DOCUMENT:Q158516 08-AUG-2001 [winnt] TITLE :Access Violation in RPCRT4.DLL When Pickling Buffered RPC Data PRODUCT :Microsoft Windows NT PROD/VER:WinNT:4.0 OPER/SYS: KEYWORDS:kbnetwork kbWinNT400sp4fix kbAPI kbRPC kbSDKPlatform kbGrpDSNet ====================================================================== ------------------------------------------------------------------------------- The information in this article applies to: - Microsoft Windows NT Workstation version 4.0 - Microsoft Windows NT Server version 4.0 - Microsoft Windows NT Server version 4.0, Terminal Server Edition ------------------------------------------------------------------------------- SYMPTOMS ======== Pickling, or serialization, is a Remote Procedure Call (RPC) process of marshaling data (encoding) and unmarshaling data (decoding) from buffers that you own. When you pickle and use wire_marshal, you may experience an Access Violation in Rpcrt4.dll. The wire_marshal attribute specifies a data type that will be used for transmission (the wire-type) instead of an application-specific data type (the userm-type). Each userm-type has a one- to-one correspondence with a wire-type that defines the wire representation of the type. You must supply routines to size the data for marshaling, to marshal and unmarshal the data, and to free memory. NOTE: If there are embedded types in your data that are also defined with wire_marshal or user_marshal, you need to manage the servicing of those embedded types as well. CAUSE ===== An uninitialized (NULL) buffer pointer is dereferenced to see if the underlying buffer was overwritten, causing an Access Violation. RESOLUTION ========== To resolve this problem, obtain the latest service pack for Windows NT 4.0 or Windows NT Server 4.0, Terminal Server Edition. For additional information, please see the following article in the Microsoft Knowledge Base: Q152734 How to Obtain the Latest Windows NT 4.0 Service Pack STATUS ====== Microsoft has confirmed this to be a problem in Windows NT 4.0 and Windows NT Server 4.0, Terminal Server Edition. This problem was first corrected in Windows NT 4.0 Service Pack 4.0 and Windows NT Server 4.0, Terminal Server Edition Service Pack 4. ====================================================================== Keywords : kbnetwork kbWinNT400sp4fix kbAPI kbRPC kbSDKPlatform kbGrpDSNet Technology : kbWinNTsearch kbWinNTWsearch kbWinNTW400 kbWinNTW400search kbWinNT400search kbWinNTSsearch kbWinNTS400search kbWinNTS400 kbNTTermServ400 kbNTTermServSearch Version : WinNT:4.0 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 2001.