Created attachment 1333422 [details]
File: backtrace

Created attachment 1333423 [details]
File: cgroup

Created attachment 1333424 [details]
File: core_backtrace

Created attachment 1333425 [details]
File: cpuinfo

Created attachment 1333426 [details]
File: dso_list

Created attachment 1333427 [details]
File: environ

Created attachment 1333428 [details]
File: exploitable

Created attachment 1333429 [details]
File: limits

Created attachment 1333430 [details]
File: maps

Created attachment 1333431 [details]
File: open_fds

Created attachment 1333432 [details]
File: proc_pid_status

Created attachment 1333433 [details]
File: var_log_messages

Similar problem has been detected:

I had just quit the new skype. 

reporter:       libreport-2.9.1
backtrace_rating: 4
cmdline:        /usr/bin/xembedsniproxy
crash_function: SNIProxy::getImageNonComposite
executable:     /usr/bin/xembedsniproxy
journald_cursor: s=8033d5bb4a9c4f9fac9ec0301c998d87;i=1333c8;b=9800c3f04a6a4ce08ff41b01c8a4e42f;m=17e5e158b;t=55ccb97b2e2bd;x=ac5b713dd7a4e4fc
kernel:         4.13.9-200.fc26.x86_64
package:        plasma-workspace-5.10.5-3.fc26
reason:         xembedsniproxy killed by SIGSEGV
rootdir:        /
runlevel:       N 5
type:           CCpp
uid:            1004

*** Bug 1517417 has been marked as a duplicate of this bug. ***

I have exactly the same problem. It's reproducible every time I login to KDE (from SDDM).


(gdb) where
#0  SNIProxy::getImageNonComposite (this=this@entry=0x7fb8dc006820) at /usr/src/debug/plasma-workspace-5.11.4-1.fc27.x86_64/xembed-sni-proxy/sniproxy.cpp:291
#1  0x00005632d3892424 in SNIProxy::update (this=0x7fb8dc006820) at /usr/src/debug/plasma-workspace-5.11.4-1.fc27.x86_64/xembed-sni-proxy/sniproxy.cpp:232
#2  0x00005632d388f5ad in FdoSelectionManager::nativeEventFilter (this=0x7ffee259a780, eventType=..., message=0x5632d5804de0, result=<optimized out>)
    at /usr/src/debug/plasma-workspace-5.11.4-1.fc27.x86_64/xembed-sni-proxy/fdoselectionmanager.cpp:154
#3  0x00007fb8f1a44be4 in QAbstractEventDispatcher::filterNativeEvent(QByteArray const&, void*, long*) () from /lib64/libQt5Core.so.5
#4  0x00007fb8e2c01fe0 in QXcbConnection::handleXcbEvent(xcb_generic_event_t*) () from /lib64/libQt5XcbQpa.so.5
#5  0x00007fb8e2c02c6c in QXcbConnection::processXcbEvents() () from /lib64/libQt5XcbQpa.so.5
#6  0x00007fb8f1a7091a in QObject::event(QEvent*) () from /lib64/libQt5Core.so.5
#7  0x00007fb8f1a4727a in doNotify(QObject*, QEvent*) () from /lib64/libQt5Core.so.5
#8  0x00007fb8f1a47367 in QCoreApplication::notifyInternal2(QObject*, QEvent*) () from /lib64/libQt5Core.so.5
#9  0x00007fb8f1a49aeb in QCoreApplicationPrivate::sendPostedEvents(QObject*, int, QThreadData*) () from /lib64/libQt5Core.so.5
#10 0x00007fb8f1a98553 in postEventSourceDispatch(_GSource*, int (*)(void*), void*) () from /lib64/libQt5Core.so.5
#11 0x00007fb8ebb53bb7 in g_main_context_dispatch () from /lib64/libglib-2.0.so.0
#12 0x00007fb8ebb53f60 in g_main_context_iterate.isra () from /lib64/libglib-2.0.so.0
#13 0x00007fb8ebb53fec in g_main_context_iteration () from /lib64/libglib-2.0.so.0
#14 0x00007fb8f1a9833f in QEventDispatcherGlib::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () from /lib64/libQt5Core.so.5
#15 0x00007fb8f1a460ea in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) () from /lib64/libQt5Core.so.5
#16 0x00007fb8f1a4e744 in QCoreApplication::exec() () from /lib64/libQt5Core.so.5
#17 0x00005632d388ca53 in main (argc=<optimized out>, argv=<optimized out>) at /usr/src/debug/plasma-workspace-5.11.4-1.fc27.x86_64/xembed-sni-proxy/main.cpp:68


Is there any other debug/info needed?

My system is Fedora 27 and plasma-workspace.x86_64 5.11.4-1.fc27

I managed to mitigate (fix?) the problem by checking if 'image' object got from 'xcb_image_get()' is not null.

Patch below:

--- plasma-workspace-5.11.4/xembed-sni-proxy/sniproxy.cpp_orig  2018-01-08 13:40:42.070485134 +0100
+++ plasma-workspace-5.11.4/xembed-sni-proxy/sniproxy.cpp       2018-01-08 13:42:03.734526387 +0100
@@ -288,7 +288,13 @@
     xcb_image_t *image = xcb_image_get(c, m_windowId, 0, 0, geom->width, geom->height, 0xFFFFFFFF, XCB_IMAGE_FORMAT_Z_PIXMAP);
 
     // Don't hook up cleanup yet, we may use a different QImage after all
-    QImage naiveConversion = QImage(image->data, image->width, image->height, QImage::Format_ARGB32);
+    QImage naiveConversion;
+       if (nullptr != image) {
+        naiveConversion = QImage(image->data, image->width, image->height, QImage::Format_ARGB32);
+    } else {
+        qCDebug(SNIPROXY) << "Skip NULL image returned from xcb_image_get() for" << m_windowId << Title();
+        return QImage();
+    }
 
     if (isTransparentImage(naiveConversion)) {
         QImage elaborateConversion = QImage(convertFromNative(image));

Upstream KDE bug:
https://bugs.kde.org/show_bug.cgi?id=359664

%changelog
* Mon Jan 08 2018 Rex Dieter <rdieter> - 5.11.4-4
- use upstreamed version of previous commit/patch

* Mon Jan 08 2018 Rex Dieter <rdieter> - 5.11.4-3
- include candidate crash fix for xembedsniproxy (#1497829,kde#359664)

fix will be included when plasma-5.11.5 rolls out.

(that will most likely include f26 too, depending on discussion in tomorrow's kde-sig meeting)

*** Bug 1536425 has been marked as a duplicate of this bug. ***