Bug 491051

SUMMARY
xdg-desktop-portal-kde crashes in such a fatal way that it brings down the whole session. The screen goes black and even other TTYs seem to be unusable (no login prompt).

STEPS TO REPRODUCE
I cannot reproduce this consistently but the steps below indicate what i did before the crash occurred for the stack trace below.

1. Open firefox.
2. Make sure it is configured to use XDG Desktop Portals. e.g. widget.use-xdg-desktop-portal.* config variables set to 1 and maybe the environment variable GTK_USE_PORTAL = 1. Also ensure that "Always ask you where to save files" is checked in the settings.
3. Navigate to a page which offers files for download
4. Click link to download file.

OBSERVED RESULT
System crashes catastrophically and the screen goes black. I cannot even login to another TTY (no login prompt when switching) and I have to hard reboot by holding down the power button.

EXPECTED RESULT
I should be offered the Dolphin file picker via the relevant XDG Desktop Portal.

SOFTWARE/OS VERSIONS
Operating System: Fedora Linux 40
KDE Plasma Version: 6.1.3
KDE Frameworks Version: 6.4.0
Qt Version: 6.7.2

ADDITIONAL INFORMATION
Output from DrKonqi:
           PID: 2828 (xdg-desktop-por)
           UID: 1000 (miren)
           GID: 1000 (miren)
        Signal: 6 (ABRT)
     Timestamp: Tue 2024-07-30 23:13:59 BST (5min ago)
  Command Line: /usr/libexec/xdg-desktop-portal-kde
    Executable: /usr/libexec/xdg-desktop-portal-kde
 Control Group: /user.slice/user-1000.slice/user@1000.service/session.slice/plasma-xdg-desktop-portal-kde.service
          Unit: user@1000.service
     User Unit: plasma-xdg-desktop-portal-kde.service
         Slice: user-1000.slice
     Owner UID: 1000 (miren)
       Boot ID: fa5c3186fda94c108dd38bb950850548
    Machine ID: 1070f46aee274a6794979042aa1a7634
      Hostname: framira
       Storage: /var/lib/systemd/coredump/core.xdg-desktop-por.1000.fa5c3186fda94c108dd38bb950850548.2828.1722377639000000.zst (present)
  Size on Disk: 1.3M
       Package: xdg-desktop-portal-kde/6.1.3-2.fc40
      build-id: 1a917ec04f124e08f30d7ebe717e1f29ecaba7b3
       Message: Process 2828 (xdg-desktop-por) of user 1000 dumped core.
                
