PH05676: IBM MQ ABEND0C4 00000010 LOC=CSQXRCTL CSQXBPAL

Obtain the fix for this APAR.

APAR status

• Closed as program error.

Error description

• User reports abend with symptom string returned
  ABN= 0C4-00000010,LOC=CSQXRCTL.CSQXBPAL
  Change Team finds the problem occurs when a client application
  issues an MQGET with MQGMO_PROPERTIES_IN_HANDLE, and the
  combined length of the message data and message properties is
  larger than the staging buffer originally allocated by the
  CHINIT.
  In function rriAddMPHToAPIReply, MQ attempts to allocate a
  larger buffer, but the calculation of the required buffer
  size is incorrect and results in a buffer which is still too
  small. The processing then goes on to copy data beyond the end
  of the allocated buffer causing a storage overlay.
  During the Hursley recreate the overlay goes into unallocated
  storage and results in a dump with the symptom string :
  ABN=0C4-00000011,M=CSQXDISP,
  LOC=CSQXRCTL.CMQXRSRV
  In the user reported case the storage beyond the end of the
  buffer was allocated, so the overlay corrupted the data in that
  storage and caused the various 0C4 abends reported.
  

Local fix

Problem summary

• ****************************************************************
  * USERS AFFECTED: All users of IBM MQ for z/OS Version 9       *
  *                 Release 0 Modification 0, Release 1          *
  *                 Modification 0 and Release 2 Modification 0. *
  ****************************************************************
  * PROBLEM DESCRIPTION: Storage overlay in the channel          *
  *                      initiator address space leading to      *
  *                      unpredictable symptoms including:       *
  *                                                              *
  *                      - S0C4 abends                           *
  *                      - client connections failing with       *
  *                      MQRC_CHANNEL_NOT_AVAILABLE (2537)       *
  *                      - channels terminating or hanging       *
  ****************************************************************
  While returning a message containing message properties,
  rriAddMPHToMQIReply was called to add the properties to the
  reply transmission.
  The chinit detected that the existing buffer was not large
  enough to contain the properties, and attempted to allocate
  a new buffer. However an error caused the new buffer to
  be too small.
  When the properties were copied to this buffer, they were copied
  to storage beyond the end of the new buffer, leading to
  potential storage overlay and/or abend 0C4.
  

Problem conclusion

• rriAddMPHToMQIReply has been changed to ensure a staging area
  that is big enough to contain the message and properties is
  correctly allocated.
  

Temporary fix

Comments

APAR Information

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

  PH00443

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

  UI60629 UI60630 UI75408

Modules/Macros

• CMQXRSRV
  

Fix information

• Fixed component name

  IBM MQ Z/OS V9

• Fixed component ID

  5655MQ900

Applicable component levels

• R200 PSY UI75408

     UP21/05/29 P F105 ¢

Fix is available

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