Application: kwin_x11 (5.12.7)

Qt Version: 5.9.5
Frameworks Version: 5.47.0
Operating System: Linux 4.15.0-38-generic x86_64
Distribution: Ubuntu 18.04.1 LTS

-- Information about the crash:
- What I was doing when the application crashed:
Moved mouse into an "active" screen corner to "Present Windows - All Desktops"

- Environment:
Nvidia G86 Quadro NVS 290 v340.107
Two monitors and two desktops

Sometimes there are also KWin crashes when switching between Desktop 1 and Desktop 2.

The crash does not seem to be reproducible.

-- 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 0x7f9791d90d00 (LWP 4044))]

Thread 8 (Thread 0x7f9766725700 (LWP 6192)):
#0  0x00007f978a74a9f3 in futex_wait_cancelable (private=<optimized out>, expected=0, futex_word=0x55a0b74dc730) at ../sysdeps/unix/sysv/linux/futex-internal.h:88
#1  0x00007f978a74a9f3 in __pthread_cond_wait_common (abstime=0x0, mutex=0x55a0b74dc6e0, cond=0x55a0b74dc708) at pthread_cond_wait.c:502
#2  0x00007f978a74a9f3 in __pthread_cond_wait (cond=0x55a0b74dc708, mutex=0x55a0b74dc6e0) at pthread_cond_wait.c:655
#3  0x00007f978e8b959b in QWaitCondition::wait(QMutex*, unsigned long) () at /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#4  0x00007f978991e6a8 in  () at /usr/lib/x86_64-linux-gnu/libQt5Quick.so.5
#5  0x00007f978991eb0a in  () at /usr/lib/x86_64-linux-gnu/libQt5Quick.so.5
#6  0x00007f978e8b816d in  () at /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#7  0x00007f978a7446db in start_thread (arg=0x7f9766725700) at pthread_create.c:463
#8  0x00007f97916f788f in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:95

Thread 7 (Thread 0x7f976c83c700 (LWP 6190)):
#0  0x00007f97916eacf6 in __GI_ppoll (fds=0x7f976000aef8, nfds=1, timeout=<optimized out>, sigmask=0x0) at ../sysdeps/unix/sysv/linux/ppoll.c:39
#1  0x00007f978eaeb5c1 in qt_safe_poll(pollfd*, unsigned long, timespec const*) () at /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#2  0x00007f978eaeccde in QEventDispatcherUNIX::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () at /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#3  0x00007f978ea949ea in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) () at /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#4  0x00007f978e8b322a in QThread::exec() () at /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#5  0x00007f97892306f5 in  () at /usr/lib/x86_64-linux-gnu/libQt5Qml.so.5
#6  0x00007f978e8b816d in  () at /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#7  0x00007f978a7446db in start_thread (arg=0x7f976c83c700) at pthread_create.c:463
#8  0x00007f97916f788f in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:95

Thread 6 (Thread 0x7f9765c76700 (LWP 6142)):
#0  0x00007f978a74a9f3 in futex_wait_cancelable (private=<optimized out>, expected=0, futex_word=0x55a0b72ec124) at ../sysdeps/unix/sysv/linux/futex-internal.h:88
#1  0x00007f978a74a9f3 in __pthread_cond_wait_common (abstime=0x0, mutex=0x55a0b72ec0d0, cond=0x55a0b72ec0f8) at pthread_cond_wait.c:502
#2  0x00007f978a74a9f3 in __pthread_cond_wait (cond=0x55a0b72ec0f8, mutex=0x55a0b72ec0d0) at pthread_cond_wait.c:655
#3  0x00007f978e8b959b in QWaitCondition::wait(QMutex*, unsigned long) () at /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#4  0x00007f978991e6a8 in  () at /usr/lib/x86_64-linux-gnu/libQt5Quick.so.5
#5  0x00007f978991eb0a in  () at /usr/lib/x86_64-linux-gnu/libQt5Quick.so.5
#6  0x00007f978e8b816d in  () at /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#7  0x00007f978a7446db in start_thread (arg=0x7f9765c76700) at pthread_create.c:463
#8  0x00007f97916f788f in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:95

Thread 5 (Thread 0x7f9753fff700 (LWP 4236)):
#0  0x00007f978a74a9f3 in futex_wait_cancelable (private=<optimized out>, expected=0, futex_word=0x7f978dcecfb8) at ../sysdeps/unix/sysv/linux/futex-internal.h:88
#1  0x00007f978a74a9f3 in __pthread_cond_wait_common (abstime=0x0, mutex=0x7f978dcecf68, cond=0x7f978dcecf90) at pthread_cond_wait.c:502
#2  0x00007f978a74a9f3 in __pthread_cond_wait (cond=0x7f978dcecf90, mutex=0x7f978dcecf68) at pthread_cond_wait.c:655
#3  0x00007f978d9f65f4 in  () at /usr/lib/x86_64-linux-gnu/libQt5Script.so.5
#4  0x00007f978d9f6639 in  () at /usr/lib/x86_64-linux-gnu/libQt5Script.so.5
#5  0x00007f978a7446db in start_thread (arg=0x7f9753fff700) at pthread_create.c:463
#6  0x00007f97916f788f in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:95

