IT23306: Directory /usr/lib is prepended to LIBPATH on AIX for client applications establishing TLS connections to queue managers

APAR status

• Closed as program error.

Error description

• When running a native MQ C application on AIX that establishes a
  TLS connection to a queue manager, the MQ client library alters
  the value of the system library path (LIBPATH) by adding the
  directory where the MQ installation of GSKit is located, for
  example:
  
    /usr/mqm/gskit8/lib64
  
  followed by:
  
    /usr/lib
  
  during an MQCONN(X) API call.
  
  For example, if the value of LIBPATH before the MQ connection
  API call was:
  
    /opt/myproduct/mylibs
  
  the value of LIBPATH after the MQ connection API call would be:
  
    /usr/mqm/gskit8/lib64:/usr/lib:/opt/myproduct/mylibs
  
  The addition of /usr/lib can cause library loading issues for
  the application after the MQ connection API call completes as it
  could result in an incompatible, but equivalently named, library
  being loaded form /usr/lib rather than the configured
  /opt/myproduct/mylibs directory.
  

Local fix

• Configure the system such that the libraries required by the
  application exist at the appropriate level in /usr/lib, or such
  that no versions of those libraries exist in /usr/lib
  

Problem summary

• ****************************************************************
  USERS AFFECTED:
  This issue affects users of native MQ C applications on AIX that
  establish TLS secured connections to queue managers before
  attempting to load other libraries from the system.
  
  
  Platforms affected:
  AIX
  
  ****************************************************************
  PROBLEM DESCRIPTION:
  Due to way in which libraries are loaded on AIX and to ensure
  the MQ installation of GSKit and its inter-library dependencies
  are loaded for client applications establishing TLS connections
  to queue managers, the MQ client adds the directory location of
  MQ's GSKit installation to the front of the library path
  (LIBPATH) when the application attempts to connect to an MQ
  queue manager.  The directory /usr/lib is also prepended, after
  the location of GSKit, to the library path.
  
  After connecting to an MQ queue manager, if the application then
  attempted to load a named library from the system and a library
  of that name was found in /usr/lib, an attempt to load that copy
  would be made.  If the library in /usr/lib was incompatible with
  the application compared to an equivalently named one that can
  be found in a different directory listed later in the library
  path, which the application expected to load, then a library
  loading error would occur.
  

Problem conclusion

• This APAR adds a configuration environment variable by the name
  of:
  
    AMQ_GSKIT_CLIENT_NO_PREPEND_USRLIB_LIBPATH
  
  This new environment variable can be used to suppress the
  prepending of /usr/lib by setting the environment variable to a
  non-empty value in the environment used to run the MQ client
  application, for example:
  
    export AMQ_GSKIT_CLIENT_NO_PREPEND_USRLIB_LIBPATH=TRUE
  
  When this environment variable is set to a non-empty value, the
  MQ client code will not add the directory /usr/lib to the front
  of the library path (LIBPATH) after the the location of the MQ
  installation of GSKit.
  
  ---------------------------------------------------------------
  The fix is targeted for delivery in the following PTFs:
  
  Version    Maintenance Level
  v8.0       8.0.0.9
  v9.0 CD    9.0.5
  v9.0 LTS   9.0.0.4
  
  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

  IBM MQ BASE MP

• Fixed component ID

  5724H7251

Applicable component levels