Application: kwin_x11 (5.9.4)

Qt Version: 5.7.1
Frameworks Version: 5.31.0
Operating System: Linux 4.10.0-21-generic x86_64
Distribution: Ubuntu 17.04

-- Information about the crash:
After making changes to a VMs using virt-manager remotely using X11 forwarding KWIN crashes

The crash can be reproduced every time.

-- 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 0x7fb0bc392900 (LWP 1688))]

Thread 5 (Thread 0x7fb07e348700 (LWP 1951)):
#0  0x00007fb0b54b7510 in pthread_cond_wait@@GLIBC_2.3.2 () at ../sysdeps/unix/sysv/linux/x86_64/pthread_cond_wait.S:185
#1  0x00007fb0b87e22c4 in  () at /usr/lib/x86_64-linux-gnu/libQt5Script.so.5
#2  0x00007fb0b87e2309 in  () at /usr/lib/x86_64-linux-gnu/libQt5Script.so.5
#3  0x00007fb0b54b16da in start_thread (arg=0x7fb07e348700) at pthread_create.c:456
#4  0x00007fb0bbdbd17f in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:105

Thread 4 (Thread 0x7fb08535f700 (LWP 1936)):
#0  0x00007fb0bbdb1251 in __GI_ppoll (fds=0x7fb078000ac8, nfds=1, timeout=<optimized out>, sigmask=0x0) at ../sysdeps/unix/sysv/linux/ppoll.c:39
#1  0x00007fb0b9678251 in qt_safe_poll(pollfd*, unsigned long, timespec const*) () at /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#2  0x00007fb0b9679b4a in QEventDispatcherUNIX::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () at /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#3  0x00007fb0b962688a in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) () at /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#4  0x00007fb0b9453fe3 in QThread::exec() () at /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#5  0x00007fb0b421edf5 in  () at /usr/lib/x86_64-linux-gnu/libQt5Qml.so.5
#6  0x00007fb0b9458c98 in  () at /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#7  0x00007fb0b54b16da in start_thread (arg=0x7fb08535f700) at pthread_create.c:456
#8  0x00007fb0bbdbd17f in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:105

Thread 3 (Thread 0x7fb097558700 (LWP 1776)):
#0  0x00007fb0b944fdf9 in QMutex::lock() () at /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#1  0x00007fb0b962ae0c in QCoreApplicationPrivate::sendPostedEvents(QObject*, int, QThreadData*) () at /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#2  0x00007fb0b9679977 in QEventDispatcherUNIX::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () at /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#3  0x00007fb0b962688a in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) () at /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#4  0x00007fb0b9453fe3 in QThread::exec() () at /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#5  0x00007fb0b421edf5 in  () at /usr/lib/x86_64-linux-gnu/libQt5Qml.so.5
#6  0x00007fb0b9458c98 in  () at /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#7  0x00007fb0b54b16da in start_thread (arg=0x7fb097558700) at pthread_create.c:456
#8  0x00007fb0bbdbd17f in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:105

Thread 2 (Thread 0x7fb0a5391700 (LWP 1704)):
#0  0x00007fb0bbdb118d in poll () at ../sysdeps/unix/syscall-template.S:84
#1  0x00007fb0b0a83576 in  () at /lib/x86_64-linux-gnu/libglib-2.0.so.0
#2  0x00007fb0b0a8368c in g_main_context_iteration () at /lib/x86_64-linux-gnu/libglib-2.0.so.0
#3  0x00007fb0b967cf2b in QEventDispatcherGlib::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () at /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#4  0x00007fb0b962688a in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) () at /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#5  0x00007fb0b9453fe3 in QThread::exec() () at /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#6  0x00007fb0b33f75c5 in  () at /usr/lib/x86_64-linux-gnu/libQt5DBus.so.5
#7  0x00007fb0b9458c98 in  () at /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#8  0x00007fb0b54b16da in start_thread (arg=0x7fb0a5391700) at pthread_create.c:456
#9  0x00007fb0bbdbd17f in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:105

Thread 1 (Thread 0x7fb0bc392900 (LWP 1688)):
[KCrash Handler]
#6  0x000029c2745e8888 in  ()
#7  0x00007fb0b965a6e0 in QObject::connect(QObject const*, char const*, QObject const*, char const*, Qt::ConnectionType) () at /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#8  0x00007fb0b8823037 in  () at /usr/lib/x86_64-linux-gnu/libQt5Script.so.5
#9  0x00007fb0b88230ff in  () at /usr/lib/x86_64-linux-gnu/libQt5Script.so.5
#10 0x00007fb0b8823382 in QScriptEngine::newQObject(QObject*, QScriptEngine::ValueOwnership, QFlags<QScriptEngine::QObjectWrapOption> const&) () at /usr/lib/x86_64-linux-gnu/libQt5Script.so.5
#11 0x00007fb0bb99995f in  () at /usr/lib/x86_64-linux-gnu/libkwin.so.5
#12 0x00007fb0b88235e5 in  () at /usr/lib/x86_64-linux-gnu/libQt5Script.so.5
#13 0x00007fb0b884abf6 in  () at /usr/lib/x86_64-linux-gnu/libQt5Script.so.5
#14 0x00007fb0b8852ba1 in  () at /usr/lib/x86_64-linux-gnu/libQt5Script.so.5
#15 0x00007fb0b9654644 in QMetaObject::activate(QObject*, int, int, void**) () at /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#16 0x00007fb0b8e13e28 in KWin::EffectsHandler::desktopPresenceChanged(KWin::EffectWindow*, int, int) () at /usr/lib/x86_64-linux-gnu/libkwineffects.so.10
#17 0x00007fb0b8e157f1 in  () at /usr/lib/x86_64-linux-gnu/libkwineffects.so.10
#18 0x00007fb0b9655359 in QObject::event(QEvent*) () at /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#19 0x00007fb0ba30035c in QApplicationPrivate::notify_helper(QObject*, QEvent*) () at /usr/lib/x86_64-linux-gnu/libQt5Widgets.so.5
#20 0x00007fb0ba307b11 in QApplication::notify(QObject*, QEvent*) () at /usr/lib/x86_64-linux-gnu/libQt5Widgets.so.5
#21 0x00007fb0b96288a0 in QCoreApplication::notifyInternal2(QObject*, QEvent*) () at /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#22 0x00007fb0b962b02d in QCoreApplicationPrivate::sendPostedEvents(QObject*, int, QThreadData*) () at /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#23 0x00007fb0b9679977 in QEventDispatcherUNIX::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () at /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#24 0x00007fb0a44659fd in  () at /usr/lib/x86_64-linux-gnu/libQt5XcbQpa.so.5
#25 0x00007fb0b962688a in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) () at /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#26 0x00007fb0b962effc in QCoreApplication::exec() () at /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#27 0x00007fb0bc085112 in kdemain () at /usr/lib/x86_64-linux-gnu/libkdeinit5_kwin_x11.so
#28 0x00007fb0bbcd53f1 in __libc_start_main (main=0x55ee415377e0, argc=3, argv=0x7ffcecd8e048, init=<optimized out>, fini=<optimized out>, rtld_fini=<optimized out>, stack_end=0x7ffcecd8e038) at ../csu/libc-start.c:291
#29 0x000055ee4153781a in _start ()

Reported using DrKonqi