Bug 408094

SUMMARY
Woke PC after sleep, Kwin crashed in the process and let me in without prompting for the password or any lock screen. Segmentation fault 11 reported

EXPECTED RESULT
Bring up sddm and the login prompt

SOFTWARE/OS VERSIONS

Linux/KDE Plasma: Arch Linux 
(available in About System)
KDE Plasma Version: 5.15.5
KDE Frameworks Version: 5.58.0
Qt Version: 5.12.3

ADDITIONAL INFORMATION 
Crash log:

Application: KWin (kwin_x11), signal: Segmentation fault
Using host libthread_db library "/usr/lib/libthread_db.so.1".
[Current thread is 1 (Thread 0x7f9e6eacb880 (LWP 3967))]

Thread 10 (Thread 0x7f9dbd387700 (LWP 27393)):
[KCrash Handler]
#6  0x00007f9e5326a020 in  () at /usr/lib/libnvidia-glcore.so.430.14
#7  0x00007f9e5315a1ea in  () at /usr/lib/libnvidia-glcore.so.430.14
#8  0x00007f9e5315e593 in  () at /usr/lib/libnvidia-glcore.so.430.14
#9  0x00007f9e531cbca3 in  () at /usr/lib/libnvidia-glcore.so.430.14
#10 0x00007f9e531cbe69 in  () at /usr/lib/libnvidia-glcore.so.430.14
#11 0x00007f9e531ce631 in  () at /usr/lib/libnvidia-glcore.so.430.14
#12 0x00007f9e531ced0e in  () at /usr/lib/libnvidia-glcore.so.430.14
#13 0x00007f9e53163d73 in  () at /usr/lib/libnvidia-glcore.so.430.14
#14 0x00007f9e52d6431b in  () at /usr/lib/libnvidia-glcore.so.430.14
#15 0x00007f9e746409cd in QSGBatchRenderer::Renderer::renderBatches() () at /usr/lib/libQt5Quick.so.5
#16 0x00007f9e7464629f in QSGBatchRenderer::Renderer::render() () at /usr/lib/libQt5Quick.so.5
#17 0x00007f9e74636c7e in QSGRenderer::renderScene(QSGBindable const&) () at /usr/lib/libQt5Quick.so.5
#18 0x00007f9e7463714c in QSGRenderer::renderScene(unsigned int) () at /usr/lib/libQt5Quick.so.5
#19 0x00007f9e746743f0 in QSGDefaultRenderContext::renderNextFrame(QSGRenderer*, unsigned int) () at /usr/lib/libQt5Quick.so.5
#20 0x00007f9e746d8b65 in QQuickWindowPrivate::renderSceneGraph(QSize const&) () at /usr/lib/libQt5Quick.so.5
#21 0x00007f9e7467fb6b in  () at /usr/lib/libQt5Quick.so.5
#22 0x00007f9e74683918 in  () at /usr/lib/libQt5Quick.so.5
#23 0x00007f9e75b5d63c in  () at /usr/lib/libQt5Core.so.5
#24 0x00007f9e74b45a92 in start_thread () at /usr/lib/libpthread.so.0
#25 0x00007f9e7720acd3 in clone () at /usr/lib/libc.so.6

Thread 9 (Thread 0x7f9e663aa700 (LWP 27392)):
#0  0x00007f9e772001c6 in ppoll () at /usr/lib/libc.so.6
#1  0x00007f9e75d6982b in qt_safe_poll(pollfd*, unsigned long, timespec const*) () at /usr/lib/libQt5Core.so.5
#2  0x00007f9e75d6ad0b in QEventDispatcherUNIX::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () at /usr/lib/libQt5Core.so.5
#3  0x00007f9e75d174dc in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) () at /usr/lib/libQt5Core.so.5
#4  0x00007f9e75b5c239 in QThread::exec() () at /usr/lib/libQt5Core.so.5
#5  0x00007f9e742fe059 in  () at /usr/lib/libQt5Qml.so.5
#6  0x00007f9e75b5d63c in  () at /usr/lib/libQt5Core.so.5
#7  0x00007f9e74b45a92 in start_thread () at /usr/lib/libpthread.so.0
#8  0x00007f9e7720acd3 in clone () at /usr/lib/libc.so.6

