PH53907: PARAMETER VALIDATION OF CSQ4BVJ1 TO PREVENT UNEXPECTED BEHAVIOUR

Obtain the fix for this APAR.

APAR status

• Closed as program error.

Error description

• A batch job parm should have been as follows:
  
  //MQGET  EXEC PGM=CSQ4BVJ1,REGION=1024K,
  //  PARM=('QMGR,queue name,000001,B,N')
  
  However, accidentally the 3rd parameter for the number of
  messages was not passed:
  
  //MQGET  EXEC PGM=CSQ4BVJ1,REGION=1024K,
  //  PARM=('QMGR,queue name,B,N')
  
  This resulted in an unexpected destructive get of 2 messages:
  
  PARAMETERS PASSED :
  
    QMGR       - QMGR
    QNAME      - queue name
    NUMMSGS    - 000000002
    GET        - N
    SYNCPOINT  - N
  
  The "B" character in EBCDIC is C2.
  
  Because the number of messages field interprets whatever that
  was entered as number, the second nibble was assumed as the
  amount of the messages to get.
  
  So "2" was used as the number of messages to get.
  
  "N" for GET just means what was intendeded for the (N)O
  SYNCPOINT.
  
  In practice, the code of CSQ4BVJ1 checks if "B" (BROWSE-GET)
  was selected and if so, MQGMO-BROWSE-FIRST is added to
  MQGMO-OPTIONS.
  
  If not, destructive get is assumed.
  
  This APAR intends to improve the parameter validation of
  CSQ4BVJ1 to prevent this unexpected behaviour.
  

Local fix

Problem summary

• ****************************************************************
  * USERS AFFECTED: All users of IBM MQ for z/OS Version 9       *
  *                 Release 1 Modification 0,                    *
  *                 Release 2 Modification 0 and                 *
  *                 Release 3 Modification 0.                    *
  ****************************************************************
  * PROBLEM DESCRIPTION: When using the CSQ4BVJ1 COBOL getting   *
  *                      sample, it is possible to               *
  *                      unintentionally destructively get       *
  *                      messages if incorrect parameters are    *
  *                      passed to the program.                  *
  ****************************************************************
  The code that handles receiving the input parameters was not
  performing any validation on the provided input parameter
  string.
  

Problem conclusion

• The code has been changed to perform some validation on the
  input parameter string so messages can't be unintentionally
  destructively got.
  

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:

  UI92986 UI92987 UI92988

Modules/Macros

• CSQ4BCJ1 CSQ4BVJ1
  

Fix information

• Fixed component name

  IBM MQ Z/OS V9

• Fixed component ID

  5655MQ900

Applicable component levels

• R100 PSY UI92988

     UP23/08/19 P F308

• R200 PSY UI92987

     UP23/08/19 P F308

• R300 PSY UI92986

     UP23/08/19 P F308

Fix is available

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