DOCUMENT:Q150140  08-AUG-2001  [winnt]
TITLE   :STOP Msg: 0xC000021a as Application Terminates
PRODUCT :Microsoft Windows NT
PROD/VER:winnt:3.51
OPER/SYS:
KEYWORDS:kbnetwork

======================================================================
-------------------------------------------------------------------------------
The information in this article applies to:

 - Microsoft Windows NT Workstation version 3.51 
 - Microsoft Windows NT Server version 3.51 
-------------------------------------------------------------------------------


SYMPTOMS
========

When starting a console application (a Windows NT Service can qualify as a
console application) that starts another console application, an access
violation occurs in CSRSS.EXE when the second application terminates.

This results in the following error message:

   STOP: c000021a {Fatal System Error}
   The Windows SubSystem system process terminated unexpectedly with a status of
   0xc0000037 (0x5fe625cf 0x02c1faa0).
   The system has been shutdown.

CAUSE
=====

This problem is exposed by a console application (typically a service) which has
the following behavior:

 - They start new applications using LogonUser() followed by
   CreateProcessAsUser(). The allows a child process to be started with a
   different security context than the parent.

 - The parent application has a console window, and the child application is
   started in a way as to share the same console window (i.e. when using
   CreateProcessAsUser, the dwCreationFlags did not specify the use of
   CREATE_NEW_CONSOLE).

A change in WINSRV.DLL for Windows NT 3.51 Service Pack 4 prevents a process from
inheriting the window station and desktop of its parent process, if the child
process was started in a different logon context. CreateProcessAsUser is used to
start new applications under a new logon context.

As a result of this change, the application started has NO window station or
desktop defined because it is trying to use the Console of its parent which is
not permitted.

A problem in WINSRV.DLL (used by CSRSS.EXE) assumed that a desktop would always
be defined. This caused an Access Violation when the WINSRV.DLL attempted to
access the desktop while cleaning up resources owned by the process, as the
process terminated.


RESOLUTION
==========

The problem in WINSRV.DLL has been corrected for the case where no desktop has
been created.


STATUS
======

Microsoft has confirmed this to be a problem in Windows NT version 3.51. This
problem was corrected in the latest Windows NT 3.51 U.S. Service Pack. For
information on obtaining the Service Pack, query on the following word in the
Microsoft Knowledge Base (without the spaces):

   S E R V P A C K


Additional query words: prodnt WinStation

======================================================================
Keywords          : kbnetwork 
Technology        : kbWinNTsearch kbWinNTWsearch kbWinNT351search kbWinNTW351search kbWinNTW351 kbWinNTSsearch kbWinNTS351 kbWinNTS351search
Version           : winnt:3.51

=============================================================================

THE INFORMATION PROVIDED IN THE MICROSOFT KNOWLEDGE BASE IS
PROVIDED "AS IS" WITHOUT WARRANTY OF ANY KIND.  MICROSOFT DISCLAIMS
ALL WARRANTIES, EITHER EXPRESS OR IMPLIED, INCLUDING THE WARRANTIES
OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.  IN NO
EVENT SHALL MICROSOFT CORPORATION OR ITS SUPPLIERS BE LIABLE FOR
ANY DAMAGES WHATSOEVER INCLUDING DIRECT, INDIRECT, INCIDENTAL,
CONSEQUENTIAL, LOSS OF BUSINESS PROFITS OR SPECIAL DAMAGES, EVEN IF
MICROSOFT CORPORATION OR ITS SUPPLIERS HAVE BEEN ADVISED OF THE
POSSIBILITY OF SUCH DAMAGES.  SOME STATES DO NOT ALLOW THE EXCLUSION
OR LIMITATION OF LIABILITY FOR CONSEQUENTIAL OR INCIDENTAL DAMAGES
SO THE FOREGOING LIMITATION MAY NOT APPLY.

Copyright Microsoft Corporation 2001.