Application: kwin_x11 (5.2.2)
 (Compiled from sources)
Qt Version: 5.4.1
Operating System: Linux 3.19.0-15-generic x86_64
Distribution: Ubuntu 15.04

-- Information about the crash:
- What I was doing when the application crashed:
Alt tabbing between programs. Other times this has happened with normal or minimal usage.

- Unusual behavior I noticed:
Chrome application displays artifacts/confused graphics.

The crash can be reproduced sometimes.

-- Backtrace:
Application: KWin (kwin_x11), signal: Segmentation fault
Using host libthread_db library "/lib/x86_64-linux-gnu/libthread_db.so.1".
[Current thread is 1 (Thread 0x7f42312d0800 (LWP 1348))]

Thread 5 (Thread 0x7f4218d18700 (LWP 1381)):
#0  0x00007f4230d92743 in select () at ../sysdeps/unix/syscall-template.S:81
#1  0x00007f422f5dc101 in qt_safe_select (nfds=18, fdread=fdread@entry=0x7f4204000a78, fdwrite=fdwrite@entry=0x7f4204000d08, fdexcept=fdexcept@entry=0x7f4204000f98, orig_timeout=orig_timeout@entry=0x0) at kernel/qcore_unix.cpp:75
#2  0x00007f422f5ddcd2 in select (timeout=0x0, exceptfds=0x7f4204000f98, writefds=0x7f4204000d08, readfds=0x7f4204000a78, nfds=<optimized out>, this=0x7f42040008c0) at kernel/qeventdispatcher_unix.cpp:320
#3  QEventDispatcherUNIXPrivate::doSelect (this=this@entry=0x7f42040008e0, flags=..., flags@entry=..., timeout=timeout@entry=0x0) at kernel/qeventdispatcher_unix.cpp:196
#4  0x00007f422f5de275 in QEventDispatcherUNIX::processEvents (this=0x7f42040008c0, flags=...) at kernel/qeventdispatcher_unix.cpp:607
#5  0x00007f422f5853e2 in QEventLoop::exec (this=this@entry=0x7f4218d17da0, flags=..., flags@entry=...) at kernel/qeventloop.cpp:204
#6  0x00007f422f344b44 in QThread::exec (this=<optimized out>) at thread/qthread.cpp:503
#7  0x00007f42291f7f65 in ?? () from /usr/lib/x86_64-linux-gnu/libQt5Qml.so.5
#8  0x00007f422f349b0e in QThreadPrivate::start (arg=0xbf5c50) at thread/qthread_unix.cpp:337
#9  0x00007f42283c46aa in start_thread (arg=0x7f4218d18700) at pthread_create.c:333
#10 0x00007f4230d9beed in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:109

Thread 4 (Thread 0x7f42015f9700 (LWP 1408)):
#0  pthread_cond_wait@@GLIBC_2.3.2 () at ../sysdeps/unix/sysv/linux/x86_64/pthread_cond_wait.S:185
#1  0x00007f422e14e644 in ?? () from /usr/lib/x86_64-linux-gnu/libQt5Script.so.5
#2  0x00007f422e14e689 in ?? () from /usr/lib/x86_64-linux-gnu/libQt5Script.so.5
#3  0x00007f42283c46aa in start_thread (arg=0x7f42015f9700) at pthread_create.c:333
#4  0x00007f4230d9beed in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:109

Thread 3 (Thread 0x7f42026fe700 (LWP 2574)):
#0  pthread_cond_wait@@GLIBC_2.3.2 () at ../sysdeps/unix/sysv/linux/x86_64/pthread_cond_wait.S:185
#1  0x00007f422f34ac6b in wait (time=18446744073709551615, this=0x16d3f60) at thread/qwaitcondition_unix.cpp:128
#2  QWaitCondition::wait (this=<optimized out>, mutex=0x162e840, time=18446744073709551615) at thread/qwaitcondition_unix.cpp:200
#3  0x00007f422e3d5fab in ?? () from /usr/lib/x86_64-linux-gnu/libQt5Quick.so.5
#4  0x00007f422e3d63a0 in ?? () from /usr/lib/x86_64-linux-gnu/libQt5Quick.so.5
#5  0x00007f422f349b0e in QThreadPrivate::start (arg=0x162e7c0) at thread/qthread_unix.cpp:337
#6  0x00007f42283c46aa in start_thread (arg=0x7f42026fe700) at pthread_create.c:333
#7  0x00007f4230d9beed in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:109

