Unfortunately the backtrace is incomplete and missing debug symbols for the following line that we need to figure out exactly what's going wrong:

> #2  0x00007fa0e284a1b2 in  () at /usr/lib/qt/plugins/plasma/kcms/systemsettings/kcm_firewall.so

Could you please install debug symbols for plasma-firewall, reproduce the crash, and attach a new symbolicated backtrace? See https://community.kde.org/Guidelines_and_HOWTOs/Debugging/How_to_create_useful_crash_reports for details about how to do this.

Thanks!

This is the updated backtrace:

[Thread debugging using libthread_db enabled]                                                                                                                                                  
Using host libthread_db library "/usr/lib/libthread_db.so.1".
Core was generated by `/usr/bin/systemsettings'.
Program terminated with signal SIGSEGV, Segmentation fault.
#0  QString::size (this=<optimized out>, this=<optimized out>) at ../../include/QtCore/../../src/corelib/text/qstring.h:277
277         inline int size() const { return d->size; }                                                                                                                                        
[Current thread is 1 (Thread 0x7fa10a86eac0 (LWP 4290))]
(gdb) bt
#0  QString::size() const (this=0x5584d83b98b8, this=<optimized out>) at ../../include/QtCore/../../src/corelib/text/qstring.h:277
#1  (anonymous namespace)::splitString<QStringList, QString>(QString const&, QChar const*, Qt::SplitBehavior, Qt::CaseSensitivity, int)
    (source=..., sep=0x7ffd173b591e, behavior=..., cs=Qt::CaseSensitive, separatorSize=1) at text/qstring.cpp:7818
#2  0x00007fa10ff60e91 in QString::split(QChar, QFlags<Qt::SplitBehaviorFlags>, Qt::CaseSensitivity) const (this=<optimized out>, sep=..., behavior=..., 
    behavior@entry=..., cs=cs@entry=Qt::CaseSensitive) at text/qstring.cpp:7929
#3  0x00007fa0e284a1b2 in NetstatHelper::parseSSOutput(QByteArray const&) (this=0x5584d81acd50, netstatOutput=...)
    at /usr/src/debug/plasma-firewall/plasma-firewall-5.27.5/kcm/backends/netstat/netstathelper.cpp:148
#4  NetstatHelper::stepExecuteFinished(int) (this=0x5584d81acd50, exitCode=<optimized out>) at /usr/src/debug/plasma-firewall/plasma-firewall-5.27.5/kcm/backends/netstat/netstathelper.cpp:82
#5  0x00007fa1100beb41 in QtPrivate::QSlotObjectBase::call(QObject*, void**)
    (a=0x7ffd173b5b20, r=<optimized out>, this=0x5584d6bbeef0, this=<optimized out>, r=<optimized out>, a=<optimized out>)
    at ../../include/QtCore/../../src/corelib/kernel/qobjectdefs_impl.h:398
#6  doActivate<false>(QObject*, int, void**) (sender=0x5584d836f740, signal_index=11, argv=0x7ffd173b5b20) at kernel/qobject.cpp:3923
#7  0x00007fa11001862d in QProcess::finished(int, QProcess::ExitStatus) (this=<optimized out>, _t1=<optimized out>, _t2=<optimized out>) at .moc/moc_qprocess.cpp:339
#8  0x00007fa110014e32 in QProcessPrivate::_q_processDied() (this=0x5584d834adc0) at io/qprocess.cpp:1184
#9  0x00007fa110018ebe in QProcess::qt_static_metacall(QObject*, QMetaObject::Call, int, void**) (_o=<optimized out>, _c=<optimized out>, _id=<optimized out>, _a=0x7ffd173b5ca0)
    at io/qprocess.h:320
#10 0x00007fa1100becf0 in doActivate<false>(QObject*, int, void**) (sender=0x5584d81d0620, signal_index=3, argv=0x7ffd173b5ca0) at kernel/qobject.cpp:3935
#11 0x00007fa1100c09f4 in QSocketNotifier::activated(QSocketDescriptor, QSocketNotifier::Type, QSocketNotifier::QPrivateSignal)
    (this=this@entry=0x5584d81d0620, _t1=..., _t2=<optimized out>, _t3=...) at .moc/moc_qsocketnotifier.cpp:178
#12 0x00007fa1100c0b38 in QSocketNotifier::event(QEvent*) (this=0x5584d81d0620, e=<optimized out>) at kernel/qsocketnotifier.cpp:302
#13 0x00007fa110d78b5c in QApplicationPrivate::notify_helper(QObject*, QEvent*) (this=<optimized out>, receiver=0x5584d81d0620, e=0x7ffd173b5dc0) at kernel/qapplication.cpp:3640
#14 0x00007fa11008e028 in QCoreApplication::notifyInternal2(QObject*, QEvent*) (receiver=0x5584d81d0620, event=0x7ffd173b5dc0) at kernel/qcoreapplication.cpp:1064
#15 0x00007fa1100d7b96 in socketNotifierSourceDispatch(GSource*, GSourceFunc, gpointer) (source=0x5584d5a28830) at kernel/qeventdispatcher_glib.cpp:107
#16 0x00007fa10e90f53b in g_main_dispatch (context=0x7fa104000ee0) at ../glib/glib/gmain.c:3460
#17 g_main_context_dispatch (context=0x7fa104000ee0) at ../glib/glib/gmain.c:4200
#18 0x00007fa10e96c219 in g_main_context_iterate.constprop.0 (context=0x7fa104000ee0, block=1, dispatch=1, self=<optimized out>) at ../glib/glib/gmain.c:4276
#19 0x00007fa10e90e1a2 in g_main_context_iteration (context=0x7fa104000ee0, may_block=1) at ../glib/glib/gmain.c:4343
#20 0x00007fa1100d8d3c in QEventDispatcherGlib::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) (this=0x5584d59d3980, flags=...) at kernel/qeventdispatcher_glib.cpp:423
#21 0x00007fa11008668c in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) (this=0x7ffd173b6040, flags=...) at ../../include/QtCore/../../src/corelib/global/qflags.h:69
#22 0x00007fa1100912f9 in QCoreApplication::exec() () at ../../include/QtCore/../../src/corelib/global/qflags.h:121
#23 0x00007fa11053b052 in QGuiApplication::exec() () at kernel/qguiapplication.cpp:1870
#24 0x00007fa110d76f2a in QApplication::exec() () at kernel/qapplication.cpp:2832
#25 0x00005584d44d4bd9 in main(int, char**) (argc=<optimized out>, argv=<optimized out>) at /usr/src/debug/systemsettings/systemsettings-5.27.5/app/main.cpp:188
(gdb)

