PH54988: ABN=0C4-0000003B,U=XXXXXXXX,C=MQ900.920.MMC -CSQMHDRS,M=CSQGFRCV,LOC=CSQILPLM.CSQMHDRS+OFFSET

Obtain the fix for this APAR.

APAR status

• Closed as program error.

Error description

• When executing CSQUDLQH, CHIN suffers abend
  ABN=0C4-0000003B,U=XXXXXXXX,C=MQ900.920.MMC
  -CSQMHDRS,M=CSQGFRCV,LOC=CSQILPLM.CSQMHDRS+offset and CSQUDLQH
  finishes with CSQU227E Unable to get message from dead-letter
  queue, MQCC=2 MQRC=2004 (MQRC_BUFFER_ERROR).
  
  The S0C4-0000003B abend occurred in CSQMHDRS when trying to
  copy the returned message into the caller's buffer. The source
  message data address was incorrect, which resulted in the abend
  when doing the cross-memory, cross-key copy of the message data
  into the caller's buffer.
  
  The message was headed by a little-endian, ASCII DLH, which was
  followed by a little-endian, ASCII MQRFH2. The encoding and
  format data for the header chain is correct.
  
  The problem is that length field in the MQRFH2 header isn't
  being correctly byteswapped. This results in an incorrect
  calculation for the end of the MQRFH2 header. This problem only
  occurs when there is a little-endian encoded header before an
  MQRFH2 and the MQRFH2 is also little-endian.
  

Local fix

Problem summary

• ****************************************************************
  * USERS AFFECTED: All users of IBM MQ for z/OS Version 9       *
  *                 Release 2 Modification 0, Release 3          *
  *                 Modification 0.                              *
  ****************************************************************
  * PROBLEM DESCRIPTION: When trying to retrieve messages from a *
  *                      Dead Letter queue, a MQRC_BUFFER_ERROR  *
  *                      may occur, and the queue manager may    *
  *                      abend.                                  *
  ****************************************************************
  The code that retrieves the descriptors for the following header
  in the chain from the dead letter header does not account for
  the encoding of the DLH being MQENC_INTEGER_REVERSED. The values
  are then incorrectly read, eventually leading to incorrectly
  resolving the length of the following header and causing an
  abend.
  

Problem conclusion

• The code has been modified to consider the dead letter header
  encoding while reading the header fields. This ensures that the
  correct values are passed on to the subsequent message header
  calculations, preventing message errors and abends from
  occurring.
  

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:

  UI96004 UI96005

Modules/Macros

• CSQMHDRS
  

Fix information

• Fixed component name

  IBM MQ Z/OS V9

• Fixed component ID

  5655MQ900

Applicable component levels

• R200 PSY UI96005

     UP24/03/19 P F403

• R300 PSY UI96004

     UP24/03/19 P F403

Fix is available

• Select the PTF appropriate for your component level. You will be required to sign in. Distribution on physical media is not available in all countries.