9 in QTWTF::TCMalloc_PageHeap::runScavengerThread (context=0x7fb581752254) at ../3rdparty/javascriptcore/JavaScriptCore/wtf/FastMalloc.cpp:1464
#3  0x00007fb578f86d8c in start_thread (arg=0x7fb567078700) at pthread_create.c:304
#4  0x00007fb5825cc04d in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:112
#5  0x0000000000000000 in ?? ()

Thread 1 (Thread 0x7fb582d7d7a0 (LWP 3915)):
[KCrash Handler]
#6  intel_region_buffer (intel=0x4a90880, region=0x0, flag=2) at intel_regions.c:514
#7  0x00007fb56a5b86c2 in intelClearWithBlit (ctx=0x4a90880, mask=2) at intel_blit.c:262
#8  0x00007fb56a5bad2a in intelClear (ctx=0x4a90880, mask=2) at intel_clear.c:177
#9  0x00007fb582942ce7 in KWin::SceneOpenGL::paintBackground (this=<value optimized out>, region=<value optimized out>) at ../../kwin/scene_opengl.cpp:921
#10 0x00007fb58293a88f in KWin::Scene::paintGenericScreen (this=0x3875780, orig_mask=40) at ../../kwin/scene.cpp:188
#11 0x00007fb582937c7a in KWin::Scene::finalPaintScreen (this=0x3875780, mask=40, region=<value optimized out>, data=<value optimized out>) at ../../kwin/scene.cpp:178
#12 0x00007fb582955f19 in KWin::EffectsHandlerImpl::paintScreen (this=0x34c3350, mask=40, region=<value optimized out>, data=...) at ../../kwin/effects.cpp:173
#13 0x00007fb5696555a6 in KWin::StartupFeedbackEffect::paintScreen (this=0x558a310, mask=40, region=<value optimized out>, data=...) at ../../../kwin/effects/startupfeedback/startupfeedback.cpp:166
#14 0x00007fb582955fa3 in KWin::EffectsHandlerImpl::paintScreen (this=0x34c3350, mask=40, region=<value optimized out>, data=...) at ../../kwin/effects.cpp:169
#15 0x00007fb580a15a18 in KWin::Effect::paintScreen (this=<value optimized out>, mask=40, region=<value optimized out>, data=...) at ../../../kwin/lib/kwineffects.cpp:227
#16 0x00007fb582955fa3 in KWin::EffectsHandlerImpl::paintScreen (this=0x34c3350, mask=40, region=<value optimized out>, data=...) at ../../kwin/effects.cpp:169
#17 0x00007fb5695fc44d in KWin::LogoutEffect::paintScreen (this=0x53a2160, mask=40, region=..., data=...) at ../../../kwin/effects/logout/logout.cpp:207
#18 0x00007fb582955fa3 in KWin::EffectsHandlerImpl::paintScreen (this=0x34c3350, mask=40, region=<value optimized out>, data=...) at ../../kwin/effects.cpp:169
#19 0x00007fb569629e68 in KWin::BlurEffect::paintScreen (this=<value optimized out>, mask=40, region=..., data=...) at ../../../kwin/effects/blur/blur.cpp:230
#20 0x00007fb582955fa3 in KWin::EffectsHandlerImpl::paintScreen (this=0x34c3350, mask=8, region=<value optimized out>, data=...) at ../../kwin/effects.cpp:169
#21 0x00007fb569600fbd in KWin::PresentWindowsEffect::paintScreen (this=0x5535a30, mask=8, region=..., data=...) at ../../../kwin/effects/presentwindows/presentwindows.cpp:205
#22 0x00007fb582955fa3 in KWin::EffectsHandlerImpl::paintScreen (this=0x34c3350, mask=8, region=<value optimized out>, data=...) at ../../kwin/effects.cpp:169
#23 0x00007fb580a15a18 in KWin::Effect::paintScreen (this=<value optimized out>, mask=8, region=<value optimized out>, data=...) at ../../../kwin/lib/kwineffects.cpp:227
