SUMMARY
I was switching between two user accounts while testing display scale factors with them. At some point kwin_wayland crashed after login.

Operating System: Arch Linux
KDE Plasma Version: 5.25.90
KDE Frameworks Version: 5.98.0
Qt Version: 5.15.6
Graphics Platform: Wayland


Thread 10 (Thread 0x7f81a87ff6c0 (LWP 20147)):
#0  0x00007f81ad713e5f in __GI___poll (fds=0x7f81a00053e0, nfds=3, timeout=20895) at ../sysdeps/unix/sysv/linux/poll.c:29
#1  0x00007f81ac170ddf in g_main_context_poll (priority=<optimized out>, n_fds=3, fds=0x7f81a00053e0, timeout=<optimized out>, context=0x7f81a0001cf0) at ../glib/glib/gmain.c:4516
#2  g_main_context_iterate.constprop.0 (context=context@entry=0x7f81a0001cf0, block=block@entry=1, dispatch=dispatch@entry=1, self=<optimized out>) at ../glib/glib/gmain.c:4206
#3  0x00007f81ac118252 in g_main_context_iteration (context=0x7f81a0001cf0, may_block=1) at ../glib/glib/gmain.c:4276
#4  0x00007f81ae6d750c in QEventDispatcherGlib::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) (this=0x7f81a0000b70, flags=...) at kernel/qeventdispatcher_glib.cpp:423
#5  0x00007f81ae68532c in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) (this=0x7f81a87fead0, flags=...) at ../../include/QtCore/../../src/corelib/global/qflags.h:69
#6  0x00007f81ae4e749f in QThread::exec() (this=this@entry=0x7f81b044a560 <(anonymous namespace)::Q_QGS__q_manager::innerFunction()::holder>) at ../../include/QtCore/../../src/corelib/global/qflags.h:121
#7  0x00007f81b03eecba in QDBusConnectionManager::run() (this=0x7f81b044a560 <(anonymous namespace)::Q_QGS__q_manager::innerFunction()::holder>) at /usr/src/debug/qtbase/src/dbus/qdbusconnection.cpp:179
#8  0x00007f81ae4e42ba in QThreadPrivate::start(void*) (arg=0x7f81b044a560 <(anonymous namespace)::Q_QGS__q_manager::innerFunction()::holder>) at thread/qthread_unix.cpp:330
#9  0x00007f81ad69f74d in start_thread (arg=<optimized out>) at pthread_create.c:442
#10 0x00007f81ad721700 in clone3 () at ../sysdeps/unix/sysv/linux/x86_64/clone3.S:81

Thread 9 (Thread 0x7f8189fbc6c0 (LWP 20156)):
#0  __futex_abstimed_wait_common64 (private=0, cancel=true, abstime=0x0, op=393, expected=0, futex_word=0x7f8198034550) at futex-internal.c:57
#1  __futex_abstimed_wait_common (futex_word=futex_word@entry=0x7f8198034550, expected=expected@entry=0, clockid=clockid@entry=0, abstime=abstime@entry=0x0, private=private@entry=0, cancel=cancel@entry=true) at futex-internal.c:87
#2  0x00007f81ad69c36f in __GI___futex_abstimed_wait_cancelable64 (futex_word=futex_word@entry=0x7f8198034550, expected=expected@entry=0, clockid=clockid@entry=0, abstime=abstime@entry=0x0, private=private@entry=0) at futex-internal.c:139
#3  0x00007f81ad69eb20 in __pthread_cond_wait_common (abstime=0x0, clockid=0, mutex=0x7f8198034500, cond=0x7f8198034528) at pthread_cond_wait.c:503
#4  ___pthread_cond_wait (cond=0x7f8198034528, mutex=0x7f8198034500) at pthread_cond_wait.c:618
#5  0x00007f81a62b2c5c in cnd_wait () at ../mesa-22.1.7/include/c11/threads_posix.h:155
#6  util_queue_thread_func() () at ../mesa-22.1.7/src/util/u_queue.c:294
#7  0x00007f81a62ac35c in impl_thrd_routine() () at ../mesa-22.1.7/include/c11/threads_posix.h:87
#8  0x00007f81ad69f74d in start_thread (arg=<optimized out>) at pthread_create.c:442
#9  0x00007f81ad721700 in clone3 () at ../sysdeps/unix/sysv/linux/x86_64/clone3.S:81

