$  strace plasmashell |& grep kpluginindex.json
access("/usr/lib/x86_64-linux-gnu/qt5/plugins/kpackage/packagestructure/kpluginindex.json", F_OK) = -1 ENOENT (No such file or directory)
access("/usr/lib/x86_64-linux-gnu/qt5/plugins/kpackage/packagestructure/kpluginindex.json", F_OK) = -1 ENOENT (No such file or directory)
access("/home/dev/.local/share/plasma/plasmoids/kpluginindex.json", F_OK) = 0

Created attachment 118005 [details]
kpluginindex.json

Backtrace with KArchive debug symbols:



(gdb) bt
#0  0x00007fffeedf3316 in KFilterBase::device (this=0x0)
    at /home/dev/repos/karchive/src/kfilterbase.cpp:58
#1  0x00007fffeedf2310 in KCompressionDevice::open (this=0x7fffffffce50, mode=...)
    at /home/dev/repos/karchive/src/kcompressiondevice.cpp:161
#2  0x00007ffff4d9cd1b in KPackage::PackageLoader::listPackages(QString const&, QString const&) () from /usr/lib/x86_64-linux-gnu/libKF5Package.so.5
#3  0x00007ffff4d9e4d7 in KPackage::PackageLoader::findPackages(QString const&, QString const&, std::function<bool (KPluginMetaData const&)>) ()
   from /usr/lib/x86_64-linux-gnu/libKF5Package.so.5
#4  0x00007ffff64697c0 in Plasma::PluginLoader::listContainmentsOfType(QString const&, QString const&, QString const&) () from /usr/lib/x86_64-linux-gnu/libKF5Plasma.so.5
#5  0x00005555555aa104 in ShellCorona::checkAddPanelAction(QStringList const&) ()
#6  0x000055555559d8f7 in ShellCorona::ShellCorona(QObject*) ()
#7  0x00005555555c0d13 in ShellManager::loadHandlers() ()
#8  0x00005555555eabda in ShellManager::qt_static_metacall(QObject*, QMetaObject::Call, int, void**) ()
#9  0x00007ffff1b16992 in QObject::event (this=0x5555558c07d0, e=<optimized out>)
    at kernel/qobject.cpp:1249
#10 0x00007ffff348b83c in QApplicationPrivate::notify_helper (
    this=this@entry=0x55555584db50, receiver=receiver@entry=0x5555558c07d0, 
    e=e@entry=0x5555558c41a0) at kernel/qapplication.cpp:3752
#11 0x00007ffff3492dd0 in QApplication::notify (this=0x7fffffffdbf0, 
    receiver=0x5555558c07d0, e=0x5555558c41a0) at kernel/qapplication.cpp:3499
#12 0x00007ffff1ae6328 in QCoreApplication::notifyInternal2 (receiver=0x5555558c07d0, 
    event=0x5555558c41a0) at kernel/qcoreapplication.cpp:1061
#13 0x00007ffff1ae64fe in QCoreApplication::sendEvent (receiver=<optimized out>, 
    event=event@entry=0x5555558c41a0) at kernel/qcoreapplication.cpp:1451
#14 0x00007ffff1ae8e87 in QCoreApplicationPrivate::sendPostedEvents (
    receiver=receiver@entry=0x0, event_type=event_type@entry=0, data=0x5555558426e0)
    at kernel/qcoreapplication.cpp:1800
#15 0x00007ffff1ae9428 in QCoreApplication::sendPostedEvents (
    receiver=receiver@entry=0x0, event_type=event_type@entry=0)
    at kernel/qcoreapplication.cpp:1654
#16 0x00007ffff1b43b23 in postEventSourceDispatch (s=0x5555558a25e0)
    at kernel/qeventdispatcher_glib.cpp:276
#17 0x00007fffeb1dc387 in g_main_context_dispatch ()

With the attached kpluginindex.json file located in ~/.local/share/plasma/plasmoids, plasmashell reproducibly crashes with this backtrace. If I delete it and generate a new file using `kpackagetool5 --generate-index`, the crash stops reproducing.

This turned out to have been caused by a packaging bug: after a Neon upgrade, libbz2-dev got uninstalled, so Plasma crashed trying to read my kpluginindex.json file that had previously been bzip2-compressed. Reinstalling libbz2-dev fixed it.

That said, it would be nice to not have this condition cause a crash. David Edmundson has a patch that should fix this, I believe.

(This patch: https://phabricator.kde.org/file/data/gxo5dqxhfm2wfd6jrueu/PHID-FILE-ogzjhyu5mpuz6mmww22c/Masterwork_From_Distant_Lands)

Git commit 3d5713ba37609c5b0a05c1819310338e8643a3b6 by David Edmundson.
Committed on 15/02/2019 at 15:10.
Pushed by davidedmundson into branch 'master'.

Guard KCompressionDevice::open being called with no backend available

Summary:
If KArchive is built without support for a compression type, such as
bzip2, d->filter ends up as null.

It is then used in the open call and will crash.

Other calls can still crash, but they shouldn't be being called if open
fails.

Reviewers: #plasma, #frameworks, ngraham

Reviewed By: ngraham

Subscribers: ngraham, kde-frameworks-devel

Tags: #frameworks

Differential Revision: https://phabricator.kde.org/D18965

M  +3    -0    src/kcompressiondevice.cpp

https://commits.kde.org/karchive/3d5713ba37609c5b0a05c1819310338e8643a3b6