Thread 2 (Thread 0x7f421a0a6700 (LWP 3041)):
#0  pthread_cond_wait@@GLIBC_2.3.2 () at ../sysdeps/unix/sysv/linux/x86_64/pthread_cond_wait.S:185
#1  0x00007f422f34ac6b in wait (time=18446744073709551615, this=0x12ee1a0) at thread/qwaitcondition_unix.cpp:128
#2  QWaitCondition::wait (this=<optimized out>, mutex=0x128b940, time=18446744073709551615) at thread/qwaitcondition_unix.cpp:200
#3  0x00007f422e3d5fab in ?? () from /usr/lib/x86_64-linux-gnu/libQt5Quick.so.5
#4  0x00007f422e3d63a0 in ?? () from /usr/lib/x86_64-linux-gnu/libQt5Quick.so.5
#5  0x00007f422f349b0e in QThreadPrivate::start (arg=0x128b8c0) at thread/qthread_unix.cpp:337
#6  0x00007f42283c46aa in start_thread (arg=0x7f421a0a6700) at pthread_create.c:333
#7  0x00007f4230d9beed in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:109

Thread 1 (Thread 0x7f42312d0800 (LWP 1348)):
[KCrash Handler]
#6  0x00007f420935461f in ?? () from /usr/lib/dri/fglrx_dri.so
#7  0x00007f4208a46049 in ?? () from /usr/lib/dri/fglrx_dri.so
#8  0x00007f4208a462d2 in ?? () from /usr/lib/dri/fglrx_dri.so
#9  0x00007f4208e739c3 in ?? () from /usr/lib/dri/fglrx_dri.so
#10 0x00007f422e67881e in KWin::BlurEffect::doCachedBlur (this=0xbe4000, w=0x7f4227792280 <glCopyTexSubImage2D>, region=..., opacity=9.14767638e-41) at ../../effects/blur/blur.cpp:591
#11 0x00007f422e6794e1 in KWin::BlurEffect::drawWindow (this=this@entry=0xbe4000, w=w@entry=0x136f100, mask=mask@entry=10, region=..., data=...) at ../../effects/blur/blur.cpp:407
#12 0x00007f423097b0d1 in KWin::EffectsHandlerImpl::drawWindow (this=0x1199600, w=w@entry=0x136f100, mask=mask@entry=10, region=..., data=...) at ../effects.cpp:470
#13 0x00007f422eb557c1 in KWin::Effect::drawWindow (this=this@entry=0x1237ef0, w=w@entry=0x136f100, mask=mask@entry=10, region=..., data=...) at ../../libkwineffects/kwineffects.cpp:580
#14 0x00007f423097b0d1 in KWin::EffectsHandlerImpl::drawWindow (this=0x1199600, w=w@entry=0x136f100, mask=mask@entry=10, region=..., data=...) at ../effects.cpp:470
#15 0x00007f422eb557c1 in KWin::Effect::drawWindow (this=this@entry=0x1232bc0, w=w@entry=0x136f100, mask=mask@entry=10, region=..., data=...) at ../../libkwineffects/kwineffects.cpp:580
#16 0x00007f423097b0d1 in KWin::EffectsHandlerImpl::drawWindow (this=0x1199600, w=w@entry=0x136f100, mask=mask@entry=10, region=..., data=...) at ../effects.cpp:470
#17 0x00007f4230944841 in KWin::Scene::finalPaintWindow (this=<optimized out>, w=w@entry=0x136f100, mask=mask@entry=10, region=..., data=...) at ../scene.cpp:605
#18 0x00007f423097af7a in KWin::EffectsHandlerImpl::paintWindow (this=0x1199600, w=w@entry=0x136f100, mask=mask@entry=10, region=..., data=...) at ../effects.cpp:436
#19 0x00007f422eb55651 in KWin::Effect::paintWindow (this=this@entry=0x12248c0, w=w@entry=0x136f100, mask=mask@entry=10, region=..., data=...) at ../../libkwineffects/kwineffects.cpp:550
