IBM Support

IT20455: Memory exception (SIGSEGV) in MQ channel agent process, channel terminates unexpectedly.

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APAR status

  • Closed as program error.

Error description

  • During connection binding negotiation, MQ channel fails to
    connect to the Queue Manager due to a network error.
    
    If the channel is a SVRCONN the client application receives
    reason code MQRC_CONNECTION_BROKEN (2009) from MQCONN/MQCONNX.
    
    A SIGSEGV is observed and a Failure Data Capture (FDC) record is
    generated.
    

Local fix

  • N/A
    

Problem summary

  • ****************************************************************
    USERS AFFECTED:
    All users of WebSphere MQ Version 8
    
    
    Platforms affected:
    MultiPlatform
    
    ****************************************************************
    PROBLEM DESCRIPTION:
    During MQ channel connection, a process called channel binding
    negotiation occurs. If this process is interrupted by a network
    error, the channel connection is terminated causing the blocks
    in memory to be freed. A programming error meant that the code
    blocks were being freed twice and causing the memory exception.
    

Problem conclusion

  • The code has been modified to avoid the double free and the
    memory exception.
    
    ---------------------------------------------------------------
    The fix is targeted for delivery in the following PTFs:
    
    Version    Maintenance Level
    v8.0       8.0.0.13
    v9.1 CD    9.1.3
    
    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 number

    IT20455

  • Reported component name

    WMQ BASE MULTIP

  • Reported component ID

    5724H7241

  • Reported release

    750

  • Status

    CLOSED PER

  • PE

    NoPE

  • HIPER

    NoHIPER

  • Special Attention

    NoSpecatt / Xsystem

  • Submitted date

    2017-05-04

  • Closed date

    2019-05-10

  • Last modified date

    2019-05-10

  • 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

    WMQ BASE MULTIP

  • Fixed component ID

    5724H7241

Applicable component levels



Document information

More support for: WebSphere MQ
APAR / Maintenance

Software version: 7.5

Reference #: IT20455

Modified date: 10 May 2019