Thread 8 (Thread 0x7f81897796c0 (LWP 20157)):
#0  0x00007f81ad713e5f in __GI___poll (fds=0x7f81780029e0, nfds=1, timeout=-1) at ../sysdeps/unix/sysv/linux/poll.c:29
#1  0x00007f81ac170ddf in g_main_context_poll (priority=<optimized out>, n_fds=1, fds=0x7f81780029e0, timeout=<optimized out>, context=0x7f8178000c30) at ../glib/glib/gmain.c:4516
#2  g_main_context_iterate.constprop.0 (context=context@entry=0x7f8178000c30, block=block@entry=1, dispatch=dispatch@entry=1, self=<optimized out>) at ../glib/glib/gmain.c:4206
#3  0x00007f81ac118252 in g_main_context_iteration (context=0x7f8178000c30, may_block=1) at ../glib/glib/gmain.c:4276
#4  0x00007f81ae6d750c in QEventDispatcherGlib::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) (this=0x7f8178000b70, flags=...) at kernel/qeventdispatcher_glib.cpp:423
#5  0x00007f81ae68532c in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) (this=0x7f8189778ae0, flags=...) at ../../include/QtCore/../../src/corelib/global/qflags.h:69
#6  0x00007f81ae4e749f in QThread::exec() (this=this@entry=0x55a12f8f00b0) at ../../include/QtCore/../../src/corelib/global/qflags.h:121
#7  0x00007f81af4c0300 in QQmlThreadPrivate::run() (this=0x55a12f8f00b0) at /usr/src/debug/qtdeclarative/src/qml/qml/ftw/qqmlthread.cpp:155
#8  0x00007f81ae4e42ba in QThreadPrivate::start(void*) (arg=0x55a12f8f00b0) at thread/qthread_unix.cpp:330
#9  0x00007f81ad69f74d in start_thread (arg=<optimized out>) at pthread_create.c:442
#10 0x00007f81ad721700 in clone3 () at ../sysdeps/unix/sysv/linux/x86_64/clone3.S:81

Thread 7 (Thread 0x7f818affd6c0 (LWP 20154)):
#0  0x00007f81ad713e5f in __GI___poll (fds=0x7f81800029e0, nfds=1, timeout=-1) at ../sysdeps/unix/sysv/linux/poll.c:29
#1  0x00007f81ac170ddf in g_main_context_poll (priority=<optimized out>, n_fds=1, fds=0x7f81800029e0, timeout=<optimized out>, context=0x7f8180000c30) at ../glib/glib/gmain.c:4516
#2  g_main_context_iterate.constprop.0 (context=context@entry=0x7f8180000c30, block=block@entry=1, dispatch=dispatch@entry=1, self=<optimized out>) at ../glib/glib/gmain.c:4206
#3  0x00007f81ac118252 in g_main_context_iteration (context=0x7f8180000c30, may_block=1) at ../glib/glib/gmain.c:4276
#4  0x00007f81ae6d750c in QEventDispatcherGlib::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) (this=0x7f8180000b70, flags=...) at kernel/qeventdispatcher_glib.cpp:423
#5  0x00007f81ae68532c in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) (this=0x7f818affcae0, flags=...) at ../../include/QtCore/../../src/corelib/global/qflags.h:69
#6  0x00007f81ae4e749f in QThread::exec() (this=this@entry=0x55a12ef39040) at ../../include/QtCore/../../src/corelib/global/qflags.h:121
#7  0x00007f81af4c0300 in QQmlThreadPrivate::run() (this=0x55a12ef39040) at /usr/src/debug/qtdeclarative/src/qml/qml/ftw/qqmlthread.cpp:155
#8  0x00007f81ae4e42ba in QThreadPrivate::start(void*) (arg=0x55a12ef39040) at thread/qthread_unix.cpp:330
#9  0x00007f81ad69f74d in start_thread (arg=<optimized out>) at pthread_create.c:442
#10 0x00007f81ad721700 in clone3 () at ../sysdeps/unix/sysv/linux/x86_64/clone3.S:81

