Access Violation in RPCRT4.DLL When Pickling Buffered RPC Data

• 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 NT4SP4Fix kbbug4.00 kbAPI kbRPC kbSDKPlatform kbfix4.00.sp4 NTSrvWkst kbGrpNet
Version : WinNT:4.0
Platform : winnt
Issue type : kbbug