DOCUMENT:Q292041 20-MAY-2002 [winnt] TITLE :Heap Coruption in Windows NT RPCSS Service with DCOM Calls PRODUCT :Microsoft Windows NT PROD/VER::4.0,4.0 SP6a OPER/SYS: KEYWORDS:kbWinNT400PreSP7Fix ====================================================================== ------------------------------------------------------------------------------- The information in this article applies to: - Microsoft Windows NT Server versions 4.0, 4.0 SP6a - Microsoft Windows NT Server, Enterprise Edition versions 4.0, 4.0 SP6a ------------------------------------------------------------------------------- SYMPTOMS ======== Rpcss.exe may generate an access violation (C0000005) in the RtlAllocateHeap function when activating or deactivating an ATL DCOM EXE server. CAUSE ===== This problem can occur when the DCOM garbage collector frees some heap memory that is allocated for the static endpoint structure at a wrong address. This corrupts the heap free list for the process. RESOLUTION ========== A supported fix is now available from Microsoft, but it is only intended to correct the problem described in this article and should be applied only to systems experiencing this specific problem. To resolve this problem, 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 NOTE: In special cases, charges that are normally incurred for support calls may be canceled, if a Microsoft Support Professional determines that a specific update will resolve your problem. Normal support costs will apply to additional support questions and issues that do not qualify for the specific update in question. The English version of this fix should have the following file attributes or later: File name --------- Ole32.dll Rpcss.exe WORKAROUND ========== To work around this problem, use any of the following methods: - The heap corruption does not occur if you use dynamic endpoints in the DCOM configuration. - Maintain DCOM alive by using a client connection. This avoids the DCOM garbage collector cleanup. STATUS ====== Microsoft has confirmed this to be a problem in the Microsoft products that are listed at the beginning of this article. Additional query words: ====================================================================== Keywords : kbWinNT400PreSP7Fix Technology : kbWinNTsearch kbWinNT400search kbWinNTSsearch kbWinNTSEntSearch kbWinNTSEnt400 kbWinNTS400sp6 kbWinNTS400search kbWinNTS400 kbWinNTSEnt400SP6a Version : :4.0,4.0 SP6a Hardware : ALPHA x86 Issue type : kbprb ============================================================================= THE INFORMATION PROVIDED IN THE MICROSOFT KNOWLEDGE BASE IS PROVIDED "AS IS" WITHOUT WARRANTY OF ANY KIND. MICROSOFT DISCLAIMS ALL WARRANTIES, EITHER EXPRESS OR IMPLIED, INCLUDING THE WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. IN NO EVENT SHALL MICROSOFT CORPORATION OR ITS SUPPLIERS BE LIABLE FOR ANY DAMAGES WHATSOEVER INCLUDING DIRECT, INDIRECT, INCIDENTAL, CONSEQUENTIAL, LOSS OF BUSINESS PROFITS OR SPECIAL DAMAGES, EVEN IF MICROSOFT CORPORATION OR ITS SUPPLIERS HAVE BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES. SOME STATES DO NOT ALLOW THE EXCLUSION OR LIMITATION OF LIABILITY FOR CONSEQUENTIAL OR INCIDENTAL DAMAGES SO THE FOREGOING LIMITATION MAY NOT APPLY. Copyright Microsoft Corporation 2002.