PI85228: EXECUTOR CRASH WITH NAT SERVERS AND ICMP ERROR TO RETURN ADDRESS

9.0.0.5: WebSphere Application Server traditional V9.0 Fix Pack 5
9.0.0.6: WebSphere Application Server traditional V9.0 Fix Pack 6
8.5.5.13: WebSphere Application Server V8.5.5 Fix Pack 13
9.0.0.7: WebSphere Application Server traditional V9.0 Fix Pack 7
9.0.0.8: WebSphere Application Server traditional V9.0 Fix Pack 8
8.5.5.14: WebSphere Application Server V8.5.5 Fix Pack 14
9.0.0.9: WebSphere Application Server traditional V9.0 Fix Pack 9
9.0.0.10: WebSphere Application Server traditional V9.0 Fix Pack 10
8.5.5.15: WebSphere Application Server V8.5.5 Fix Pack 15
9.0.0.11: WebSphere Application Server traditional V9.0 Fix Pack 11
9.0.5.0: WebSphere Application Server traditional Version 9.0.5 Refresh Pack
9.0.5.1: WebSphere Application Server traditional Version 9.0.5 Fix Pack 1
9.0.5.2: WebSphere Application Server traditional Version 9.0.5 Fix Pack 2
8.5.5.17: WebSphere Application Server V8.5.5 Fix Pack 17
9.0.5.3: WebSphere Application Server traditional Version 9.0.5 Fix Pack 3
9.0.5.4: WebSphere Application Server traditional Version 9.0.5 Fix Pack 4
9.0.5.5: WebSphere Application Server traditional Version 9.0.5 Fix Pack 5
WebSphere Application Server traditional 9.0.5.6
9.0.5.7: WebSphere Application Server traditional Version 9.0.5 Fix Pack 7
9.0.5.8: WebSphere Application Server traditional Version 9.0.5.8
8.5.5.20: WebSphere Application Server V8.5.5.20
8.5.5.18: WebSphere Application Server V8.5.5 Fix Pack 18
8.5.5.19: WebSphere Application Server V8.5.5 Fix Pack 19
9.0.5.9: WebSphere Application Server traditional Version 9.0.5.9
9.0.5.10: WebSphere Application Server traditional Version 9.0.5.10
8.5.5.16: WebSphere Application Server V8.5.5 Fix Pack 16
8.5.5.21: WebSphere Application Server V8.5.5.21
9.0.5.11: WebSphere Application Server traditional Version 9.0.5.11

APAR status

• Closed as program error.

Error description

• Executor (ibmlb2) crash with call stack containing :
  #1  os_mutex_lock
  #2  lbll_select1
  #3  _lbicmp_pbuf_tcpudp_entry
  #4  _lbicmp_pbuf_ip_entry
  #5  lbicmp_pbuf_entry
  #6  lbip_pbuf_entry
  #7  lbipv4_entry
  

Local fix

Problem summary

• ****************************************************************
  * USERS AFFECTED:  IBM WebSphere Application Server Load       *
  *                  Balancer for IPv4 and IPv6 users            *
  ****************************************************************
  * PROBLEM DESCRIPTION: Crash occurs with NAT forwarding when   *
  *                      an ICMP error is received by a          *
  *                      returnaddress IP address.               *
  ****************************************************************
  * RECOMMENDATION:                                              *
  ****************************************************************
  Code was assuming a cluster address was present when
  processing ICMP errors which lead to a null pointer reference
  and a crash.
  

Problem conclusion

• Modified the code to check for a cluster IP when processing
  any ICMP error packets. The Load Balancer will still honor
  ICMP ping requests to the return address but will not process
  any other ICMP responses.
  
  Fix levels:
     8.5.5.13
     9.0.0.5
  

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:

Fix information

• Fixed component name

  WS EDGE LB IPV4

• Fixed component ID

  5724H8812

Applicable component levels

• R850 PSY

     UP

• R900 PSY

     UP