IT38647: SIGSEGV in MQ application within function xcsReadEnvironment under libmqe.so

APAR status

• Closed as program error.

Error description

• The application calls MQCONN or MQCONNX to connect to a queue
  manager.  The application terminates unexpectedly with a SIGSEGV
  under subroutine xcsReadEnvironment.
  
  A failure data capture (FDC) record is written with the
  following details.
  
  Probe Id :- XC130003
  Component :- xehExceptionHandler
  Arith1 :- 11 (0xb)
  Comment1 :- SIGSEGV: address not mapped((nil))
  
  MQM Function Stack
  MQCONN
  MQCONN
  reqInitClientThread
  cccGetConfig
  xcsReadEnvironment
  xcsFFST
  

Local fix

• Find the place in your application source code where you set
  environ=NULL, and remove it.
  

Problem summary

• ****************************************************************
  USERS AFFECTED:
  Applications in which the C runtime global variable 'environ' is
  NULL.
  
  
  Platforms affected:
  MultiPlatform
  
  ****************************************************************
  PROBLEM DESCRIPTION:
  The MQ routine xcsReadEnvironment uses the 'environ' global
  variable supplied by the C runtime library assuming it is never
  NULL.
  
  But a user application had set this global variable to 0 (NULL).
  
  The IBM MQ library code running in the application entered an
  internal subroutine named xcsReadEnvironment, which tried to use
  the 'environ' global variable without checking whether it was
  NULL.
  
  The MQ code did not handle that situation, leading to a SIGSEGV,
  and the ending of the application while it was calling MQCONN.
  

Problem conclusion

• The IBM MQ code has been altered to check whether 'environ' is
  NULL, and to handle this case.
  
  ---------------------------------------------------------------
  The fix is targeted for delivery in the following PTFs:
  
  Version    Maintenance Level
  v9.2 LTS   9.2.0.25
  v9.3 LTS   9.3.0.15
  v9.x CD    9.3.5
  
  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

  MQ BASE V9.2

• Fixed component ID

  5724H7281

Applicable component levels