IV29306: POTENTIAL CRASH WHEN UNCONFIGURING VSCSI CLIENT DRIVER APPLIES TO AIX 6100-07

Obtain the fix for this APAR.

APAR status

• Closed as program error.

Error description

• There is a potential crash in the client VSCSI driver
  when
  unconfiguring the adapter instance (e.g., rmdev). The
  stack
  trace looks like:
  
  (0)> f
  pvthread+095900 STACK:
  [041ADB58]vscsi_free_scsi+000138 (0000000000000000 [??])
     r31 : 0000000000000130 r30 : F1000A003EFA4000
  [041A2524]vscsi_fail_config+0000A4 (??, ??, ??)
     r31 : 8000001000000002 r30 : 00000000041C02C0 r29 :
  0000000000000000
     r28 : F1000A003EFA4000 r27 : 0000000000000002 r26 :
  8000001000000002
     r25 : 00000000DEADBEEF
  [041A5CA8]vscsi_init_config+0001A8 (??, ??, ??)
     r31 : 0000000000000002 r30 : 0000000000000000 r29 :
  0000000000000002
     r28 : 0000000000000000 r27 : 0000000000000000 r26 :
  8000001000000002
     r25 : 00000000DEADBEEF r24 : 00000000DEADBEEF r23 :
  00000000DEADBEEF
     r22 : 00000000DEADBEEF r21 : 00000000DEADBEEF r20 :
  00000000DEADBEEF
  [00665950]config_dd+000270 (??, ??, ??)
     r31 : 0000000000000006 r30 : 000000002FF22560 r29 :
  0000000000000014
     r28 : 0000000000000000 r27 : 000000000000008A r26 :
  0000000000000000
  [006666A0]sysconfig+000240 (??, ??, ??)
     r31 : 0000000000000000 r30 : 0000000010002C88 r29 :
  000000002000147C
     r28 : 0000000000000000
  [00003850]ovlya_addr_sc_flih_main+000130 ()
  [kdb_get_virtual_memory] no real storage @ 2FF22528
  [10002C84]10002C84 ()
  [kdb_read_mem] no real storage @ FFFFFFFFFFF9520
  
  (0)> dc 041ADB58
  .vscsi_free_scsi+000138       tweq    r14,r14
  

Local fix

• N/A
  

Problem summary

• ****************************************************************
  * USERS AFFECTED:
  * Systems running the 6100-07 Technology Level with the
  * devices.vdevice.IBM.v-scsi.rte fileset at the 6.1.7.15 or
  * 6.1.7.16 level.
  ****************************************************************
  * PROBLEM DESCRIPTION:
  * While unconfiguring the VSCSI client devices, the system may
  * crash in vscsi_free_scsi().
  * The issue is visible only when there are a large number of
  * LUNs exported thru a single VSCSI device. The work around is
  * to minimize the LUNs per VSCSI adapter.
  ****************************************************************
  * RECOMMENDATION:
  * Install APAR IV29306.
  ****************************************************************
  

Problem conclusion

• The crash was due to accessing a freed memory pointer during
  unconfigure code path. The corresponding code has been fixed
  so that there is no scope for accessing freed memory which will
  prevent the crash.
  

Temporary fix

Comments

APAR Information

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

  IV25755

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

Fix information

• Fixed component name

  AIX 610 STD EDI

• Fixed component ID

  5765G6200

Applicable component levels

• R610 PSY U854343

     UP12/12/06 I 1000

PTF to Fileset Mapping

• U854343 devices.vdevice.IBM.v-scsi.rte 6.1.7.17