IC64543: A GET MESSAGE OPERATION IN MQE C NATIVE CODE BASE GIVES MEMORY ACCESS VIOLATION INTERMITTENTLY

APAR status

• Closed as program error.

Error description

• MQ Everyplace (MQe) application gives a Memory Access Violation
  exception during a get message operation on a synchronous
  remote queue. This happens due to a null pointer passed to the
  GlobalHandle() function of the Microsoft libraries called by MQe
  in order to free resources. The handle returned by the
  GlobalHandle() function for the particular pointer passed to it
  is then used to free the memory allocated for the resource. The
  problem occurs very rarely in the MQe C Native code base only.
  The application program will abnormally terminate after some
  frequent memory access violations.
  

Local fix

Problem summary

• ****************************************************************
  USERS AFFECTED:
  Users of WMQe versions 2.0.2.15 and prior.
  
  Platforms affected:
  Windows
  
  ****************************************************************
  PROBLEM SUMMARY:
  MQ Everyplace (MQe) client application gives a Memory Access
  Violation exception during a get message operation.
  This happens due to a null pointer passed to the GlobalHandle()
  function of the Microsoft libraries called by MQe in order to
  free resources. A null pointer was passed to the GlobalHandle()
  function in the Kernel32 library of Windows, which then returns
  a null handle to the specified null pointer. This returned null
  value was tried to be freed up in the code which caused the
  exception.
  

Problem conclusion

• The Memory Access Violation was occurring due to the attempt to
  free up a null resource.
  The fix given was to ensure that there is null check mechanism
  introduced in the code to avoid this situation.
  ---------------------------------------------------------------
  
  
  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 EVERYPLACE

• Fixed component ID

  5724C7700

Applicable component levels

• R200 PSY

     UP