ILS Service Crashes on Multi-processor Servers

• Microsoft Commercial Internet System, version 1.0

SYMPTOMS

An access violation may randomly occur in the Internet Locator Service (ILS) on a multiprocessor system if it is under load.

CAUSE

The ILS database may be corrupted due to a data pointer being freed without the corresponding database entry being deleted. As a result, another thread finds the entry in the database, and tries to access the data which causes an access violation to occur.

Another problem was found when adding a user if the user already existed in the database, and certain conditions were met to re-add the user (that is, the correct password was passed in). The server reuses the same base user record. The problem occurs because data pointers are reallocated without first checking to see if the record is currently being used by another thread. As a result, the thread currently accessing the entry experiences an access violation when it attempt to read memory that has already been freed.

STATUS

Microsoft has confirmed this to be a problem in Microsoft Commercial Internet System, version 1.0. A supported fix is now available, but is not 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.