*** Bug 411405 has been marked as a duplicate of this bug. ***

*** Bug 415486 has been marked as a duplicate of this bug. ***

*** Bug 416228 has been marked as a duplicate of this bug. ***

*** Bug 417129 has been marked as a duplicate of this bug. ***

*** Bug 416615 has been marked as a duplicate of this bug. ***

*** Bug 420597 has been marked as a duplicate of this bug. ***

*** Bug 422113 has been marked as a duplicate of this bug. ***

*** Bug 414709 has been marked as a duplicate of this bug. ***

*** Bug 422283 has been marked as a duplicate of this bug. ***

*** Bug 430529 has been marked as a duplicate of this bug. ***

*** Bug 422954 has been marked as a duplicate of this bug. ***

*** Bug 418206 has been marked as a duplicate of this bug. ***

*** Bug 423228 has been marked as a duplicate of this bug. ***

*** Bug 432604 has been marked as a duplicate of this bug. ***

Looks like a modern incarnation of Bug 341497. See also this variant: Bug 414823.

Raising priority due to number of duplicates.

*** Bug 434154 has been marked as a duplicate of this bug. ***

*** Bug 435058 has been marked as a duplicate of this bug. ***

Some initial analysis

#6  0x00007f20d6e3b3a4 in QScreen::handle() const () at /usr/lib/x86_64-linux-gnu/libQt5Gui.so.5

This just returns the platformScreen, this is set in the ctor, so for a crash to happen here it means the QScreen object has been deleted.

In one of the dupes we can see a pointer is sent as this to QScreen::handle, which heavily implies it's a dangling pointer.

If someone can reproduce reliably valgrind will tell us in an instant what's wrong.

I attached Valgrind to running kwin_x11. It seems kwin crashes many more times than without it. It crashes on Alt+Tabs, closing windows, and minimising windows after returning from sleep (hopefully this is the reproducible case of the current ticket).

I observed the following errors:

==18204== Syscall param writev(vector[...]) points to uninitialised byte(s)
==18204==    at 0x64F21CD: __writev (writev.c:26)
==18204==    by 0x64F21CD: writev (writev.c:24)
==18204==    by 0x5B70AD2: UnknownInlinedFun (xcb_conn.c:277)
==18204==    by 0x5B70AD2: _xcb_conn_wait.part.0 (xcb_conn.c:523)
==18204==    by 0x5B70B8F: UnknownInlinedFun (xcb_out.c:463)
==18204==    by 0x5B70B8F: _xcb_out_send (xcb_out.c:464)
==18204==    by 0x5B70DE6: UnknownInlinedFun (xcb_out.c:488)
==18204==    by 0x5B70DE6: _xcb_out_flush_to (xcb_out.c:477)
==18204==    by 0x5B7242A: xcb_request_check (xcb_in.c:743)
==18204==    by 0x112601: QtPrivate::QFunctorSlotObject<KWin::ApplicationX11::performStartup()::{lambda()#2}, 0, QtPrivate::List<>, void>::impl(int, QtPrivate::QSlotObjectBase*, QObject*, void**, bool*) (main_x11.cpp:243)
==18204==    by 0x5F26945: call (qobjectdefs_impl.h:398)
==18204==    by 0x5F26945: void doActivate<false>(QObject*, int, void**) (qobject.cpp:3886)
==18204==    by 0x4BFF4C2: KSelectionOwner::Private::claimSucceeded() (kselectionowner.cpp:188)
==18204==    by 0x4C047A0: UnknownInlinedFun (kselectionowner.cpp:222)
==18204==    by 0x4C047A0: KSelectionOwner::filterEvent(void*) (kselectionowner.cpp:406)
==18204==    by 0x5EED876: QAbstractEventDispatcher::filterNativeEvent(QByteArray const&, void*, long*) (qabstracteventdispatcher.cpp:495)
==18204==    by 0xC3540E0: QXcbConnection::handleXcbEvent(xcb_generic_event_t*) (qxcbconnection.cpp:536)
==18204==    by 0xC3555F5: QXcbConnection::processXcbEvents(QFlags<QEventLoop::ProcessEventsFlag>) (qxcbconnection.cpp:1014)
==18204==  Address 0xa1bfd7a is 4,538 bytes inside a block of size 21,168 alloc'd
==18204==    at 0x4840B65: calloc (in /usr/lib64/valgrind/vgpreload_memcheck-amd64-linux.so)
==18204==    by 0x5B73050: xcb_connect_to_fd (xcb_conn.c:346)
==18204==    by 0x5B73C46: xcb_connect_to_display_with_auth_info (xcb_util.c:534)
==18204==    by 0x7BA40E1: _XConnectXCB (xcb_disp.c:78)
==18204==    by 0x7B94124: XOpenDisplay (OpenDis.c:129)
==18204==    by 0xC379926: QXcbBasicConnection::QXcbBasicConnection(char const*) (qxcbconnection_basic.cpp:114)
==18204==    by 0xC355B21: QXcbConnection::QXcbConnection(QXcbNativeInterface*, bool, unsigned int, char const*) (qxcbconnection.cpp:91)
==18204==    by 0xC358992: QXcbIntegration::QXcbIntegration(QStringList const&, int&, char**) (qxcbintegration.cpp:197)
==18204==    by 0x485E45E: create (qxcbmain.cpp:56)
==18204==    by 0x485E45E: QXcbIntegrationPlugin::create(QString const&, QStringList const&, int&, char**) (qxcbmain.cpp:53)
==18204==    by 0x55B908B: init_platform (qguiapplication.cpp:1223)
==18204==    by 0x55B908B: QGuiApplicationPrivate::createPlatformIntegration() (qguiapplication.cpp:1481)
==18204==    by 0x55BA48F: QGuiApplicationPrivate::createEventDispatcher() (qguiapplication.cpp:1498)
==18204==    by 0x5EF6DB5: QCoreApplicationPrivate::init() (qcoreapplication.cpp:834)
==18204==  Uninitialised value was created by a stack allocation
==18204==    at 0x4BFF450: KSelectionOwner::Private::claimSucceeded() (kselectionowner.cpp:170)


==18204== Invalid read of size 16
==18204==    at 0x12A6CB01: ??? (in /memfd:sljit (deleted))
==18204==    by 0xD0A5537: ???
==18204==  Address 0xd0a555e is 62 bytes inside a block of size 76 alloc'd
==18204==    at 0x483E77F: malloc (in /usr/lib64/valgrind/vgpreload_memcheck-amd64-linux.so)
==18204==    by 0x5D1A490: QArrayData::allocate(unsigned long, unsigned long, unsigned long, QFlags<QArrayData::AllocationOption>) (qarraydata.cpp:218)
==18204==    by 0x5D933F9: allocate (qarraydata.h:224)
==18204==    by 0x5D933F9: QString::fromLatin1_helper(char const*, int) (qstring.cpp:5459)
==18204==    by 0x671CE5D: KWin::GLPlatform::detect(KWin::OpenGLPlatformInterface) (qstring.h:701)
==18204==    by 0x128B5AE1: KWin::GlxBackend::init() [clone .part.0] (glxbackend.cpp:196)
==18204==    by 0x13181D88: KWin::SceneOpenGL::createScene(QObject*) (scene_opengl.cpp:449)
==18204==    by 0x13190828: KWin::OpenGLFactory::create(QObject*) const (scene_opengl.cpp:2725)
==18204==    by 0x4985E2E: KWin::Compositor::setupStart() [clone .part.0] (composite.cpp:238)
==18204==    by 0x4988B59: KWin::X11Compositor::start() (composite.cpp:815)
==18204==    by 0x5F1C350: QObject::event(QEvent*) (qobject.cpp:1314)
==18204==    by 0x4F194FE: QApplicationPrivate::notify_helper(QObject*, QEvent*) (qapplication.cpp:3632)
==18204==    by 0x5EF0329: QCoreApplication::notifyInternal2(QObject*, QEvent*) (qcoreapplication.cpp:1063)


==18204== Invalid read of size 16
==18204==    at 0x12A6C6D8: ??? (in /memfd:sljit (deleted))
==18204==    by 0xD0A5537: ???
==18204==  Address 0xd0a555e is 62 bytes inside a block of size 76 alloc'd
==18204==    at 0x483E77F: malloc (in /usr/lib64/valgrind/vgpreload_memcheck-amd64-linux.so)
==18204==    by 0x5D1A490: QArrayData::allocate(unsigned long, unsigned long, unsigned long, QFlags<QArrayData::AllocationOption>) (qarraydata.cpp:218)
==18204==    by 0x5D933F9: allocate (qarraydata.h:224)
==18204==    by 0x5D933F9: QString::fromLatin1_helper(char const*, int) (qstring.cpp:5459)
==18204==    by 0x671CE5D: KWin::GLPlatform::detect(KWin::OpenGLPlatformInterface) (qstring.h:701)
==18204==    by 0x128B5AE1: KWin::GlxBackend::init() [clone .part.0] (glxbackend.cpp:196)
==18204==    by 0x13181D88: KWin::SceneOpenGL::createScene(QObject*) (scene_opengl.cpp:449)
==18204==    by 0x13190828: KWin::OpenGLFactory::create(QObject*) const (scene_opengl.cpp:2725)
==18204==    by 0x4985E2E: KWin::Compositor::setupStart() [clone .part.0] (composite.cpp:238)
==18204==    by 0x4988B59: KWin::X11Compositor::start() (composite.cpp:815)
==18204==    by 0x5F1C350: QObject::event(QEvent*) (qobject.cpp:1314)
==18204==    by 0x4F194FE: QApplicationPrivate::notify_helper(QObject*, QEvent*) (qapplication.cpp:3632)
==18204==    by 0x5EF0329: QCoreApplication::notifyInternal2(QObject*, QEvent*) (qcoreapplication.cpp:1063)


