Re: [PATCH v2] Backport xfs security fix to 4.9 and 4.4 stable trees

[Siddharth Chandrasekaran <siddharth@embedjournal.com>]

On Fri, May 15, 2020 at 05:22:30PM +0200, Greg KH wrote:
> On Fri, May 15, 2020 at 08:41:07PM +0530, Siddharth Chandrasekaran wrote:
> > Hello,
> > 
> > Lack of proper validation that cached inodes are free during allocation can,
> > cause a crash in fs/xfs/xfs_icache.c (refer: CVE-2018-13093). To address this
> > issue, I'm backporting upstream commit [1] to 4.4 and 4.9 stable trees
> > (a backport of [1] to 4.14 already exists).
> > 
> > Also, commit [1] references another commit [2] which added checks only to
> > xfs_iget_cache_miss(). In this patch, those checks have been moved into a
> > dedicated checker method and both xfs_iget_cache_miss() and
> > xfs_iget_cache_hit() are made to call that method. This code reorg in commit
> > [1], makes commit [2] redundant in the history of the 4.9 and 4.4 stable
> > trees. So commit [2] is not being backported.
> > 
> > -- Sid
> > 
> > [1]: afca6c5b2595 ("xfs: validate cached inodes are free when allocated")
> > [2]: ee457001ed6c ("xfs: catch inode allocation state mismatch corruption")
> > 
> > change log:
> > v2:
> >  - Reword cover letter.
> >  - Fix accidental worong patch that got mailed.
> 
> As the XFS maintainers want to see xfstests pass with any changes made,
> have you done so for the 4.9 and 4.4 trees with this patch applied?

I haven't run them yet. I'll do so and get back with the results
shortly.

-- Sid.