PH13366: RECURSIVE ABENDS DURING TCP/IP SHUTDOWN WITH SSL

Obtain the fix for this APAR.

APAR status

• Closed as program error.

Error description

• Recursive abends may occur during TCP/IP shutdown when there are
  outstanding SSL handshake requests in progress.
  These abends will be logged in the TCP/IP console log.
  

Local fix

• N/A
  

Problem summary

• ****************************************************************
  * USERS AFFECTED: All TCP/IP users that secure connections     *
  *                 through the z/VM SSL server.                 *
  ****************************************************************
  * PROBLEM DESCRIPTION:                                         *
  ****************************************************************
  * RECOMMENDATION: APPLY PTF                                    *
  ****************************************************************
  Shutting down the TCP/IP stack while an SSL handshake is in
  progress may cause a recursive abend loop in the stack.
  

Problem conclusion

• Several different abends were reported within the recursive
  abend loop.  This APAR will address the following problems that
  were detected:
  
  - When an SSL handshake fails with an error other than an
    internal TCP/IP error, the handshake is attempted on the
    next available SSL server.  During TCP/IP shutdown, all
    available SSL servers are moved to the Eligible list and
    therefore no SSL servers are available.  The code has
    been updated to detect this condition and fail the
    handshake.
  
  - The SslSend routine sends data from the TCP/IP stack to
    the SSL server.  It has been updated to check that
    the control block address that is passed in is not nil.
    If it is nil, the send fails with a FatalError.
  
  - A check was added to make sure that a handshake request
    is in progress before responding to it.  Updates were
    made to set/reset the handshake in progress flag
    appropriately.
  

Temporary fix

Comments

APAR Information

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

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

  UI63805

Modules/Macros

• CMNETST  TCNOTIF  TCPREQU  TCPSSL   TCUTIL   T6PSSL
  

Fix information

• Fixed component name

  TCP/IP FOR Z/VM

• Fixed component ID

  5735FAL00

Applicable component levels

• R710 PSY UI63805

     UP19/07/03 P 2001

Fix is available

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