Thread 4 (Thread 0x7f9767d4e700 (LWP 4217)):
#0  0x00007f97916eacf6 in __GI_ppoll (fds=0x7f975c000d48, nfds=1, timeout=<optimized out>, sigmask=0x0) at ../sysdeps/unix/sysv/linux/ppoll.c:39
#1  0x00007f978eaeb5c1 in qt_safe_poll(pollfd*, unsigned long, timespec const*) () at /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#2  0x00007f978eaeccde in QEventDispatcherUNIX::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () at /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#3  0x00007f978ea949ea in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) () at /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#4  0x00007f978e8b322a in QThread::exec() () at /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#5  0x00007f97892306f5 in  () at /usr/lib/x86_64-linux-gnu/libQt5Qml.so.5
#6  0x00007f978e8b816d in  () at /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#7  0x00007f978a7446db in start_thread (arg=0x7f9767d4e700) at pthread_create.c:463
#8  0x00007f97916f788f in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:95

Thread 3 (Thread 0x7f976ee4c700 (LWP 4108)):
#0  0x00007f97916eacf6 in __GI_ppoll (fds=0x7f976800b0b8, nfds=1, timeout=<optimized out>, sigmask=0x0) at ../sysdeps/unix/sysv/linux/ppoll.c:39
#1  0x00007f978eaeb5c1 in qt_safe_poll(pollfd*, unsigned long, timespec const*) () at /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#2  0x00007f978eaeccde in QEventDispatcherUNIX::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () at /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#3  0x00007f978ea949ea in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) () at /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#4  0x00007f978e8b322a in QThread::exec() () at /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#5  0x00007f9788100d45 in  () at /usr/lib/x86_64-linux-gnu/libQt5DBus.so.5
#6  0x00007f978e8b816d in  () at /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#7  0x00007f978a7446db in start_thread (arg=0x7f976ee4c700) at pthread_create.c:463
#8  0x00007f97916f788f in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:95

Thread 2 (Thread 0x7f9775689700 (LWP 4077)):
#0  0x00007f97916eabf9 in __GI___poll (fds=0x7f9775688c28, nfds=1, timeout=-1) at ../sysdeps/unix/sysv/linux/poll.c:29
#1  0x00007f97905f3747 in  () at /usr/lib/x86_64-linux-gnu/libxcb.so.1
#2  0x00007f97905f536a in xcb_wait_for_event () at /usr/lib/x86_64-linux-gnu/libxcb.so.1
#3  0x00007f97765682a9 in  () at /usr/lib/x86_64-linux-gnu/libQt5XcbQpa.so.5
#4  0x00007f978e8b816d in  () at /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#5  0x00007f978a7446db in start_thread (arg=0x7f9775689700) at pthread_create.c:463
#6  0x00007f97916f788f in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:95

Thread 1 (Thread 0x7f9791d90d00 (LWP 4044)):
[KCrash Handler]
#6  0x000055a0b75d9700 in  ()
#7  0x00007f97911f23aa in KWin::Workspace::workspaceEvent(xcb_generic_event_t*) () at /usr/lib/x86_64-linux-gnu/libkwin.so.5
#8  0x00007f978ea9358f in QAbstractEventDispatcher::filterNativeEvent(QByteArray const&, void*, long*) () at /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#9  0x00007f9776569820 in QXcbConnection::handleXcbEvent(xcb_generic_event_t*) () at /usr/lib/x86_64-linux-gnu/libQt5XcbQpa.so.5
#10 0x00007f977656a4ac in QXcbConnection::processXcbEvents() () at /usr/lib/x86_64-linux-gnu/libQt5XcbQpa.so.5
#11 0x00007f978eac6122 in QObject::event(QEvent*) () at /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#12 0x00007f978f81482c in QApplicationPrivate::notify_helper(QObject*, QEvent*) () at /usr/lib/x86_64-linux-gnu/libQt5Widgets.so.5
#13 0x00007f978f81c0f4 in QApplication::notify(QObject*, QEvent*) () at /usr/lib/x86_64-linux-gnu/libQt5Widgets.so.5
#14 0x00007f978ea969a8 in QCoreApplication::notifyInternal2(QObject*, QEvent*) () at /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#15 0x00007f978ea9911d in QCoreApplicationPrivate::sendPostedEvents(QObject*, int, QThreadData*) () at /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#16 0x00007f978eaecaf4 in QEventDispatcherUNIX::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () at /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#17 0x00007f97765cb5cd in  () at /usr/lib/x86_64-linux-gnu/libQt5XcbQpa.so.5
#18 0x00007f978ea949ea in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) () at /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#19 0x00007f978ea9da84 in QCoreApplication::exec() () at /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#20 0x00007f97919cfdbb in kdemain () at /usr/lib/x86_64-linux-gnu/libkdeinit5_kwin_x11.so
#21 0x00007f97915f7b97 in __libc_start_main (main=0x55a0b509c730, argc=3, argv=0x7ffe50313d88, init=<optimized out>, fini=<optimized out>, rtld_fini=<optimized out>, stack_end=0x7ffe50313d78) at ../csu/libc-start.c:310
#22 0x000055a0b509c76a in _start ()

Reported using DrKonqi