[CVE-2012-4508] ext4: race-condition protection for ext4_convert_unwritten_extents_endio

[Luis Henriques]

Race condition in fs/ext4/extents.c in the Linux kernel before 3.4.16
allows local users to obtain sensitive information from a deleted file by
reading an extent that was not properly marked as uninitialized.

Following this email there are two patches that fix this issue for
Oneiric:

* "ext4: quiet 'unused variables' compile warnings"
  Strictly speaking, this commit isn't actually required -- it just cleans
  up an unused variable.  The reason to include this patch is that it
  makes the application of the second commit cleaner.  This is a clean
  cherry-pick from mainline 9331b6261058eb85ae7c57ab8ac279e7fdaa9f04.

* "ext4: race-condition protection for ext4_convert_unwritten_extents_endio"
  This is the actual fix for this CVE and it is a backport of commit
  dee1f973ca341c266229faa5a1a5bb268bed3531 from mainline.

These patches have been tested on kvm using xfstests and no regressions
were found.

Dmitry Monakhov (1):
  ext4: race-condition protection for
    ext4_convert_unwritten_extents_endio

Yongqiang Yang (1):
  ext4: quiet 'unused variables' compile warnings

 fs/ext4/extents.c | 59 +++++++++++++++++++++++++++++++++++++++++++------------
 fs/ext4/mballoc.c |  2 --
 2 files changed, 46 insertions(+), 15 deletions(-)

-- 
1.8.0