XCON: MTA Heap Corruption With Misconfigured TP4/TCP Connection (152951)



The information in this article applies to:

  • Microsoft Exchange Server 4.0

This article was previously published under Q152951

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


Modification Type:MinorLast Reviewed:4/28/2005
Keywords:kbbug kbfix kbusage KB152951