[aandrejevic] 67676: [NTVDM] Fix the XMS driver (again): - Don't return handle information for unallocated handles. - Don't allow freeing unallocated handles.

Author: aandrejevic
Date: Tue May 12 03:47:10 2015
New Revision: 67676

URL: http://svn.reactos.org/svn/reactos?rev=67676&view=rev
Log:
[NTVDM]
Fix the XMS driver (again):
- Don't return handle information for unallocated handles.
- Don't allow freeing unallocated handles.

Modified:
    trunk/reactos/subsystems/mvdm/ntvdm/dos/dos32krnl/himem.c

Modified: trunk/reactos/subsystems/mvdm/ntvdm/dos/dos32krnl/himem.c
URL: http://svn.reactos.org/svn/reactos/trunk/reactos/subsystems/mvdm/ntvdm/dos/d...
==============================================================================
--- trunk/reactos/subsystems/mvdm/ntvdm/dos/dos32krnl/himem.c	[iso-8859-1] (original)
+++ trunk/reactos/subsystems/mvdm/ntvdm/dos/dos32krnl/himem.c	[iso-8859-1] Tue May 12 03:47:10 2015
@@ -281,7 +281,7 @@
     DWORD BlockNumber;
     PXMS_HANDLE HandleEntry = GetHandleRecord(Handle);

-    if (HandleEntry == NULL) return XMS_STATUS_INVALID_HANDLE;
+    if (HandleEntry == NULL || HandleEntry->Handle == 0) return XMS_STATUS_INVALID_HANDLE;
     if (HandleEntry->LockCount) return XMS_STATUS_LOCKED;

BlockNumber = (HandleEntry->Address - XMS_ADDRESS) / XMS_BLOCK_SIZE;
@@ -540,7 +540,7 @@
         {
             PXMS_HANDLE Entry = GetHandleRecord(getDX());

-            if (Entry)
+            if (Entry && Entry->Handle != 0)
             {
                 INT i;
                 UCHAR Handles = 0;