From d375b7f6c5f6d78830670e88b7ea9063598d4354 Mon Sep 17 00:00:00 2001
From: Serge Gautherie <32623169+SergeGautherie@users.noreply.github.com>
Date: Sun, 19 Dec 2021 23:34:35 +0100
Subject: [PATCH] [WIN32K:NTUSER] Make sure to hold User Global Lock before
 mapping desktop heap (#4144)

Addendum to 8c098ee8d.
CORE-17890
---
 win32ss/user/ntuser/desktop.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/win32ss/user/ntuser/desktop.c b/win32ss/user/ntuser/desktop.c
index 4d8f2956b44..43120cc7750 100644
--- a/win32ss/user/ntuser/desktop.c
+++ b/win32ss/user/ntuser/desktop.c
@@ -202,12 +202,16 @@ NTAPI
 IntDesktopObjectOpen(
     _In_ PVOID Parameters)
 {
+    NTSTATUS Ret;
     PWIN32_OPENMETHOD_PARAMETERS OpenParameters = Parameters;
     PPROCESSINFO ppi = PsGetProcessWin32Process(OpenParameters->Process);
     if (ppi == NULL)
         return STATUS_SUCCESS;
 
-    return IntMapDesktopView((PDESKTOP)OpenParameters->Object);
+    UserEnterExclusive();
+    Ret = IntMapDesktopView((PDESKTOP)OpenParameters->Object);
+    UserLeave();
+    return Ret;
 }
 
 NTSTATUS