Thread 6 (Thread 0x7f818b7fe6c0 (LWP 20153)):
#0  __futex_abstimed_wait_common64 (private=0, cancel=true, abstime=0x7f818b7fda60, op=137, expected=0, futex_word=0x55a12ee52de4) at futex-internal.c:57
#1  __futex_abstimed_wait_common (futex_word=futex_word@entry=0x55a12ee52de4, expected=expected@entry=0, clockid=clockid@entry=1, abstime=abstime@entry=0x7f818b7fda60, private=private@entry=0, cancel=cancel@entry=true) at futex-internal.c:87
#2  0x00007f81ad69c36f in __GI___futex_abstimed_wait_cancelable64 (futex_word=futex_word@entry=0x55a12ee52de4, expected=expected@entry=0, clockid=clockid@entry=1, abstime=abstime@entry=0x7f818b7fda60, private=private@entry=0) at futex-internal.c:139
#3  0x00007f81ad69ee24 in __pthread_cond_wait_common (abstime=0x7f818b7fda60, clockid=1, mutex=0x55a12ee52d90, cond=0x55a12ee52db8) at pthread_cond_wait.c:503
#4  ___pthread_cond_timedwait64 (cond=0x55a12ee52db8, mutex=0x55a12ee52d90, abstime=0x7f818b7fda60) at pthread_cond_wait.c:643
#5  0x00007f81ae4eb6d4 in QWaitConditionPrivate::wait_relative(QDeadlineTimer) (deadline=..., this=0x55a12ee52d90) at thread/qwaitcondition_unix.cpp:136
#6  QWaitConditionPrivate::wait(QDeadlineTimer) (deadline=..., this=0x55a12ee52d90) at thread/qwaitcondition_unix.cpp:144
#7  QWaitCondition::wait(QMutex*, QDeadlineTimer) (this=<optimized out>, mutex=0x55a12ee3ec38, deadline=...) at thread/qwaitcondition_unix.cpp:225
#8  0x00007f81ae4e8537 in QThreadPoolThread::run() (this=0x55a12ee45720) at thread/qthreadpool.cpp:140
#9  0x00007f81ae4e42ba in QThreadPrivate::start(void*) (arg=0x55a12ee45720) at thread/qthread_unix.cpp:330
#10 0x00007f81ad69f74d in start_thread (arg=<optimized out>) at pthread_create.c:442
#11 0x00007f81ad721700 in clone3 () at ../sysdeps/unix/sysv/linux/x86_64/clone3.S:81

Thread 5 (Thread 0x7f818bfff6c0 (LWP 20152)):
#0  __futex_abstimed_wait_common64 (private=0, cancel=true, abstime=0x0, op=393, expected=0, futex_word=0x7f81a4cc4550) at futex-internal.c:57
#1  __futex_abstimed_wait_common (futex_word=futex_word@entry=0x7f81a4cc4550, expected=expected@entry=0, clockid=clockid@entry=0, abstime=abstime@entry=0x0, private=private@entry=0, cancel=cancel@entry=true) at futex-internal.c:87
#2  0x00007f81ad69c36f in __GI___futex_abstimed_wait_cancelable64 (futex_word=futex_word@entry=0x7f81a4cc4550, expected=expected@entry=0, clockid=clockid@entry=0, abstime=abstime@entry=0x0, private=private@entry=0) at futex-internal.c:139
#3  0x00007f81ad69eb20 in __pthread_cond_wait_common (abstime=0x0, clockid=0, mutex=0x7f81a4cc4500, cond=0x7f81a4cc4528) at pthread_cond_wait.c:503
#4  ___pthread_cond_wait (cond=0x7f81a4cc4528, mutex=0x7f81a4cc4500) at pthread_cond_wait.c:618
#5  0x00007f81a62b2c5c in cnd_wait () at ../mesa-22.1.7/include/c11/threads_posix.h:155
#6  util_queue_thread_func() () at ../mesa-22.1.7/src/util/u_queue.c:294
#7  0x00007f81a62ac35c in impl_thrd_routine() () at ../mesa-22.1.7/include/c11/threads_posix.h:87
#8  0x00007f81ad69f74d in start_thread (arg=<optimized out>) at pthread_create.c:442
#9  0x00007f81ad721700 in clone3 () at ../sysdeps/unix/sysv/linux/x86_64/clone3.S:81

