IC65055: Unmanaged .NET client specifying MQGMO_CONVERT on a get fails with AccessViolationException at IBM.WMQ.Nmqi.Native.zstMQGET

WebSphere MQ V7.0 Fix Pack 7.0.1.2
WebSphere MQ V7.0.1 for i5/OS Fix Pack 7.0.1.2

APAR status

• Closed as program error.

Error description

• Unmanaged .NET client application attempting to get a message
  from a queue with the MQGMO_CONVERT option specified fails
  with:
  Unhandled Exception: System.AccessViolationException: Attempted
  to read or write protected memory. This is often an indication
  that other memory is corrupt.
  at IBM.WMQ.Nmqi.Native.zstMQGET(Int32 hConn, Int32 hObj,
  MQMD& md, MQGMO& gmo, Int32 bufferLength, Byte[] buffer, Int32&
  dataLength, lpiGETOPT lpiGetOpts, Int32& compCode, Int32&
  reason)
  at IBM.WMQ.Nmqi.UnmanagedNmqiMQ.zstMQGET(Hconn hConn, Hobj
  hObj, MQMessageDescriptor& md, MQGetMessageOptions& gmo, Int32
  bufferLength, Byte[] buffer, Int32& dataLength, MQLPIGetOpts
  lpiGetOpts, Int32& compCode, Int32& reason)
  at IBM.WMQ.MQDestination.Get(MQMessage message,
  MQGetMessageOptions gmo, Int32 maxMsgSize)
  at IBM.WMQ.MQDestination.Get(MQMessage message,
  MQGetMessageOptions gmo)
  at nmqsget.nmqsget.Main(String[] args)
  

Local fix

Problem summary

• ****************************************************************
  USERS AFFECTED:
  Any users of WebSphere MQ using the unmanaged .NET client to
  perform get requests with MQGMO_CONVERT specified.
  
  Platforms affected:
  Windows
  
  ****************************************************************
  PROBLEM SUMMARY:
  The problem was caused by a mismatch in the declarations of a
  function in the .NET layer as compared with the function in the
  native c layer. The .NET layer was passing an option by value
  whilst the c layer was expecting a pointer to the field. As a
  result, this led to the misinterpretation of the parameters on
  the stack in the c layer, leading to the invalid memory access
  operation.
  

Problem conclusion

• WebSphere MQ was modified to ensure that the parameters passed
  from the .NET layer to the C layer were passed by reference and
  not by value.
  
  ---------------------------------------------------------------
  The fix is targeted for delivery in the following PTFs:
  
                     v7.0
  Platform           Fix Pack 7.0.1.2
  --------           --------------------
  Windows            U200316
  
  The latest available maintenance can be obtained from
  'WebSphere MQ Recommended Fixes'
  http://www-1.ibm.com/support/docview.wss?rs=171&uid=swg27006037
  
  If the maintenance level is not yet available, information on
  its planned availability can be found in 'WebSphere MQ
  Planned Maintenance Release Dates'
  http://www-1.ibm.com/support/docview.wss?rs=171&uid=swg27006309
  ---------------------------------------------------------------
  

Temporary fix

Comments

APAR Information

• APAR is sysrouted FROM one or more of the following:

• APAR is sysrouted TO one or more of the following:

Fix information

• Fixed component name

  WMQ WINDOWS V7

• Fixed component ID

  5724H7220

Applicable component levels

• R701 PSY

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