[hbirr] 14493: Check for an valid mdl pointer before calling IoFreeMdl in IoReadWriteCompletion.

Check for an valid mdl pointer before calling IoFreeMdl in
IoReadWriteCompletion.
Modified: trunk/reactos/ntoskrnl/io/cleanup.c
  _____  

Modified: trunk/reactos/ntoskrnl/io/cleanup.c
--- trunk/reactos/ntoskrnl/io/cleanup.c	2005-04-04 23:09:15 UTC (rev
14492)
+++ trunk/reactos/ntoskrnl/io/cleanup.c	2005-04-04 23:11:19 UTC (rev
14493)
@@ -1,4 +1,4 @@

-/* $Id:$
+/* $Id$
  * 
  * COPYRIGHT:       See COPYING in the top level directory
  * PROJECT:         ReactOS kernel
@@ -109,7 +109,10 @@
 
    if (DeviceObject->Flags & DO_DIRECT_IO)
    {
-      IoFreeMdl(Irp->MdlAddress);
+      if (Irp->MdlAddress)
+      {
+         IoFreeMdl(Irp->MdlAddress);
+      }
    }
 }