[Trusty][SRU][PATCH 0/1] btrfs: fix defrag 32-bit integer overflow

[Joseph Salisbury]

BugLink: http://bugs.launchpad.net/bugs/1324953

== Trusty SRU Justification ==
A kernel crash happens when defragmenting large files on Trusty using btrfs.  When defragging a very large file, the cluster variable can wrap its 32-bit signed int type and become negative, which eventually gets passed to btrfs_force_ra() as a very large unsigned long value.  On 32-bit platforms, this eventually results in an Oops from the SLAB allocator.  This issue is fixed in mainline as of 3.14-rc2.  However, the fix was not cc'd to stable.
  
== Fix ==
commit c41570c9d29764f797fa35490d72b7395a0105c3
Author: Justin Maggard <jmaggard10 at gmail.com>
Date:   Tue Jan 21 11:18:29 2014 -0800

    btrfs: fix defrag 32-bit integer overflow

== Test Case ==

A test kernel was built with this patch and tested by the original bug reporter.  The bug reporter states the test kernel resolved the bug.

Justin Maggard (1):
  btrfs: fix defrag 32-bit integer overflow

 fs/btrfs/ioctl.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

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2.0.0