PK33200: ABEND S0C4 IN DFHSOS20 (UK15933) +X'1B6'. R6 BAD

Obtain the fix for this APAR.

APAR status

• Closed as program error.

Error description

• If a CICS task loses control while in rutk_lookup procedure, to
  validate an instance token, an abend S0C4 may later occur out of
  DFHSOS20.  R6 will have an invalid address. In the diagnosed
  case, CICS was executing an MVC instruction at DFHSOS20
  (UK15933) +x'1B6'.
  .
  ADDITIONAL KEYWORDS: DFHSOCK X'1BC' 1BC
  DFHSO0001 An abend (code 0C4/AKEA) has occurred at
            offset X'01BC' in module DFHSOS20
  

Local fix

Problem summary

• ****************************************************************
  * USERS AFFECTED: All.                                         *
  ****************************************************************
  * PROBLEM DESCRIPTION: AbendS0C4 in DFHSOS20 due to invalid    *
  *                      socket address when reserving socket.   *
  ****************************************************************
  * RECOMMENDATION:                                              *
  ****************************************************************
  Some data is received from a TCPIP connection. DFHWBSO is called
  for notify_callback processing and this attaches a task (CWXN)
  to process the received data. DFHWBSO then tries to reserve the
  socket associated with the TCPIPSERVICE for the use of the newly
  attached task.
  However, the new task, running on a different TCB, has already
  started to run and closes the socket before the reserve
  processing is complete. In this case the socket is closed during
  the verify_socket_token call which reserve_sock does first
  to validate the socket instance number.
  The result of the socket being closed at this point is that a
  bad address is returned from the socket, which later causes an
  abend during reserve processing when the task number is set in
  the socket.
  If the socket is closed at a less crucial point then reserve
  processing may complete with an unknown_session_token exception,
  but this will not cause an abend, the task will be allowed to
  continue with the socket not having been reserved for the
  attached task.
  Additional Symptom: An HTTP TCPIPSERVICE socket cannot be
  closed because there is a hanging client socket. The socket
  has a TASKASOC on its reserved collection chain for a task
  which has terminated (see PK40828).
  

Problem conclusion

• DFHSOS23 has been altered so that the socket attach lock is
  held during the notify call to DFHWBSO. This will prevent
  the attached task from executing until the lock is freed
  after reserve processing is complete. This also fixes the
  problem reported in PK40828.
  

Temporary fix

• FIX AVAILABLE BY PTF ONLY
  

Comments

APAR Information

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

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

  UK26477 PK48199

Modules/Macros

•    DESPIDC  DESPIDM  DESPIIM  DESPIIS  DESPILN
  DESPIPM  DESPIRE  DESPIRM  DESPIRS  DESPIWT  DESRUTK  DESRZDM
  DESRZDUF DESRZIS  DESRZLN  DESRZNR  DESRZOFX DESRZRG  DESRZRJ
  DESRZRM  DESRZRS  DESRZRT  DESRZRTX DESRZSK  DESRZST  DESRZTC
  DESRZTR  DESRZTRI DESRZVPX DESRZXM  DESSOAD  DESSOCK  DESSODM
  DESSODUF DESSOIS  DESSOLS  DESSOLT  DESSOMG  DESSORD  DESSOSO
  DESSOST  DESSOTB  DESSOTD  DESSOTI  DESSOUS  DESSOXM  DESWBSO
  DFHPIDM  DFHPILN  DFHPIPM  DFHPIRE  DFHPIRM  DFHPIRS  DFHPIWT
  DFHRUTKC DFHRZDM  DFHRZDUF DFHRZIX  DFHRZLN  DFHRZNR2 DFHRZOFI
  DFHRZRG2 DFHRZRJ  DFHRZRM  DFHRZRS1 DFHRZRT  DFHRZRT1 DFHRZRT2
  DFHRZSO  DFHRZSO1 DFHRZTA  DFHRZTCX DFHRZTRI DFHRZTR1 DFHRZVP1
  DFHRZXM  DFHSOAD  DFHSOCBA DFHSOCBM DFHSOCBT DFHSOCK  DFHSODM
  DFHSODUF DFHSOIS  DFHSOLS  DFHSOM01 DFHSOM02 DFHSOM03 DFHSORD
  DFHSOST  DFHSOS00 DFHSOS01 DFHSOS02 DFHSOS03 DFHSOS04 DFHSOS05
  DFHSOS06 DFHSOS07 DFHSOS08 DFHSOS09 DFHSOS10 DFHSOS11 DFHSOS12
  DFHSOS13 DFHSOS14 DFHSOS15 DFHSOS16 DFHSOS17 DFHSOS18 DFHSOS19
  DFHSOS20 DFHSOS21 DFHSOS22 DFHSOS23 DFHSOTB  DFHSOTI  DFHSOXM
  DFHWBSO
  

Fix information

• Fixed component name

  CICSTS 3.1 Z/OS

• Fixed component ID

  5655M1500

Applicable component levels

• R400 PSY UK26477

     UP07/06/30 P F706

Fix is available

• Select the PTF appropriate for your component level. You will be required to sign in. Distribution on physical media is not available in all countries.