First argument doesn't need to be a physical device object, it only needs to be in a PDO driver stack.

svn path=/trunk/; revision=22982

reactos/ntoskrnl/include/internal/io.h

@@ -542,7 +542,13 @@ IoDestroyDriverList(
     VOID
 );
 
-NTSTATUS 
+PDEVICE_OBJECT
+NTAPI
+IopGetLowestDevice(
+    IN PDEVICE_OBJECT DeviceObject
+);
+
+NTSTATUS
 INIT_FUNCTION
 IopInitPlugPlayEvents(VOID);
 

reactos/ntoskrnl/io/iomgr/deviface.c

@@ -635,6 +635,7 @@ IoRegisterDeviceInterface(IN PDEVICE_OBJECT PhysicalDeviceObject,
     ASSERT_IRQL(PASSIVE_LEVEL);
 
     /* Parameters must pass three border of checks */
+    PhysicalDeviceObject = IopGetLowestDevice(PhysicalDeviceObject);
     DeviceObjectExtension = (PEXTENDED_DEVOBJ_EXTENSION)PhysicalDeviceObject->DeviceObjectExtension;
 
     /* 1st level: Presence of a Device Node */