Application: kwin_x11 (5.8.9)

Qt Version: 5.6.1
Frameworks Version: 5.36.0
Operating System: Linux 4.15.0-24-generic x86_64
Distribution: Linux Mint 18.3 Sylvia

-- Information about the crash:
- What I was doing when the application crashed:
Starting Firefox

- Unusual behavior I noticed:
Lately KDE hasn't been working fine. I had to switch off Bliss because some applications' menus weren't working (i.e. KTorrent, Amarok...); even after that Firefox menus on the top-right aren't working, and the security status button on the left of the address bar isn't showing the usual window; also, gksu/gksudo now just seems to freeze X until I press Esc.

- Custom settings of the application:
Due to the aforementioned bugs I changed a bunch of themes all at once. That's when I started noticing KWin crashes.
Also, I have KDE set up to start Firefox on login.

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 0x7f6b8fbf6940 (LWP 1654))]

Thread 6 (Thread 0x7f6b6d48c700 (LWP 3451)):
#0  __libc_enable_asynccancel () at ../sysdeps/unix/sysv/linux/x86_64/cancellation.S:58
#1  0x00007f6b8f6f65c5 in select () at ../sysdeps/unix/syscall-template.S:84
#2  0x00007f6b8d564bcf in qt_safe_select(int, fd_set*, fd_set*, fd_set*, timespec const*) () from /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#3  0x00007f6b8d56660e in QEventDispatcherUNIXPrivate::doSelect(QFlags<QEventLoop::ProcessEventsFlag>, timespec*) () from /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#4  0x00007f6b8d566b22 in QEventDispatcherUNIX::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () from /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#5  0x00007f6b8d511ffa in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) () from /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#6  0x00007f6b8d33a9e4 in QThread::exec() () from /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#7  0x00007f6b8850a6b5 in ?? () from /usr/lib/x86_64-linux-gnu/libQt5Qml.so.5
#8  0x00007f6b8d33f808 in ?? () from /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#9  0x00007f6b893b06ba in start_thread (arg=0x7f6b6d48c700) at pthread_create.c:333
#10 0x00007f6b8f70041d in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:109

Thread 5 (Thread 0x7f6b59c03700 (LWP 1795)):
#0  pthread_cond_wait@@GLIBC_2.3.2 () at ../sysdeps/unix/sysv/linux/x86_64/pthread_cond_wait.S:185
#1  0x00007f6b8c6d8574 in ?? () from /usr/lib/x86_64-linux-gnu/libQt5Script.so.5
#2  0x00007f6b8c6d85b9 in ?? () from /usr/lib/x86_64-linux-gnu/libQt5Script.so.5
#3  0x00007f6b893b06ba in start_thread (arg=0x7f6b59c03700) at pthread_create.c:333
#4  0x00007f6b8f70041d in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:109

Thread 4 (Thread 0x7f6b6e521700 (LWP 1777)):
#0  0x00007ffeb8f2b979 in ?? ()
#1  0x00007ffeb8f2bcb8 in clock_gettime ()
#2  0x00007f6b8f70e876 in __GI___clock_gettime (clock_id=1, tp=0x7f6b6e520a10) at ../sysdeps/unix/clock_gettime.c:115
#3  0x00007f6b8d3eb6c6 in ?? () from /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#4  0x00007f6b8d566f09 in QTimerInfoList::updateCurrentTime() () from /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#5  0x00007f6b8d56630b in QEventDispatcherUNIXPrivate::doSelect(QFlags<QEventLoop::ProcessEventsFlag>, timespec*) () from /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#6  0x00007f6b8d566b22 in QEventDispatcherUNIX::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () from /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#7  0x00007f6b8d511ffa in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) () from /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#8  0x00007f6b8d33a9e4 in QThread::exec() () from /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#9  0x00007f6b8850a6b5 in ?? () from /usr/lib/x86_64-linux-gnu/libQt5Qml.so.5
#10 0x00007f6b8d33f808 in ?? () from /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#11 0x00007f6b893b06ba in start_thread (arg=0x7f6b6e521700) at pthread_create.c:333
#12 0x00007f6b8f70041d in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:109

Thread 3 (Thread 0x7f6b74dd0700 (LWP 1750)):
#0  0x00007f6b8f6f65d3 in select () at ../sysdeps/unix/syscall-template.S:84
#1  0x00007f6b8d564bcf in qt_safe_select(int, fd_set*, fd_set*, fd_set*, timespec const*) () from /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#2  0x00007f6b8d56660e in QEventDispatcherUNIXPrivate::doSelect(QFlags<QEventLoop::ProcessEventsFlag>, timespec*) () from /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#3  0x00007f6b8d566b22 in QEventDispatcherUNIX::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () from /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#4  0x00007f6b8d511ffa in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) () from /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#5  0x00007f6b8d33a9e4 in QThread::exec() () from /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#6  0x00007f6b8fd1e515 in ?? () from /usr/lib/x86_64-linux-gnu/libQt5DBus.so.5
#7  0x00007f6b8d33f808 in ?? () from /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#8  0x00007f6b893b06ba in start_thread (arg=0x7f6b74dd0700) at pthread_create.c:333
#9  0x00007f6b8f70041d in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:109