                Module libuuid.so.1 from rpm util-linux-2.40.1-1.fc40.x86_64
                Module libxcb-util.so.1 from rpm xcb-util-0.4.1-5.fc40.x86_64
                Module libxkbcommon-x11.so.0 from rpm libxkbcommon-1.6.0-2.fc40.x86_64
                Module libICE.so.6 from rpm libICE-1.1.1-3.fc40.x86_64
                Module libSM.so.6 from rpm libSM-1.2.4-3.fc40.x86_64
                Module libX11-xcb.so.1 from rpm libX11-1.8.9-1.fc40.x86_64
                Module libxcb-xkb.so.1 from rpm libxcb-1.17.0-1.fc40.x86_64
                Module libxcb-xfixes.so.0 from rpm libxcb-1.17.0-1.fc40.x86_64
                Module libxcb-sync.so.1 from rpm libxcb-1.17.0-1.fc40.x86_64
                Module libxcb-shm.so.0 from rpm libxcb-1.17.0-1.fc40.x86_64
                Module libxcb-shape.so.0 from rpm libxcb-1.17.0-1.fc40.x86_64
                Module libxcb-render-util.so.0 from rpm xcb-util-renderutil-0.3.10-5.fc40.x86_64
                Module libxcb-render.so.0 from rpm libxcb-1.17.0-1.fc40.x86_64
                Module libxcb-randr.so.0 from rpm libxcb-1.17.0-1.fc40.x86_64
                Module libxcb-image.so.0 from rpm xcb-util-image-0.4.1-5.fc40.x86_64
                Module libxcb-icccm.so.4 from rpm xcb-util-wm-0.4.2-5.fc40.x86_64
                Module libxcb-cursor.so.0 from rpm xcb-util-cursor-0.1.4-4.fc40.x86_64
                Module libQt6XcbQpa.so.6 from rpm qt6-qtbase-6.7.2-4.fc40.x86_64
                Module libqxcb.so from rpm qt6-qtbase-6.7.2-4.fc40.x86_64
                Module libcrypt.so.2 from rpm libxcrypt-4.4.36-5.fc40.x86_64
                Module libsasl2.so.3 from rpm cyrus-sasl-2.1.28-19.fc40.x86_64
                Module libevent-2.1.so.7 from rpm libevent-2.1.12-12.fc40.x86_64
                Module libunistring.so.5 from rpm libunistring-1.1-7.fc40.x86_64
                Module libgmodule-2.0.so.0 from rpm glib2-2.80.3-1.fc40.x86_64
                Module libpsl.so.5 from rpm libpsl-0.21.5-3.fc40.x86_64
                Module libssh.so.4 from rpm libssh-0.10.6-5.fc40.x86_64
                Module libidn2.so.0 from rpm libidn2-2.3.7-1.fc40.x86_64
                Module libnghttp2.so.14 from rpm nghttp2-1.59.0-3.fc40.x86_64
                Module libduktape.so.207 from rpm duktape-2.7.0-7.fc40.x86_64
                Module libgio-2.0.so.0 from rpm glib2-2.80.3-1.fc40.x86_64
                Module libcurl.so.4 from rpm curl-8.6.0-8.fc40.x86_64
                Module libogg.so.0 from rpm libogg-1.3.5-8.fc40.x86_64
                Module libvorbis.so.0 from rpm libvorbis-1.3.7-10.fc40.x86_64
                Module libgobject-2.0.so.0 from rpm glib2-2.80.3-1.fc40.x86_64
                Module libpxbackend-1.0.so from rpm libproxy-0.5.5-1.fc40.x86_64
                Module libbrotlicommon.so.1 from rpm brotli-1.1.0-3.fc40.x86_64
                Module libkeyutils.so.1 from rpm keyutils-1.6.3-3.fc40.x86_64
                Module libkrb5support.so.0 from rpm krb5-1.21.3-1.fc40.x86_64
                Module libcom_err.so.2 from rpm e2fsprogs-1.47.0-5.fc40.x86_64
                Module libk5crypto.so.3 from rpm krb5-1.21.3-1.fc40.x86_64
                Module libkrb5.so.3 from rpm krb5-1.21.3-1.fc40.x86_64
                Module libssl.so.3 from rpm openssl-3.2.1-2.fc40.x86_64
                Module libusbmuxd-2.0.so.6 from rpm libusbmuxd-2.0.2^20230620git8d30a55-5.fc40.x86_64
                Module libimobiledevice-glue-1.0.so.0 from rpm libimobiledevice-glue-1.0.0-3.fc40.x86_64
                Module liblz4.so.1 from rpm lz4-1.9.4-6.fc40.x86_64
                Module libicudata.so.74 from rpm icu-74.2-1.fc40.x86_64
                Module libgraphite2.so.3 from rpm graphite2-1.3.14-15.fc40.x86_64
                Module libXext.so.6 from rpm libXext-1.3.6-1.fc40.x86_64
                Module libpcre2-8.so.0 from rpm pcre2-10.44-1.fc40.x86_64
                Module libxml2.so.2 from rpm libxml2-2.12.8-1.fc40.x86_64
                Module libGLdispatch.so.0 from rpm libglvnd-1.7.0-4.fc40.x86_64
                Module libcap.so.2 from rpm libcap-2.69-8.fc40.x86_64
                Module libselinux.so.1 from rpm libselinux-3.6-4.fc40.x86_64
                Module libblkid.so.1 from rpm util-linux-2.40.1-1.fc40.x86_64
                Module libattr.so.1 from rpm attr-2.5.2-3.fc40.x86_64
