Application: kwin_x11 (5.12.7)

Qt Version: 5.9.5
Frameworks Version: 5.44.0
Operating System: Linux 4.15.0-43-generic x86_64
Distribution: Ubuntu 18.04.1 LTS

-- Information about the crash:
- What I was doing when the application crashed:
Just opened Firefox.  Screen flicker, then Kwin resets itself.

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 0x7fa49abdbd00 (LWP 1295))]

Thread 6 (Thread 0x7fa46553f700 (LWP 1433)):
#0  0x00007fa49a52ecf6 in __GI_ppoll (fds=0x7fa45c000d28, nfds=1, timeout=<optimized out>, sigmask=0x0) at ../sysdeps/unix/sysv/linux/ppoll.c:39
#1  0x00007fa4979305c1 in qt_safe_poll(pollfd*, unsigned long, timespec const*) () at /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#2  0x00007fa497931cde in QEventDispatcherUNIX::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () at /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#3  0x00007fa4978d99ea in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) () at /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#4  0x00007fa4976f822a in QThread::exec() () at /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#5  0x00007fa4920806f5 in  () at /usr/lib/x86_64-linux-gnu/libQt5Qml.so.5
#6  0x00007fa4976fd16d in  () at /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#7  0x00007fa4935946db in start_thread (arg=0x7fa46553f700) at pthread_create.c:463
#8  0x00007fa49a53b88f in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:95

Thread 5 (Thread 0x7fa466298700 (LWP 1430)):
#0  0x00007fa49359a9f3 in futex_wait_cancelable (private=<optimized out>, expected=0, futex_word=0x7fa496b31fb8) at ../sysdeps/unix/sysv/linux/futex-internal.h:88
#1  0x00007fa49359a9f3 in __pthread_cond_wait_common (abstime=0x0, mutex=0x7fa496b31f68, cond=0x7fa496b31f90) at pthread_cond_wait.c:502
#2  0x00007fa49359a9f3 in __pthread_cond_wait (cond=0x7fa496b31f90, mutex=0x7fa496b31f68) at pthread_cond_wait.c:655
#3  0x00007fa49683b5f4 in  () at /usr/lib/x86_64-linux-gnu/libQt5Script.so.5
#4  0x00007fa49683b639 in  () at /usr/lib/x86_64-linux-gnu/libQt5Script.so.5
#5  0x00007fa4935946db in start_thread (arg=0x7fa466298700) at pthread_create.c:463
#6  0x00007fa49a53b88f in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:95

Thread 4 (Thread 0x7fa475436700 (LWP 1369)):
#0  0x00007fa49a52ecf6 in __GI_ppoll (fds=0x7fa46c000d48, nfds=1, timeout=<optimized out>, sigmask=0x0) at ../sysdeps/unix/sysv/linux/ppoll.c:39
#1  0x00007fa4979305c1 in qt_safe_poll(pollfd*, unsigned long, timespec const*) () at /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#2  0x00007fa497931cde in QEventDispatcherUNIX::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () at /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#3  0x00007fa4978d99ea in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) () at /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#4  0x00007fa4976f822a in QThread::exec() () at /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#5  0x00007fa4920806f5 in  () at /usr/lib/x86_64-linux-gnu/libQt5Qml.so.5
#6  0x00007fa4976fd16d in  () at /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#7  0x00007fa4935946db in start_thread (arg=0x7fa475436700) at pthread_create.c:463
#8  0x00007fa49a53b88f in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:95

Thread 3 (Thread 0x7fa477bd9700 (LWP 1316)):
#0  0x00007fff5d666c27 in clock_gettime ()
#1  0x00007fa49a54aea6 in __GI___clock_gettime (clock_id=1, tp=0x7fa477bd8b40) at ../sysdeps/unix/clock_gettime.c:115
#2  0x00007fa497934221 in  () at /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#3  0x00007fa497932a59 in QTimerInfoList::updateCurrentTime() () at /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#4  0x00007fa497933035 in QTimerInfoList::timerWait(timespec&) () at /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#5  0x00007fa497931fe4 in QEventDispatcherUNIX::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () at /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#6  0x00007fa4978d99ea in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) () at /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#7  0x00007fa4976f822a in QThread::exec() () at /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#8  0x00007fa490f59d45 in  () at /usr/lib/x86_64-linux-gnu/libQt5DBus.so.5
#9  0x00007fa4976fd16d in  () at /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#10 0x00007fa4935946db in start_thread (arg=0x7fa477bd9700) at pthread_create.c:463
#11 0x00007fa49a53b88f in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:95

Thread 2 (Thread 0x7fa47e4e1700 (LWP 1313)):
#0  0x00007fa49a52ebf9 in __GI___poll (fds=0x7fa47e4e0c28, nfds=1, timeout=-1) at ../sysdeps/unix/sysv/linux/poll.c:29
#1  0x00007fa499438747 in  () at /usr/lib/x86_64-linux-gnu/libxcb.so.1
#2  0x00007fa49943a36a in xcb_wait_for_event () at /usr/lib/x86_64-linux-gnu/libxcb.so.1
#3  0x00007fa47f3c02a9 in  () at /usr/lib/x86_64-linux-gnu/libQt5XcbQpa.so.5
#4  0x00007fa4976fd16d in  () at /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#5  0x00007fa4935946db in start_thread (arg=0x7fa47e4e1700) at pthread_create.c:463
#6  0x00007fa49a53b88f in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:95

