From 01b580d8760be6870964ecd7b18ae2fab5fa250f Mon Sep 17 00:00:00 2001
From: Pierre Schweitzer <pierre@reactos.org>
Date: Mon, 31 Dec 2018 20:33:59 +0100
Subject: [PATCH] [WIN32K] Deny deviceless calls to EngDeviceIoControl

This fixes BSOD happening in ntoskrnl coming from win32k under certain
conditions with 3rd party display drivers (such as VBox or VMware)
---
 win32ss/gdi/eng/device.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/win32ss/gdi/eng/device.c b/win32ss/gdi/eng/device.c
index 0123a2713c9..6d20e30de55 100644
--- a/win32ss/gdi/eng/device.c
+++ b/win32ss/gdi/eng/device.c
@@ -485,6 +485,11 @@ EngDeviceIoControl(
 
     TRACE("EngDeviceIoControl() called\n");
 
+    if (!hDevice)
+    {
+        return ERROR_INVALID_HANDLE;
+    }
+
     KeInitializeEvent(&Event, SynchronizationEvent, FALSE);
 
     DeviceObject = (PDEVICE_OBJECT) hDevice;