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IV91339: POTENTIAL DATA ANOMALY FOR LINUX USING VSCSI IF LPM FAILS APPLIES TO AIX 6100-09

A fix is available

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APAR status

  • Closed as program error.

Error description

  • **************************************************************
    * USERS AFFECTED:
    * Systems running VIOS 2.2.3.x with
    * devices.vdevice.IBM.v-scsi-host.rte
    * at 6.1.9.48 level or below
    * OR
    * VIOS 2.2.4.x with
    * devices.vdevice.IBM.v-scsi-host.rte
    * at 6.1.9.102 level or below
    * OR
    * VIOS 2.2.5.x with
    * devices.vdevice.IBM.v-scsi-host.rte
    * at 6.1.9.200 level or below
    **************************************************************
    * PROBLEM DESCRIPTION:
    * A VIOS vSCSI defect was discovered in an IBM Live Partition
    * Mobility (LPM) test environment.
    * A very small timing window was found in the simulated LPM
    * failure path that if hit, could affect vSCSI I/O completion
    * processing in a way that could potentially result in data
    * corruption in Linux on Power LPARs.
    *
    * The risk of hitting this exposure outside of the IBM test
    * lab has had extensive evaluation and is considered
    * extremely small.  The controlled test environment where
    * this problem was observed makes use of a high-precision
    * test injection tool that was able to inject a specific
    * error within a tiny window. The chances of hitting this
    * window outside of the IBM test lab are highly unlikely and
    * there is no known occurrence of this issue outside of the
    * IBM test lab.  Only the vSCSI device type and Linux (i.e.
    * the LPAR being LPM'd) are vulnerable; NPIV, AIX, and IBM i
    * are not vulnerable.
    *
    * APAR IV91339 is the VIOS patch to close the vulnerability.
    **************************************************************
    * RECOMMENDATION:
    * Install APAR IV91339.
    * Prior to fix availability, an interim fix is available from
    * either
    * ftp://aix.software.ibm.com/aix/ifixes/iv91339/
    * https://aix.software.ibm.com/aix/ifixes/iv91339/
    * Installation of the ifix requires a reboot.
    **************************************************************
    

Local fix

Problem summary

  • A VIOS vSCSI defect was discovered in an IBM Live Partition
    Mobility (LPM) test environment.
    A very small timing window was found in the simulated LPM
    failure path that if hit, could affect vSCSI I/O completion
    processing in a way that could potentially result in data
    corruption in Linux on Power LPARs.
    .
    The risk of hitting this exposure outside of the IBM test
    lab has had extensive evaluation and is considered
    extremely small.  The controlled test environment where
    this problem was observed makes use of a high-precision
    test injection tool that was able to inject a specific
    error within a tiny window. The chances of hitting this
    window outside of the IBM test lab are highly unlikely and
    there is no known occurrence of this issue outside of the
    IBM test lab.  Only the vSCSI device type and Linux (i.e.
    the LPAR being LPM'd) are vulnerable; NPIV, AIX, and IBM i
    are not vulnerable.
    .
    APAR IV91339 is the VIOS patch to close the vulnerability.
    

Problem conclusion

  • Fix command processing on the VIOS so that we do not
    prematurely report I/Os as complete to the client.
    

Temporary fix

  •   *********
      * HIPER *
      *********
    

Comments

APAR Information

  • APAR number

    IV91339

  • Reported component name

    AIX 610 STD EDI

  • Reported component ID

    5765G6200

  • Reported release

    610

  • Status

    CLOSED PER

  • PE

    NoPE

  • HIPER

    YesHIPER

  • Submitted date

    2016-12-07

  • Closed date

    2016-12-07

  • Last modified date

    2017-08-24

  • APAR is sysrouted FROM one or more of the following:

  • APAR is sysrouted TO one or more of the following:

    U876522 IV99274

Fix information

  • Fixed component name

    AIX 610 STD EDI

  • Fixed component ID

    5765G6200

Applicable component levels

  • R610 PSY U876522

       UP17/04/14 I 1000 Ž



Document information

More support for: AIX Standard Edition

Software version: 610

Operating system(s): AIX

Reference #: IV91339

Modified date: 24 August 2017


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