                Module liblzma.so.5 from rpm xz-5.4.6-3.fc40.x86_64
                Module libbz2.so.1 from rpm bzip2-1.0.8-18.fc40.x86_64
                Module libltdl.so.7 from rpm libtool-2.4.7-10.fc40.x86_64
                Module libtdb.so.1 from rpm libtdb-1.4.10-1.fc40.x86_64
                Module libvorbisfile.so.3 from rpm libvorbis-1.3.7-10.fc40.x86_64
                Module libXau.so.6 from rpm libXau-1.0.11-6.fc40.x86_64
                Module libproxy.so.1 from rpm libproxy-0.5.5-1.fc40.x86_64
                Module libbrotlidec.so.1 from rpm brotli-1.1.0-3.fc40.x86_64
                Module libgssapi_krb5.so.2 from rpm krb5-1.21.3-1.fc40.x86_64
                Module libKF6Codecs.so.6 from rpm kf6-kcodecs-6.4.0-2.fc40.x86_64
                Module libplist-2.0.so.4 from rpm libplist-2.3.0-4.fc40.x86_64
                Module libimobiledevice-1.0.so.6 from rpm libimobiledevice-1.3.0^20230705git6fc41f5-4.fc40.x86_64
                Module libcrypto.so.3 from rpm openssl-3.2.1-2.fc40.x86_64
                Module libpcre2-16.so.0 from rpm pcre2-10.44-1.fc40.x86_64
                Module libb2.so.1 from rpm libb2-0.98.1-11.fc40.x86_64
                Module libdouble-conversion.so.3 from rpm double-conversion-3.3.0-3.fc40.x86_64
                Module libsystemd.so.0 from rpm systemd-255.10-1.fc40.x86_64
                Module libzstd.so.1 from rpm zstd-1.5.6-1.fc40.x86_64
                Module libicuuc.so.74 from rpm icu-74.2-1.fc40.x86_64
                Module libicui18n.so.74 from rpm icu-74.2-1.fc40.x86_64
                Module libz.so.1 from rpm zlib-ng-2.1.7-1.fc40.x86_64
                Module libfreetype.so.6 from rpm freetype-2.13.2-5.fc40.x86_64
                Module libharfbuzz.so.0 from rpm harfbuzz-8.5.0-1.fc40.x86_64
                Module libpng16.so.16 from rpm libpng-1.6.40-3.fc40.x86_64
                Module libOpenGL.so.0 from rpm libglvnd-1.7.0-4.fc40.x86_64
                Module libGLX.so.0 from rpm libglvnd-1.7.0-4.fc40.x86_64
                Module libglib-2.0.so.0 from rpm glib2-2.80.3-1.fc40.x86_64
                Module libfontconfig.so.1 from rpm fontconfig-2.15.0-6.fc40.x86_64
                Module libEGL.so.1 from rpm libglvnd-1.7.0-4.fc40.x86_64
                Module libdbus-1.so.3 from rpm dbus-1.14.10-3.fc40.x86_64
                Module libudev.so.1 from rpm systemd-255.10-1.fc40.x86_64
                Module libmount.so.1 from rpm util-linux-2.40.1-1.fc40.x86_64
                Module libacl.so.1 from rpm acl-2.3.2-1.fc40.x86_64
                Module libKF6AuthCore.so.6 from rpm kf6-kauth-6.4.0-2.fc40.x86_64
                Module libKF6Crash.so.6 from rpm kf6-kcrash-6.4.0-2.fc40.x86_64
                Module libQt6OpenGL.so.6 from rpm qt6-qtbase-6.7.2-4.fc40.x86_64
                Module libQt6QmlModels.so.6 from rpm qt6-qtdeclarative-6.7.2-2.fc40.x86_64
                Module libKF6BreezeIcons.so.6 from rpm kf6-breeze-icons-6.4.0-2.fc40.x86_64
                Module libKF6Archive.so.6 from rpm kf6-karchive-6.4.0-2.fc40.x86_64
                Module libxcb-keysyms.so.1 from rpm xcb-util-keysyms-0.4.1-5.fc40.x86_64
                Module libXfixes.so.3 from rpm libXfixes-6.0.1-3.fc40.x86_64
                Module libxcb-res.so.0 from rpm libxcb-1.17.0-1.fc40.x86_64
                Module libxcb.so.1 from rpm libxcb-1.17.0-1.fc40.x86_64
                Module libX11.so.6 from rpm libX11-1.8.9-1.fc40.x86_64
                Module libwayland-cursor.so.0 from rpm wayland-1.22.0-3.fc40.x86_64
                Module libQt6Network.so.6 from rpm qt6-qtbase-6.7.2-4.fc40.x86_64
                Module libKF6JobWidgets.so.6 from rpm kf6-kjobwidgets-6.4.0-2.fc40.x86_64
                Module libKF6WidgetsAddons.so.6 from rpm kf6-kwidgetsaddons-6.4.1-1.fc40.x86_64
                Module libKF6GuiAddons.so.6 from rpm kf6-kguiaddons-6.4.0-2.fc40.x86_64
                Module libKF6ColorScheme.so.6 from rpm kf6-kcolorscheme-6.4.0-2.fc40.x86_64
                Module libKF6ConfigWidgets.so.6 from rpm kf6-kconfigwidgets-6.4.0-2.fc40.x86_64
                Module libQt6Xml.so.6 from rpm qt6-qtbase-6.7.2-4.fc40.x86_64
                Module libKF6Bookmarks.so.6 from rpm kf6-kbookmarks-6.4.0-2.fc40.x86_64
                Module libKF6Completion.so.6 from rpm kf6-kcompletion-6.4.0-2.fc40.x86_64