Thread 1 (Thread 0x7fa49abdbd00 (LWP 1295)):
[KCrash Handler]
#6  0x0000000040d9268f in  ()
#7  0x00007fa4887c82d0 in  () at /usr/lib/x86_64-linux-gnu/libnvidia-glcore.so.340.107
#8  0x00007fa4887cf360 in  () at /usr/lib/x86_64-linux-gnu/libnvidia-glcore.so.340.107
#9  0x00007fa48843c378 in  () at /usr/lib/x86_64-linux-gnu/libnvidia-glcore.so.340.107
#10 0x00007fa4981e80b5 in QOpenGLTextureGlyphCache::resizeTextureData(int, int) () at /usr/lib/x86_64-linux-gnu/libQt5Gui.so.5
#11 0x00007fa49816c9da in QTextureGlyphCache::fillInPendingGlyphs() () at /usr/lib/x86_64-linux-gnu/libQt5Gui.so.5
#12 0x00007fa492757c56 in  () at /usr/lib/x86_64-linux-gnu/libQt5Quick.so.5
#13 0x00007fa492754949 in  () at /usr/lib/x86_64-linux-gnu/libQt5Quick.so.5
#14 0x00007fa492803158 in QQuickTextNode::addGlyphs(QPointF const&, QGlyphRun const&, QColor const&, QQuickText::TextStyle, QColor const&, QSGNode*) () at /usr/lib/x86_64-linux-gnu/libQt5Quick.so.5
#15 0x00007fa492808264 in  () at /usr/lib/x86_64-linux-gnu/libQt5Quick.so.5
#16 0x00007fa4928040ba in QQuickTextNode::addTextLayout(QPointF const&, QTextLayout*, QColor const&, QQuickText::TextStyle, QColor const&, QColor const&, QColor const&, QColor const&, int, int, int, int) () at /usr/lib/x86_64-linux-gnu/libQt5Quick.so.5
#17 0x00007fa492802d21 in QQuickText::updatePaintNode(QSGNode*, QQuickItem::UpdatePaintNodeData*) () at /usr/lib/x86_64-linux-gnu/libQt5Quick.so.5
#18 0x00007fa4927bda18 in QQuickWindowPrivate::updateDirtyNode(QQuickItem*) () at /usr/lib/x86_64-linux-gnu/libQt5Quick.so.5
#19 0x00007fa4927be293 in QQuickWindowPrivate::updateDirtyNodes() () at /usr/lib/x86_64-linux-gnu/libQt5Quick.so.5
#20 0x00007fa4927bf512 in QQuickWindowPrivate::syncSceneGraph() () at /usr/lib/x86_64-linux-gnu/libQt5Quick.so.5
#21 0x00007fa4928784a8 in QQuickRenderControl::grab() () at /usr/lib/x86_64-linux-gnu/libQt5Quick.so.5
#22 0x00007fa475454292 in  () at /usr/lib/x86_64-linux-gnu/qt5/plugins/org.kde.kdecoration2/kwin5_aurorae.so
#23 0x00007fa49790a6cf in QMetaObject::activate(QObject*, int, int, void**) () at /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#24 0x00007fa497917027 in QTimer::timeout(QTimer::QPrivateSignal) () at /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#25 0x00007fa497917388 in QTimer::timerEvent(QTimerEvent*) () at /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#26 0x00007fa49790b0db in QObject::event(QEvent*) () at /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#27 0x00007fa49865982c in QApplicationPrivate::notify_helper(QObject*, QEvent*) () at /usr/lib/x86_64-linux-gnu/libQt5Widgets.so.5
#28 0x00007fa4986610f4 in QApplication::notify(QObject*, QEvent*) () at /usr/lib/x86_64-linux-gnu/libQt5Widgets.so.5
#29 0x00007fa4978db9a8 in QCoreApplication::notifyInternal2(QObject*, QEvent*) () at /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#30 0x00007fa497933d8e in QTimerInfoList::activateTimers() () at /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#31 0x00007fa497931f42 in QEventDispatcherUNIX::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () at /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#32 0x00007fa47f4235cd in  () at /usr/lib/x86_64-linux-gnu/libQt5XcbQpa.so.5
#33 0x00007fa4978d99ea in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) () at /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#34 0x00007fa4978e2a84 in QCoreApplication::exec() () at /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#35 0x00007fa49a813dbb in kdemain () at /usr/lib/x86_64-linux-gnu/libkdeinit5_kwin_x11.so
#36 0x00007fa49a43bb97 in __libc_start_main (main=0x564441a80730, argc=3, argv=0x7fff5d5fe1f8, init=<optimized out>, fini=<optimized out>, rtld_fini=<optimized out>, stack_end=0x7fff5d5fe1e8) at ../csu/libc-start.c:310
#37 0x0000564441a8076a in _start ()

Reported using DrKonqi