IJ28579: POSSIBLE DATA CORRUPTION USING ZLIBNX LIBRARY

APAR status

• Closed as fixed if next.

Error description

• **************************************************************
  * USERS AFFECTED:
  * Systems running the AIX 7200-04 Technology Level
  * with "IBM AIX V7.2 Expansion Pack 11/2019" or
  * "IBM AIX V7.2 Expansion Pack 5/2020" with
  * zlibNX.rte between and including 7.2.4.0 and
  * 7.2.4.2.
    **************************************************************
  * Compression using the zlibNX library in "IBM AIX V7.2
  * Expansion Pack 11/2019" or "IBM AIX V7.2 Expansion
  * Pack 5/2020" may appear to succeed. However, the resulting
  * data may not be able to be uncompressed, with any attempts to
  * uncompress it failing due to checksum mismatch or "invalid
  * distance: too far back". If the compressing application did
  * not preserve the original data, then access to the data is
  * lost.
  *
  * We have seen this compression issue with the "pigz" command,
  * but it can occur in any application that dynamically links
  * with zlibNX.
    **************************************************************
  * RECOMMENDATION:
  * An interim fix is available from either
  * ftp://aix.software.ibm.com/aix/ifixes/ij28579/
  * https://aix.software.ibm.com/aix/ifixes/ij28579/
  * Installation of the ifix does not require a reboot.
    **************************************************************
  

Local fix

Problem summary

• Compression using the zlibNX library in "IBM AIX V7.2 Expansion
  Pack 11/2019" and "IBM AIX V7.2 Expansion Pack 5/2020" will
  appear to succeed.  However, the resulting data cannot be
  uncompressed, with any attempts to uncompress it failing due to
  checksum mismatch or "invalid distance: too far back".
  
  If the compressing application did not preserve the original
  data, then access to the data is lost.
  

Problem conclusion

Temporary fix

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

Comments

• This APAR is being closed FIN. This means that a solution to
  this APAR is expected to be delivered from IBM in a release
  (if any) to be available within the next 24 months.
  

APAR Information

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

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

Fix information

Applicable component levels