DOCUMENT:Q295573 08-MAY-2002 [winnt] TITLE :Random Access Violation in RPC Client in Low-Memory Conditions PRODUCT :Microsoft Windows NT PROD/VER::4.0 OPER/SYS: KEYWORDS:kbWinNT400PreSP7Fix ====================================================================== ------------------------------------------------------------------------------- The information in this article applies to: - Microsoft Windows NT Server, Enterprise Edition version 4.0 - Microsoft Windows NT Workstation version 4.0 ------------------------------------------------------------------------------- SYMPTOMS ======== A Remote Procedure Call (RPC) program may stop working with an attempt to use memory that has already been freed. When this problem occurs, you may see a call stack that is similar to: 0:006> kb ChildEBP RetAddr Args to Child 029dfd98 4ef9805b 00000048 4efe1724 02486a3c RPCRT4!GENERIC_OBJECT__InvalidHandle+0xe 029dfdb0 4ef9d3fb 1ba821b0 02539b78 029dfe48 RPCRT4!RpcBindingFree+0x46 029dfdd0 4efd14c9 029dff4c 02539b78 02486a28 RPCRT4!NDRCContextUnmarshall+0x5b 029dfdec 0057d069 029dfe44 029dff4c 02539b78 RPCRT4!NdrClientContextUnmarshall+0x26 029dff14 0046b626 029dff4c 029dff38 00000000 emsmta!_MtaUnbindBack+0xef [G:\MTA\src\emsmta\sysglue\mtarpc_c.c @ 585] 029dff8c 0046d9ce 00000000 010dfd50 00000005 emsmta!oeprfree+0x1f4 [G:\MTA\src\emsmta\sysglue\oentdmod.c @ 10354] 029dffb8 77f04ede 00000005 00000000 010dfd50 emsmta!sbpiwbep+0x67 [G:\MTA\src\emsmta\sysglue\sbnilnt.c @ 377] 029dffec 00000000 0046d976 00000005 00000000 KERNEL32!BaseThreadStart+0x51 CAUSE ===== This problem occurs because a pointer to memory is being saved in an object (Object1). Object1 copies the pointer to another object (Object2). Both objects now have a pointer to the same memory location. Typically, Object1 will set its pointer to null (thereby releasing ownership of the memory to the second object). In a low-memory condition, however, Object1 does not release ownership of the memory that has been shared to Object2. When these objects are destroyed, they release the memory they point to, in this case causing the same memory location to be freed twice. 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: Date Time Size File name Platform ------------------------------------------------- 05/10/2001 07:36p 343,312 Rpcrt4.dll Intel 05/10/2001 04:32p 602,896 Rpcrt4.dll Alpha NOTE: Because of file dependencies, this hotfix requires Microsoft Windows NT 4.0 Service Pack 6a. 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 kbWinNTWsearch kbWinNTW400 kbWinNTW400search kbWinNT400search kbWinNTSsearch kbWinNTSEntSearch kbWinNTSEnt400 kbWinNTS400search Version : :4.0 Hardware : ALPHA x86 Issue type : kbbug Solution Type : kbfix ============================================================================= 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.