Application: kwin_x11 (5.6.5)

Qt Version: 5.6.0
Frameworks Version: 5.22.0
Operating System: Linux 4.5.7-300.fc24.x86_64 x86_64
Distribution (Platform): Fedora RPMs

-- Information about the crash:
KWin crashes everytime when I open "preferences" in VirtualBox and then close it

The crash can be reproduced every time.

-- Backtrace:
Application: KWin (kwin_x11), signal: Segmentation fault
Using host libthread_db library "/lib64/libthread_db.so.1".
[Current thread is 1 (Thread 0x7f3aaeae1940 (LWP 6740))]

Thread 6 (Thread 0x7f3a7b799700 (LWP 6751)):
#0  0x00007f3ac1a5ebd0 in pthread_cond_wait@@GLIBC_2.3.2 () at /lib64/libpthread.so.0
#1  0x00007f3ac76e9424 in QTWTF::TCMalloc_PageHeap::scavengerThread() () at /lib64/libQt5Script.so.5
#2  0x00007f3ac76e9469 in  () at /lib64/libQt5Script.so.5
#3  0x00007f3ac1a595ca in start_thread () at /lib64/libpthread.so.0
#4  0x00007f3abedd1ead in clone () at /lib64/libc.so.6

Thread 5 (Thread 0x7f3a8b262700 (LWP 6748)):
#0  0x00007f3abedc8103 in select () at /lib64/libc.so.6
#1  0x00007f3ac02e4aef in qt_safe_select(int, fd_set*, fd_set*, fd_set*, timespec const*) () at /lib64/libQt5Core.so.5
#2  0x00007f3ac02e61e4 in QEventDispatcherUNIXPrivate::doSelect(QFlags<QEventLoop::ProcessEventsFlag>, timespec*) () at /lib64/libQt5Core.so.5
#3  0x00007f3ac02e671a in QEventDispatcherUNIX::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () at /lib64/libQt5Core.so.5
#4  0x00007f3ac0297a6a in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) () at /lib64/libQt5Core.so.5
#5  0x00007f3ac00f7a03 in QThread::exec() () at /lib64/libQt5Core.so.5
#6  0x00007f3ac6715145 in QQmlThreadPrivate::run() () at /lib64/libQt5Qml.so.5
#7  0x00007f3ac00fc03a in QThreadPrivate::start(void*) () at /lib64/libQt5Core.so.5
#8  0x00007f3ac1a595ca in start_thread () at /lib64/libpthread.so.0
#9  0x00007f3abedd1ead in clone () at /lib64/libc.so.6

Thread 4 (Thread 0x7f3a97fff700 (LWP 6747)):
#0  0x00007f3abedc8103 in select () at /lib64/libc.so.6
#1  0x00007f3ac02e4aef in qt_safe_select(int, fd_set*, fd_set*, fd_set*, timespec const*) () at /lib64/libQt5Core.so.5
#2  0x00007f3ac02e61e4 in QEventDispatcherUNIXPrivate::doSelect(QFlags<QEventLoop::ProcessEventsFlag>, timespec*) () at /lib64/libQt5Core.so.5
#3  0x00007f3ac02e671a in QEventDispatcherUNIX::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () at /lib64/libQt5Core.so.5
#4  0x00007f3ac0297a6a in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) () at /lib64/libQt5Core.so.5
#5  0x00007f3ac00f7a03 in QThread::exec() () at /lib64/libQt5Core.so.5
#6  0x00007f3ac6715145 in QQmlThreadPrivate::run() () at /lib64/libQt5Qml.so.5
#7  0x00007f3ac00fc03a in QThreadPrivate::start(void*) () at /lib64/libQt5Core.so.5
#8  0x00007f3ac1a595ca in start_thread () at /lib64/libpthread.so.0
#9  0x00007f3abedd1ead in clone () at /lib64/libc.so.6

Thread 3 (Thread 0x7f3aa5d41700 (LWP 6745)):
#0  0x00007f3abedc8103 in select () at /lib64/libc.so.6
#1  0x00007f3ac02e4aef in qt_safe_select(int, fd_set*, fd_set*, fd_set*, timespec const*) () at /lib64/libQt5Core.so.5
#2  0x00007f3ac02e61e4 in QEventDispatcherUNIXPrivate::doSelect(QFlags<QEventLoop::ProcessEventsFlag>, timespec*) () at /lib64/libQt5Core.so.5
#3  0x00007f3ac02e671a in QEventDispatcherUNIX::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () at /lib64/libQt5Core.so.5
#4  0x00007f3ac0297a6a in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) () at /lib64/libQt5Core.so.5
#5  0x00007f3ac00f7a03 in QThread::exec() () at /lib64/libQt5Core.so.5
#6  0x00007f3ac15583b9 in QDBusConnectionManager::run() () at /lib64/libQt5DBus.so.5
#7  0x00007f3ac00fc03a in QThreadPrivate::start(void*) () at /lib64/libQt5Core.so.5
#8  0x00007f3ac1a595ca in start_thread () at /lib64/libpthread.so.0
#9  0x00007f3abedd1ead in clone () at /lib64/libc.so.6