==16985== Invalid read of size 8
==16985==    at 0x5F44682: QEventDispatcherUNIXPrivate::markPendingSocketNotifiers() (qeventdispatcher_unix.cpp:273)
==16985==    by 0x5F44BB3: QEventDispatcherUNIXPrivate::activateSocketNotifiers() (qeventdispatcher_unix.cpp:294)
==16985==    by 0x5F4508A: QEventDispatcherUNIX::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) (qeventdispatcher_unix.cpp:511)
==16985==    by 0x5EEECEA: QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) (qeventloop.cpp:232)
==16985==    by 0x5D0DDAD: QThread::exec() (qthread.cpp:547)
==16985==    by 0x5BAA7B6: QDBusConnectionManager::run() (qdbusconnection.cpp:179)
==16985==    by 0x5D0EEF0: QThreadPrivate::start(void*) (qthread_unix.cpp:329)
==16985==    by 0x6E67298: start_thread (pthread_create.c:473)
==16985==    by 0x64FB3B2: clone (clone.S:95)
==16985==  Address 0xce6b038 is 24 bytes inside a block of size 40 free'd
==16985==    at 0x483F9AB: free (in /usr/lib64/valgrind/vgpreload_memcheck-amd64-linux.so)
==16985==    by 0x5F453ED: deleteNode (qhash.h:586)
==16985==    by 0x5F453ED: QHash<int, QSocketNotifierSetUNIX>::erase(QHash<int, QSocketNotifierSetUNIX>::const_iterator) (qhash.h:886)
==16985==    by 0x5CEBFF3: QEventDispatcherUNIXPrivate::markPendingSocketNotifiers() [clone .cold] (qeventdispatcher_unix.cpp:281)
==16985==    by 0x5F44BB3: QEventDispatcherUNIXPrivate::activateSocketNotifiers() (qeventdispatcher_unix.cpp:294)
==16985==    by 0x5F4508A: QEventDispatcherUNIX::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) (qeventdispatcher_unix.cpp:511)
==16985==    by 0x5EEECEA: QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) (qeventloop.cpp:232)
==16985==    by 0x5D0DDAD: QThread::exec() (qthread.cpp:547)
==16985==    by 0x5BAA7B6: QDBusConnectionManager::run() (qdbusconnection.cpp:179)
==16985==    by 0x5D0EEF0: QThreadPrivate::start(void*) (qthread_unix.cpp:329)
==16985==    by 0x6E67298: start_thread (pthread_create.c:473)
==16985==    by 0x64FB3B2: clone (clone.S:95)
==16985==  Block was alloc'd at
==16985==    at 0x483E77F: malloc (in /usr/lib64/valgrind/vgpreload_memcheck-amd64-linux.so)
==16985==    by 0x5D49897: QHashData::allocateNode(int) (qhash.cpp:479)
==16985==    by 0x5F43F51: createNode (qhash.h:610)
==16985==    by 0x5F43F51: operator[] (qhash.h:761)
==16985==    by 0x5F43F51: QEventDispatcherUNIX::registerSocketNotifier(QSocketNotifier*) (qeventdispatcher_unix.cpp:408)
==16985==    by 0x5F29F66: QSocketNotifier::QSocketNotifier(long long, QSocketNotifier::Type, QObject*) (qsocketnotifier.cpp:170)
==16985==    by 0x5BB6099: qDBusAddWatch (qdbusintegrator.cpp:214)
==16985==    by 0x7EB4D71: _dbus_watch_list_set_functions (dbus-watch.c:321)
==16985==    by 0x7EA3E8C: dbus_connection_set_watch_functions (dbus-connection.c:4966)
==16985==    by 0x5BBC957: q_dbus_connection_set_watch_functions (qdbus_symbols_p.h:244)
==16985==    by 0x5BBC957: QDBusConnectionPrivate::setConnection(DBusConnection*, QDBusErrorInternal const&) (qdbusintegrator.cpp:1829)
==16985==    by 0x5BAB2A5: QDBusConnectionManager::executeConnectionRequest(QDBusConnectionManager::ConnectionRequestData*) (qdbusconnection.cpp:290)
==16985==    by 0x5F1C350: QObject::event(QEvent*) (qobject.cpp:1314)
==16985==    by 0x5EF02FE: doNotify (qcoreapplication.cpp:1153)
==16985==    by 0x5EF02FE: notify (qcoreapplication.cpp:1139)
==16985==    by 0x5EF02FE: QCoreApplication::notifyInternal2(QObject*, QEvent*) (qcoreapplication.cpp:1063)
==16985==    by 0x5EF2D60: QCoreApplicationPrivate::sendPostedEvents(QObject*, int, QThreadData*) (qcoreapplication.cpp:1817)


==16985== Invalid read of size 8
==16985==    at 0x5F4469F: QEventDispatcherUNIXPrivate::markPendingSocketNotifiers() (qeventdispatcher_unix.cpp:273)
==16985==    by 0x5F44BB3: QEventDispatcherUNIXPrivate::activateSocketNotifiers() (qeventdispatcher_unix.cpp:294)
==16985==    by 0x5F4508A: QEventDispatcherUNIX::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) (qeventdispatcher_unix.cpp:511)
==16985==    by 0x5EEECEA: QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) (qeventloop.cpp:232)
==16985==    by 0x5D0DDAD: QThread::exec() (qthread.cpp:547)
==16985==    by 0x5BAA7B6: QDBusConnectionManager::run() (qdbusconnection.cpp:179)
==16985==    by 0x5D0EEF0: QThreadPrivate::start(void*) (qthread_unix.cpp:329)
==16985==    by 0x6E67298: start_thread (pthread_create.c:473)
==16985==    by 0x64FB3B2: clone (clone.S:95)
==16985==  Address 0xce6b040 is 32 bytes inside a block of size 40 free'd
==16985==    at 0x483F9AB: free (in /usr/lib64/valgrind/vgpreload_memcheck-amd64-linux.so)
==16985==    by 0x5F453ED: deleteNode (qhash.h:586)
==16985==    by 0x5F453ED: QHash<int, QSocketNotifierSetUNIX>::erase(QHash<int, QSocketNotifierSetUNIX>::const_iterator) (qhash.h:886)
==16985==    by 0x5CEBFF3: QEventDispatcherUNIXPrivate::markPendingSocketNotifiers() [clone .cold] (qeventdispatcher_unix.cpp:281)
==16985==    by 0x5F44BB3: QEventDispatcherUNIXPrivate::activateSocketNotifiers() (qeventdispatcher_unix.cpp:294)
==16985==    by 0x5F4508A: QEventDispatcherUNIX::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) (qeventdispatcher_unix.cpp:511)
==16985==    by 0x5EEECEA: QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) (qeventloop.cpp:232)
==16985==    by 0x5D0DDAD: QThread::exec() (qthread.cpp:547)
==16985==    by 0x5BAA7B6: QDBusConnectionManager::run() (qdbusconnection.cpp:179)
==16985==    by 0x5D0EEF0: QThreadPrivate::start(void*) (qthread_unix.cpp:329)
==16985==    by 0x6E67298: start_thread (pthread_create.c:473)
==16985==    by 0x64FB3B2: clone (clone.S:95)
==16985==  Block was alloc'd at
==16985==    at 0x483E77F: malloc (in /usr/lib64/valgrind/vgpreload_memcheck-amd64-linux.so)
==16985==    by 0x5D49897: QHashData::allocateNode(int) (qhash.cpp:479)
==16985==    by 0x5F43F51: createNode (qhash.h:610)
==16985==    by 0x5F43F51: operator[] (qhash.h:761)
==16985==    by 0x5F43F51: QEventDispatcherUNIX::registerSocketNotifier(QSocketNotifier*) (qeventdispatcher_unix.cpp:408)
==16985==    by 0x5F29F66: QSocketNotifier::QSocketNotifier(long long, QSocketNotifier::Type, QObject*) (qsocketnotifier.cpp:170)
==16985==    by 0x5BB6099: qDBusAddWatch (qdbusintegrator.cpp:214)
==16985==    by 0x7EB4D71: _dbus_watch_list_set_functions (dbus-watch.c:321)
==16985==    by 0x7EA3E8C: dbus_connection_set_watch_functions (dbus-connection.c:4966)
==16985==    by 0x5BBC957: q_dbus_connection_set_watch_functions (qdbus_symbols_p.h:244)
==16985==    by 0x5BBC957: QDBusConnectionPrivate::setConnection(DBusConnection*, QDBusErrorInternal const&) (qdbusintegrator.cpp:1829)
==16985==    by 0x5BAB2A5: QDBusConnectionManager::executeConnectionRequest(QDBusConnectionManager::ConnectionRequestData*) (qdbusconnection.cpp:290)
==16985==    by 0x5F1C350: QObject::event(QEvent*) (qobject.cpp:1314)
==16985==    by 0x5EF02FE: doNotify (qcoreapplication.cpp:1153)
==16985==    by 0x5EF02FE: notify (qcoreapplication.cpp:1139)
==16985==    by 0x5EF02FE: QCoreApplication::notifyInternal2(QObject*, QEvent*) (qcoreapplication.cpp:1063)
==16985==    by 0x5EF2D60: QCoreApplicationPrivate::sendPostedEvents(QObject*, int, QThreadData*) (qcoreapplication.cpp:1817)
==16985== 
==16985== 
==16985== Process terminating with default action of signal 11 (SIGSEGV): dumping core
==16985==    at 0x6438483: raise (raise.c:45)
==16985==    by 0x4BD8E90: KCrash::defaultCrashHandler(int) (kcrash.cpp:576)
==16985==    by 0x643852F: ??? (in /lib64/libc-2.33.so)
==16985==    by 0x122B15D9: ??? (in /memfd:sljit (deleted))
==16985== 
==16985== FILE DESCRIPTORS: 3 open at exit.
==16985== Open file descriptor 2: /dev/pts/5
==16985==    <inherited from parent>
==16985== 
==16985== Open file descriptor 1: /dev/pts/5
==16985==    <inherited from parent>
==16985== 
==16985== Open file descriptor 0: /dev/null
==16985==    <inherited from parent>


