PI25167: EZBTCRD S0C4/00000 WHEN RUNNING AT-TLS

Obtain the fix for this APAR.

APAR status

• Closed as unreproducible in next release.

Error description

• A timing window exists in AT-TLS which can cause data to be
  decrypted when processing inbound data and a SRB to be scheduled
  to decrypt the same data.  The SRB will not find any data to
  decrypt and will abend.  The timing windows exists if data
  arrives in to be decrypted after AT-TLS already scheduled a SRB
  to decrypt the data.
  

Local fix

• none
  .
  KEYWORDS: SYSROUTE OF: PI27764
  

Problem summary

• ****************************************************************
  * USERS AFFECTED:                                              *
  * All users of the IBM Communications Server for z/OS Version  *
  * 2 Release(s) 1 IP: ATTLS                                     *
  ****************************************************************
  * PROBLEM DESCRIPTION:                                         *
  * EZBTCRD abends processing an ATTLS connection because there  *
  * is no data available to be decrypted.                        *
  ****************************************************************
  * RECOMMENDATION:                                              *
  * Apply PTF.                                                   *
  ****************************************************************
  Encrypted data arrives while the SSL handshake is completing.  A
  timing window exists where two threads can try to decrypt data.
  This can cause the second thread to abend because there is no
  data available on the TLSX receive queue to decrypt.
  

Problem conclusion

• ATTLS is updated to set a flag which will prevent decryption
  from scheduling decryption until the SSL handshake is complete.
  

Temporary fix

Comments

• This is a logical route of PI27764.
  This APAR contains the fix for defect 21941
  

APAR Information

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

  PI24894

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

  UI28306

Modules/Macros

• EZBTLWRQ EZBTLCWK
  

Fix information

• Fixed component name

  TCP/IP V3 MVS

• Fixed component ID

  5655HAL00

Applicable component levels

• R210 PSY UI28306

     UP15/06/23 P F506

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.