Created attachment 163254 [details]
Full trace of all threads of plasmashell crash

SUMMARY

I was using Plasma 5.27.9 on Wayland in a Fedora 39 KDE Plasma installation. I started Firefox 121.0a1 (2023-11-17) on Wayland. I logged into my Instagram account. I played various videos in posts and stories. plasmashell crashed while playing a video in a post. I clicked on the mute button on the video around the time of the crash though that might've been right after the crash. The panel disappeared from the bottom of the screen and reappeared automatically a few seconds later. drkonqi didn't appear. abrt and selinux notifications appeared. plasmashell crashed in QObject::parent according to coredumpctl gdb.

Core was generated by `/usr/bin/plasmashell --no-respawn'.
Program terminated with signal SIGSEGV, Segmentation fault.
#0  0x00007ff1f4b63209 in QObject::parent (this=<optimized out>, this=<optimized out>)
    at /usr/include/qt5/QtCore/qscopedpointer.h:116
116         T *operator->() const noexcept
[Current thread is 1 (Thread 0x7ff1f47b9a00 (LWP 29651))]

(gdb) bt
#0  0x00007ff1f4b63209 in QObject::parent() const (this=0x55f8b5f92910, this=<optimized out>)
    at /usr/include/qt5/QtCore/qscopedpointer.h:116
#1  Plasma::DataContainer::getDataEngine() (this=this@entry=0x55f8b5f92910)
    at /usr/src/debug/kf5-plasma-5.111.0-1.fc39.x86_64/src/plasma/datacontainer.cpp:202
#2  0x00007ff18f1f1fed in MultiplexedService::activePlayerChanged(PlayerContainer*)
    (this=this@entry=0x55f8b785cf80, container=0x55f8b5f92910)
    at /usr/src/debug/plasma-workspace-5.27.9.1-2.fc39.x86_64/dataengines/mpris2/multiplexedservice.cpp:58
#3  0x00007ff18f1f91d8 in MultiplexedService::MultiplexedService(Multiplexer*, QObject*)
    (parent=<optimized out>, multiplexer=0x55f8b757d270, this=0x55f8b785cf80)
    at /usr/src/debug/plasma-workspace-5.27.9.1-2.fc39.x86_64/dataengines/mpris2/multiplexedservice.cpp:25
#4  Mpris2Engine::serviceForSource(QString const&) (this=<optimized out>, source=<optimized out>)
    at /usr/src/debug/plasma-workspace-5.27.9.1-2.fc39.x86_64/dataengines/mpris2/mpris2engine.cpp:40
#5  0x00007ff1cfefe130 in Plasma::DataSource::serviceForSource(QString const&)
    (source=..., this=0x55f8b51b36a0)
    at /usr/src/debug/kf5-plasma-5.111.0-1.fc39.x86_64/src/declarativeimports/core/datasource.cpp:208
#6  Plasma::DataSource::qt_static_metacall(QObject*, QMetaObject::Call, int, void**)
    (_o=0x55f8b51b36a0, _c=QMetaObject::InvokeMetaMethod, _id=<optimized out>, _a=<optimized out>)
    at /usr/src/debug/kf5-plasma-5.111.0-1.fc39.x86_64/redhat-linux-build/src/declarativeimports/core/corebindingsplugin_autogen/include/moc_datasource.cpp:201
#7  0x00007ff1cfeff922 in Plasma::DataSource::qt_metacall(QMetaObject::Call, int, void**)
    (this=0x55f8b51b36a0, _c=QMetaObject::InvokeMetaMethod, _id=16, _a=0x7ffcd7984990)
--Type <RET> for more, q to quit, c to continue without paging--c
    at /usr/src/debug/kf5-plasma-5.111.0-1.fc39.x86_64/redhat-linux-build/src/declarativeimports/core/corebindingsplugin_autogen/include/moc_datasource.cpp:370
#8  0x00007ff1f3ef532a in QQmlObjectOrGadget::metacall(QMetaObject::Call, int, void**) const
    (this=this@entry=0x7ffcd7984c30, type=type@entry=QMetaObject::InvokeMetaMethod, index=<optimized out>, index@entry=21, argv=<optimized out>) at qml/qqmlobjectorgadget.cpp:51
#9  0x00007ff1f3dc7e13 in CallMethod
    (callType=<optimized out>, callArgs=0x7ffcd7984990, engine=<optimized out>, argTypes=<optimized out>, argCount=<optimized out>, returnType=<optimized out>, index=<optimized out>, object=...)
    at /usr/include/qt5/QtCore/qvarlengtharray.h:189
#10 CallPrecise(QQmlObjectOrGadget const&, QQmlPropertyData const&, QV4::ExecutionEngine*, QV4::CallData*, QMetaObject::Call)
    (object=..., data=<optimized out>, engine=engine@entry=0x55f8b48decf0, callArgs=callArgs@entry=0x7ff1adfbd588, callType=callType@entry=QMetaObject::InvokeMetaMethod)
    at jsruntime/qv4qobjectwrapper.cpp:1553
#11 0x00007ff1f3dc9c12 in CallOverloaded
    (callType=<optimized out>, propertyCache=<optimized out>, callArgs=<optimized out>, engine=<optimized out>, data=<optimized out>, object=<optimized out>) at jsruntime/qv4qobjectwrapper.cpp:1629
#12 QV4::QObjectMethod::callInternal(QV4::Value const*, QV4::Value const*, int) const
    (this=<optimized out>, thisObject=<optimized out>, argv=<optimized out>, argc=<optimized out>)
    at jsruntime/qv4qobjectwrapper.cpp:2117
#13 0x00007ff1f3dfa6c1 in QV4::FunctionObject::call(QV4::Value const*, QV4::Value const*, int) const
    (argc=1, argv=0x7ff1adfbd550, thisObject=0x7ff1adfbd538, this=0x7ffcd7984d58)
    at jsruntime/qv4functionobject_p.h:202
#14 QV4::Runtime::CallPropertyLookup::call(QV4::ExecutionEngine*, QV4::Value const&, unsigned int, QV4::Value*, int) (engine=0x55f8b48decf0, base=..., index=<optimized out>, argv=0x7ff1adfbd550, argc=1)
    at jsruntime/qv4runtime.cpp:1460
#15 0x00007ff199b7cebf in  ()
#16 0x0000000000000000 in  ()

