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

Obtain the fix for this APAR.

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 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