Thread 8 (Thread 0x7f9dcbfff700 (LWP 11253)):
#0  0x00007f9e74b4bbac in pthread_cond_wait@@GLIBC_2.3.2 () at /usr/lib/libpthread.so.0
#1  0x00007f9e75b6391c in QWaitCondition::wait(QMutex*, QDeadlineTimer) () at /usr/lib/libQt5Core.so.5
#2  0x00007f9e75b63a0a in QWaitCondition::wait(QMutex*, unsigned long) () at /usr/lib/libQt5Core.so.5
#3  0x00007f9e746836ed in  () at /usr/lib/libQt5Quick.so.5
#4  0x00007f9e7468395c in  () at /usr/lib/libQt5Quick.so.5
#5  0x00007f9e75b5d63c in  () at /usr/lib/libQt5Core.so.5
#6  0x00007f9e74b45a92 in start_thread () at /usr/lib/libpthread.so.0
#7  0x00007f9e7720acd3 in clone () at /usr/lib/libc.so.6

Thread 7 (Thread 0x7f9e67fff700 (LWP 6844)):
#0  0x00007ffee25af625 in  ()
#1  0x00007f9e77218ba2 in clock_gettime () at /usr/lib/libc.so.6
#2  0x00007f9e75d6d272 in  () at /usr/lib/libQt5Core.so.5
#3  0x00007f9e75d6ba5a in QTimerInfoList::updateCurrentTime() () at /usr/lib/libQt5Core.so.5
#4  0x00007f9e75d6c056 in QTimerInfoList::timerWait(timespec&) () at /usr/lib/libQt5Core.so.5
#5  0x00007f9e75d6af55 in QEventDispatcherUNIX::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () at /usr/lib/libQt5Core.so.5
#6  0x00007f9e75d174dc in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) () at /usr/lib/libQt5Core.so.5
#7  0x00007f9e75b5c239 in QThread::exec() () at /usr/lib/libQt5Core.so.5
#8  0x00007f9e75b5d63c in  () at /usr/lib/libQt5Core.so.5
#9  0x00007f9e74b45a92 in start_thread () at /usr/lib/libpthread.so.0
#10 0x00007f9e7720acd3 in clone () at /usr/lib/libc.so.6

Thread 6 (Thread 0x7f9e64a41700 (LWP 6460)):
#0  0x00007f9e74b4bbac in pthread_cond_wait@@GLIBC_2.3.2 () at /usr/lib/libpthread.so.0
#1  0x00007f9e75b6391c in QWaitCondition::wait(QMutex*, QDeadlineTimer) () at /usr/lib/libQt5Core.so.5
#2  0x00007f9e75b63a0a in QWaitCondition::wait(QMutex*, unsigned long) () at /usr/lib/libQt5Core.so.5
#3  0x00007f9e746836ed in  () at /usr/lib/libQt5Quick.so.5
#4  0x00007f9e7468395c in  () at /usr/lib/libQt5Quick.so.5
#5  0x00007f9e75b5d63c in  () at /usr/lib/libQt5Core.so.5
#6  0x00007f9e74b45a92 in start_thread () at /usr/lib/libpthread.so.0
#7  0x00007f9e7720acd3 in clone () at /usr/lib/libc.so.6

Thread 5 (Thread 0x7f9e52337700 (LWP 4102)):
#0  0x00007f9e74b4bbac in pthread_cond_wait@@GLIBC_2.3.2 () at /usr/lib/libpthread.so.0
#1  0x00007f9e75652e5c in  () at /usr/lib/libQt5Script.so.5
#2  0x00007f9e75652e79 in  () at /usr/lib/libQt5Script.so.5
#3  0x00007f9e74b45a92 in start_thread () at /usr/lib/libpthread.so.0
#4  0x00007f9e7720acd3 in clone () at /usr/lib/libc.so.6

Thread 4 (Thread 0x7f9e67612700 (LWP 4058)):
#0  0x00007f9e772001c6 in ppoll () at /usr/lib/libc.so.6
#1  0x00007f9e75d6982b in qt_safe_poll(pollfd*, unsigned long, timespec const*) () at /usr/lib/libQt5Core.so.5
#2  0x00007f9e75d6ad0b in QEventDispatcherUNIX::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () at /usr/lib/libQt5Core.so.5
#3  0x00007f9e75d174dc in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) () at /usr/lib/libQt5Core.so.5
#4  0x00007f9e75b5c239 in QThread::exec() () at /usr/lib/libQt5Core.so.5
#5  0x00007f9e742fe059 in  () at /usr/lib/libQt5Qml.so.5
#6  0x00007f9e75b5d63c in  () at /usr/lib/libQt5Core.so.5
#7  0x00007f9e74b45a92 in start_thread () at /usr/lib/libpthread.so.0
#8  0x00007f9e7720acd3 in clone () at /usr/lib/libc.so.6