I'm attaching the full trace of all threads. The pointer de was null in frames 0 in QObject::parent() and 1 in Plasma::DataContainer::getDataEngine() of the crashing thread 1 in the full trace.

This crash was the first with this trace I've seen. The functions like MultiplexedService::activePlayerChanged in frames 2 to 4 might indicate that the media player applet was involved.

STEPS TO REPRODUCE
1. boot a Fedora 39 KDE Plasma installation
2. log in to Plasma 5.27.9 on Wayland from sddm
3. start Firefox 121.0a1 (2023-11-17) on Wayland
4. log in to your Instagram account
5. play videos in Instagram posts until the problem happens. pressing the mute button on the video might be involved. This problem didn't normally happen so it might take a long time before it does.

OBSERVED RESULT
plasmashell crashed in QObject::parent when playing a video in Firefox

EXPECTED RESULT
plasmashell shouldn't have crashed

SOFTWARE/OS VERSIONS
Linux/KDE Plasma: Fedora 39
(available in About System)
KDE Plasma Version: 5.27.9
KDE Frameworks Version: 5.111.0
Qt Version: 5.15.11

ADDITIONAL INFORMATION

I've seen occasional plasmashell crashes when playing Instagram videos in Firefox which I reported at Bug 471248. I don't know if that problem is related to this one as those crashes didn't create core dumps. Journal messages like the following were repeatedly shown shortly before this crash as also happened with Bug 471248
Nov 17 19:06:41 plasmashell[29651]: file:///usr/share/plasma/plasmoids/org.kde.plasma.private.systemtray/contents/ui/items/PlasmoidItem.qml:125: TypeError: Cannot read property 'compactRepresentationItem' of null