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

[Jan Stancek]

----- Original Message -----
> On Thu, Jun 14, 2018 at 02:24:25PM +0530, Naresh Kamboju wrote:
> > On 14 June 2018 at 12:04, Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
> > wrote:
> > > On Wed, Jun 13, 2018 at 10:48:50PM -0300, Rafael Tinoco wrote:
> > >> On 13 June 2018 at 18:08, Rafael David Tinoco
> > >> <rafaeldtinoco@xxxxxxxxxxxxxx> wrote:
> > >> > 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:
> > >> >>>
> > >> >>>      https://github.com/linux-test-project/ltp/issues/341
> > >> >>>
> > >> >>>    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.
> > >>
> > >> To clarify this a bit further.
> > >>
> > >> The LTP CVE test is breaking in the first call to mmap(), even before
> > >> trying to remap and test the security issue. That start happening in
> > >> this round because of those mmap() changes and the offset used in the
> > >> LTP test. Linus changed limit checks and made them to be related to
> > >> MAX_LFS_FILESIZE. Unfortunately, in 4.4 stable, we were missing the
> > >> fix for MAX_LFS_FILESIZE (which before commit 0cc3b0ec23ce was less
> > >> than the REAL 32 bit limit).
> > >>
> > >> Commit 0cc3b0ec23ce was made because an user noticed the FS limit not
> > >> being what it should be. In our case, the 4.4 stable kernel, we are
> > >> facing this 32 bit lower limit (than the real 32 bit real limit),
> > >> because of the LTP CVE test, so we need this fix to have the real 32
> > >> bit limit set for that macro (mmap limits did not use that macro
> > >> before).
> > >>
> > >> I have tested in arm32 and Jan Stancek, who first responded to LTP
> > >> issue, has tested this in i686 and both worked after that patch was
> > >> included to v4.4-137-rc1 (my last test was even with 4.4.138-rc1).
> > >>
> > >> Hope that helps a bit.
> > >
> > > Ok, thanks, it didn't apply cleanly but I've fixed it up now.
> > 
> > On the latest 4.4.138-rc1,
> > LTP "cve-2011-2496" test still fails on arm32 beagleboard x15 and qemu_arm.
> > 
> > Summary
> > ------------------------------------------------------------------------
> > kernel: 4.4.138-rc1
> > git repo:
> > https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux-stable-rc.git
> > git branch: linux-4.4.y
> > git commit: 7d690c56754ef7be647fbcf7bcdceebd59926b3f
> > git describe: v4.4.137-15-g7d690c56754e
> > Test details:
> > https://qa-reports.linaro.org/lkft/linux-stable-rc-4.4-oe/build/v4.4.137-15-g7d690c56754e
> 
> Ok, but what does this mean?  Is there a commit somewhere that I need to
> pick up for 4.4.y that is already in newer kernels?

Hi Greg,

I think the expectations was that:
  0cc3b0ec23ce Clarify (and fix) MAX_LFS_FILESIZE macros
has been included to linux-4.4.y HEAD, so they re-ran the tests.

Report from Naresh above looks like original report: LTP vma03 is cve-2011-2496 test.

Regards,
Jan

> 
> I have no idea what that cve is
>, as I never track them, and it's
> something that was reported to predate the 4.4 kernel release :)
> 
> thanks,
> 
> greg k-h
> 
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