Can you inform which backend, are you using?

(In reply to Lucas Biaggi from comment #3)
> Can you inform which backend, are you using?

I'm using ufw, this problem happens only after fresh login then accessing for the first or second time "View Connections" in Plasma settings.

I just did an update ~100 MiB, and went back to the firewall settings. I chose the View Connections and it worked. I started Firefox to report the development here, and while that was starting, the settings crashed again. But for at least 30 seconds, I saw the entries in View Connections. I have also been getting notifications about incomplete language packs.

Can you get a backtrace of that crash? https://community.kde.org/Guidelines_and_HOWTOs/Debugging/How_to_create_useful_crash_reports#Retrieving_a_backtrace_using_coredumpctl

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On Plasma 5.27.10/Manjaro, the crash seems to be gone, but can't confirm for other users.

Well you're the bug reporter, so if it's gone for you let's call it gone for everyone until and unless we get some more reports. :)

*** Bug 478407 has been marked as a duplicate of this bug. ***

*** Bug 493408 has been marked as a duplicate of this bug. ***

Re-opening since it was marked as fixed in 5.27.10, but we got a new report from someone using 5.27.11. No reports from anyone using Plasma 6, though. Might be fixed there. Would be good if anyone who hit this on Plasma 5 can try again with Plasma 6.

*** This bug has been marked as a duplicate of bug 455385 ***