                Module libKF6Solid.so.6 from rpm kf6-solid-6.4.0-2.fc40.x86_64
                Module libKF6BookmarksWidgets.so.6 from rpm kf6-kbookmarks-6.4.0-2.fc40.x86_64
                Module libKF6IconWidgets.so.6 from rpm kf6-kiconthemes-6.4.0-2.fc40.x86_64
                Module libQt6Core5Compat.so.6 from rpm qt6-qt5compat-6.7.2-1.fc40.x86_64
                Module libffi.so.8 from rpm libffi-3.4.4-7.fc40.x86_64
                Module libQt6Core.so.6 from rpm qt6-qtbase-6.7.2-4.fc40.x86_64
                Module libQt6Gui.so.6 from rpm qt6-qtbase-6.7.2-4.fc40.x86_64
                Module libQt6Widgets.so.6 from rpm qt6-qtbase-6.7.2-4.fc40.x86_64
                Module libQt6PrintSupport.so.6 from rpm qt6-qtbase-6.7.2-4.fc40.x86_64
                Module libxkbcommon.so.0 from rpm libxkbcommon-1.6.0-2.fc40.x86_64
                Module libQt6DBus.so.6 from rpm qt6-qtbase-6.7.2-4.fc40.x86_64
                Module libKF6ConfigCore.so.6 from rpm kf6-kconfig-6.4.0-2.fc40.x86_64
                Module libKF6CoreAddons.so.6 from rpm kf6-kcoreaddons-6.4.0-2.fc40.x86_64
                Module libKF6Service.so.6 from rpm kf6-kservice-6.4.0-2.fc40.x86_64
                Module libKF6I18n.so.6 from rpm kf6-ki18n-6.4.0-2.fc40.x86_64
                Module libKF6KIOCore.so.6 from rpm kf6-kio-6.4.1-1.fc40.x86_64
                Module libQt6Qml.so.6 from rpm qt6-qtdeclarative-6.7.2-2.fc40.x86_64
                Module libQt6Quick.so.6 from rpm qt6-qtdeclarative-6.7.2-2.fc40.x86_64
                Module libKF6IconThemes.so.6 from rpm kf6-kiconthemes-6.4.0-2.fc40.x86_64
                Module libKF6ItemViews.so.6 from rpm kf6-kitemviews-6.4.0-2.fc40.x86_64
                Module libKF6ConfigGui.so.6 from rpm kf6-kconfig-6.4.0-2.fc40.x86_64
                Module libKF6Notifications.so.6 from rpm kf6-knotifications-6.4.0-2.fc40.x86_64
                Module libKF6WindowSystem.so.6 from rpm kf6-kwindowsystem-6.4.0-2.fc40.x86_64
                Module libKF6KIOGui.so.6 from rpm kf6-kio-6.4.1-1.fc40.x86_64
                Module libQt6WaylandClient.so.6 from rpm qt6-qtwayland-6.7.2-2.fc40.x86_64
                Module libKF6KIOWidgets.so.6 from rpm kf6-kio-6.4.1-1.fc40.x86_64
                Module libKF6KIOFileWidgets.so.6 from rpm kf6-kio-6.4.1-1.fc40.x86_64
                Module libwayland-client.so.0 from rpm wayland-1.22.0-3.fc40.x86_64
                Module libKF6StatusNotifierItem.so.6 from rpm kf6-kstatusnotifieritem-6.4.0-2.fc40.x86_64
                Module libKWaylandClient.so.6 from rpm kwayland-6.1.3-2.fc40.x86_64
                Module libKF6GlobalAccel.so.6 from rpm kf6-kglobalaccel-6.4.0-2.fc40.x86_64
                Module xdg-desktop-portal-kde from rpm xdg-desktop-portal-kde-6.1.3-2.fc40.x86_64
                Stack trace of thread 2828:
                #0  0x00007fa248aa84a4 __pthread_kill_implementation (libc.so.6 + 0x994a4)
                #1  0x00007fa248a4fc4e raise (libc.so.6 + 0x40c4e)
                #2  0x00007fa248a37902 abort (libc.so.6 + 0x28902)
                #3  0x00007fa2490cb631 _Z6qAbortv (libQt6Core.so.6 + 0xcb631)
                #4  0x00007fa249119e27 _ZL10qt_message9QtMsgTypeRK18QMessageLogContextPKcP13__va_list_tag (libQt6Core.so.6 + 0x119e27)
                #5  0x00007fa2490cc4d3 _ZNK14QMessageLogger5fatalEPKcz (libQt6Core.so.6 + 0xcc4d3)
                #6  0x00007fa249939f44 _ZL13init_platformRK7QStringS1_S1_RiPPc.cold (libQt6Gui.so.6 + 0x139f44)
                #7  0x00007fa2499dcba4 _ZN22QGuiApplicationPrivate25createPlatformIntegrationEv (libQt6Gui.so.6 + 0x1dcba4)
                #8  0x00007fa2499dd600 _ZN22QGuiApplicationPrivate21createEventDispatcherEv (libQt6Gui.so.6 + 0x1dd600)
                #9  0x00007fa24919e335 _ZN23QCoreApplicationPrivate4initEv (libQt6Core.so.6 + 0x19e335)
                #10 0x00007fa2499e11ad _ZN22QGuiApplicationPrivate4initEv (libQt6Gui.so.6 + 0x1e11ad)
                #11 0x00007fa24a3917f5 _ZN19QApplicationPrivate4initEv (libQt6Widgets.so.6 + 0x1917f5)
                #12 0x0000556b3232811d main (xdg-desktop-portal-kde + 0x2e11d)
                #13 0x00007fa248a39088 __libc_start_call_main (libc.so.6 + 0x2a088)
                #14 0x00007fa248a3914b __libc_start_main@@GLIBC_2.34 (libc.so.6 + 0x2a14b)
                #15 0x0000556b32328645 _start (xdg-desktop-portal-kde + 0x2e645)
                
