WFWG/LAN Manager Race Condition Problem

• Microsoft LAN Manager, versions 2.1, 2.1a, 2.2

SUMMARY

If a Windows for Workgroups workstation opens a file on a LAN Manager server and then closes it, the workstation may not immediately send the Close Server Message Block (SMB). WFWG sends the Close SMB asynchronously: it returns immediately to the calling program (which closed the file) without checking whether the close succeeded or failed.

This "overlapping" can cause a problem if the WFWG machine immediately tries to reopen the same file. The LAN Manager server may process the reopen before it processes the close, or the WFWG machine may send the open and close in reverse order. If either of these conditions occurs, the LAN Manager server sees that the client is attempting to open a file that is already open, and sends a "sharing violation" to the client.

Microsoft is researching this problem and will post new information here in the Microsoft Knowledge Base as it becomes available.

Additional query words: wfw wfwg 2.10 2.1 2.10a 2.1a 2.20 2.2

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Version : :2.1,2.1a,2.2
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