Application: kwin_x11 (5.27.9)
 (Compiled from sources)
Qt Version: 5.15.12
Frameworks Version: 5.111.0
Operating System: Linux 6.5.10_p1-debian-sources x86_64
Windowing System: X11
Distribution: Funtoo Linux
DrKonqi: 5.27.9 [KCrashBackend]

-- Information about the crash:
Frequently when I start GZDoom (a classic Doom source port), `kwin` segfaults.  GZDoom is using the OpenGL renderer when this happens.  The compositor turns off while GZDoom is running.  The segfault reliably occurs every time.  Initially the GZDoom window is very small, despite being set to 1080p resolution.  I used a KWin window rule to force it to fullscreen without decorations.  

Dristribution method Other is  "Funtoo packages"; KDE is available for Funtoo Linux in a similar way as on Gentoo.

The crash can be reproduced every time.

-- Backtrace:
Application: KWin (kwin_x11), signal: Segmentation fault

[KCrash Handler]
#4  0x00005622c9515aa6 in ?? ()
#5  0x00005622c9516213 in ?? ()
#6  0x00007f2ee369fe8a in KWin::EffectsHandlerImpl::prePaintWindow(KWin::EffectWindow*, KWin::WindowPrePaintData&, std::chrono::duration<long, std::ratio<1l, 1000l> >) () from /usr/lib/libkwin.so.5
#7  0x00007f2ee373f714 in KWin::WorkspaceScene::preparePaintSimpleScreen() () from /usr/lib/libkwin.so.5
#8  0x00007f2ee373fc25 in KWin::WorkspaceScene::prePaint(KWin::SceneDelegate*) () from /usr/lib/libkwin.so.5
#9  0x00007f2ee3659aef in KWin::Compositor::prePaintPass(KWin::RenderLayer*) () from /usr/lib/libkwin.so.5
#10 0x00007f2ee365ccff in KWin::Compositor::composite(KWin::RenderLoop*) () from /usr/lib/libkwin.so.5
#11 0x00007f2ee365eccb in KWin::X11Compositor::composite(KWin::RenderLoop*) () from /usr/lib/libkwin.so.5
#12 0x00007f2ee1eb8374 in ?? () from /usr/lib/libQt5Core.so.5
#13 0x00007f2ee360e232 in KWin::RenderLoop::frameRequested(KWin::RenderLoop*) () from /usr/lib/libkwin.so.5
#14 0x00007f2ee3666c83 in KWin::RenderLoopPrivate::dispatch() () from /usr/lib/libkwin.so.5
#15 0x00007f2ee1eb8374 in ?? () from /usr/lib/libQt5Core.so.5
#16 0x00007f2ee1ebc6da in QTimer::timeout(QTimer::QPrivateSignal) () from /usr/lib/libQt5Core.so.5
#17 0x00007f2ee1eb00c5 in QObject::event(QEvent*) () from /usr/lib/libQt5Core.so.5
#18 0x00007f2ee116340e in QApplicationPrivate::notify_helper(QObject*, QEvent*) () from /usr/lib/libQt5Widgets.so.5
#19 0x00007f2ee1e84ec8 in QCoreApplication::notifyInternal2(QObject*, QEvent*) () from /usr/lib/libQt5Core.so.5
#20 0x00007f2ee1ed5ef9 in QTimerInfoList::activateTimers() () from /usr/lib/libQt5Core.so.5
#21 0x00007f2ee1ed67c1 in ?? () from /usr/lib/libQt5Core.so.5
#22 0x00007f2edf92d168 in g_main_context_dispatch () from /usr/lib/libglib-2.0.so.0
#23 0x00007f2edf92d408 in ?? () from /usr/lib/libglib-2.0.so.0
#24 0x00007f2edf92d49c in g_main_context_iteration () from /usr/lib/libglib-2.0.so.0
#25 0x00007f2ee1ed6b56 in QEventDispatcherGlib::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () from /usr/lib/libQt5Core.so.5
#26 0x00007f2ee1e838eb in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) () from /usr/lib/libQt5Core.so.5
#27 0x00007f2ee1e8bbc6 in QCoreApplication::exec() () from /usr/lib/libQt5Core.so.5
#28 0x00005622c94a4244 in ?? ()
#29 0x00007f2ee0a627b4 in __libc_start_main () from /lib/libc.so.6
#30 0x00005622c94a56ea in ?? ()
[Inferior 1 (process 13128) detached]

Reported using DrKonqi