                Stack trace of thread 2853:
                #0  0x00007fa248b1c67d __poll (libc.so.6 + 0x10d67d)
                #1  0x00007fa246c44c34 g_main_context_iterate_unlocked.isra.0 (libglib-2.0.so.0 + 0xbec34)
                #2  0x00007fa246be4383 g_main_context_iteration (libglib-2.0.so.0 + 0x5e383)
                #3  0x00007fa2494850a3 _ZN20QEventDispatcherGlib13processEventsE6QFlagsIN10QEventLoop17ProcessEventsFlagEE (libQt6Core.so.6 + 0x4850a3)
                #4  0x00007fa2491a3b03 _ZN10QEventLoop4execE6QFlagsINS_17ProcessEventsFlagEE (libQt6Core.so.6 + 0x1a3b03)
                #5  0x00007fa2492b7e4f _ZN7QThread4execEv (libQt6Core.so.6 + 0x2b7e4f)
                #6  0x00007fa24ab94e41 _ZN22QDBusConnectionManager3runEv (libQt6DBus.so.6 + 0x3ce41)
                #7  0x00007fa24935463c _ZN14QThreadPrivate5startEPv (libQt6Core.so.6 + 0x35463c)
                #8  0x00007fa248aa6507 start_thread (libc.so.6 + 0x97507)
                #9  0x00007fa248b2a40c __clone3 (libc.so.6 + 0x11b40c)
                ELF object binary architecture: AMD x86-64

