Application: kwin_x11 (5.9.5)

Qt Version: 5.8.0
Frameworks Version: 5.34.0
Operating System: Linux 4.11.3-1-ARCH x86_64
Distribution (Platform): Archlinux Packages

-- Information about the crash:
- What I was doing when the application crashed:
previously plasmashell crashed due to OOM.  i was changing kernel memory settings and it reduced my available memory by 75%, which crashed plasmashell and google-chrome.  I ran without plasmashell for a while finishing some work, and kwin had no issues.  I then restarted plasmashell manually, at which point kwin immediately crashed.  upon manually restarting kwin, it continued to crash (4 times actually).

- Unusual behavior I noticed:
my playing with memory settings might have caused something to become unstable, but everything else seems to be running ok.

The crash can be reproduced every time.

-- Backtrace:
Application: KWin (kwin_x11), signal: Segmentation fault
Using host libthread_db library "/usr/lib/libthread_db.so.1".
[Current thread is 1 (Thread 0x7f120f59a840 (LWP 5523))]

Thread 7 (Thread 0x7f11bbdaf700 (LWP 5532)):
#0  0x00007f12081fd39d in pthread_cond_wait@@GLIBC_2.3.2 () at /usr/lib/libpthread.so.0
#1  0x00007f120b574234 in  () at /usr/lib/libQt5Script.so.5
#2  0x00007f120b574279 in  () at /usr/lib/libQt5Script.so.5
#3  0x00007f12081f7297 in start_thread () at /usr/lib/libpthread.so.0
#4  0x00007f120efe425f in clone () at /usr/lib/libc.so.6

Thread 6 (Thread 0x7f11c247b700 (LWP 5530)):
#0  0x00007f120efda396 in ppoll () at /usr/lib/libc.so.6
#1  0x00007f120c642511 in qt_safe_poll(pollfd*, unsigned long, timespec const*) () at /usr/lib/libQt5Core.so.5
#2  0x00007f120c643bfe in QEventDispatcherUNIX::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () at /usr/lib/libQt5Core.so.5
#3  0x00007f120c5ee3aa in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) () at /usr/lib/libQt5Core.so.5
#4  0x00007f120c40644a in QThread::exec() () at /usr/lib/libQt5Core.so.5
#5  0x00007f120c40ae9c in  () at /usr/lib/libQt5Core.so.5
#6  0x00007f12081f7297 in start_thread () at /usr/lib/libpthread.so.0
#7  0x00007f120efe425f in clone () at /usr/lib/libc.so.6

Thread 5 (Thread 0x7f11cc4b2700 (LWP 5529)):
#0  0x00007f120efda396 in ppoll () at /usr/lib/libc.so.6
#1  0x00007f120c642511 in qt_safe_poll(pollfd*, unsigned long, timespec const*) () at /usr/lib/libQt5Core.so.5
#2  0x00007f120c643bfe in QEventDispatcherUNIX::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () at /usr/lib/libQt5Core.so.5
#3  0x00007f120c5ee3aa in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) () at /usr/lib/libQt5Core.so.5
#4  0x00007f120c40644a in QThread::exec() () at /usr/lib/libQt5Core.so.5
#5  0x00007f1206f1e085 in  () at /usr/lib/libQt5Qml.so.5
#6  0x00007f120c40ae9c in  () at /usr/lib/libQt5Core.so.5
#7  0x00007f12081f7297 in start_thread () at /usr/lib/libpthread.so.0
#8  0x00007f120efe425f in clone () at /usr/lib/libc.so.6

Thread 4 (Thread 0x7f11ecb88700 (LWP 5528)):
#0  0x00007f120efda396 in ppoll () at /usr/lib/libc.so.6
#1  0x00007f120c642511 in qt_safe_poll(pollfd*, unsigned long, timespec const*) () at /usr/lib/libQt5Core.so.5
#2  0x00007f120c643bfe in QEventDispatcherUNIX::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () at /usr/lib/libQt5Core.so.5
#3  0x00007f120c5ee3aa in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) () at /usr/lib/libQt5Core.so.5
#4  0x00007f120c40644a in QThread::exec() () at /usr/lib/libQt5Core.so.5
#5  0x00007f1206f1e085 in  () at /usr/lib/libQt5Qml.so.5
#6  0x00007f120c40ae9c in  () at /usr/lib/libQt5Core.so.5
#7  0x00007f12081f7297 in start_thread () at /usr/lib/libpthread.so.0
#8  0x00007f120efe425f in clone () at /usr/lib/libc.so.6

