RDR Sessions on UNC Name Images May Log Off Prematurely

 Last reviewed: January 30, 1998
Article ID: Q179983
The information in this article applies to:
  • Microsoft Windows NT Workstation version 4.0
  • Microsoft Windows NT Server version 4.0

SYMPTOMS

The problem occurs when multiple sessions access an image as a UNC name. When the first session to access the file logs off, the second session can no longer access the image.

Example

Thread A impersonates a user and maps a file (typically, loads an image) using a UNC name. Another thread (thread B) impersonates a different user and maps the same file. Thread A logs off and thread A’s session is logged off the server. Thread B cannot access the mapped file any longer.

CAUSE

Because of the way RDR and memory management work, thread B is accessing the mapped file on thread A’s user ID. When both threads first access the server, two separate sessions are opened, creating two separate user IDs. However, when the session object is created to access the mapped file by thread B, and because it is the same file, it uses the same file object that was opened by thread A. The file object contains session information that the redirector uses to access the remote computer; therefore, thread B accesses the file on thread A’s session.

RESOLUTION

To resolve this problem, obtain the following fix or wait for the next Windows NT service pack.

This fix should have the following time stamp: 

   01/13/98  03:55                264,112 Rdr.sys (Intel)
   01/13/98  03:51                511,312 Rdr.sys (Alpha)

STATUS

Microsoft has confirmed this to be a problem in Windows NT version 4.0. A supported fix is now available, but has not been fully regression tested and should be applied only to systems experiencing this specific problem. Unless you are severely impacted by this specific problem, Microsoft recommends that you wait for the next Service Pack that contains this fix. Contact Microsoft Technical Support for more information. 

Keywords          : kbbug4.00 kbfix4.00 NTSrvWkst
Version           : WinNT:4.0
Platform          : winnt
Issue type        : kbbug
Solution Type     : kbfix

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Last reviewed: January 30, 1998
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