==16985== 1 errors in context 2 of 96:
==16985== Invalid read of size 16
==16985==    at 0x122B1B01: ??? (in /memfd:sljit (deleted))
==16985==    by 0x123B1567: ???
==16985==  Address 0x123b158e is 62 bytes inside a block of size 76 alloc'd
==16985==    at 0x483E77F: malloc (in /usr/lib64/valgrind/vgpreload_memcheck-amd64-linux.so)
==16985==    by 0x5D1A490: QArrayData::allocate(unsigned long, unsigned long, unsigned long, QFlags<QArrayData::AllocationOption>) (qarraydata.cpp:218)
==16985==    by 0x5D933F9: allocate (qarraydata.h:224)
==16985==    by 0x5D933F9: QString::fromLatin1_helper(char const*, int) (qstring.cpp:5459)
==16985==    by 0x671CE5D: KWin::GLPlatform::detect(KWin::OpenGLPlatformInterface) (qstring.h:701)
==16985==    by 0x134B5AE1: KWin::GlxBackend::init() [clone .part.0] (glxbackend.cpp:196)
==16985==    by 0x1228AD88: KWin::SceneOpenGL::createScene(QObject*) (scene_opengl.cpp:449)
==16985==    by 0x12299828: KWin::OpenGLFactory::create(QObject*) const (scene_opengl.cpp:2725)
==16985==    by 0x4985E2E: KWin::Compositor::setupStart() [clone .part.0] (composite.cpp:238)
==16985==    by 0x4988B59: KWin::X11Compositor::start() (composite.cpp:815)
==16985==    by 0x4987E92: KWin::Compositor::reinitialize() (composite.cpp:560)
==16985==    by 0x5F26945: call (qobjectdefs_impl.h:398)
==16985==    by 0x5F26945: void doActivate<false>(QObject*, int, void**) (qobject.cpp:3886)
==16985==    by 0x5F1C350: QObject::event(QEvent*) (qobject.cpp:1314)
==16985== 
==16985== 
==16985== 1 errors in context 3 of 96:
==16985== Invalid read of size 16
==16985==    at 0x122B1B01: ??? (in /memfd:sljit (deleted))
==16985==    by 0xDEAB157: ???
==16985==  Address 0xdeab17e is 62 bytes inside a block of size 76 alloc'd
==16985==    at 0x483E77F: malloc (in /usr/lib64/valgrind/vgpreload_memcheck-amd64-linux.so)
==16985==    by 0x5D1A490: QArrayData::allocate(unsigned long, unsigned long, unsigned long, QFlags<QArrayData::AllocationOption>) (qarraydata.cpp:218)
==16985==    by 0x5D933F9: allocate (qarraydata.h:224)
==16985==    by 0x5D933F9: QString::fromLatin1_helper(char const*, int) (qstring.cpp:5459)
==16985==    by 0x671CE5D: KWin::GLPlatform::detect(KWin::OpenGLPlatformInterface) (qstring.h:701)
==16985==    by 0x134B5AE1: KWin::GlxBackend::init() [clone .part.0] (glxbackend.cpp:196)
==16985==    by 0x1228AD88: KWin::SceneOpenGL::createScene(QObject*) (scene_opengl.cpp:449)
==16985==    by 0x12299828: KWin::OpenGLFactory::create(QObject*) const (scene_opengl.cpp:2725)
==16985==    by 0x4985E2E: KWin::Compositor::setupStart() [clone .part.0] (composite.cpp:238)
==16985==    by 0x4988B59: KWin::X11Compositor::start() (composite.cpp:815)
==16985==    by 0x5F1C350: QObject::event(QEvent*) (qobject.cpp:1314)
==16985==    by 0x4F194FE: QApplicationPrivate::notify_helper(QObject*, QEvent*) (qapplication.cpp:3632)
==16985==    by 0x5EF0329: QCoreApplication::notifyInternal2(QObject*, QEvent*) (qcoreapplication.cpp:1063)
==16985== 
==16985== 
==16985== 2 errors in context 4 of 96:
==16985== Invalid read of size 16
==16985==    at 0x122B16D8: ??? (in /memfd:sljit (deleted))
==16985==    by 0x123B1567: ???
==16985==  Address 0x123b158e is 62 bytes inside a block of size 76 alloc'd
==16985==    at 0x483E77F: malloc (in /usr/lib64/valgrind/vgpreload_memcheck-amd64-linux.so)
==16985==    by 0x5D1A490: QArrayData::allocate(unsigned long, unsigned long, unsigned long, QFlags<QArrayData::AllocationOption>) (qarraydata.cpp:218)
==16985==    by 0x5D933F9: allocate (qarraydata.h:224)
==16985==    by 0x5D933F9: QString::fromLatin1_helper(char const*, int) (qstring.cpp:5459)
==16985==    by 0x671CE5D: KWin::GLPlatform::detect(KWin::OpenGLPlatformInterface) (qstring.h:701)
==16985==    by 0x134B5AE1: KWin::GlxBackend::init() [clone .part.0] (glxbackend.cpp:196)
==16985==    by 0x1228AD88: KWin::SceneOpenGL::createScene(QObject*) (scene_opengl.cpp:449)
==16985==    by 0x12299828: KWin::OpenGLFactory::create(QObject*) const (scene_opengl.cpp:2725)
==16985==    by 0x4985E2E: KWin::Compositor::setupStart() [clone .part.0] (composite.cpp:238)
==16985==    by 0x4988B59: KWin::X11Compositor::start() (composite.cpp:815)
==16985==    by 0x4987E92: KWin::Compositor::reinitialize() (composite.cpp:560)
==16985==    by 0x5F26945: call (qobjectdefs_impl.h:398)
==16985==    by 0x5F26945: void doActivate<false>(QObject*, int, void**) (qobject.cpp:3886)
==16985==    by 0x5F1C350: QObject::event(QEvent*) (qobject.cpp:1314)
==16985== 
==16985== 
==16985== 2 errors in context 5 of 96:
==16985== Invalid read of size 16
==16985==    at 0x122B16D8: ??? (in /memfd:sljit (deleted))
==16985==    by 0xDEAB157: ???
==16985==  Address 0xdeab17e is 62 bytes inside a block of size 76 alloc'd
==16985==    at 0x483E77F: malloc (in /usr/lib64/valgrind/vgpreload_memcheck-amd64-linux.so)
==16985==    by 0x5D1A490: QArrayData::allocate(unsigned long, unsigned long, unsigned long, QFlags<QArrayData::AllocationOption>) (qarraydata.cpp:218)
==16985==    by 0x5D933F9: allocate (qarraydata.h:224)
==16985==    by 0x5D933F9: QString::fromLatin1_helper(char const*, int) (qstring.cpp:5459)
==16985==    by 0x671CE5D: KWin::GLPlatform::detect(KWin::OpenGLPlatformInterface) (qstring.h:701)
==16985==    by 0x134B5AE1: KWin::GlxBackend::init() [clone .part.0] (glxbackend.cpp:196)
==16985==    by 0x1228AD88: KWin::SceneOpenGL::createScene(QObject*) (scene_opengl.cpp:449)
==16985==    by 0x12299828: KWin::OpenGLFactory::create(QObject*) const (scene_opengl.cpp:2725)
==16985==    by 0x4985E2E: KWin::Compositor::setupStart() [clone .part.0] (composite.cpp:238)
==16985==    by 0x4988B59: KWin::X11Compositor::start() (composite.cpp:815)
==16985==    by 0x5F1C350: QObject::event(QEvent*) (qobject.cpp:1314)
==16985==    by 0x4F194FE: QApplicationPrivate::notify_helper(QObject*, QEvent*) (qapplication.cpp:3632)
==16985==    by 0x5EF0329: QCoreApplication::notifyInternal2(QObject*, QEvent*) (qcoreapplication.cpp:1063)
==16985== 
==16985== 
==16985== 3 errors in context 6 of 96:
==16985== Thread 3 QDBusConnectionM:
==16985== Invalid read of size 8
==16985==    at 0x5F4469F: QEventDispatcherUNIXPrivate::markPendingSocketNotifiers() (qeventdispatcher_unix.cpp:273)
==16985==    by 0x5F44BB3: QEventDispatcherUNIXPrivate::activateSocketNotifiers() (qeventdispatcher_unix.cpp:294)
==16985==    by 0x5F4508A: QEventDispatcherUNIX::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) (qeventdispatcher_unix.cpp:511)
==16985==    by 0x5EEECEA: QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) (qeventloop.cpp:232)
==16985==    by 0x5D0DDAD: QThread::exec() (qthread.cpp:547)
==16985==    by 0x5BAA7B6: QDBusConnectionManager::run() (qdbusconnection.cpp:179)
==16985==    by 0x5D0EEF0: QThreadPrivate::start(void*) (qthread_unix.cpp:329)
==16985==    by 0x6E67298: start_thread (pthread_create.c:473)
==16985==    by 0x64FB3B2: clone (clone.S:95)
==16985==  Address 0xce6b040 is 32 bytes inside a block of size 40 free'd
==16985==    at 0x483F9AB: free (in /usr/lib64/valgrind/vgpreload_memcheck-amd64-linux.so)
==16985==    by 0x5F453ED: deleteNode (qhash.h:586)
==16985==    by 0x5F453ED: QHash<int, QSocketNotifierSetUNIX>::erase(QHash<int, QSocketNotifierSetUNIX>::const_iterator) (qhash.h:886)
==16985==    by 0x5CEBFF3: QEventDispatcherUNIXPrivate::markPendingSocketNotifiers() [clone .cold] (qeventdispatcher_unix.cpp:281)
==16985==    by 0x5F44BB3: QEventDispatcherUNIXPrivate::activateSocketNotifiers() (qeventdispatcher_unix.cpp:294)
==16985==    by 0x5F4508A: QEventDispatcherUNIX::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) (qeventdispatcher_unix.cpp:511)
==16985==    by 0x5EEECEA: QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) (qeventloop.cpp:232)
==16985==    by 0x5D0DDAD: QThread::exec() (qthread.cpp:547)
==16985==    by 0x5BAA7B6: QDBusConnectionManager::run() (qdbusconnection.cpp:179)
==16985==    by 0x5D0EEF0: QThreadPrivate::start(void*) (qthread_unix.cpp:329)
==16985==    by 0x6E67298: start_thread (pthread_create.c:473)
==16985==    by 0x64FB3B2: clone (clone.S:95)
==16985==  Block was alloc'd at
==16985==    at 0x483E77F: malloc (in /usr/lib64/valgrind/vgpreload_memcheck-amd64-linux.so)
==16985==    by 0x5D49897: QHashData::allocateNode(int) (qhash.cpp:479)
==16985==    by 0x5F43F51: createNode (qhash.h:610)
==16985==    by 0x5F43F51: operator[] (qhash.h:761)
==16985==    by 0x5F43F51: QEventDispatcherUNIX::registerSocketNotifier(QSocketNotifier*) (qeventdispatcher_unix.cpp:408)
==16985==    by 0x5F29F66: QSocketNotifier::QSocketNotifier(long long, QSocketNotifier::Type, QObject*) (qsocketnotifier.cpp:170)
==16985==    by 0x5BB6099: qDBusAddWatch (qdbusintegrator.cpp:214)
==16985==    by 0x7EB4D71: _dbus_watch_list_set_functions (dbus-watch.c:321)
==16985==    by 0x7EA3E8C: dbus_connection_set_watch_functions (dbus-connection.c:4966)
==16985==    by 0x5BBC957: q_dbus_connection_set_watch_functions (qdbus_symbols_p.h:244)
==16985==    by 0x5BBC957: QDBusConnectionPrivate::setConnection(DBusConnection*, QDBusErrorInternal const&) (qdbusintegrator.cpp:1829)
==16985==    by 0x5BAB2A5: QDBusConnectionManager::executeConnectionRequest(QDBusConnectionManager::ConnectionRequestData*) (qdbusconnection.cpp:290)
==16985==    by 0x5F1C350: QObject::event(QEvent*) (qobject.cpp:1314)
==16985==    by 0x5EF02FE: doNotify (qcoreapplication.cpp:1153)
==16985==    by 0x5EF02FE: notify (qcoreapplication.cpp:1139)
==16985==    by 0x5EF02FE: QCoreApplication::notifyInternal2(QObject*, QEvent*) (qcoreapplication.cpp:1063)
==16985==    by 0x5EF2D60: QCoreApplicationPrivate::sendPostedEvents(QObject*, int, QThreadData*) (qcoreapplication.cpp:1817)
==16985== 
==16985== 
==16985== 3 errors in context 7 of 96:
==16985== Invalid read of size 8
==16985==    at 0x5F44682: QEventDispatcherUNIXPrivate::markPendingSocketNotifiers() (qeventdispatcher_unix.cpp:273)
==16985==    by 0x5F44BB3: QEventDispatcherUNIXPrivate::activateSocketNotifiers() (qeventdispatcher_unix.cpp:294)
==16985==    by 0x5F4508A: QEventDispatcherUNIX::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) (qeventdispatcher_unix.cpp:511)
==16985==    by 0x5EEECEA: QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) (qeventloop.cpp:232)
==16985==    by 0x5D0DDAD: QThread::exec() (qthread.cpp:547)
==16985==    by 0x5BAA7B6: QDBusConnectionManager::run() (qdbusconnection.cpp:179)
==16985==    by 0x5D0EEF0: QThreadPrivate::start(void*) (qthread_unix.cpp:329)
==16985==    by 0x6E67298: start_thread (pthread_create.c:473)
==16985==    by 0x64FB3B2: clone (clone.S:95)
==16985==  Address 0xce6b038 is 24 bytes inside a block of size 40 free'd
==16985==    at 0x483F9AB: free (in /usr/lib64/valgrind/vgpreload_memcheck-amd64-linux.so)
==16985==    by 0x5F453ED: deleteNode (qhash.h:586)
==16985==    by 0x5F453ED: QHash<int, QSocketNotifierSetUNIX>::erase(QHash<int, QSocketNotifierSetUNIX>::const_iterator) (qhash.h:886)
==16985==    by 0x5CEBFF3: QEventDispatcherUNIXPrivate::markPendingSocketNotifiers() [clone .cold] (qeventdispatcher_unix.cpp:281)
==16985==    by 0x5F44BB3: QEventDispatcherUNIXPrivate::activateSocketNotifiers() (qeventdispatcher_unix.cpp:294)
==16985==    by 0x5F4508A: QEventDispatcherUNIX::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) (qeventdispatcher_unix.cpp:511)
==16985==    by 0x5EEECEA: QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) (qeventloop.cpp:232)
==16985==    by 0x5D0DDAD: QThread::exec() (qthread.cpp:547)
==16985==    by 0x5BAA7B6: QDBusConnectionManager::run() (qdbusconnection.cpp:179)
==16985==    by 0x5D0EEF0: QThreadPrivate::start(void*) (qthread_unix.cpp:329)
==16985==    by 0x6E67298: start_thread (pthread_create.c:473)
==16985==    by 0x64FB3B2: clone (clone.S:95)
==16985==  Block was alloc'd at
==16985==    at 0x483E77F: malloc (in /usr/lib64/valgrind/vgpreload_memcheck-amd64-linux.so)
==16985==    by 0x5D49897: QHashData::allocateNode(int) (qhash.cpp:479)
==16985==    by 0x5F43F51: createNode (qhash.h:610)
==16985==    by 0x5F43F51: operator[] (qhash.h:761)
==16985==    by 0x5F43F51: QEventDispatcherUNIX::registerSocketNotifier(QSocketNotifier*) (qeventdispatcher_unix.cpp:408)
==16985==    by 0x5F29F66: QSocketNotifier::QSocketNotifier(long long, QSocketNotifier::Type, QObject*) (qsocketnotifier.cpp:170)
==16985==    by 0x5BB6099: qDBusAddWatch (qdbusintegrator.cpp:214)
==16985==    by 0x7EB4D71: _dbus_watch_list_set_functions (dbus-watch.c:321)
==16985==    by 0x7EA3E8C: dbus_connection_set_watch_functions (dbus-connection.c:4966)
==16985==    by 0x5BBC957: q_dbus_connection_set_watch_functions (qdbus_symbols_p.h:244)
==16985==    by 0x5BBC957: QDBusConnectionPrivate::setConnection(DBusConnection*, QDBusErrorInternal const&) (qdbusintegrator.cpp:1829)
==16985==    by 0x5BAB2A5: QDBusConnectionManager::executeConnectionRequest(QDBusConnectionManager::ConnectionRequestData*) (qdbusconnection.cpp:290)
==16985==    by 0x5F1C350: QObject::event(QEvent*) (qobject.cpp:1314)
==16985==    by 0x5EF02FE: doNotify (qcoreapplication.cpp:1153)
==16985==    by 0x5EF02FE: notify (qcoreapplication.cpp:1139)
==16985==    by 0x5EF02FE: QCoreApplication::notifyInternal2(QObject*, QEvent*) (qcoreapplication.cpp:1063)
==16985==    by 0x5EF2D60: QCoreApplicationPrivate::sendPostedEvents(QObject*, int, QThreadData*) (qcoreapplication.cpp:1817)
==16985== 
==16985== 
==16985== 110 errors in context 8 of 96:
==16985== Thread 1:
==16985== Syscall param writev(vector[...]) points to uninitialised byte(s)
==16985==    at 0x64F21CD: __writev (writev.c:26)
==16985==    by 0x64F21CD: writev (writev.c:24)
==16985==    by 0x5B70AD2: UnknownInlinedFun (xcb_conn.c:277)
==16985==    by 0x5B70AD2: _xcb_conn_wait.part.0 (xcb_conn.c:523)
==16985==    by 0x5B70B8F: UnknownInlinedFun (xcb_out.c:463)
==16985==    by 0x5B70B8F: _xcb_out_send (xcb_out.c:464)
==16985==    by 0x5B70DE6: UnknownInlinedFun (xcb_out.c:488)
==16985==    by 0x5B70DE6: _xcb_out_flush_to (xcb_out.c:477)
==16985==    by 0x5B7242A: xcb_request_check (xcb_in.c:743)
==16985==    by 0x112601: QtPrivate::QFunctorSlotObject<KWin::ApplicationX11::performStartup()::{lambda()#2}, 0, QtPrivate::List<>, void>::impl(int, QtPrivate::QSlotObjectBase*, QObject*, void**, bool*) (main_x11.cpp:243)
==16985==    by 0x5F26945: call (qobjectdefs_impl.h:398)
==16985==    by 0x5F26945: void doActivate<false>(QObject*, int, void**) (qobject.cpp:3886)
==16985==    by 0x4BFF4C2: KSelectionOwner::Private::claimSucceeded() (kselectionowner.cpp:188)
==16985==    by 0x4C047A0: UnknownInlinedFun (kselectionowner.cpp:222)
==16985==    by 0x4C047A0: KSelectionOwner::filterEvent(void*) (kselectionowner.cpp:406)
==16985==    by 0x5EED876: QAbstractEventDispatcher::filterNativeEvent(QByteArray const&, void*, long*) (qabstracteventdispatcher.cpp:495)
==16985==    by 0xC3540E0: QXcbConnection::handleXcbEvent(xcb_generic_event_t*) (qxcbconnection.cpp:536)
==16985==    by 0xC3555F5: QXcbConnection::processXcbEvents(QFlags<QEventLoop::ProcessEventsFlag>) (qxcbconnection.cpp:1014)
==16985==  Address 0xa1bfd7a is 4,538 bytes inside a block of size 21,168 alloc'd
==16985==    at 0x4840B65: calloc (in /usr/lib64/valgrind/vgpreload_memcheck-amd64-linux.so)
==16985==    by 0x5B73050: xcb_connect_to_fd (xcb_conn.c:346)
==16985==    by 0x5B73C46: xcb_connect_to_display_with_auth_info (xcb_util.c:534)
==16985==    by 0x7BA40E1: _XConnectXCB (xcb_disp.c:78)
==16985==    by 0x7B94124: XOpenDisplay (OpenDis.c:129)
==16985==    by 0xC379926: QXcbBasicConnection::QXcbBasicConnection(char const*) (qxcbconnection_basic.cpp:114)
==16985==    by 0xC355B21: QXcbConnection::QXcbConnection(QXcbNativeInterface*, bool, unsigned int, char const*) (qxcbconnection.cpp:91)
==16985==    by 0xC358992: QXcbIntegration::QXcbIntegration(QStringList const&, int&, char**) (qxcbintegration.cpp:197)
==16985==    by 0x485E45E: create (qxcbmain.cpp:56)
==16985==    by 0x485E45E: QXcbIntegrationPlugin::create(QString const&, QStringList const&, int&, char**) (qxcbmain.cpp:53)
==16985==    by 0x55B908B: init_platform (qguiapplication.cpp:1223)
==16985==    by 0x55B908B: QGuiApplicationPrivate::createPlatformIntegration() (qguiapplication.cpp:1481)
==16985==    by 0x55BA48F: QGuiApplicationPrivate::createEventDispatcher() (qguiapplication.cpp:1498)
==16985==    by 0x5EF6DB5: QCoreApplicationPrivate::init() (qcoreapplication.cpp:834)
==16985==  Uninitialised value was created by a stack allocation
==16985==    at 0x4BFF450: KSelectionOwner::Private::claimSucceeded() (kselectionowner.cpp:170)
==16985== 
==16985== 
==16985== 670 errors in context 9 of 96:
==16985== Thread 7 Thread (pooled):
==16985== Conditional jump or move depends on uninitialised value(s)
==16985==    at 0xEEF521D: glXWaitVideoSyncSGI (in /usr/lib64/libGLX_nvidia.so.460.67)
==16985==    by 0x134B07A2: KWin::SGIVideoSyncVsyncMonitorHelper::poll() (sgivideosyncvsyncmonitor.cpp:122)
==16985==    by 0x5F1C350: QObject::event(QEvent*) (qobject.cpp:1314)
==16985==    by 0x4F194FE: QApplicationPrivate::notify_helper(QObject*, QEvent*) (qapplication.cpp:3632)
==16985==    by 0x5EF0329: QCoreApplication::notifyInternal2(QObject*, QEvent*) (qcoreapplication.cpp:1063)
==16985==    by 0x5EF2D60: QCoreApplicationPrivate::sendPostedEvents(QObject*, int, QThreadData*) (qcoreapplication.cpp:1817)
==16985==    by 0x5F44D89: QEventDispatcherUNIX::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) (qeventdispatcher_unix.cpp:468)
==16985==    by 0x5EEECEA: QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) (qeventloop.cpp:232)
==16985==    by 0x5D0DDAD: QThread::exec() (qthread.cpp:547)
==16985==    by 0x5D0EEF0: QThreadPrivate::start(void*) (qthread_unix.cpp:329)
==16985==    by 0x6E67298: start_thread (pthread_create.c:473)
==16985==    by 0x64FB3B2: clone (clone.S:95)
==16985==  Uninitialised value was created by a stack allocation
==16985==    at 0x5F17F50: QMetaCallEvent::placeMetaCall(QObject*) (qobject.cpp:613)


