Access Violation with Long NDS Context in CSNW/GSNW (156091)

SYMPTOMS

Windows NT Workstations using Client Services for NetWare (CSNW), or Windows NT Servers using Gateway (and Client) Services for NetWare (GSNW) to specify a default tree and context in a NetWare Directory Services (NDS) tree may experience heap corruption, often resulting in an access violation in Services.exe.

The heap corruption can be identified by an access violation in Services.exe, or failure of the CSNW or GSNW Control Panel tools to load after the logon process.

Another symptom of this problem is that the server will simply hang with no Pop-up messages or anything logging in the Event Viewer.

CAUSE

The maximum allowable context that can be safely specified as a default in CSNW, or GSNW was 32 characters including the length of the tree name. Because of the 32 character restriction, using NDS contexts with more than 32 characters results in stack corruption, usually leading to heap corruption as well.

RESOLUTION

One of the following resolution methods should correct this problem:

Obtain the fix referenced below. Nwwks.dll was modified to allow NDS contexts as large as 256 characters including the tree name. - OR -
Install Service Pack 2 - OR -
Go into the Registry and change the following:

WARNING: Using Registry Editor incorrectly can cause serious, system-wide problems that may require you to reinstall Windows NT to correct them. Microsoft cannot guarantee that any problems resulting from the use of Registry Editor can be solved. Use this tool at your own risk.

Under the subtree HKEY_LOCAL_MACHINE, find the OPTION parameter under the following subkey:

\SYSTEM\CurrentControlSet\Services\NwcWorkstation\Parameters\Option

Under the Option key will be SIDs for the users that have gone through the Gateway. Either delete each SID under the Option key and reboot machine or Pick each user, on the right hand side of the panel highlight the PREFERREDSERVER entry and delete this entry. Then reboot.

STATUS

Microsoft has confirmed this to be a problem in Windows NT version 4.00. This problem was corrected in the latest Microsoft Windows NT 4.0 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