IBM Support

IT29344: MEMORY CORRUPTION / TRAP IN ALLOCMEM TERMFASTALLOC DURING COLUMNAR DATA PROCESSING

Fixes are available

Db2 Version 11.1 Mod 4 Fix Pack 5 for Linux, UNIX, and Windows
Db2 Version 11.1 Mod 4 Fix Pack 6 for Linux, UNIX, and Windows
Db2 Version 11.1 Mod 4 Fix Pack 6 for Linux, UNIX, and Windows

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You can track all active APARs for this component.

 

APAR status

  • Closed as program error.

Error description

  • During re-execution of a statement processing columnar data, a
cached invalid pointer is accessed resulting in memory
corruption.  The overwritten memory is often memory allocation
metadata, resulting in traps while allocating or freeing memory.

Trapping functions may vary widely, but the most common
functions are :
allocMem / sqloFastThreadAllocator::allocMem
termFastAlloc / sqloFastThreadAllocator::termFastAlloc

Local fix

  • db2set -im DB2_REDUCED_OPTIMIZATION="COL_IXSCAN_ALL_V1133 OFF"
db2 connect to <database>
db2 flush package cache dynamic
- the "flush" is required to invalidate vulnerable cached SQL
execution plans

Problem summary

  • ****************************************************************
* USERS AFFECTED:                                              *
* ALL                                                          *
****************************************************************
* PROBLEM DESCRIPTION:                                         *
* See Error Description                                        *
****************************************************************
* RECOMMENDATION:                                              *
* Upgrade to Db2 11.1 Mod 4 Fixpack 5 or higher                *
****************************************************************

Problem conclusion

  • First fixed in Db2 11.1 Mod 4 Fixpack 5

Temporary fix

  • 



Comments


    

  • 



APAR Information




    

  • APAR number
    IT29344
    • 

  • Reported component name
    DB2 FOR LUW
    • 

  • Reported component ID
    DB2FORLUW
    • 

  • Reported release
    B10
    • 

  • Status
    CLOSED  PER
    • 

  • PE
    NoPE
    • 

  • HIPER
    NoHIPER
    • 

  • Special Attention
    NoSpecatt / Xsystem
    • 

  • Submitted date
    2019-06-05
    • 

  • Closed date
    2020-01-20
    • 

  • Last modified date
    2020-01-20
    • 





    

  • 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
    DB2 FOR LUW
    • 

  • Fixed component ID
    DB2FORLUW
    • 



Applicable component levels


    

  • RB10  PSN
       UP
    • 








      
              
                            

              

              [{"Business Unit":{"code":"BU058","label":"IBM Infrastructure w\/TPS"},"Product":{"code":"SSEPGG","label":"DB2 for Linux- UNIX and Windows"},"Platform":[{"code":"PF025","label":"Platform Independent"}],"Version":"11.1","Line of Business":{"code":"LOB10","label":"Data and AI"}}]
              

                          

          
 
        

      

    

      

        

          

            
Document Information


            

            


                        

            Modified date:
            

            03 May 2022
            

            
                      

        


        

        


      

    

  



    

  

  
    
            

          
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