I saw many of these repeated, however, I think they are not very helpful:

==18205== 1 errors in context 866 of 868:
==18205== Conditional jump or move depends on uninitialised value(s)
==18205==    at 0xEF0C3DE: ??? (in /memfd:sljit (deleted))
==18205==    by 0xB5A6E77: ???


kwin_x11 related leaks:

==16985== Thread 1:
==16985== 8 bytes in 1 blocks are definitely lost in loss record 414 of 14,666
==16985==    at 0x483E77F: malloc (in /usr/lib64/valgrind/vgpreload_memcheck-amd64-linux.so)
==16985==    by 0xEEF3798: glXChooseFBConfig (in /usr/lib64/libGLX_nvidia.so.460.67)
==16985==    by 0x92A3FE6: glXChooseFBConfig (libglx.c:1491)
==16985==    by 0xE5FD8B4: QGLXContext::init(QXcbScreen*, QPlatformOpenGLContext*, QVariant const&) (qglxintegration.cpp:484)
==16985==    by 0xE5FC1D6: QXcbGlxIntegration::createPlatformOpenGLContext(QOpenGLContext*) const (qxcbglxintegration.cpp:191)
==16985==    by 0x560889C: QOpenGLContext::create() (qopenglcontext.cpp:612)
==16985==    by 0x134B5A9D: UnknownInlinedFun (glxbackend.cpp:380)
==16985==    by 0x134B5A9D: KWin::GlxBackend::init() [clone .part.0] (glxbackend.cpp:189)
==16985==    by 0x1228AD88: KWin::SceneOpenGL::createScene(QObject*) (scene_opengl.cpp:449)
==16985==    by 0x12299828: KWin::OpenGLFactory::create(QObject*) const (scene_opengl.cpp:2725)
==16985==    by 0x4985E2E: KWin::Compositor::setupStart() [clone .part.0] (composite.cpp:238)
==16985==    by 0x4988B59: KWin::X11Compositor::start() (composite.cpp:815)
==16985==    by 0x5F1C350: QObject::event(QEvent*) (qobject.cpp:1314)
==16985== 
==16985== 8 bytes in 1 blocks are definitely lost in loss record 415 of 14,666
==16985==    at 0x483E77F: malloc (in /usr/lib64/valgrind/vgpreload_memcheck-amd64-linux.so)
==16985==    by 0xEEF3798: glXChooseFBConfig (in /usr/lib64/libGLX_nvidia.so.460.67)
==16985==    by 0x92A3FE6: glXChooseFBConfig (libglx.c:1491)
==16985==    by 0xE5FD8B4: QGLXContext::init(QXcbScreen*, QPlatformOpenGLContext*, QVariant const&) (qglxintegration.cpp:484)
==16985==    by 0xE5FC1D6: QXcbGlxIntegration::createPlatformOpenGLContext(QOpenGLContext*) const (qxcbglxintegration.cpp:191)
==16985==    by 0x560889C: QOpenGLContext::create() (qopenglcontext.cpp:612)
==16985==    by 0x134B5A9D: UnknownInlinedFun (glxbackend.cpp:380)
==16985==    by 0x134B5A9D: KWin::GlxBackend::init() [clone .part.0] (glxbackend.cpp:189)
==16985==    by 0x1228AD88: KWin::SceneOpenGL::createScene(QObject*) (scene_opengl.cpp:449)
==16985==    by 0x12299828: KWin::OpenGLFactory::create(QObject*) const (scene_opengl.cpp:2725)
==16985==    by 0x4985E2E: KWin::Compositor::setupStart() [clone .part.0] (composite.cpp:238)
==16985==    by 0x4988B59: KWin::X11Compositor::start() (composite.cpp:815)
==16985==    by 0x4987E92: KWin::Compositor::reinitialize() (composite.cpp:560)


I hope these traces are useful; if not, I'll gladly collect more. The core files created during crashes are still available in case you need them.