Thread 4 (Thread 0x7f8198dff6c0 (LWP 20151)):
#0  __futex_abstimed_wait_common64 (private=0, cancel=true, abstime=0x0, op=393, expected=0, futex_word=0x7f81a4d3a550) at futex-internal.c:57
#1  __futex_abstimed_wait_common (futex_word=futex_word@entry=0x7f81a4d3a550, expected=expected@entry=0, clockid=clockid@entry=0, abstime=abstime@entry=0x0, private=private@entry=0, cancel=cancel@entry=true) at futex-internal.c:87
#2  0x00007f81ad69c36f in __GI___futex_abstimed_wait_cancelable64 (futex_word=futex_word@entry=0x7f81a4d3a550, expected=expected@entry=0, clockid=clockid@entry=0, abstime=abstime@entry=0x0, private=private@entry=0) at futex-internal.c:139
#3  0x00007f81ad69eb20 in __pthread_cond_wait_common (abstime=0x0, clockid=0, mutex=0x7f81a4d3a500, cond=0x7f81a4d3a528) at pthread_cond_wait.c:503
#4  ___pthread_cond_wait (cond=0x7f81a4d3a528, mutex=0x7f81a4d3a500) at pthread_cond_wait.c:618
#5  0x00007f81a62b2c5c in cnd_wait () at ../mesa-22.1.7/include/c11/threads_posix.h:155
#6  util_queue_thread_func() () at ../mesa-22.1.7/src/util/u_queue.c:294
#7  0x00007f81a62ac35c in impl_thrd_routine() () at ../mesa-22.1.7/include/c11/threads_posix.h:87
#8  0x00007f81ad69f74d in start_thread (arg=<optimized out>) at pthread_create.c:442
#9  0x00007f81ad721700 in clone3 () at ../sysdeps/unix/sysv/linux/x86_64/clone3.S:81

Thread 3 (Thread 0x7f81a5df26c0 (LWP 20149)):
#0  __futex_abstimed_wait_common64 (private=0, cancel=true, abstime=0x0, op=393, expected=0, futex_word=0x55a12eb938c8) at futex-internal.c:57
#1  __futex_abstimed_wait_common (futex_word=futex_word@entry=0x55a12eb938c8, expected=expected@entry=0, clockid=clockid@entry=0, abstime=abstime@entry=0x0, private=private@entry=0, cancel=cancel@entry=true) at futex-internal.c:87
#2  0x00007f81ad69c36f in __GI___futex_abstimed_wait_cancelable64 (futex_word=futex_word@entry=0x55a12eb938c8, expected=expected@entry=0, clockid=clockid@entry=0, abstime=abstime@entry=0x0, private=private@entry=0) at futex-internal.c:139
#3  0x00007f81ad69eb20 in __pthread_cond_wait_common (abstime=0x0, clockid=0, mutex=0x55a12eb93878, cond=0x55a12eb938a0) at pthread_cond_wait.c:503
#4  ___pthread_cond_wait (cond=0x55a12eb938a0, mutex=0x55a12eb93878) at pthread_cond_wait.c:618
#5  0x00007f81a62b2c5c in cnd_wait () at ../mesa-22.1.7/include/c11/threads_posix.h:155
#6  util_queue_thread_func() () at ../mesa-22.1.7/src/util/u_queue.c:294
#7  0x00007f81a62ac35c in impl_thrd_routine() () at ../mesa-22.1.7/include/c11/threads_posix.h:87
#8  0x00007f81ad69f74d in start_thread (arg=<optimized out>) at pthread_create.c:442
#9  0x00007f81ad721700 in clone3 () at ../sysdeps/unix/sysv/linux/x86_64/clone3.S:81

