STOP Msg: 0xC000021a as Application Terminates

• Microsoft Windows NT Workstation versions 3.51
• Microsoft Windows NT Server versions 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).

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