Re: [PATCH 4.4 00/24] 4.4.137-stable review

From: Rafael David Tinoco
Date: Wed Jun 13 2018 - 17:08:54 EST

On Wed, Jun 13, 2018 at 6:00 PM, Greg Kroah-Hartman
<gregkh@xxxxxxxxxxxxxxxxxxx> wrote:
> On Wed, Jun 13, 2018 at 05:47:49PM -0300, Rafael Tinoco wrote:
>> Results from Linaroâs test farm.
>> Regressions detected.
>> NOTE:
>> 1) LTP vma03 test (cve-2011-2496) broken on v4.4-137-rc1 because of:
>> 6ea1dc96a03a mmap: relax file size limit for regular files
>> bd2f9ce5bacb mmap: introduce sane default mmap limits
>> discussion:
>> mainline commit (v4.13-rc7):
>> 0cc3b0ec23ce Clarify (and fix) MAX_LFS_FILESIZE macros
>> should be backported to 4.4.138-rc2 and fixes the issue.
> Really? That commit says it fixes c2a9737f45e2 ("vfs,mm: fix a dead
> loop in truncate_inode_pages_range()") which is not in 4.4.y at all.
> Did you test this out?

Yes, the LTP contains the tests (last comment is the final test for
arm32, right before Jan tests i686).

Fixing MAX_LFS_FILESIZE fixes the new limit for mmap() brought by
those 2 commits (file_mmap_size_max()).
offset tested by the LTP test is 0xfffffffe000.
file_mmap_size_max gives: 0xFFFFFFFF000 as max value, but only after
the mentioned patch.

Original intent for this fix was other though.

> thanks,
> greg k-h