Operating System: openSUSE Tumbleweed 20210330
KDE Plasma Version: 5.21.3
KDE Frameworks Version: 5.80.0
Qt Version: 5.15.2
Kernel Version: 5.11.6-1-default
OS Type: 64-bit
Graphics Platform: X11
Graphics Processor: GeForce GTX 960/PCIe/SSE2

During the day kwin was running in Valgrind and it crashed seven times and produced 19 different Valgrind .log files. I tried my best to de-duplicate the error and leak messages there (there were many repeating).

Here come the errors from Valgrind:

==18204== Thread 7 vsync event moni:
==18204== Conditional jump or move depends on uninitialised value(s)
==18204==    at 0xEEF521D: glXWaitVideoSyncSGI (in /usr/lib64/libGLX_nvidia.so.460.67)
==18204==    by 0x128B07A2: KWin::SGIVideoSyncVsyncMonitorHelper::poll() (sgivideosyncvsyncmonitor.cpp:122)
==18204==    by 0x5F1C350: QObject::event(QEvent*) (qobject.cpp:1314)
==18204==    by 0x4F194FE: QApplicationPrivate::notify_helper(QObject*, QEvent*) (qapplication.cpp:3632)
==18204==    by 0x5EF0329: QCoreApplication::notifyInternal2(QObject*, QEvent*) (qcoreapplication.cpp:1063)
==18204==    by 0x5EF2D60: QCoreApplicationPrivate::sendPostedEvents(QObject*, int, QThreadData*) (qcoreapplication.cpp:1817)
==18204==    by 0x5F44D89: QEventDispatcherUNIX::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) (qeventdispatcher_unix.cpp:468)
==18204==    by 0x5EEECEA: QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) (qeventloop.cpp:232)
==18204==    by 0x5D0DDAD: QThread::exec() (qthread.cpp:547)
==18204==    by 0x5D0EEF0: QThreadPrivate::start(void*) (qthread_unix.cpp:329)
==18204==    by 0x6E67298: start_thread (pthread_create.c:473)
==18204==    by 0x64FB3B2: clone (clone.S:95)
==18204==  Uninitialised value was created by a stack allocation
==18204==    at 0x5F17F50: QMetaCallEvent::placeMetaCall(QObject*) (qobject.cpp:613)


==23403== Invalid read of size 16
==23403==    at 0x122B1B01: ??? (in /memfd:sljit (deleted))
==23403==    by 0xD0C4EB7: ???
==23403==  Address 0xd0c4ede is 62 bytes inside a block of size 76 alloc'd
==23403==    at 0x483E77F: malloc (in /usr/lib64/valgrind/vgpreload_memcheck-amd64-linux.so)
==23403==    by 0x5D1A490: QArrayData::allocate(unsigned long, unsigned long, unsigned long, QFlags<QArrayData::AllocationOption>) (qarraydata.cpp:218)
==23403==    by 0x5D933F9: allocate (qarraydata.h:224)
==23403==    by 0x5D933F9: QString::fromLatin1_helper(char const*, int) (qstring.cpp:5459)
==23403==    by 0x671CE5D: KWin::GLPlatform::detect(KWin::OpenGLPlatformInterface) (qstring.h:701)
==23403==    by 0x134B5AE1: KWin::GlxBackend::init() [clone .part.0] (glxbackend.cpp:196)
==23403==    by 0x1228AD88: KWin::SceneOpenGL::createScene(QObject*) (scene_opengl.cpp:449)
==23403==    by 0x12299828: KWin::OpenGLFactory::create(QObject*) const (scene_opengl.cpp:2725)
==23403==    by 0x4985E2E: KWin::Compositor::setupStart() [clone .part.0] (composite.cpp:238)
==23403==    by 0x4988B59: KWin::X11Compositor::start() (composite.cpp:815)
==23403==    by 0x5F1C350: QObject::event(QEvent*) (qobject.cpp:1314)
==23403==    by 0x4F194FE: QApplicationPrivate::notify_helper(QObject*, QEvent*) (qapplication.cpp:3632)
==23403==    by 0x5EF0329: QCoreApplication::notifyInternal2(QObject*, QEvent*) (qcoreapplication.cpp:1063)


==23403== Syscall param writev(vector[...]) points to uninitialised byte(s)
==23403==    at 0x64F21CD: __writev (writev.c:26)
==23403==    by 0x64F21CD: writev (writev.c:24)
==23403==    by 0x5B70AD2: UnknownInlinedFun (xcb_conn.c:277)
==23403==    by 0x5B70AD2: _xcb_conn_wait.part.0 (xcb_conn.c:523)
==23403==    by 0x5B70B8F: UnknownInlinedFun (xcb_out.c:463)
==23403==    by 0x5B70B8F: _xcb_out_send (xcb_out.c:464)
==23403==    by 0x5B70DE6: UnknownInlinedFun (xcb_out.c:488)
==23403==    by 0x5B70DE6: _xcb_out_flush_to (xcb_out.c:477)
==23403==    by 0x5B7242A: xcb_request_check (xcb_in.c:743)
==23403==    by 0x112601: QtPrivate::QFunctorSlotObject<KWin::ApplicationX11::performStartup()::{lambda()#2}, 0, QtPrivate::List<>, void>::impl(int, QtPrivate::QSlotObjectBase*, QObject*, void**, bool*) (main_x11.cpp:243)
==23403==    by 0x5F26945: call (qobjectdefs_impl.h:398)
==23403==    by 0x5F26945: void doActivate<false>(QObject*, int, void**) (qobject.cpp:3886)
==23403==    by 0x4BFF4C2: KSelectionOwner::Private::claimSucceeded() (kselectionowner.cpp:188)
==23403==    by 0x4C047A0: UnknownInlinedFun (kselectionowner.cpp:222)
==23403==    by 0x4C047A0: KSelectionOwner::filterEvent(void*) (kselectionowner.cpp:406)
==23403==    by 0x5EED876: QAbstractEventDispatcher::filterNativeEvent(QByteArray const&, void*, long*) (qabstracteventdispatcher.cpp:495)
==23403==    by 0xC3540E0: QXcbConnection::handleXcbEvent(xcb_generic_event_t*) (qxcbconnection.cpp:536)
==23403==    by 0xC3555F5: QXcbConnection::processXcbEvents(QFlags<QEventLoop::ProcessEventsFlag>) (qxcbconnection.cpp:1014)
==23403==  Address 0xa1bfd7a is 4,538 bytes inside a block of size 21,168 alloc'd
==23403==    at 0x4840B65: calloc (in /usr/lib64/valgrind/vgpreload_memcheck-amd64-linux.so)
==23403==    by 0x5B73050: xcb_connect_to_fd (xcb_conn.c:346)
==23403==    by 0x5B73C46: xcb_connect_to_display_with_auth_info (xcb_util.c:534)
==23403==    by 0x7BA40E1: _XConnectXCB (xcb_disp.c:78)
==23403==    by 0x7B94124: XOpenDisplay (OpenDis.c:129)
==23403==    by 0xC379926: QXcbBasicConnection::QXcbBasicConnection(char const*) (qxcbconnection_basic.cpp:114)
==23403==    by 0xC355B21: QXcbConnection::QXcbConnection(QXcbNativeInterface*, bool, unsigned int, char const*) (qxcbconnection.cpp:91)
==23403==    by 0xC358992: QXcbIntegration::QXcbIntegration(QStringList const&, int&, char**) (qxcbintegration.cpp:197)
==23403==    by 0x485E45E: create (qxcbmain.cpp:56)
==23403==    by 0x485E45E: QXcbIntegrationPlugin::create(QString const&, QStringList const&, int&, char**) (qxcbmain.cpp:53)
==23403==    by 0x55B908B: init_platform (qguiapplication.cpp:1223)
==23403==    by 0x55B908B: QGuiApplicationPrivate::createPlatformIntegration() (qguiapplication.cpp:1481)
==23403==    by 0x55BA48F: QGuiApplicationPrivate::createEventDispatcher() (qguiapplication.cpp:1498)
==23403==    by 0x5EF6DB5: QCoreApplicationPrivate::init() (qcoreapplication.cpp:834)
==23403==  Uninitialised value was created by a stack allocation
==23403==    at 0x4BFF450: KSelectionOwner::Private::claimSucceeded() (kselectionowner.cpp:170)


==24377== Thread 3 QDBusConnectionM:
==24377== Invalid read of size 8
==24377==    at 0x5F44682: QEventDispatcherUNIXPrivate::markPendingSocketNotifiers() (qeventdispatcher_unix.cpp:273)
==24377==    by 0x5F44BB3: QEventDispatcherUNIXPrivate::activateSocketNotifiers() (qeventdispatcher_unix.cpp:294)
==24377==    by 0x5F4508A: QEventDispatcherUNIX::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) (qeventdispatcher_unix.cpp:511)
==24377==    by 0x5EEECEA: QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) (qeventloop.cpp:232)
==24377==    by 0x5D0DDAD: QThread::exec() (qthread.cpp:547)
==24377==    by 0x5BAA7B6: QDBusConnectionManager::run() (qdbusconnection.cpp:179)
==24377==    by 0x5D0EEF0: QThreadPrivate::start(void*) (qthread_unix.cpp:329)
==24377==    by 0x6E67298: start_thread (pthread_create.c:473)
==24377==    by 0x64FB3B2: clone (clone.S:95)
==24377==  Address 0xd261c08 is 24 bytes inside a block of size 40 free'd
==24377==    at 0x483F9AB: free (in /usr/lib64/valgrind/vgpreload_memcheck-amd64-linux.so)
==24377==    by 0x5F453ED: deleteNode (qhash.h:586)
==24377==    by 0x5F453ED: QHash<int, QSocketNotifierSetUNIX>::erase(QHash<int, QSocketNotifierSetUNIX>::const_iterator) (qhash.h:886)
==24377==    by 0x5CEBFF3: QEventDispatcherUNIXPrivate::markPendingSocketNotifiers() [clone .cold] (qeventdispatcher_unix.cpp:281)
==24377==    by 0x5F44BB3: QEventDispatcherUNIXPrivate::activateSocketNotifiers() (qeventdispatcher_unix.cpp:294)
==24377==    by 0x5F4508A: QEventDispatcherUNIX::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) (qeventdispatcher_unix.cpp:511)
==24377==    by 0x5EEECEA: QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) (qeventloop.cpp:232)
==24377==    by 0x5D0DDAD: QThread::exec() (qthread.cpp:547)
==24377==    by 0x5BAA7B6: QDBusConnectionManager::run() (qdbusconnection.cpp:179)
==24377==    by 0x5D0EEF0: QThreadPrivate::start(void*) (qthread_unix.cpp:329)
==24377==    by 0x6E67298: start_thread (pthread_create.c:473)
==24377==    by 0x64FB3B2: clone (clone.S:95)
==24377==  Block was alloc'd at
==24377==    at 0x483E77F: malloc (in /usr/lib64/valgrind/vgpreload_memcheck-amd64-linux.so)
==24377==    by 0x5D49897: QHashData::allocateNode(int) (qhash.cpp:479)
==24377==    by 0x5F43F51: createNode (qhash.h:610)
==24377==    by 0x5F43F51: operator[] (qhash.h:761)
==24377==    by 0x5F43F51: QEventDispatcherUNIX::registerSocketNotifier(QSocketNotifier*) (qeventdispatcher_unix.cpp:408)
==24377==    by 0x5F29F66: QSocketNotifier::QSocketNotifier(long long, QSocketNotifier::Type, QObject*) (qsocketnotifier.cpp:170)
==24377==    by 0x5BB6099: qDBusAddWatch (qdbusintegrator.cpp:214)
==24377==    by 0x7EB4D71: _dbus_watch_list_set_functions (dbus-watch.c:321)
==24377==    by 0x7EA3E8C: dbus_connection_set_watch_functions (dbus-connection.c:4966)
==24377==    by 0x5BBC957: q_dbus_connection_set_watch_functions (qdbus_symbols_p.h:244)
==24377==    by 0x5BBC957: QDBusConnectionPrivate::setConnection(DBusConnection*, QDBusErrorInternal const&) (qdbusintegrator.cpp:1829)
==24377==    by 0x5BAB3BF: QDBusConnectionManager::executeConnectionRequest(QDBusConnectionManager::ConnectionRequestData*) (qdbusconnection.cpp:290)
==24377==    by 0x5F1C350: QObject::event(QEvent*) (qobject.cpp:1314)
==24377==    by 0x5EF02FE: doNotify (qcoreapplication.cpp:1153)
==24377==    by 0x5EF02FE: notify (qcoreapplication.cpp:1139)
==24377==    by 0x5EF02FE: QCoreApplication::notifyInternal2(QObject*, QEvent*) (qcoreapplication.cpp:1063)
==24377==    by 0x5EF2D60: QCoreApplicationPrivate::sendPostedEvents(QObject*, int, QThreadData*) (qcoreapplication.cpp:1817)