#24 0x00007fb582955fa3 in KWin::EffectsHandlerImpl::paintScreen (this=0x34c3350, mask=8, region=<value optimized out>, data=...) at ../../kwin/effects.cpp:169
#25 0x00007fb569647c05 in KWin::FlipSwitchEffect::paintScreen (this=0x3519a10, mask=8, region=..., data=...) at ../../../kwin/effects/flipswitch/flipswitch.cpp:148
#26 0x00007fb582955fa3 in KWin::EffectsHandlerImpl::paintScreen (this=0x34c3350, mask=8, region=<value optimized out>, data=...) at ../../kwin/effects.cpp:169
#27 0x00007fb5695e8365 in KWin::DesktopGridEffect::paintScreen (this=0x4b393e0, mask=8, region=..., data=...) at ../../../kwin/effects/desktopgrid/desktopgrid.cpp:155
#28 0x00007fb582955fa3 in KWin::EffectsHandlerImpl::paintScreen (this=0x34c3350, mask=8, region=<value optimized out>, data=...) at ../../kwin/effects.cpp:169
#29 0x00007fb5695e1bad in KWin::BoxSwitchEffect::paintScreen (this=0x4b582c0, mask=8, region=..., data=...) at ../../../kwin/effects/boxswitch/boxswitch.cpp:143
#30 0x00007fb582955fa3 in KWin::EffectsHandlerImpl::paintScreen (this=0x34c3350, mask=8, region=<value optimized out>, data=...) at ../../kwin/effects.cpp:169
#31 0x00007fb569638256 in KWin::CubeEffect::paintScreen (this=<value optimized out>, mask=8, region=..., data=...) at ../../../kwin/effects/cube/cube.cpp:698
#32 0x00007fb582955fa3 in KWin::EffectsHandlerImpl::paintScreen (this=0x34c3350, mask=8, region=<value optimized out>, data=...) at ../../kwin/effects.cpp:169
#33 0x00007fb580a15a18 in KWin::Effect::paintScreen (this=<value optimized out>, mask=8, region=<value optimized out>, data=...) at ../../../kwin/lib/kwineffects.cpp:227
#34 0x00007fb582955fa3 in KWin::EffectsHandlerImpl::paintScreen (this=0x34c3350, mask=8, region=<value optimized out>, data=...) at ../../kwin/effects.cpp:169
#35 0x00007fb569641fa4 in KWin::CubeSlideEffect::paintScreen (this=<value optimized out>, mask=8, region=..., data=...) at ../../../kwin/effects/cube/cubeslide.cpp:111
#36 0x00007fb582955fa3 in KWin::EffectsHandlerImpl::paintScreen (this=0x34c3350, mask=8, region=<value optimized out>, data=...) at ../../kwin/effects.cpp:169
#37 0x00007fb580a15a18 in KWin::Effect::paintScreen (this=<value optimized out>, mask=8, region=<value optimized out>, data=...) at ../../../kwin/lib/kwineffects.cpp:227
#38 0x00007fb582955fa3 in KWin::EffectsHandlerImpl::paintScreen (this=0x34c3350, mask=8, region=<value optimized out>, data=...) at ../../kwin/effects.cpp:169
#39 0x00007fb580a15a18 in KWin::Effect::paintScreen (this=<value optimized out>, mask=8, region=<value optimized out>, data=...) at ../../../kwin/lib/kwineffects.cpp:227
#40 0x00007fb582955fa3 in KWin::EffectsHandlerImpl::paintScreen (this=0x34c3350, mask=8, region=<value optimized out>, data=...) at ../../kwin/effects.cpp:169
#41 0x00007fb569630d86 in KWin::CoverSwitchEffect::paintScreen (this=0x559a3b0, mask=8, region=..., data=...) at ../../../kwin/effects/coverswitch/coverswitch.cpp:126
#42 0x00007fb582955fa3 in KWin::EffectsHandlerImpl::paintScreen (this=0x34c3350, mask=8, region=<value optimized out>, data=...) at ../../kwin/effects.cpp:169