Thread 2 (Thread 0x7f81a55f16c0 (LWP 20150)):
#0  0x00007f81ad713e5f in __GI___poll (fds=0x7f818c0029e0, nfds=2, timeout=-1) at ../sysdeps/unix/sysv/linux/poll.c:29
#1  0x00007f81ac170ddf in g_main_context_poll (priority=<optimized out>, n_fds=2, fds=0x7f818c0029e0, timeout=<optimized out>, context=0x7f818c000c30) at ../glib/glib/gmain.c:4516
#2  g_main_context_iterate.constprop.0 (context=context@entry=0x7f818c000c30, block=block@entry=1, dispatch=dispatch@entry=1, self=<optimized out>) at ../glib/glib/gmain.c:4206
#3  0x00007f81ac118252 in g_main_context_iteration (context=0x7f818c000c30, may_block=1) at ../glib/glib/gmain.c:4276
#4  0x00007f81ae6d750c in QEventDispatcherGlib::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) (this=0x7f818c000b70, flags=...) at kernel/qeventdispatcher_glib.cpp:423
#5  0x00007f81ae68532c in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) (this=0x7f81a55f0b00, flags=...) at ../../include/QtCore/../../src/corelib/global/qflags.h:69
#6  0x00007f81ae4e749f in QThread::exec() (this=<optimized out>) at ../../include/QtCore/../../src/corelib/global/qflags.h:121
#7  0x00007f81ae4e42ba in QThreadPrivate::start(void*) (arg=0x55a12ec58d28) at thread/qthread_unix.cpp:330
#8  0x00007f81ad69f74d in start_thread (arg=<optimized out>) at pthread_create.c:442
#9  0x00007f81ad721700 in clone3 () at ../sysdeps/unix/sysv/linux/x86_64/clone3.S:81