==26719== Conditional jump or move depends on uninitialised value(s)
==26719==    at 0x682D9D6: isPossibleCell (Collector.cpp:785)
==26719==    by 0x682D9D6: QTJSC::Heap::markConservatively(QTJSC::MarkStack&, void*, void*) (Collector.cpp:807)
==26719==    by 0x682DC0F: QTJSC::Heap::markCurrentThreadConservativelyInternal(QTJSC::MarkStack&) (Collector.cpp:834)
==26719==    by 0x682DC97: QTJSC::Heap::markCurrentThreadConservatively(QTJSC::MarkStack&) (Collector.cpp:856)
==26719==    by 0x682E2FF: markStackObjectsConservatively (Collector.cpp:1008)
==26719==    by 0x682E2FF: QTJSC::Heap::markRoots() (Collector.cpp:1148)
==26719==    by 0x682E60E: reset (Collector.cpp:1269)
==26719==    by 0x682E60E: QTJSC::Heap::allocate(unsigned long) (Collector.cpp:405)
==26719==    by 0x68CC6DA: operator new (JSCell.h:162)
==26719==    by 0x68CC6DA: QScriptContext::argumentsObject() const (qscriptcontext.cpp:348)
==26719==    by 0x68CCCDD: QScriptContext::argument(int) const (qscriptcontext.cpp:281)
==26719==    by 0x4A3E33C: KWin::kwinEffectRetarget(QScriptContext*, QScriptEngine*) (scriptedeffect.cpp:408)
==26719==    by 0x68F7778: QScript::FunctionWrapper::proxyCall(QTJSC::ExecState*, QTJSC::JSObject*, QTJSC::JSValue, QTJSC::ArgList const&) (qscriptfunction.cpp:98)
==26719==    by 0x682D46D: QTJSC::NativeFuncWrapper::operator()(QTJSC::ExecState*, QTJSC::JSObject*, QTJSC::JSValue, QTJSC::ArgList const&) const (CallData.cpp:46)
==26719==    by 0x680A732: cti_op_call_NotJSFunction (JITStubs.cpp:1780)
==26719==    by 0x59CEEA19: ???
==26719==  Uninitialised value was created by a stack allocation
==26719==    at 0x682DB50: QTJSC::Heap::markCurrentThreadConservativelyInternal(QTJSC::MarkStack&) (Collector.cpp:830)


==26719== Conditional jump or move depends on uninitialised value(s)
==26719==    at 0x682DA5D: QTJSC::Heap::markConservatively(QTJSC::MarkStack&, void*, void*) (Collector.cpp:820)
==26719==    by 0x682DC0F: QTJSC::Heap::markCurrentThreadConservativelyInternal(QTJSC::MarkStack&) (Collector.cpp:834)
==26719==    by 0x682DC97: QTJSC::Heap::markCurrentThreadConservatively(QTJSC::MarkStack&) (Collector.cpp:856)
==26719==    by 0x682E2FF: markStackObjectsConservatively (Collector.cpp:1008)
==26719==    by 0x682E2FF: QTJSC::Heap::markRoots() (Collector.cpp:1148)
==26719==    by 0x682E60E: reset (Collector.cpp:1269)
==26719==    by 0x682E60E: QTJSC::Heap::allocate(unsigned long) (Collector.cpp:405)
==26719==    by 0x68CC6DA: operator new (JSCell.h:162)
==26719==    by 0x68CC6DA: QScriptContext::argumentsObject() const (qscriptcontext.cpp:348)
==26719==    by 0x68CCCDD: QScriptContext::argument(int) const (qscriptcontext.cpp:281)
==26719==    by 0x4A3E33C: KWin::kwinEffectRetarget(QScriptContext*, QScriptEngine*) (scriptedeffect.cpp:408)
==26719==    by 0x68F7778: QScript::FunctionWrapper::proxyCall(QTJSC::ExecState*, QTJSC::JSObject*, QTJSC::JSValue, QTJSC::ArgList const&) (qscriptfunction.cpp:98)
==26719==    by 0x682D46D: QTJSC::NativeFuncWrapper::operator()(QTJSC::ExecState*, QTJSC::JSObject*, QTJSC::JSValue, QTJSC::ArgList const&) const (CallData.cpp:46)
==26719==    by 0x680A732: cti_op_call_NotJSFunction (JITStubs.cpp:1780)
==26719==    by 0x59CEEA19: ???
==26719==  Uninitialised value was created by a stack allocation
==26719==    at 0x682DC70: QTJSC::Heap::markCurrentThreadConservatively(QTJSC::MarkStack&) (Collector.cpp:844)

==30515== Use of uninitialised value of size 8
==30515==    at 0x682DA68: get (Collector.h:215)
==30515==    by 0x682DA68: isCellMarked (Collector.h:269)
==30515==    by 0x682DA68: append (JSCell.h:329)
==30515==    by 0x682DA68: QTJSC::Heap::markConservatively(QTJSC::MarkStack&, void*, void*) (Collector.cpp:822)
==30515==    by 0x682DC0F: QTJSC::Heap::markCurrentThreadConservativelyInternal(QTJSC::MarkStack&) (Collector.cpp:834)
==30515==    by 0x682DC97: QTJSC::Heap::markCurrentThreadConservatively(QTJSC::MarkStack&) (Collector.cpp:856)
==30515==    by 0x682E2FF: markStackObjectsConservatively (Collector.cpp:1008)
==30515==    by 0x682E2FF: QTJSC::Heap::markRoots() (Collector.cpp:1148)
==30515==    by 0x682E60E: reset (Collector.cpp:1269)
==30515==    by 0x682E60E: QTJSC::Heap::allocate(unsigned long) (Collector.cpp:405)
==30515==    by 0x6848399: operator new (JSCell.h:162)
==30515==    by 0x6848399: jsString (JSString.h:445)
==30515==    by 0x6848399: QTJSC::InternalFunction::InternalFunction(QTJSC::JSGlobalData*, QTWTF::NonNullPassRefPtr<QTJSC::Structure>, QTJSC::Identifier const&) (InternalFunction.cpp:43)
==30515==    by 0x68FE370: QScript::QtPropertyFunction::QtPropertyFunction(QMetaObject const*, int, QTJSC::JSGlobalData*, QTWTF::PassRefPtr<QTJSC::Structure>, QTJSC::Identifier const&) (qscriptqobject.cpp:1061)
==30515==    by 0x6907CD0: QScript::QObjectDelegate::getOwnPropertySlot(QScriptObject*, QTJSC::ExecState*, QTJSC::Identifier const&, QTJSC::PropertySlot&) (qscriptqobject.cpp:1262)
==30515==    by 0x67CD57C: fastGetOwnPropertySlot (JSObject.h:382)
==30515==    by 0x67CD57C: QTJSC::JSValue::get(QTJSC::ExecState*, QTJSC::Identifier const&, QTJSC::PropertySlot&) const (JSObject.h:618)
==30515==    by 0x6806FEE: cti_op_get_by_id_generic (JITStubs.cpp:1237)
==30515==    by 0x59CE5AEC: ???
==30515==    by 0x67BFE39: execute (JITCode.h:79)
==30515==    by 0x67BFE39: QTJSC::Interpreter::execute(QTJSC::FunctionExecutable*, QTJSC::ExecState*, QTJSC::JSFunction*, QTJSC::JSObject*, QTJSC::ArgList const&, QTJSC::ScopeChainNode*, QTJSC::JSValue*) (Interpreter.cpp:718)
==30515==  Uninitialised value was created by a stack allocation
==30515==    at 0x6907697: QScript::QObjectDelegate::getOwnPropertySlot(QScriptObject*, QTJSC::ExecState*, QTJSC::Identifier const&, QTJSC::PropertySlot&) (qscriptqobject.cpp:1206)


==26719== Conditional jump or move depends on uninitialised value(s)
==26719==    at 0x68FC3E7: append (JSCell.h:329)
==26719==    by 0x68FC3E7: append (JSCell.h:340)
==26719==    by 0x68FC3E7: QScript::QtFunction::markChildren(QTJSC::MarkStack&) (qscriptqobject.cpp:238)
==26719==    by 0x682F9C4: markChildren (JSArray.h:178)
==26719==    by 0x682F9C4: QTJSC::MarkStack::drain() (JSArray.h:220)
==26719==    by 0x682DA96: QTJSC::Heap::markConservatively(QTJSC::MarkStack&, void*, void*) (Collector.cpp:823)
==26719==    by 0x682DC0F: QTJSC::Heap::markCurrentThreadConservativelyInternal(QTJSC::MarkStack&) (Collector.cpp:834)
==26719==    by 0x682DC97: QTJSC::Heap::markCurrentThreadConservatively(QTJSC::MarkStack&) (Collector.cpp:856)
==26719==    by 0x682E2FF: markStackObjectsConservatively (Collector.cpp:1008)
==26719==    by 0x682E2FF: QTJSC::Heap::markRoots() (Collector.cpp:1148)
==26719==    by 0x682E60E: reset (Collector.cpp:1269)
==26719==    by 0x682E60E: QTJSC::Heap::allocate(unsigned long) (Collector.cpp:405)
==26719==    by 0x68CC6DA: operator new (JSCell.h:162)
==26719==    by 0x68CC6DA: QScriptContext::argumentsObject() const (qscriptcontext.cpp:348)
==26719==    by 0x68CCCDD: QScriptContext::argument(int) const (qscriptcontext.cpp:281)
==26719==    by 0x4A3E33C: KWin::kwinEffectRetarget(QScriptContext*, QScriptEngine*) (scriptedeffect.cpp:408)
==26719==    by 0x68F7778: QScript::FunctionWrapper::proxyCall(QTJSC::ExecState*, QTJSC::JSObject*, QTJSC::JSValue, QTJSC::ArgList const&) (qscriptfunction.cpp:98)
==26719==    by 0x682D46D: QTJSC::NativeFuncWrapper::operator()(QTJSC::ExecState*, QTJSC::JSObject*, QTJSC::JSValue, QTJSC::ArgList const&) const (CallData.cpp:46)
==26719==  Uninitialised value was created by a stack allocation
==26719==    at 0x4A3E215: KWin::kwinEffectRetarget(QScriptContext*, QScriptEngine*) (scriptedeffect.cpp:402)

Here are the reported definite leaks:

