XCON: MTA Heap Corruption With Misconfigured TP4/TCP Connection

ID: Q152951

The information in this article applies to:

Microsoft Exchange Server, version 4.0

SYMPTOMS

The Microsoft Exchange Message Transfer Agent (MTA) may experience heap corruption if there is a misconfigured incoming TCP/IP or TP4 connection. The heap corruption will exhibit itself as Dr. Watson errors in the MTA.

CAUSE

Microsoft Exchange Server is leaking buffers from SBPDSACP in the WinSock code. WINSOCK DMOD (TP4/TCP) creates too many threads when many connections are started and stopped. Threads of different types (TP4/TCP) can be created on the same Thread Control Block (CB) causing two WINSOCK threads to update the pointers in a select call simultaneously. This can cause heap corruption.

STATUS

Microsoft has confirmed this to be a problem in Microsoft Exchange Server version 4.0. This problem was corrected in the latest Microsoft Exchange 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: Dr. Watson Crash

Keywords : kbusage kbbug4.00 kbfix4.00.sp3 XCON
Version : winnt:4.0
Platform : winnt
Issue type : kbbug