#20 0x00007f423097af21 in KWin::EffectsHandlerImpl::paintWindow (this=0x1199600, w=w@entry=0x136f100, mask=mask@entry=10, region=..., data=...) at ../effects.cpp:433
#21 0x00007f422eb55651 in KWin::Effect::paintWindow (this=this@entry=0xbe4000, w=w@entry=0x136f100, mask=mask@entry=10, region=..., data=...) at ../../libkwineffects/kwineffects.cpp:550
#22 0x00007f423097af21 in KWin::EffectsHandlerImpl::paintWindow (this=0x1199600, w=0x136f100, mask=mask@entry=10, region=..., data=...) at ../effects.cpp:433
#23 0x00007f422e6efb64 in KWin::HighlightWindowEffect::paintWindow (this=this@entry=0x1237ef0, w=w@entry=0x136f100, mask=mask@entry=10, region=..., data=...) at ../../effects/highlightwindow/highlightwindow.cpp:101
#24 0x00007f423097af21 in KWin::EffectsHandlerImpl::paintWindow (this=0x1199600, w=w@entry=0x136f100, mask=mask@entry=10, region=..., data=...) at ../effects.cpp:433
#25 0x00007f422eb63937 in KWin::AnimationEffect::paintWindow (this=this@entry=0x1232bc0, w=w@entry=0x136f100, mask=mask@entry=10, region=..., data=...) at ../../libkwineffects/kwinanimationeffect.cpp:585
#26 0x00007f423097af21 in KWin::EffectsHandlerImpl::paintWindow (this=0x1199600, w=0x136f100, mask=mask@entry=10, region=..., data=...) at ../effects.cpp:433
#27 0x00007f4230948ee8 in KWin::Scene::paintWindow (this=this@entry=0x11796c0, w=0x136f000, mask=10, region=..., quads=...) at ../scene.cpp:477
#28 0x00007f4230946c0e in KWin::Scene::paintSimpleScreen (this=this@entry=0x11796c0, orig_mask=orig_mask@entry=8, region=...) at ../scene.cpp:380
#29 0x00007f4230957513 in KWin::SceneOpenGL2::paintSimpleScreen (this=this@entry=0x11796c0, mask=mask@entry=8, region=...) at ../scene_opengl.cpp:1005
#30 0x00007f4230944205 in KWin::Scene::finalPaintScreen (this=0x11796c0, mask=mask@entry=8, region=..., data=...) at ../scene.cpp:199
#31 0x00007f423097acff in KWin::EffectsHandlerImpl::paintScreen (this=0x1199600, mask=mask@entry=8, region=..., data=...) at ../effects.cpp:393
#32 0x00007f422eb5557f in KWin::Effect::paintScreen (this=this@entry=0x12248c0, mask=mask@entry=8, region=..., data=...) at ../../libkwineffects/kwineffects.cpp:535
#33 0x00007f423097acad in KWin::EffectsHandlerImpl::paintScreen (this=0x1199600, mask=mask@entry=8, region=..., data=...) at ../effects.cpp:390
#34 0x00007f422eb5557f in KWin::Effect::paintScreen (this=this@entry=0xbe4000, mask=mask@entry=8, region=..., data=...) at ../../libkwineffects/kwineffects.cpp:535
#35 0x00007f423097acad in KWin::EffectsHandlerImpl::paintScreen (this=0x1199600, mask=mask@entry=8, region=..., data=...) at ../effects.cpp:390
#36 0x00007f422eb5557f in KWin::Effect::paintScreen (this=this@entry=0x1237ef0, mask=mask@entry=8, region=..., data=...) at ../../libkwineffects/kwineffects.cpp:535