Thread 3 (Thread 0x7f9e6d364700 (LWP 4033)):
#0  0x00007f9e772001c6 in ppoll () at /usr/lib/libc.so.6
#1  0x00007f9e75d6982b in qt_safe_poll(pollfd*, unsigned long, timespec const*) () at /usr/lib/libQt5Core.so.5
#2  0x00007f9e75d6ad0b in QEventDispatcherUNIX::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () at /usr/lib/libQt5Core.so.5
#3  0x00007f9e75d174dc in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) () at /usr/lib/libQt5Core.so.5
#4  0x00007f9e75b5c239 in QThread::exec() () at /usr/lib/libQt5Core.so.5
#5  0x00007f9e73d4aba6 in  () at /usr/lib/libQt5DBus.so.5
#6  0x00007f9e75b5d63c in  () at /usr/lib/libQt5Core.so.5
#7  0x00007f9e74b45a92 in start_thread () at /usr/lib/libpthread.so.0
#8  0x00007f9e7720acd3 in clone () at /usr/lib/libc.so.6

Thread 2 (Thread 0x7f9e6e21b700 (LWP 3991)):
#0  0x00007f9e772000d1 in poll () at /usr/lib/libc.so.6
#1  0x00007f9e75a81630 in  () at /usr/lib/libxcb.so.1
#2  0x00007f9e75a832db in xcb_wait_for_event () at /usr/lib/libxcb.so.1
#3  0x00007f9e6e537b69 in  () at /usr/lib/libQt5XcbQpa.so.5
#4  0x00007f9e75b5d63c in  () at /usr/lib/libQt5Core.so.5
#5  0x00007f9e74b45a92 in start_thread () at /usr/lib/libpthread.so.0
#6  0x00007f9e7720acd3 in clone () at /usr/lib/libc.so.6

Thread 1 (Thread 0x7f9e6eacb880 (LWP 3967)):
#0  0x00007f9e74b4bbac in pthread_cond_wait@@GLIBC_2.3.2 () at /usr/lib/libpthread.so.0
#1  0x00007f9e75b6391c in QWaitCondition::wait(QMutex*, QDeadlineTimer) () at /usr/lib/libQt5Core.so.5
#2  0x00007f9e75b63a0a in QWaitCondition::wait(QMutex*, unsigned long) () at /usr/lib/libQt5Core.so.5
#3  0x00007f9e74681d63 in  () at /usr/lib/libQt5Quick.so.5
#4  0x00007f9e74682cd7 in  () at /usr/lib/libQt5Quick.so.5
#5  0x00007f9e7468333b in  () at /usr/lib/libQt5Quick.so.5
#6  0x00007f9e760fceb5 in QWindow::event(QEvent*) () at /usr/lib/libQt5Gui.so.5
#7  0x00007f9e746e467c in QQuickWindow::event(QEvent*) () at /usr/lib/libQt5Quick.so.5
#8  0x00007f9e766e5da4 in QApplicationPrivate::notify_helper(QObject*, QEvent*) () at /usr/lib/libQt5Widgets.so.5
#9  0x00007f9e766ed3c1 in QApplication::notify(QObject*, QEvent*) () at /usr/lib/libQt5Widgets.so.5
#10 0x00007f9e75d18849 in QCoreApplication::notifyInternal2(QObject*, QEvent*) () at /usr/lib/libQt5Core.so.5
#11 0x00007f9e760f2741 in QGuiApplicationPrivate::processExposeEvent(QWindowSystemInterfacePrivate::ExposeEvent*) () at /usr/lib/libQt5Gui.so.5
#12 0x00007f9e760f29de in QGuiApplicationPrivate::processWindowSystemEvent(QWindowSystemInterfacePrivate::WindowSystemEvent*) () at /usr/lib/libQt5Gui.so.5
#13 0x00007f9e760cbd9c in QWindowSystemInterface::sendWindowSystemEvents(QFlags<QEventLoop::ProcessEventsFlag>) () at /usr/lib/libQt5Gui.so.5
#14 0x00007f9e6e538f56 in  () at /usr/lib/libQt5XcbQpa.so.5
#15 0x00007f9e75d174dc in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) () at /usr/lib/libQt5Core.so.5
#16 0x00007f9e75d1f596 in QCoreApplication::exec() () at /usr/lib/libQt5Core.so.5
#17 0x00007f9e772de593 in kdemain () at /usr/lib/libkdeinit5_kwin_x11.so
#18 0x00007f9e77133ce3 in __libc_start_main () at /usr/lib/libc.so.6
#19 0x000055dcbe0c705e in _start ()
[Inferior 1 (process 3967) detached]