sddm: fix CVE-2015-0856

Thanks to Armin Kuster for heads up.

Signed-off-by: Andreas Müller <schnitzeltony@googlemail.com>

recipes-misc/recipes-graphics/sddm/files/0002-Disable-greeters-from-loading-KDE-s-debug-hander.patch

@@ -0,0 +1,39 @@
+From 4cfed6b0a625593fb43876f04badc4dd99799d86 Mon Sep 17 00:00:00 2001
+From: David Edmundson <kde@davidedmundson.co.uk>
+Date: Wed, 14 Oct 2015 00:08:59 +0100
+Subject: [PATCH] Disable greeters from loading KDE's debug hander
+
+Some themes may use KDE components which will automatically load KDE's
+crash handler.
+
+If the greeter were to then somehow crash, that would leave a crash
+handler allowing other actions, albeit as the locked down SDDM user.
+
+Only SDDM users using the breeze theme from plasma-workspace are
+affected. Safest and simplest fix is to handle this inside SDDM
+disabling kcrash via an environment variable for all future themes that
+may use these libraries.
+
+CVE-2015-0856
+---
+ src/daemon/Greeter.cpp | 4 ++++
+ 1 file changed, 4 insertions(+)
+
+diff --git a/src/daemon/Greeter.cpp b/src/daemon/Greeter.cpp
+index 68c4dc3..8c936b7 100644
+--- a/src/daemon/Greeter.cpp
++++ b/src/daemon/Greeter.cpp
+@@ -145,6 +145,10 @@ namespace SDDM {
+             env.insert(QStringLiteral("XDG_VTNR"), QString::number(m_display->terminalId()));
+             env.insert(QStringLiteral("XDG_SESSION_CLASS"), QStringLiteral("greeter"));
+             env.insert(QStringLiteral("XDG_SESSION_TYPE"), m_display->sessionType());
++
++            //some themes may use KDE components and that will automatically load KDE's crash handler which we don't want
++            //counterintuitively setting this env disables that handler
++            env.insert(QStringLiteral("KDE_DEBUG"), QStringLiteral("1"));
+             m_auth->insertEnvironment(env);
+ 
+             // log message
+-- 
+2.1.0
+

recipes-misc/recipes-graphics/sddm/sddm_git.bb

@@ -17,6 +17,7 @@ DEPENDS += "libpam"
 SRC_URI = " \
     git://github.com/sddm/${BPN}.git;protocol=git;branch=master \
     file://0001-fix-qml-install-dir.patch \
+    file://0002-Disable-greeters-from-loading-KDE-s-debug-hander.patch \
     file://sddm.pam \
     file://sddm.conf \
 "