Thread 2 (Thread 0x7f3aa7479700 (LWP 6744)):
#0  0x00007f3abedc632d in poll () at /lib64/libc.so.6
#1  0x00007f3abfe3ef80 in _xcb_conn_wait () at /lib64/libxcb.so.1
#2  0x00007f3abfe40b79 in xcb_wait_for_event () at /lib64/libxcb.so.1
#3  0x00007f3aa7ce00f9 in QXcbEventReader::run() () at /lib64/libQt5XcbQpa.so.5
#4  0x00007f3ac00fc03a in QThreadPrivate::start(void*) () at /lib64/libQt5Core.so.5
#5  0x00007f3ac1a595ca in start_thread () at /lib64/libpthread.so.0
#6  0x00007f3abedd1ead in clone () at /lib64/libc.so.6

Thread 1 (Thread 0x7f3aaeae1940 (LWP 6740)):
[KCrash Handler]
#5  0x0000000000000000 in  ()
#6  0x00007f3ac02c7028 in QObject::connect(QObject const*, char const*, QObject const*, char const*, Qt::ConnectionType) () at /lib64/libQt5Core.so.5
#7  0x00007f3ac772c06f in QScriptEnginePrivate::qobjectData(QObject*) () at /lib64/libQt5Script.so.5
#8  0x00007f3ac772c134 in QScriptEnginePrivate::newQObject(QObject*, QScriptEngine::ValueOwnership, QFlags<QScriptEngine::QObjectWrapOption> const&) () at /lib64/libQt5Script.so.5
#9  0x00007f3ac772c3b2 in QScriptEngine::newQObject(QObject*, QScriptEngine::ValueOwnership, QFlags<QScriptEngine::QObjectWrapOption> const&) () at /lib64/libQt5Script.so.5
#10 0x00007f3ac8103fac in KWin::effectWindowToScriptValue(QScriptEngine*, KWin::EffectWindow* const&) () at /lib64/libkwin.so.5
#11 0x00007f3ac772c6e5 in QScriptEnginePrivate::create(QTJSC::ExecState*, int, void const*) () at /lib64/libQt5Script.so.5
#12 0x00007f3ac77554ee in QScript::QObjectConnectionManager::execute(int, void**) () at /lib64/libQt5Script.so.5
#13 0x00007f3ac775d841 in QScript::QObjectConnectionManager::qt_metacall(QMetaObject::Call, int, void**) () at /lib64/libQt5Script.so.5
#14 0x00007f3ac02c1186 in QMetaObject::activate(QObject*, int, int, void**) () at /lib64/libQt5Core.so.5
#15 0x00007f3ac7d32b68 in KWin::EffectsHandler::desktopPresenceChanged(KWin::EffectWindow*, int, int) () at /lib64/libkwineffects.so.8
#16 0x00007f3ac7d3415c in KWin::EffectsHandler::qt_static_metacall(QObject*, QMetaObject::Call, int, void**) () at /lib64/libkwineffects.so.8
#17 0x00007f3ac02c2059 in QObject::event(QEvent*) () at /lib64/libQt5Core.so.5
#18 0x00007f3ac0b2b34c in QApplicationPrivate::notify_helper(QObject*, QEvent*) () at /lib64/libQt5Widgets.so.5
#19 0x00007f3ac0b3052f in QApplication::notify(QObject*, QEvent*) () at /lib64/libQt5Widgets.so.5
#20 0x00007f3ac0298bfa in QCoreApplication::notifyInternal2(QObject*, QEvent*) () at /lib64/libQt5Core.so.5
#21 0x00007f3ac029ac9f in QCoreApplicationPrivate::sendPostedEvents(QObject*, int, QThreadData*) () at /lib64/libQt5Core.so.5
#22 0x00007f3ac02e65f2 in QEventDispatcherUNIX::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () at /lib64/libQt5Core.so.5
#23 0x00007f3aa7d530fd in QUnixEventDispatcherQPA::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () at /lib64/libQt5XcbQpa.so.5
#24 0x00007f3ac0297a6a in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) () at /lib64/libQt5Core.so.5
#25 0x00007f3ac029f5fc in QCoreApplication::exec() () at /lib64/libQt5Core.so.5
#26 0x00007f3ac841ab3d in kdemain () at /lib64/libkdeinit5_kwin_x11.so
#27 0x00007f3abecef731 in __libc_start_main () at /lib64/libc.so.6
#28 0x000055d2df778cf9 in _start ()

Reported using DrKonqi