From d21895e6ef982c2927857cb18d6fb30370b5db04 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Herm=C3=A8s=20B=C3=A9lusca-Ma=C3=AFto?=
 <hermes.belusca-maito@reactos.org>
Date: Fri, 6 May 2022 20:34:52 +0200
Subject: [PATCH] [WIN32K:NTUSER] Only call IntFreeSecurityBuffer() when
 needed, don't free NULL buffers.

Addendum to 878c2f44.
---
 win32ss/user/ntuser/desktop.c | 19 ++++++++-----------
 1 file changed, 8 insertions(+), 11 deletions(-)

diff --git a/win32ss/user/ntuser/desktop.c b/win32ss/user/ntuser/desktop.c
index fcb3a8aa009..2344fea0c01 100644
--- a/win32ss/user/ntuser/desktop.c
+++ b/win32ss/user/ntuser/desktop.c
@@ -563,7 +563,7 @@ IntResolveDesktop(
     LUID ProcessLuid;
     USHORT StrSize;
     SIZE_T MemSize;
-    PSECURITY_DESCRIPTOR ServiceSD = NULL;
+    PSECURITY_DESCRIPTOR ServiceSD;
     POBJECT_ATTRIBUTES ObjectAttributes = NULL;
     PUNICODE_STRING ObjectName;
     UNICODE_STRING WinStaName, DesktopName;
@@ -1022,16 +1022,15 @@ IntResolveDesktop(
             ObjectName->Length = (USHORT)(wcslen(ObjectName->Buffer) * sizeof(WCHAR));
 
             /*
-             * Set up a security descriptor for the service.
-             * A service is generally based upon a desktop
-             * and a window station. The newly created window
-             * station and desktop will get this security descriptor
+             * Set up a security descriptor for the new service's window station.
+             * A service has an associated window station and desktop. The newly
+             * created window station and desktop will get this security descriptor
              * if such objects weren't created before.
              */
             Status = IntCreateServiceSecurity(&ServiceSD);
             if (!NT_SUCCESS(Status))
             {
-                ERR("Failed to create a security descriptor for default window station, Status 0x%08lx\n", Status);
+                ERR("Failed to create a security descriptor for service window station, Status 0x%08lx\n", Status);
                 goto Quit;
             }
 
@@ -1051,6 +1050,9 @@ IntResolveDesktop(
                                             KernelMode,
                                             MAXIMUM_ALLOWED,
                                             0, 0, 0, 0, 0);
+
+            IntFreeSecurityBuffer(ServiceSD);
+
             if (!NT_SUCCESS(Status))
             {
                 ASSERT(hWinSta == NULL);
@@ -1200,8 +1202,6 @@ Quit:
     {
         *phWinSta  = hWinSta;
         *phDesktop = hDesktop;
-
-        IntFreeSecurityBuffer(ServiceSD);
         return STATUS_SUCCESS;
     }
     else
@@ -1218,9 +1218,6 @@ Quit:
         if (hWinSta)
             ObCloseHandle(hWinSta, UserMode);
 
-        if (ServiceSD)
-            IntFreeSecurityBuffer(ServiceSD);
-
         SetLastNtError(Status);
         return Status;
     }