IBM Support

IT21770: The loading and Unloading of amqmtsxatm.dll causes MSDTC.exe to crash

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APAR status

  • Closed as program error.

Error description

  • A user may receive an MQRC_UOW_ENLISTMENT_ERROR in  the Windows
    Application Event Log. This issue results in the   MSDTC.EXE
    service crashing in amqmtsxatm!zswLock method. No errors being
    written to the MQ Error log and no FDC files generated.
    
    MSDTC crash dumps shows the following call stack :-
    
    amqmtsxatm!zswLock+0x1ba
    amqmtsxatm!zswUnsaveOurInstallation+0x168
    amqmtsxatm!DllMain+0x259
    amqmtsxatm!__DllMainCRTStartup+0x8d
    ntdll!LdrpCallInitRoutine+0x3f
    ntdll!LdrpProcessDetachNode+0xfe
    ntdll!LdrpUnloadNode+0x57
    ntdll!LdrpDecrementNodeLoadCount+0x101
    ntdll!LdrUnloadDll+0x34
    KERNELBASE!FreeLibrary+0x2a
    msdtctm!CXaRm1PipeConn_State_Validating::XaNotify+0x1d
    msdtcprx!CClique::DeliverIncomingMessages+0x297
    msdtcprx!CClique::ManagedToGrabTheGuard+0x55
    msdtcprx!CClique::AttemptToDeliverMessages+0x65
    msdtcprx!CImpICliqueSignal::Signal+0x51
    msdtctm!CValidateTask::TaskRoutine+0x1f8
    msdtctm!CTaskManager::ValidateThreadRoutine+0xb9
    kernel32!BaseThreadInitThunk+0x1a
    ntdll!RtlUserThreadStart+0x1d
    
    This issue occurs with the following conditions:
    - XA transaction is enabled in Windows
    - DTC Login account is configured with a user that has
    permissions to make MQ calls,
    - XADLL registry key points to a valid XA resource manager DLL
    

Local fix

Problem summary

  • ****************************************************************
    USERS AFFECTED:
    Users running MQ application processes such that MQ libraries
    may be reloaded by Windows. The problem is most commonly seen
    where an application is using Microsoft distributed transactions
    and the MSDTC process unloads and later reloads the module that
    gives addressability to the MQ API.
    
    
    Platforms affected:
    Windows
    
    ****************************************************************
    PROBLEM DESCRIPTION:
    Coding error in MQ caused a crash in MSDTC while unloading
    amqmtsxatm.dll.
    

Problem conclusion

  • Validation has been introduced to ensure that access violation
    does not occur while unloading amqmtsxatm.dll
    
    ---------------------------------------------------------------
    The fix is targeted for delivery in the following PTFs:
    
    Version    Maintenance Level
    v9.0 CD    9.0.4
    v9.0 LTS   9.0.0.3
    
    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

    IT21770

  • Reported component name

    IBM MQ BASE M/P

  • Reported component ID

    5724H7261

  • Reported release

    900

  • Status

    CLOSED PER

  • PE

    NoPE

  • HIPER

    NoHIPER

  • Special Attention

    NoSpecatt / Xsystem

  • Submitted date

    2017-08-03

  • Closed date

    2017-09-22

  • Last modified date

    2018-02-27

  • 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 M/P

  • Fixed component ID

    5724H7261

Applicable component levels

[{"Business Unit":{"code":"BU053","label":"Cloud & Data Platform"},"Product":{"code":"SSYHRD","label":"IBM MQ"},"Component":"","ARM Category":[],"Platform":[{"code":"PF025","label":"Platform Independent"}],"Version":"9.0","Edition":"","Line of Business":{"code":"LOB36","label":"IBM Automation"}}]

Document Information

Modified date:
27 February 2018