IIS Access Violates Calling Local COM Server

ID: Q182110

The information in this article applies to:

Microsoft Windows NT Server version 4.0
Microsoft Internet Information Server versions 3.0, 4.0

SYMPTOMS

Internet Information Server (IIS) may access violate when using an in- process COM object to expose methods for a local COM server that is running as a service. The access violation is more likely to occur on multi- processor servers that are extremely busy. The access violation will occur in seemingly unrelated areas because the problem affects several areas of the COM support code.

The debug stack will look similar to the following example:


   Example Stack:
   DbgBreakPoint
   RtlpBreakPointHeap
   RtlpValidateHeapEntry
   RtlDebugSizeHeap
   RtlSizeHeap
   CRetailMalloc_GetSize
   MemSize(void * 0xfeeefeee)
   MemFree(void * 0xfeeefeee)
   CTypeLib2::~CTypeLib2() line 56 + 15 bytes
   CTypeLib2::`scalar deleting destructor'() + 20 bytes
   CTypeLib2::Release(CTypeLib2 * const 0x0344e428)
   CTypeInfo2::Release(CTypeInfo2 * const 0x0344eac8)
   CreateRealProxy
   CProxyWrapper::Connect
   ConnectIPIDEntry@CStdMarsha
   MakeCliIPIDEntry@CStdMarshal
   UnmarshalIPID@CStdMarshal
   RemQIAndUnmarshal@CStdMarshal
   QueryRemoteInterfaces@CStdMarshal
   QueryMultipleInterfaces@CInternalUnk
   QueryInterface@CInternalUnk@CStdIdentity
   CreateInstance
   CreateInstance
   ::FinalConstruct()

CAUSE

The ref count for a contained local servers Type Library can be incorrectly set when the OLE automation code is set to multithreading. As a result, the Type Library is released too soon.

The access violation occurs when the in-process object creates or references methods in the local server after the Type Library has been released.

This problem only occurs when the multiprocessor IIS computer is under stress and the time frame of the ref counter is incorrectly set too small.

RESOLUTION

A supported fix that corrects this problem is now available from Microsoft, but has not been fully regression tested and should be applied only to systems experiencing this specific problem. If you are not severely affected by this specific problem, Microsoft recommends that you wait for the next service pack.

To resolve this problem immediately, contact Microsoft Product Support Services to obtain the fix. For a complete list of Microsoft Product Support Services phone numbers and information on support costs, please go to the following address on the World Wide Web:

http://support.microsoft.com/support/supportnet/default.asp

NOTE: If you contact Microsoft to obtain this fix, a fee may be charged. This fee is refundable if it is determined that you only require the fix you requested. However, this fee is non-refundable if you request additional technical support, if your no-charge technical support period has expired, or if you are not eligible for standard no-charge technical support.

For more information about eligibility for no-charge technical support, see the following article in the Microsoft Knowledge Base:

Q154871 : Determining If Your Product Is Eligible for No-Charge Technical Support

STATUS

Microsoft has confirmed this to be a problem in Windows NT version 4.0.

MORE INFORMATION

A fix was made to the Oleaut32.dll file to add additional thread synchronization so that the ref counter is protected when it is under stress.

Keywords :
Version : WINNT:3.0,4.0
Platform : winnt
Issue type : kbbug