and backtrace using debugging symbols in GDB:

#0  __pthread_kill_implementation (threadid=<optimized out>, signo=signo@entry=6, no_tid=no_tid@entry=0)
    at pthread_kill.c:44
#1  0x00007fa248aa8513 in __pthread_kill_internal (threadid=<optimized out>, signo=6) at pthread_kill.c:78
#2  0x00007fa248a4fc4e in __GI_raise (sig=sig@entry=6) at ../sysdeps/posix/raise.c:26
#3  0x00007fa248a37902 in __GI_abort () at abort.c:79
#4  0x00007fa2490cb631 in qAbort ()
    at /usr/src/debug/qt6-qtbase-6.7.2-4.fc40.x86_64/src/corelib/global/qglobal.cpp:161
#5  0x00007fa249119e27 in qt_message_fatal<QString&> (context=<optimized out>, message=...)
    at /usr/src/debug/qt6-qtbase-6.7.2-4.fc40.x86_64/src/corelib/global/qlogging.cpp:2025
#6  qt_message(QtMsgType, const QMessageLogContext &, const char *, typedef __va_list_tag __va_list_tag *)
    (msgType=msgType@entry=QtFatalMsg, context=<optimized out>, msg=<optimized out>, ap=ap@entry=0x7ffe4e3e4650) at /usr/src/debug/qt6-qtbase-6.7.2-4.fc40.x86_64/src/corelib/global/qlogging.cpp:374
#7  0x00007fa2490cc4d3 in QMessageLogger::fatal (this=<optimized out>, msg=<optimized out>)
    at /usr/src/debug/qt6-qtbase-6.7.2-4.fc40.x86_64/src/corelib/global/qlogging.cpp:889
#8  0x00007fa249939f44 in init_platform(QString const&, QString const&, QString const&, int&, char**) [clone .cold] () at /lib64/libQt6Gui.so.6
#9  0x00007fa2499dcba4 in QGuiApplicationPrivate::createPlatformIntegration() () at /lib64/libQt6Gui.so.6
#10 0x00007fa2499dd600 in QGuiApplicationPrivate::createEventDispatcher() () at /lib64/libQt6Gui.so.6
#11 0x00007fa24919e335 in QCoreApplicationPrivate::init (this=<optimized out>)
    at /usr/src/debug/qt6-qtbase-6.7.2-4.fc40.x86_64/src/corelib/kernel/qcoreapplication.cpp:905
#12 0x00007fa2499e11ad in QGuiApplicationPrivate::init() () at /lib64/libQt6Gui.so.6
#13 0x00007fa24a3917f5 in QApplicationPrivate::init (this=0x556b46ad9140)
    at /usr/src/debug/qt6-qtbase-6.7.2-4.fc40.x86_64/src/widgets/kernel/qapplication.cpp:472
#14 0x00007fa24a3918bd in QApplication::QApplication
    (this=<optimized out>, argc=<optimized out>, argv=<optimized out>)
    at /usr/src/debug/qt6-qtbase-6.7.2-4.fc40.x86_64/src/widgets/kernel/qapplication.cpp:460
#15 0x0000556b3232811d in main (argc=<optimized out>, argv=<optimized out>)
    at /usr/src/debug/xdg-desktop-portal-kde-6.1.3-2.fc40.x86_64/src/xdg-desktop-portal-kde.cpp:25