Microsoft KB Archive/182110

= IIS Access Violates Calling Local COM Server =

Article ID: 182110

Article Last Modified on 9/22/2005

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APPLIES TO


 * Microsoft Windows NT Server 4.0 Standard Edition
 * Microsoft Internet Information Server 3.0
 * Microsoft Internet Information Server 4.0

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This article was previously published under Q182110



We strongly recommend that all users upgrade to Microsoft Internet Information Services (IIS) version 6.0 running on Microsoft Windows Server 2003. IIS 6.0 significantly increases Web infrastructure security. For more information about IIS security-related topics, visit the following Microsoft Web site:

http://www.microsoft.com/technet/security/prodtech/IIS.mspx



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/default.aspx?scid=fh;EN-US;CNTACTMS



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: kbbug kbfix kbqfe kbhotfixserver KB182110

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