Thread 3 (Thread 0x7f11ef6dc700 (LWP 5525)):
#0  0x00007f120efda396 in ppoll () at /usr/lib/libc.so.6
#1  0x00007f120c642511 in qt_safe_poll(pollfd*, unsigned long, timespec const*) () at /usr/lib/libQt5Core.so.5
#2  0x00007f120c643bfe in QEventDispatcherUNIX::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () at /usr/lib/libQt5Core.so.5
#3  0x00007f120c5ee3aa in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) () at /usr/lib/libQt5Core.so.5
#4  0x00007f120c40644a in QThread::exec() () at /usr/lib/libQt5Core.so.5
#5  0x00007f12060c8c45 in  () at /usr/lib/libQt5DBus.so.5
#6  0x00007f120c40ae9c in  () at /usr/lib/libQt5Core.so.5
#7  0x00007f12081f7297 in start_thread () at /usr/lib/libpthread.so.0
#8  0x00007f120efe425f in clone () at /usr/lib/libc.so.6

Thread 2 (Thread 0x7f11f5c95700 (LWP 5524)):
#0  0x00007f120efda2bd in poll () at /usr/lib/libc.so.6
#1  0x00007f120e0f28e0 in  () at /usr/lib/libxcb.so.1
#2  0x00007f120e0f4679 in xcb_wait_for_event () at /usr/lib/libxcb.so.1
#3  0x00007f11f6d711d9 in  () at /usr/lib/libQt5XcbQpa.so.5
#4  0x00007f120c40ae9c in  () at /usr/lib/libQt5Core.so.5
#5  0x00007f12081f7297 in start_thread () at /usr/lib/libpthread.so.0
#6  0x00007f120efe425f in clone () at /usr/lib/libc.so.6

Thread 1 (Thread 0x7f120f59a840 (LWP 5523)):
[KCrash Handler]
#6  0x00007f120b488ee3 in  () at /usr/lib/libQt5Script.so.5
#7  0x00007f120b515548 in  () at /usr/lib/libQt5Script.so.5
#8  0x00007f120b5159f8 in  () at /usr/lib/libQt5Script.so.5
#9  0x00007f120b5bcad6 in  () at /usr/lib/libQt5Script.so.5
#10 0x00007f120b5bd43f in QScriptEngine::QScriptEngine(QObject*) () at /usr/lib/libQt5Script.so.5
#11 0x00007f120ebbd789 in  () at /usr/lib/libkwin.so.5
#12 0x00007f120ebbf230 in KWin::Scripting::loadScript(QString const&, QString const&) () at /usr/lib/libkwin.so.5
#13 0x00007f120ebc248c in KWin::Scripting::start() () at /usr/lib/libkwin.so.5
#14 0x00007f120ec3e745 in  () at /usr/lib/libkwin.so.5
#15 0x00007f120c61d693 in QMetaObject::activate(QObject*, int, int, void**) () at /usr/lib/libQt5Core.so.5
#16 0x00007f120c61e332 in QObject::event(QEvent*) () at /usr/lib/libQt5Core.so.5
#17 0x00007f120d2fad7c in QApplicationPrivate::notify_helper(QObject*, QEvent*) () at /usr/lib/libQt5Widgets.so.5
#18 0x00007f120d302494 in QApplication::notify(QObject*, QEvent*) () at /usr/lib/libQt5Widgets.so.5
#19 0x00007f120c5efd38 in QCoreApplication::notifyInternal2(QObject*, QEvent*) () at /usr/lib/libQt5Core.so.5
#20 0x00007f120c5f1efd in QCoreApplicationPrivate::sendPostedEvents(QObject*, int, QThreadData*) () at /usr/lib/libQt5Core.so.5
#21 0x00007f120c643a14 in QEventDispatcherUNIX::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () at /usr/lib/libQt5Core.so.5
#22 0x00007f11f6dd38cd in  () at /usr/lib/libQt5XcbQpa.so.5
#23 0x00007f120c5ee3aa in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) () at /usr/lib/libQt5Core.so.5
#24 0x00007f120c5f6744 in QCoreApplication::exec() () at /usr/lib/libQt5Core.so.5
#25 0x00007f120f2a5391 in kdemain () at /usr/lib/libkdeinit5_kwin_x11.so
#26 0x00007f120ef1743a in __libc_start_main () at /usr/lib/libc.so.6
#27 0x000000000040069a in _start ()

Reported using DrKonqi