DB2 FOR LUW / DB2FORLUW / 970 - DB2

Memory corruption message in db2diag.log, application fails, 
Instance services 
 
db2diag.log entries:- 
---------------------- 
2011-04-20-09.02.15.137242+060 I24164020A1473     LEVEL: Severe 
 
PID     : 737418               TID  : 1           PROC : db2bp 
 
INSTANCE: pi3snap              NODE : 000 
 
APPID   : *LOCAL.pi3snap.110419110035 
 
EDUID   : 1 
 
FUNCTION: DB2 UDB, SQO Memory Management, 
sqloDiagnoseFreeBlockFailure, 
probe:10 
 
MESSAGE : Possible memory corruption detected. 
 
DATA #1 : ZRC, PD_TYPE_ZRC, 4 bytes 
 
0x820F0002 
 
DATA #2 : Corrupt block address, PD_TYPE_CORRUPT_BLK_PTR, 8 
bytes 
0x000000011014d500 
 
DATA #3 : Block header, PD_TYPE_BLK_HEADER, 24 bytes 
 
0x000000011014D4E8 : 0000 0000 0000 0000 0000 0000 0000 0000 
 
................ 
 
0x000000011014D4F8 : 0000 0000 0000 0000 
........ 
DATA #4 : Data header, PD_TYPE_BLK_DATA_HEAD, 48 bytes 
 
0x000000011014D500 : 0000 0000 0000 0000 0000 0000 0000 0000 
 
................ 
 
0x000000011014D510 : 0000 0000 0000 0000 0000 0000 0000 0000 
 
................ 
 
0x000000011014D520 : 0000 0000 0000 0000 0000 0000 0000 0000 
 
................ 
 
CALLSTCK: 
 
  [0] 0x09000000033A2084 pdLog + 0x88 
 
  [1] 0x0900000002F10018 
@28@sqloDiagnoseFreeBlockFailure__FP8SMemFBlk 
+ 0x15C 
 
  [2] 0x09000000030CE274 sqlofmblkEx + 0x568 
 
  [3] 0x0900000002ED4054 clpPostLoadFreeDynMem + 0xA0 
 
  [4] 0x000000010003B858 clpbp_exe_sqluload__Fv + 0x138 
 
  [5] 0x0000000100001658 clp_bp_con__Fv + 0x638 
 
  [6] 0x0000000100000A84 main + 0x204 
 
  [7] 0x0000000100000320 __start + 0x98 
 
  [8] 0x0000000000000000 ?unknown + 0x0 
 
  [9] 0x0000000000000000 ?unknown + 0x0 
--------------------------------------------------------------- 
The issue happened because once the memory was allocated 
successfully and also de-allocated by OSS, then clp tried 
freeing the same memory. CLP did not actually allocate the 
memory block. 
 
Traces are confirming it: 
1511461     | | | sqlage_prepare_sqlca exit 
1511464     | | clp_prep_sqlca exit 
1511475     | | clpgendb2loadstruct entry 
1511481     | | clpgendb2loadstruct exit 
1511487     | | clp_send_cmdcb entry 
 
The memory that clp tried freeing was allocated by OSS while it 
was writing to the queue and OSS freed it after the write was 
successful. 
 
Free: 
1512220     | | | | | sqlowqueInternal entry 
1512241     | | | | | sqlowqueInternal exit 
1512243     | | | | | sqlofmblkEx entry 
1512250     | | | | | sqlofmblkEx mbt 
[Marker:PD_OSS_FREED_MEMORY ] 
1512264     | | | | | sqlofmblkEx exit 
1512269     | | | | sqlowque exit 
1512278     | | | clp_wque 
 
 
1512243 entry DB2 UDB SQO Memory Management sqlofmblkEx cei 
(1.3.129.33.2) 
        pid 1970186 tid 1 cpid 37690 node 0 sec 0 nsec 343426849 
 
        bytes 50 
 
        Data1   (PD_TYPE_PTR,8) Pointer: 
        0x00000001103d2080 
        Data2   (PD_TYPE_OSS_MEM_FILE_NAME,10) File name: 
        sqloqaix.C 
        Data3   (PD_TYPE_OSS_MEM_LINE_NUM,8) Line of code: 
        2147 
 
1512250 mbt DB2 UDB SQO Memory Management sqlofmblkEx cei 
(6.3.129.33.2.32770) 
        pid 1970186 tid 1 cpid 37690 node 0 sec 0 nsec 343427962 
 
        Marker:PD_OSS_FREED_MEMORY 
        Description: Freeing memory 
        bytes 16 
 
        Data1   (PD_TYPE_PTR,8) Pointer: 
        0x00000001103d2080 
 
1512264 exit DB2 UDB SQO Memory Management sqlofmblkEx cei 
(2.3.129.33.2) 
        pid 1970186 tid 1 cpid 37690 node 0 sec 0 nsec 343428923 
        rc = 0

**************************************************************** 
* USERS AFFECTED:                                              * 
* ALL DB2 USERS                                                * 
**************************************************************** 
* PROBLEM DESCRIPTION:                                         * 
* Memory corruption message "sqloDiagnoseFreeBlockFailure" in  * 
* db2diag.log                                                  * 
**************************************************************** 
* RECOMMENDATION:                                              * 
* The customer need to upgrade to db2_v97fp6  or higher        * 
* versions to resolve the problem.                             * 
****************************************************************

DB2 Version 9.7 Fix Pack 6 for Linux, UNIX, and Windows
 DB2 Version 9.7 Fix Pack 7 for Linux, UNIX, and Windows
 DB2 Version 9.7 Fix Pack 8 for Linux, UNIX, and Windows
 DB2 Version 9.7 Fix Pack 9 for Linux, UNIX, and Windows
 DB2 Version 9.7 Fix Pack 9a for Linux, UNIX, and Windows
 DB2 Version 9.7 Fix Pack 10 for Linux, UNIX, and Windows
 

Users won't see the Memory corruption message 
"sqloDiagnoseFreeBlockFailure" in db2diag.log after applying the 
Fixpack db2_v97fp6 or higher versions.

not known / see Local fix

Date  - problem reported    :
Date  - problem closed      :
Date  - last modified       :

04.08.2011
08.06.2012
08.06.2012