Thread 2 (Thread 0x7f6b76b7c700 (LWP 1693)):
#0  0x00007f6b8f6f474d in poll () at ../sysdeps/unix/syscall-template.S:84
#1  0x00007f6b8e859c62 in ?? () from /usr/lib/x86_64-linux-gnu/libxcb.so.1
#2  0x00007f6b8e85b8d7 in xcb_wait_for_event () from /usr/lib/x86_64-linux-gnu/libxcb.so.1
#3  0x00007f6b77829d29 in ?? () from /usr/lib/x86_64-linux-gnu/libQt5XcbQpa.so.5
#4  0x00007f6b8d33f808 in ?? () from /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#5  0x00007f6b893b06ba in start_thread (arg=0x7f6b76b7c700) at pthread_create.c:333
#6  0x00007f6b8f70041d in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:109

Thread 1 (Thread 0x7f6b8fbf6940 (LWP 1654)):
[KCrash Handler]
#6  0x00007f6b884f65e9 in QQmlBinding::write(QQmlPropertyData const&, QV4::Value const&, bool, QFlags<QQmlPropertyPrivate::WriteFlag>) () from /usr/lib/x86_64-linux-gnu/libQt5Qml.so.5
#7  0x00007f6b884f753a in QQmlBinding::update(QFlags<QQmlPropertyPrivate::WriteFlag>) () from /usr/lib/x86_64-linux-gnu/libQt5Qml.so.5
#8  0x00007f6b8850084f in ?? () from /usr/lib/x86_64-linux-gnu/libQt5Qml.so.5
#9  0x00007f6b8848d20e in QQmlComponentPrivate::complete(QQmlEnginePrivate*, QQmlComponentPrivate::ConstructionState*) () from /usr/lib/x86_64-linux-gnu/libQt5Qml.so.5
#10 0x00007f6b8848d2d7 in QQmlComponentPrivate::completeCreate() () from /usr/lib/x86_64-linux-gnu/libQt5Qml.so.5
#11 0x00007f6b8848d140 in QQmlComponent::create(QQmlContext*) () from /usr/lib/x86_64-linux-gnu/libQt5Qml.so.5
#12 0x00007f6b6e540047 in ?? () from /usr/lib/x86_64-linux-gnu/qt5/plugins/org.kde.kdecoration2/kwin5_aurorae.so
#13 0x00007f6b8f2ff831 in ?? () from /usr/lib/x86_64-linux-gnu/libkwin.so.5
#14 0x00007f6b8f1df791 in KWin::Client::createDecoration(QRect const&) () from /usr/lib/x86_64-linux-gnu/libkwin.so.5
#15 0x00007f6b8f1e0383 in KWin::Client::updateDecoration(bool, bool) () from /usr/lib/x86_64-linux-gnu/libkwin.so.5
#16 0x00007f6b8f23fd27 in KWin::Client::manage(unsigned int, bool) () from /usr/lib/x86_64-linux-gnu/libkwin.so.5
#17 0x00007f6b8f1c1574 in KWin::Workspace::createClient(unsigned int, bool) () from /usr/lib/x86_64-linux-gnu/libkwin.so.5
#18 0x00007f6b8f22d02f in KWin::Workspace::workspaceEvent(xcb_generic_event_t*) () from /usr/lib/x86_64-linux-gnu/libkwin.so.5
#19 0x00007f6b8d51116f in QAbstractEventDispatcher::filterNativeEvent(QByteArray const&, void*, long*) () from /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#20 0x00007f6b7782dca5 in QXcbConnection::handleXcbEvent(xcb_generic_event_t*) () from /usr/lib/x86_64-linux-gnu/libQt5XcbQpa.so.5
#21 0x00007f6b7782ec06 in QXcbConnection::processXcbEvents() () from /usr/lib/x86_64-linux-gnu/libQt5XcbQpa.so.5
#22 0x00007f6b8d541719 in QObject::event(QEvent*) () from /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#23 0x00007f6b8de49afc in QApplicationPrivate::notify_helper(QObject*, QEvent*) () from /usr/lib/x86_64-linux-gnu/libQt5Widgets.so.5
#24 0x00007f6b8de4f036 in QApplication::notify(QObject*, QEvent*) () from /usr/lib/x86_64-linux-gnu/libQt5Widgets.so.5
#25 0x00007f6b8d5142a8 in QCoreApplication::notifyInternal2(QObject*, QEvent*) () from /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#26 0x00007f6b8d51616a in QCoreApplicationPrivate::sendPostedEvents(QObject*, int, QThreadData*) () from /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#27 0x00007f6b8d566a02 in QEventDispatcherUNIX::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () from /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#28 0x00007f6b7789d8fd in ?? () from /usr/lib/x86_64-linux-gnu/libQt5XcbQpa.so.5
#29 0x00007f6b8d511ffa in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) () from /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#30 0x00007f6b8d51a6bc in QCoreApplication::exec() () from /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#31 0x00007f6b8f9cc226 in kdemain () from /usr/lib/x86_64-linux-gnu/libkdeinit5_kwin_x11.so
#32 0x00007f6b8f619830 in __libc_start_main (main=0x400730, argc=3, argv=0x7ffeb8e77a18, init=<optimized out>, fini=<optimized out>, rtld_fini=<optimized out>, stack_end=0x7ffeb8e77a08) at ../csu/libc-start.c:291
#33 0x0000000000400769 in _start ()

Possible duplicates by query: bug 393063, bug 389936.

Reported using DrKonqi