==23403== 128 (24 direct, 104 indirect) bytes in 1 blocks are definitely lost in loss record 715 of 1,029
==23403==    at 0x483EDEF: operator new(unsigned long) (in /usr/lib64/valgrind/vgpreload_memcheck-amd64-linux.so)
==23403==    by 0x49BDDD4: KWin::Workspace::registerEventFilter(KWin::X11EventFilter*) (events.cpp:171)
==23403==    by 0x1349E201: KWin::X11StandalonePlatform::createScreenEdge(KWin::ScreenEdges*) (screenedges_filter.cpp:20)
==23403==    by 0x4A332F4: KWin::ScreenEdges::createEdge(KWin::ElectricBorder, int, int, int, int, bool) (screenedge.cpp:1106)
==23403==    by 0x4A342A2: KWin::ScreenEdges::createVerticalEdge(KWin::ElectricBorder, QRect const&, QRect const&) (screenedge.cpp:1061)
==23403==    by 0x4A34792: KWin::ScreenEdges::recreateEdges() (screenedge.cpp:1001)
==23403==    by 0x4A8DE54: KWin::Workspace::init() (workspace.cpp:218)
==23403==    by 0x4A8CE82: KWin::Workspace::Workspace() (workspace.cpp:204)
==23403==    by 0x49FE22F: KWin::Application::createWorkspace() (main.cpp:272)
==23403==    by 0x111D08: KWin::ApplicationX11::continueStartupWithScreens() (main_x11.cpp:272)
==23403==    by 0x5F26945: call (qobjectdefs_impl.h:398)
==23403==    by 0x5F26945: void doActivate<false>(QObject*, int, void**) (qobject.cpp:3886)
==23403==    by 0x134AE5D8: void KWin::X11StandalonePlatform::doUpdateOutputs<KWin::Xcb::RandR::ScreenResources>() (x11_platform.cpp:603)


==23403== 128 (24 direct, 104 indirect) bytes in 1 blocks are definitely lost in loss record 720 of 1,029
==23403==    at 0x483EDEF: operator new(unsigned long) (in /usr/lib64/valgrind/vgpreload_memcheck-amd64-linux.so)
==23403==    by 0x49BDDD4: KWin::Workspace::registerEventFilter(KWin::X11EventFilter*) (events.cpp:171)
==23403==    by 0x4AC1C71: KWin::X11EventFilter::X11EventFilter(int, int, int) (x11eventfilter.cpp:25)
==23403==    by 0x134A41FF: KWin::X11StandalonePlatform::init() (x11_platform.cpp:66)
==23403==    by 0x1127E6: QtPrivate::QFunctorSlotObject<KWin::ApplicationX11::performStartup()::{lambda()#2}, 0, QtPrivate::List<>, void>::impl(int, QtPrivate::QSlotObjectBase*, QObject*, void**, bool*) (main_x11.cpp:259)
==23403==    by 0x5F26945: call (qobjectdefs_impl.h:398)
==23403==    by 0x5F26945: void doActivate<false>(QObject*, int, void**) (qobject.cpp:3886)
==23403==    by 0x4BFF4C2: KSelectionOwner::Private::claimSucceeded() (kselectionowner.cpp:188)
==23403==    by 0x4C047A0: UnknownInlinedFun (kselectionowner.cpp:222)
==23403==    by 0x4C047A0: KSelectionOwner::filterEvent(void*) (kselectionowner.cpp:406)
==23403==    by 0x5EED876: QAbstractEventDispatcher::filterNativeEvent(QByteArray const&, void*, long*) (qabstracteventdispatcher.cpp:495)
==23403==    by 0xC3540E0: QXcbConnection::handleXcbEvent(xcb_generic_event_t*) (qxcbconnection.cpp:536)
==23403==    by 0xC3555F5: QXcbConnection::processXcbEvents(QFlags<QEventLoop::ProcessEventsFlag>) (qxcbconnection.cpp:1014)
==23403==    by 0xC37835B: QXcbUnixEventDispatcher::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) (qxcbeventdispatcher.cpp:61)


==24377== 8 bytes in 1 blocks are definitely lost in loss record 758 of 21,144
==24377==    at 0x483E77F: malloc (in /usr/lib64/valgrind/vgpreload_memcheck-amd64-linux.so)
==24377==    by 0xEEF3798: glXChooseFBConfig (in /usr/lib64/libGLX_nvidia.so.460.67)
==24377==    by 0x92A3FE6: glXChooseFBConfig (libglx.c:1491)
==24377==    by 0xE5FD8B4: QGLXContext::init(QXcbScreen*, QPlatformOpenGLContext*, QVariant const&) (qglxintegration.cpp:484)
==24377==    by 0xE5FC1D6: QXcbGlxIntegration::createPlatformOpenGLContext(QOpenGLContext*) const (qxcbglxintegration.cpp:191)
==24377==    by 0x560889C: QOpenGLContext::create() (qopenglcontext.cpp:612)
==24377==    by 0x128AFA9D: UnknownInlinedFun (glxbackend.cpp:380)
==24377==    by 0x128AFA9D: KWin::GlxBackend::init() [clone .part.0] (glxbackend.cpp:189)
==24377==    by 0x1268AD88: KWin::SceneOpenGL::createScene(QObject*) (scene_opengl.cpp:449)
==24377==    by 0x12699828: KWin::OpenGLFactory::create(QObject*) const (scene_opengl.cpp:2725)
==24377==    by 0x4985E2E: KWin::Compositor::setupStart() [clone .part.0] (composite.cpp:238)
==24377==    by 0x4988B59: KWin::X11Compositor::start() (composite.cpp:815)
==24377==    by 0x5F1C350: QObject::event(QEvent*) (qobject.cpp:1314)


==24377== 16 bytes in 2 blocks are definitely lost in loss record 1,669 of 21,144
==24377==    at 0x483F50F: operator new[](unsigned long) (in /usr/lib64/valgrind/vgpreload_memcheck-amd64-linux.so)
==24377==    by 0x77489FE: QLinkedStringHash<QPair<int, QQmlPropertyData*> >::linkAndReserve(QLinkedStringHash<QPair<int, QQmlPropertyData*> > const&, int) (qlinkedstringhash_p.h:82)
==24377==    by 0x77440B1: copy (qqmlpropertycache.cpp:262)
==24377==    by 0x77440B1: QQmlPropertyCache::copyAndReserve(int, int, int, int) (qqmlpropertycache.cpp:278)
==24377==    by 0x76F05E0: QQmlPropertyCacheCreator<QV4::ExecutableCompilationUnit>::createMetaObject(int, QV4::CompiledData::Object const*, QQmlRefPointer<QQmlPropertyCache> const&) (qqmlpropertycachecreator_p.h:351)
==24377==    by 0x76F2156: QQmlPropertyCacheCreator<QV4::ExecutableCompilationUnit>::buildMetaObjectRecursively(int, QQmlBindingInstantiationContext const&, QQmlPropertyCacheCreator<QV4::ExecutableCompilationUnit>::VMEMetaObjectIsRequired) (qqmlpropertycachecreator_p.h:269)
==24377==    by 0x76F2CD5: QQmlPropertyCacheCreator<QV4::ExecutableCompilationUnit>::buildMetaObjects() (qqmlpropertycachecreator_p.h:213)
==24377==    by 0x76EA11B: QQmlTypeData::createTypeAndPropertyCaches(QQmlRefPointer<QQmlTypeNameCache> const&, QV4::ResolvedTypeReferenceMap const&) (qqmltypedata.cpp:247)
==24377==    by 0x76EBF93: QQmlTypeData::done() (qqmltypedata.cpp:457)
==24377==    by 0x76D9E04: tryDone (qqmldatablob.cpp:524)
==24377==    by 0x76D9E04: QQmlDataBlob::tryDone() (qqmldatablob.cpp:515)
==24377==    by 0x7733B74: QQmlTypeLoader::setData(QQmlDataBlob*, QQmlDataBlob::SourceCodeData const&) (qqmltypeloader.cpp:457)
==24377==    by 0x7734231: QQmlTypeLoader::setData(QQmlDataBlob*, QString const&) (qqmltypeloader.cpp:437)
==24377==    by 0x77354AB: QQmlTypeLoader::loadThread(QQmlDataBlob*) (qqmltypeloader.cpp:299)


==24377== 40 bytes in 5 blocks are definitely lost in loss record 8,895 of 21,144
==24377==    at 0x483F50F: operator new[](unsigned long) (in /usr/lib64/valgrind/vgpreload_memcheck-amd64-linux.so)
==24377==    by 0x7744AE6: linkAndReserve (qlinkedstringhash_p.h:82)
==24377==    by 0x7744AE6: copy (qqmlpropertycache.cpp:262)
==24377==    by 0x7744AE6: QQmlPropertyCache::copy() (qqmlpropertycache.cpp:272)
==24377==    by 0x7729E04: QQmlMetaTypeData::propertyCache(QQmlType const&, int) (qqmlmetatypedata.cpp:175)
==24377==    by 0x771DC11: QQmlMetaType::propertyCache(QQmlType const&, int) (qqmlmetatype.cpp:1242)
==24377==    by 0x76E6CCD: cache (qqmlengine_p.h:410)
==24377==    by 0x76E6CCD: cache (qqmlengine_p.h:402)
==24377==    by 0x76E6CCD: QQmlTypeData::buildTypeResolutionCaches(QQmlRefPointer<QQmlTypeNameCache>*, QV4::ResolvedTypeReferenceMap*) const (qqmltypedata.cpp:975)
==24377==    by 0x76EAEB2: QQmlTypeData::done() (qqmltypedata.cpp:424)
==24377==    by 0x76D9E04: tryDone (qqmldatablob.cpp:524)
==24377==    by 0x76D9E04: QQmlDataBlob::tryDone() (qqmldatablob.cpp:515)
==24377==    by 0x7733B74: QQmlTypeLoader::setData(QQmlDataBlob*, QQmlDataBlob::SourceCodeData const&) (qqmltypeloader.cpp:457)
==24377==    by 0x7734231: QQmlTypeLoader::setData(QQmlDataBlob*, QString const&) (qqmltypeloader.cpp:437)
==24377==    by 0x77354AB: QQmlTypeLoader::loadThread(QQmlDataBlob*) (qqmltypeloader.cpp:299)
==24377==    by 0x76F459C: QQmlTypeLoaderThread::loadThread(QQmlDataBlob*) (qqmltypeloaderthread.cpp:162)
==24377==    by 0x77A674E: QQmlThreadPrivate::threadEvent() (qqmlthread.cpp:198)

I'm not so much interested in the leaks, but I want a trace of a time when we're calling createPlatformOpenGLContext with an invalid screen

I usually get this kind of crash when I regularly switch between the two inputs (DisplayPort and HDMI) of my monitor. I'll continue testing with this pattern in a few days, therefore anyone who has a better reproducible or can jump in sooner, feel free to do :).

On a related note, may I ask what will be the fate of the other kwin Valgrind errors from Comment 20? Should I open separate bug tickets for them? As kwin crashes under Valgrind quite often it'd also ease further debugging if we didn't need to filter out duplicate reportings.