#43 0x00007fb580a15a18 in KWin::Effect::paintScreen (this=<value optimized out>, mask=8, region=<value optimized out>, data=...) at ../../../kwin/lib/kwineffects.cpp:227
#44 0x00007fb582955fa3 in KWin::EffectsHandlerImpl::paintScreen (this=0x34c3350, mask=8, region=<value optimized out>, data=...) at ../../kwin/effects.cpp:169
#45 0x00007fb56962739b in KWin::ZoomEffect::paintScreen (this=0x50124e0, mask=8, region=..., data=...) at ../../../kwin/effects/zoom/zoom.cpp:341
#46 0x00007fb582955fa3 in KWin::EffectsHandlerImpl::paintScreen (this=0x34c3350, mask=8, region=<value optimized out>, data=...) at ../../kwin/effects.cpp:169
#47 0x00007fb58293a0af in KWin::Scene::paintScreen (this=0x3875780, mask=0x7fff1ada861c, region=0x7fff1ada86e0) at ../../kwin/scene.cpp:137
#48 0x00007fb58294def3 in KWin::SceneOpenGL::paint (this=0x3875780, damage=..., toplevels=<value optimized out>) at ../../kwin/scene_opengl.cpp:772
#49 0x00007fb582935396 in KWin::Workspace::performCompositing (this=0x2326bf0) at ../../kwin/composite.cpp:448
#50 0x00007fb57e98e1c9 in QObject::event (this=0x2326bf0, e=<value optimized out>) at kernel/qobject.cpp:1190
#51 0x00007fb57dd3b9e4 in QApplicationPrivate::notify_helper (this=0x2286520, receiver=0x2326bf0, e=0x7fff1ada8e70) at kernel/qapplication.cpp:4462
#52 0x00007fb57dd403aa in QApplication::notify (this=<value optimized out>, receiver=0x2326bf0, e=0x7fff1ada8e70) at kernel/qapplication.cpp:4341
#53 0x00007fb5820c7866 in KApplication::notify (this=0x7fff1ada9270, receiver=0x2326bf0, event=0x7fff1ada8e70) at ../../kdeui/kernel/kapplication.cpp:311
#54 0x00007fb57e97a49c in QCoreApplication::notifyInternal (this=0x7fff1ada9270, receiver=0x2326bf0, event=0x7fff1ada8e70) at kernel/qcoreapplication.cpp:731
#55 0x00007fb57e9a7f12 in sendEvent (this=0x2287ee0) at ../../include/QtCore/../../src/corelib/kernel/qcoreapplication.h:215
#56 QTimerInfoList::activateTimers (this=0x2287ee0) at kernel/qeventdispatcher_unix.cpp:604
#57 0x00007fb57e9a805b in QEventDispatcherUNIX::processEvents (this=0x222b340, flags=...) at kernel/qeventdispatcher_unix.cpp:923
#58 0x00007fb57dde3c0c in QEventDispatcherX11::processEvents (this=0x222b340, flags=...) at kernel/qeventdispatcher_x11.cpp:152
#59 0x00007fb57e979882 in QEventLoop::processEvents (this=<value optimized out>, flags=...) at kernel/qeventloop.cpp:149
#60 0x00007fb57e979abc in QEventLoop::exec (this=0x7fff1ada91b0, flags=...) at kernel/qeventloop.cpp:201
#61 0x00007fb57e97decb in QCoreApplication::exec () at kernel/qcoreapplication.cpp:1008
#62 0x00007fb5828d31ec in kdemain (argc=<value optimized out>, argv=0x7fff1ada9908) at ../../kwin/main.cpp:542
#63 0x00007fb582504eff in __libc_start_main (main=0x400740 <main(int, char**)>, argc=3, ubp_av=0x7fff1ada9908, init=<value optimized out>, fini=<value optimized out>, rtld_fini=<value optimized out>, stack_end=0x7fff1ada98f8) at libc-start.c:226
#64 0x0000000000400669 in _start ()

Possible duplicates by query: bug 275478, bug 275202, bug 275176, bug 274967, bug 273989.

Reported using DrKonqi