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PI59235: Problems with serialization code

Fixes are available

16.0.0.2: WebSphere Application Server Liberty 16.0.0.2
16.0.0.3: WebSphere Application Server Liberty 16.0.0.3
16.0.0.4: WebSphere Application Server Liberty 16.0.0.4
17.0.0.1: WebSphere Application Server Liberty 17.0.0.1
17.0.0.2: WebSphere Application Server Liberty 17.0.0.2
17.0.0.3: WebSphere Application Server Liberty 17.0.0.3
17.0.0.4: WebSphere Application Server Liberty 17.0.0.4
18.0.0.1: WebSphere Application Server Liberty 18.0.0.1
18.0.0.2: WebSphere Application Server Liberty 18.0.0.2
18.0.0.3: WebSphere Application Server Liberty 18.0.0.3
18.0.0.4: WebSphere Application Server Liberty 18.0.0.4
19.0.0.1: WebSphere Application Server Liberty 19.0.0.1
19.0.0.2: WebSphere Application Server Liberty 19.0.0.2
19.0.0.3: WebSphere Application Server Liberty 19.0.0.3
19.0.0.4: WebSphere Application Server Liberty 19.0.0.4
19.0.0.5: WebSphere Application Server Liberty 19.0.0.5
19.0.0.6: WebSphere Application Server Liberty 19.0.0.6
19.0.0.7: WebSphere Application Server Liberty 19.0.0.7
19.0.0.8: WebSphere Application Server Liberty 19.0.0.8
19.0.0.9: WebSphere Application Server Liberty 19.0.0.9
19.0.0.10: WebSphere Application Server Liberty 19.0.0.10
19.0.0.11: WebSphere Application Server Liberty 19.0.0.11
19.0.0.12: WebSphere Application Server Liberty 19.0.0.12
20.0.0.1: WebSphere Application Server Liberty 20.0.0.1
20.0.0.2: WebSphere Application Server Liberty 20.0.0.2
20.0.0.3: WebSphere Application Server Liberty 20.0.0.3
20.0.0.4: WebSphere Application Server Liberty 20.0.0.4
20.0.0.5: WebSphere Application Server Liberty 20.0.0.5
20.0.0.6: WebSphere Application Server Liberty 20.0.0.6
20.0.0.7: WebSphere Application Server Liberty 20.0.0.7
20.0.0.8: WebSphere Application Server Liberty 20.0.0.8
20.0.0.9: WebSphere Application Server Liberty 20.0.0.9
20.0.0.10: WebSphere Application Server Liberty 20.0.0.10
20.0.0.11: WebSphere Application Server Liberty 20.0.0.11
20.0.0.12: WebSphere Application Server Liberty 20.0.0.12

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APAR status

  • Closed as program error.

Error description

  • 1.) The Serialisation code of Websphere Liberty / Apache
    Yoko
    is broken in that it serializes fields of enums while it
    should
    only serialize  the enum name.
    
    2.) The Deserialization code assigns fields from the stream
    to
    fields,  even if the type does not match the target type.
    This
    leads to JVM crashes.
    

Local fix

Problem summary

  • ****************************************************************
    * USERS AFFECTED:  All users of IBM WebSphere Application      *
    *                  Server Liberty making remote EJB calls      *
    *                  using objects with enum values containing   *
    *                  custom fields.                              *
    ****************************************************************
    * PROBLEM DESCRIPTION: The Liberty server crashes when running *
    *                      certain applications.                   *
    ****************************************************************
    * RECOMMENDATION:                                              *
    ****************************************************************
    Rather than serializing just the enum name as discussed in the
    Java Serialization specification, the Apache Yoko code
    serializes all enum fields. This does not present a problem as
    long as only the standard name and ordinal fields are present
    since the deserialization side handles these. However, custom
    enum fields will also be serialized but skipped over on the
    deserialization side. This can result in incorrect type
    assignments and lead to a JVM crash.
    

Problem conclusion

  • The Apache Yoko code will now follow the Java Serialization
    specification and send only the enum name when talking to
    anything other than older versions of Yoko. The fix will
    maintain interoperability with the IBM SDK ORB (traditional
    WebSphere Application Server) and earlier Liberty versions
    supporting EE7.
    
    The fix for this APAR is currently targeted for inclusion in
    fix pack 16.0.0.2.  Please refer to the Recommended Updates
    page for delivery information:
    http://www.ibm.com/support/docview.wss?rs=180&uid=swg27004980
    

Temporary fix

  • Mark the custom enum fields as transient in the source code.
    

Comments

APAR Information

  • APAR number

    PI59235

  • Reported component name

    WAS LIBERTY COR

  • Reported component ID

    5725L2900

  • Reported release

    855

  • Status

    CLOSED PER

  • PE

    NoPE

  • HIPER

    NoHIPER

  • Special Attention

    NoSpecatt / Xsystem

  • Submitted date

    2016-03-16

  • Closed date

    2016-04-22

  • Last modified date

    2016-06-13

  • 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

    WAS LIBERTY COR

  • Fixed component ID

    5725L2900

Applicable component levels

  • R855 PSY

       UP

[{"Business Unit":{"code":"BU053","label":"Cloud \u0026 Data Platform"},"Product":{"code":"SSD28V","label":"WebSphere Application Server Liberty Core"},"Platform":[{"code":"PF025","label":"Platform Independent"}],"Version":"855","Line of Business":{"code":"LOB36","label":"IBM Automation"}}]

Document Information

Modified date:
16 October 2021