#37 0x00007f423097acad in KWin::EffectsHandlerImpl::paintScreen (this=0x1199600, mask=mask@entry=8, region=..., data=...) at ../effects.cpp:390
#38 0x00007f422eb5557f in KWin::Effect::paintScreen (this=this@entry=0x1232bc0, mask=mask@entry=8, region=..., data=...) at ../../libkwineffects/kwineffects.cpp:535
#39 0x00007f423097acad in KWin::EffectsHandlerImpl::paintScreen (this=0x1199600, mask=8, region=..., data=...) at ../effects.cpp:390
#40 0x00007f4230943e6a in KWin::Scene::paintScreen (this=this@entry=0x11796c0, mask=mask@entry=0x7fff589bdf2c, damage=..., repaint=..., updateRegion=updateRegion@entry=0x7fff589bdf40, validRegion=validRegion@entry=0x7fff589bdf50) at ../scene.cpp:149
#41 0x00007f423095dda7 in KWin::SceneOpenGL::paint (this=0x11796c0, damage=..., toplevels=...) at ../scene_opengl.cpp:651
#42 0x00007f423093d973 in KWin::Compositor::performCompositing (this=0xad27c0) at ../composite.cpp:658
#43 0x00007f422f5b96f3 in QObject::event (this=0xad27c0, e=<optimized out>) at kernel/qobject.cpp:1267
#44 0x00007f422fe91b2c in QApplicationPrivate::notify_helper (this=0xa511b0, receiver=0xad27c0, e=0x7fff589be360) at kernel/qapplication.cpp:3720
#45 0x00007f422fe97000 in QApplication::notify (this=0x7fff589be5a0, receiver=0xad27c0, e=0x7fff589be360) at kernel/qapplication.cpp:3503
#46 0x00007f422f587c2b in QCoreApplication::notifyInternal (this=0x7fff589be5a0, receiver=0xad27c0, event=event@entry=0x7fff589be360) at kernel/qcoreapplication.cpp:935
#47 0x00007f422f5dfae5 in sendEvent (event=0x7fff589be360, receiver=<optimized out>) at ../../include/QtCore/../../src/corelib/kernel/qcoreapplication.h:228
#48 QTimerInfoList::activateTimers (this=0xa88728) at kernel/qtimerinfo_unix.cpp:635
#49 0x00007f422f5dd6a0 in QEventDispatcherUNIX::activateTimers (this=this@entry=0xa86870) at kernel/qeventdispatcher_unix.cpp:549
#50 0x00007f422f5de243 in QEventDispatcherUNIX::processEvents (this=0xa86870, flags=flags@entry=...) at kernel/qeventdispatcher_unix.cpp:611
#51 0x00007f421d4c796d in QUnixEventDispatcherQPA::processEvents (this=<optimized out>, flags=...) at eventdispatchers/qunixeventdispatcher.cpp:62
#52 0x00007f422f5853e2 in QEventLoop::exec (this=this@entry=0x7fff589be4c0, flags=..., flags@entry=...) at kernel/qeventloop.cpp:204
#53 0x00007f422f58d02c in QCoreApplication::exec () at kernel/qcoreapplication.cpp:1188
#54 0x00007f422f8cc31c in QGuiApplication::exec () at kernel/qguiapplication.cpp:1510
#55 0x00007f422fe8d7a5 in QApplication::exec () at kernel/qapplication.cpp:2956
#56 0x00007f42310638c3 in kdemain (argc=1, argv=0x7fff589be6f8) at ../main_x11.cpp:294
#57 0x00007f4230cb5a40 in __libc_start_main (main=0x400790 <main(int, char**)>, argc=1, argv=0x7fff589be6f8, init=<optimized out>, fini=<optimized out>, rtld_fini=<optimized out>, stack_end=0x7fff589be6e8) at libc-start.c:289
#58 0x00000000004007c9 in _start ()

Reported using DrKonqi