Thread 1 (Thread 0x7f81a8bcf0c0 (LWP 20131)):
#0  __pthread_kill_implementation (threadid=<optimized out>, signo=signo@entry=6, no_tid=no_tid@entry=0) at pthread_kill.c:44
#1  0x00007f81ad6a1503 in __pthread_kill_internal (signo=6, threadid=<optimized out>) at pthread_kill.c:78
#2  0x00007f81ad651958 in __GI_raise (sig=sig@entry=6) at ../sysdeps/posix/raise.c:26
#3  0x00007f81ad63b53d in __GI_abort () at abort.c:79
#4  0x00007f81af6dbc8e in egl_provider_resolver (name=name@entry=0x7f81af701b5c <entrypoint_strings+988> "eglDestroyImageKHR", providers=providers@entry=0x7f81af701704 <providers.23.lto_priv>, entrypoints=entrypoints@entry=0x7f81af7016f8 <entrypoints.22.lto_priv>) at src/egl_generated_dispatch.c:3911
#5  0x00007f81af6df52a in epoxy_eglDestroyImageKHR_resolver () at src/egl_generated_dispatch.c:4264
#6  epoxy_eglDestroyImageKHR_global_rewrite_ptr (dpy=0x55a12eb81920, image=0x55a12fee16e0) at src/egl_generated_dispatch.c:5059
#7  0x00007f81b01f9017 in KWin::EglDmabufBuffer::removeImages() (this=this@entry=0x55a12fee1dd0) at /usr/src/debug/kwin-5.25.90/src/platformsupport/scenes/opengl/egl_dmabuf.cpp:131
#8  0x00007f81b01f9177 in KWin::EglDmabufBuffer::~EglDmabufBuffer() (this=0x55a12fee1dd0, this=<optimized out>) at /usr/src/debug/kwin-5.25.90/src/platformsupport/scenes/opengl/egl_dmabuf.cpp:115
#9  KWin::EglDmabufBuffer::~EglDmabufBuffer() (this=0x55a12fee1dd0, this=<optimized out>) at /usr/src/debug/kwin-5.25.90/src/platformsupport/scenes/opengl/egl_dmabuf.cpp:116
#10 0x00007f81acf9389f in wl_priv_signal_final_emit (data=<optimized out>, signal=<optimized out>) at ../wayland-1.21.0/src/wayland-server.c:2315
#11 destroy_resource (element=0x55a12ffe0a40, data=data@entry=0x0, flags=0) at ../wayland-1.21.0/src/wayland-server.c:727
#12 0x00007f81acf95689 in wl_resource_destroy (resource=<optimized out>) at ../wayland-1.21.0/src/wayland-server.c:747
#13 0x00007f81ab956536 in ffi_call_unix64 () at ../src/x86/unix64.S:105
#14 0x00007f81ab953037 in ffi_call_int (cif=<optimized out>, fn=<optimized out>, rvalue=<optimized out>, avalue=<optimized out>, closure=<optimized out>) at ../src/x86/ffi64.c:672
#15 0x00007f81acf90ada in wl_closure_invoke (closure=closure@entry=0x55a12f8b63c0, target=<optimized out>, target@entry=0x55a12ffe0a40, opcode=opcode@entry=0, data=<optimized out>, data@entry=0x55a12ff1df90, flags=2) at ../wayland-1.21.0/src/connection.c:1025
#16 0x00007f81acf95010 in wl_client_connection_data (fd=<optimized out>, mask=<optimized out>, data=<optimized out>) at ../wayland-1.21.0/src/wayland-server.c:437
#17 0x00007f81acf939e2 in wl_event_loop_dispatch (loop=0x55a12eb8d630, timeout=<optimized out>) at ../wayland-1.21.0/src/event-loop.c:1027
#18 0x00007f81b0196c4a in KWaylandServer::Display::dispatchEvents() (this=<optimized out>) at /usr/src/debug/kwin-5.25.90/src/wayland/display.cpp:114
#19 0x00007f81ae6bd381 in QtPrivate::QSlotObjectBase::call(QObject*, void**) (a=0x7ffcc0490570, r=<optimized out>, this=0x55a12f85d0b0, this=<optimized out>, r=<optimized out>, a=<optimized out>) at ../../include/QtCore/../../src/corelib/kernel/qobjectdefs_impl.h:398
#20 doActivate<false>(QObject*, int, void**) (sender=0x55a12eb152b0, signal_index=3, argv=0x7ffcc0490570) at kernel/qobject.cpp:3919
#21 0x00007f81ae6bf234 in QSocketNotifier::activated(QSocketDescriptor, QSocketNotifier::Type, QSocketNotifier::QPrivateSignal) (this=this@entry=0x55a12eb152b0, _t1=..., _t2=<optimized out>, _t3=...) at .moc/moc_qsocketnotifier.cpp:178
#22 0x00007f81ae6bf378 in QSocketNotifier::event(QEvent*) (this=0x55a12eb152b0, e=<optimized out>) at kernel/qsocketnotifier.cpp:302
#23 0x00007f81add78b1c in QApplicationPrivate::notify_helper(QObject*, QEvent*) (this=<optimized out>, receiver=0x55a12eb152b0, e=0x7ffcc0490690) at kernel/qapplication.cpp:3637
#24 0x00007f81ae68cb88 in QCoreApplication::notifyInternal2(QObject*, QEvent*) (receiver=0x55a12eb152b0, event=0x7ffcc0490690) at kernel/qcoreapplication.cpp:1064
#25 0x00007f81ae6d61cc in QEventDispatcherUNIXPrivate::activateSocketNotifiers() (this=0x55a12eb553d0) at kernel/qeventdispatcher_unix.cpp:304
#26 0x00007f81ae6d72c1 in QEventDispatcherUNIX::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) (this=<optimized out>, flags=...) at kernel/qeventdispatcher_unix.cpp:511
#27 0x000055a12dd663d2 in QUnixEventDispatcherQPA::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) ()
#28 0x00007f81ae68532c in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) (this=0x7ffcc0490820, flags=...) at ../../include/QtCore/../../src/corelib/global/qflags.h:69
#29 0x00007f81ae68fe59 in QCoreApplication::exec() () at ../../include/QtCore/../../src/corelib/global/qflags.h:121
#30 0x00007f81aeb3a0e2 in QGuiApplication::exec() () at kernel/qguiapplication.cpp:1870
#31 0x00007f81add76f2a in QApplication::exec() () at kernel/qapplication.cpp:2829
#32 0x000055a12dc875bc in main(int, char**) (argc=<optimized out>, argv=<optimized out>) at /usr/src/debug/kwin-5.25.90/src/main_wayland.cpp:620