IJ53372: GPFS SLAB LEAK

APAR status

• Closed as program error.

Error description

• memory leaks when access is denied to a user and that
  user is in more than 32 groups.
  

Local fix

Problem summary

• GPFS leaks kernel memory every time a user that is a member in
  more than 32 groups tries to access an inode that denies access
  to that user through simple modebits (no ACL). This might go
  unnoticed, but if these conditions occur repeatedly, the kernel
  memory leak can affect the node operations, requiring a reboot
  to avoid outages.
  

Problem conclusion

• This problem is fixed in 5.1.9.8
  To see all Spectrum Scale APARs and their respective
  Fix solutions refer to page: 
  https://public.dhe.ibm.com/storage/spectrumscale/spectrum_scale
  _apars.html
  
  Benefits of the solution:
  The fix ensure that the allocated memory is freed again and does
  not leak.
  
  Problem trigger:
  All of the conditions in the problem description are required
  for the problem to occur: A user needs to be a member in more
  than 32 groups, an inode needs to have simple modebits (no ACL)
  that deny access for that user and the user needs to try to
  access that inode.
  
  Work Around:
  The only workaround would be reducing the number of groups to
  ensure that no user is a member in more than 32 groups.
  
  Symptom:
  Abend/Crash(in the worst case that the kernel memory leak goes
  undetected, leading to OOM kills and node outage)
  
  Platforms affected:
  ALL Linux OS environments
  
  Functional Area affected:
  All Scale Users
  
  Customer Impact:
  High Importance
  

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

  SPEC SCALE STD

• Fixed component ID

  5737F33AP

Applicable component levels