Post NetWare 6.5SP8 CIFS abends "DQ_RMV would cause memory corruption"

  • Document ID:7004247
  • Creation Date:20-Aug-2009
  • Modified Date:07-Jun-2013
    • Micro Focus Products:
      NetWare

Environment

Novell NetWare 6.5 Support Pack 8
n65NSS8a.exe

Situation

Novell NetWare 6.5 SP8 with the latest CIFS.NLM v3.27.01 from April 7th, 2009 as found in post sp8 patch n65nss8a.exe abends with the following reason: 

Break caused by Abend: DQ_RMV would cause memory corruption

Resolution

Apply n65nss8c available from https://download.novell.com/Download?buildid=tMWCI1cdI7s~

There is a special case instance where this problem still occurs with the n65nss8c patch applied and this has been reported to Engineering.

Additional Information

The coredump has the  following characteristics:
P00# r
exception Processor: 00
Current Focus Processor: 00
EAX = 2ACEAD80 EBX = 2ACEAC00 ECX = A9E05B08 EDX = 2ACEAB40
ESI = 86F66F2C EDI = 00000246 EBP = 86F66F08 ESP = 86F66EF8
EIP = A7A9FA39 FLAGS = 00000006 (PF)
A7A9FA39 83C404         ADD     ESP, 00000004
P00# .a
Debug entry: 260
Break caused by Abend: DQ_RMV would cause memory corruption
Error code: None

Address in CIFS.NLM at code start +00032A39h
Previous:  -000000D9  A7A9F960 CIFS.NLM|CCBFree
Current:    00000000  A7A9FA39
Next:      +00000117  A7A9FB50 CIFS.NLM|CCBAllocNBNS
P00# sw
Current EIP: A7A9FA39  CIFS.NLM|CCBFree+D9
86F66F0C  A7AA8D30  CIFS.NLM|FreeTcpCCBAndNBTSession+100
86F66F24  A7AA8DB7  CIFS.NLM|FreeTcpSession+37
86F66F40  A7AA8E4B  CIFS.NLM|FreeTCPSessionWTD+7B
86F66F58  0036F202  SERVER.NLM|StartWorkToDo+23
86F66F70  0023258B  SERVER.NLM|kWorkerThread+DF
86F66F88  0022C028  SERVER.NLM|TcoNewSystemThreadEntryPoint+40
(stack end)
P00#

We abend because we try to free a pointer that has already been free. 
Novell engineering are investigating who has freed the pointer before us that caused us to abend.

Note: a variety of memory corruption related abends may show as a DQ_RMV abend, however since they all may have different root causes, typically all 
encountered DQ_RMV abends in generally require a separate coredump to be captured and analyzed.