For me it usually happen after a VT switch.
Trying to reproduce it with plasmashell under valgrind leads to this use after free that makes me think it's a pure QT bug:

==1964973== Invalid read of size 8
==1964973==    at 0x631FB85: ??? (in /usr/qt5/lib/libQt5Gui.so.5.15.2)
==1964973==    by 0x60857E9: QOpenGLContextGroupPrivate::deletePendingResources(QOpenGLContext*) (in /usr/qt5/lib/libQt5Gui.so.5.15.2)
==1964973==    by 0x608763B: QOpenGLSharedResource::free() (in /usr/qt5/lib/libQt5Gui.so.5.15.2)
==1964973==    by 0x631FC29: QOpenGLTextureCache::invalidateResource() (in /usr/qt5/lib/libQt5Gui.so.5.15.2)
==1964973==    by 0x6087796: QOpenGLMultiGroupSharedResource::cleanup(QOpenGLContextGroup*, QOpenGLSharedResource*) (in /usr/qt5/lib/libQt5Gui.so.5.15.2)
==1964973==    by 0x6087867: QOpenGLContextGroupPrivate::cleanup() (in /usr/qt5/lib/libQt5Gui.so.5.15.2)
==1964973==    by 0x6087E37: QOpenGLContextGroupPrivate::removeContext(QOpenGLContext*) (in /usr/qt5/lib/libQt5Gui.so.5.15.2)
==1964973==    by 0x6087FAD: QOpenGLContext::destroy() (in /usr/qt5/lib/libQt5Gui.so.5.15.2)
==1964973==    by 0x6088229: QOpenGLContext::create() (in /usr/qt5/lib/libQt5Gui.so.5.15.2)
==1964973==    by 0x4E0C7C3: ??? (in /usr/qt5/lib/libQt5Quick.so.5.15.2)
==1964973==    by 0x4E0E58D: ??? (in /usr/qt5/lib/libQt5Quick.so.5.15.2)
==1964973==    by 0x4E0F2A6: ??? (in /usr/qt5/lib/libQt5Quick.so.5.15.2)
==1964973==    by 0x66A58A9: ??? (in /usr/qt5/lib/libQt5Core.so.5.15.2)
==1964973==    by 0x797AD1D: start_thread (in /usr/lib/libpthread-2.33.so)
==1964973==    by 0x6DD05BE: clone (in /usr/lib/libc-2.33.so)
==1964973==  Address 0x3646e6a0 is 96 bytes inside a block of size 2,936 free'd
==1964973==    at 0x4840B52: operator delete(void*, unsigned long) (in /usr/libexec/valgrind/vgpreload_memcheck-amd64-linux.so)
==1964973==    by 0x60857B5: QOpenGLContextGroupPrivate::deletePendingResources(QOpenGLContext*) (in /usr/qt5/lib/libQt5Gui.so.5.15.2)
==1964973==    by 0x608763B: QOpenGLSharedResource::free() (in /usr/qt5/lib/libQt5Gui.so.5.15.2)
==1964973==    by 0x6087707: QOpenGLMultiGroupSharedResource::cleanup(QOpenGLContextGroup*, QOpenGLSharedResource*) (in /usr/qt5/lib/libQt5Gui.so.5.15.2)
==1964973==    by 0x6087867: QOpenGLContextGroupPrivate::cleanup() (in /usr/qt5/lib/libQt5Gui.so.5.15.2)
==1964973==    by 0x6087E37: QOpenGLContextGroupPrivate::removeContext(QOpenGLContext*) (in /usr/qt5/lib/libQt5Gui.so.5.15.2)
==1964973==    by 0x6087FAD: QOpenGLContext::destroy() (in /usr/qt5/lib/libQt5Gui.so.5.15.2)
==1964973==    by 0x6088229: QOpenGLContext::create() (in /usr/qt5/lib/libQt5Gui.so.5.15.2)
==1964973==    by 0x4E0C7C3: ??? (in /usr/qt5/lib/libQt5Quick.so.5.15.2)
==1964973==    by 0x4E0E58D: ??? (in /usr/qt5/lib/libQt5Quick.so.5.15.2)
==1964973==    by 0x4E0F2A6: ??? (in /usr/qt5/lib/libQt5Quick.so.5.15.2)
==1964973==    by 0x66A58A9: ??? (in /usr/qt5/lib/libQt5Core.so.5.15.2)
==1964973==    by 0x797AD1D: start_thread (in /usr/lib/libpthread-2.33.so)
==1964973==    by 0x6DD05BE: clone (in /usr/lib/libc-2.33.so)
==1964973==  Block was alloc'd at
==1964973==    at 0x483DF82: operator new(unsigned long) (in /usr/libexec/valgrind/vgpreload_memcheck-amd64-linux.so)
==1964973==    by 0x6313078: ??? (in /usr/qt5/lib/libQt5Gui.so.5.15.2)
==1964973==    by 0x63131EE: QOpenGLFunctions::QOpenGLFunctions(QOpenGLContext*) (in /usr/qt5/lib/libQt5Gui.so.5.15.2)
==1964973==    by 0x6085211: QOpenGLContext::functions() const (in /usr/qt5/lib/libQt5Gui.so.5.15.2)
==1964973==    by 0x4E01EC4: QSGDefaultRenderContext::initialize(QSGRenderContext::InitParams const*) (in /usr/qt5/lib/libQt5Quick.so.5.15.2)
==1964973==    by 0x4E0F4DB: ??? (in /usr/qt5/lib/libQt5Quick.so.5.15.2)
==1964973==    by 0x66A58A9: ??? (in /usr/qt5/lib/libQt5Core.so.5.15.2)
==1964973==    by 0x797AD1D: start_thread (in /usr/lib/libpthread-2.33.so)
==1964973==    by 0x6DD05BE: clone (in /usr/lib/libc-2.33.so)

In the next days, I will try to reproduce it again with a QT debug build.

Found it:

 QPlatformOpenGLContext *QXcbIntegration::createPlatformOpenGLContext(QOpenGLContext *context) const
 {
-    QXcbScreen *screen = static_cast<QXcbScreen *>(context->screen()->handle());
-    QXcbGlIntegration *glIntegration = screen->connection()->glIntegration();
+    QXcbGlIntegration *glIntegration = defaultConnection()->glIntegration();



It appears it is fixed in Qt6 with 590ac717a2c073292027111d5c99d68fb17b160c

I'll see if we can get it backported.

1e39b39ddb478719682948bed329e891b26d7bf6 and 590ac717a2c073292027111d5c99d68fb17b160c apply cleanly on qt 5.15.2. Do you think it would be enough?

I would suggest taking https://invent.kde.org/qt/qt/qtbase/-/merge_requests/33 as a backportable patch.

*** Bug 439005 has been marked as a duplicate of this bug. ***

*** Bug 414823 has been marked as a duplicate of this bug. ***

*** Bug 440124 has been marked as a duplicate of this bug. ***

*** Bug 441744 has been marked as a duplicate of this bug. ***

*** Bug 442126 has been marked as a duplicate of this bug. ***

*** Bug 444386 has been marked as a duplicate of this bug. ***

*** Bug 445327 has been marked as a duplicate of this bug. ***

*** Bug 445498 has been marked as a duplicate of this bug. ***

*** Bug 445498 has been marked as a duplicate of this bug. ***

*** Bug 447751 has been marked as a duplicate of this bug. ***

I see the backport was merged into KDE Qt repos 6 months ago. I use openSUSE Tumbleweed 20220103 with libqt5 5.15.2+kde268-1.1 (so its seems it has KDE patches).

For some reason I still daily meet this crash after I change monitor outputs (once for KWin after an Alt+Tab, then in Krunner when I press Alt+F2, finally in plasmashell when I click on volume slider).

In the distro libqt5 changelog (https://build.opensuse.org/package/view_file/openSUSE:Factory/libqt5-qtbase/libqt5-qtbase.changes?expand=1 ) I don't see the explicit mentioning of this backport fix, however, I do see that it's getting the sources from invent.kde (https://build.opensuse.org/package/view_file/openSUSE:Factory/libqt5-qtbase/_service?expand=1 )

My question is, how certain you are that this patch fixed the issue or should I post some backtraces to verify whether we're talking about the same crash?

I reported the phenomenon I referred above in Bug 449270 separately to be able to track it independently.

*** Bug 449288 has been marked as a duplicate of this bug. ***

Created attachment 146271 [details]
New crash information added by DrKonqi

plasmashell (5.23.4) using Qt 5.15.2

Unfortunately, it seems that the very same crash happens with the Qt patch applied (my libqt5-base version is 5.15.2+kde268). Once after each monitor input change I can reproduce it.

I understand that this is a Qt problem (presumably), however, the number of duplicates tells that it widely affects KDE users.

My question is, despite that this is an external problem, should we reopen it? Do other people face the same problem also with KDE-patched Qt?

-- Backtrace (Reduced):
#6  0x00007f32b4a46794 in QScreen::handle() const (this=0x559f268d9ca0) at kernel/qscreen.cpp:182
#7  0x00007f32aec95150 in QXcbGlxIntegration::createPlatformOpenGLContext(QOpenGLContext*) const (this=<optimized out>, context=0x7f32a80043b0) at qxcbglxintegration.cpp:195
#8  0x00007f32b4a63bed in QOpenGLContext::create() (this=0x7f32a80043b0) at kernel/qopenglcontext.cpp:612
#9  0x00007f32b60924b8 in QSGRenderThread::sync(bool, bool) (this=this@entry=0x559f29d4a650, inExpose=inExpose@entry=true, inGrab=inGrab@entry=false) at /usr/src/debug/libqt5-qtdeclarative-5.15.2+kde36-1.3.x86_64/src/quick/scenegraph/qsgthreadedrenderloop.cpp:620
#10 0x00007f32b609425c in QSGRenderThread::syncAndRender(QImage*) (this=0x559f29d4a650, grabImage=0x0) at /usr/src/debug/libqt5-qtdeclarative-5.15.2+kde36-1.3.x86_64/src/quick/scenegraph/qsgthreadedrenderloop.cpp:778

*** Bug 471417 has been marked as a duplicate of this bug. ***

*** Bug 474721 has been marked as a duplicate of this bug. ***

*** Bug 474935 has been marked as a duplicate of this bug. ***

*** Bug 475350 has been marked as a duplicate of this bug. ***

*** Bug 475545 has been marked as a duplicate of this bug. ***

*** Bug 475618 has been marked as a duplicate of this bug. ***

*** Bug 475739 has been marked as a duplicate of this bug. ***

*** Bug 415485 has been marked as a duplicate of this bug. ***

*** Bug 476713 has been marked as a duplicate of this bug. ***

*** Bug 478941 has been marked as a duplicate of this bug. ***

*** Bug 478183 has been marked as a duplicate of this bug. ***

*** Bug 480308 has been marked as a duplicate of this bug. ***

*** Bug 481190 has been marked as a duplicate of this bug. ***

*** Bug 481022 has been marked as a duplicate of this bug. ***

*** Bug 479408 has been marked as a duplicate of this bug. ***

Demoting this from being a VHI priority bug since the X11 session is no longer default in Plasma 6.

I'm also interested in learning whether anyone using X11 on Plasma 6 can still reproduce the issue.

I use KDE Neon and preferably use X11 sessions. I did the update process for Plasma 6 via "sudo pkcon refresh && sudo pkcon update -v ; flatpak update -y" and then restarted.


I don't know if this is a new bug, however when putting KDE Neon into sleep mode and waking it up, instead of seeing the login screen I only see the mouse arrow on a 100% black screen on all monitors. The login screen does not return even after waiting a few minutes and then I am forced to open a terminal session (CRTL + ALT + F4) and perform a manual restart, which involves having to manually kill all instances of Google Chrome (so as not to lose my open tabs) and only then perform reboot.

That is a different bug, yes. This one is about a crash in QScreen::handle() after QXcbIntegration::createPlatformOpenGLContext().

(In reply to Nate Graham from comment #59)
> Demoting this from being a VHI priority bug since the X11 session is no
> longer default in Plasma 6.
> 
> I'm also interested in learning whether anyone using X11 on Plasma 6 can
> still reproduce the issue.

I can test this on my Debian 12 system. I am not super fimiliar with the organization of the repositories, and I am assuming that I am targeting the xdg-desktop-portal-kde project?

You'll need to upgrade everything to Plasma 6, not just one package. It's something typically a distro does for you, either in your main repo once their ready, or a "testing" repo you enable yourself.

Regardless, let's avoid discussing the details of how to perform system upgrades, as 36 people are CCd to this bug report and probably will not appreciate the email spam resulting from it.

*** Bug 483633 has been marked as a duplicate of this bug. ***