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Date: Thu, 12 Jul 2018 20:23:28 -0300
From: Ernesto =?utf-8?Q?A=2E_Fern=C3=A1ndez?=
        <ernesto.mnd.fernandez@gmail.com>
To: Andrew Morton <akpm@linux-foundation.org>
Cc: linux-fsdevel@vger.kernel.org, "Xu, Wen" <wen.xu@gatech.edu>
Subject: Re: [PATCH] hfsplus: fix NULL dereference in hfsplus_lookup()
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On Thu, Jul 12, 2018 at 04:19:07PM -0700, Andrew Morton wrote:
> On Thu, 12 Jul 2018 20:07:51 -0300 Ernesto A. Fernández <ernesto.mnd.fernandez@gmail.com> wrote:
> 
> > On Thu, Jul 12, 2018 at 03:33:11PM -0700, Andrew Morton wrote:
> > > On Thu, 12 Jul 2018 18:53:47 -0300 Ernesto A. Fernández <ernesto.mnd.fernandez@gmail.com> wrote:
> > > 
> > > > Check that the hidden directory is not NULL before using it, instead of
> > > > after.
> > > > 
> > > 
> > > Under what circumstances does the crash happen?  Mount of a corrupted fs?
> > 
> > No, when looking up corrupted catalog data (dentry) on a filesystem with
> > no metadata directory (this could only ever happen on a read-only mount).
> > Wen Xu sent the replication steps in detail to the fsdevel list, here is
> > a link:
> > 
> > https://bugzilla.kernel.org/show_bug.cgi?id=200297
> > 
> > I did not explain this because I think the diff makes it clear that there
> > is a bug at least.
> 
> It is important that we know what circumstances lead to the bug being
> triggered, so that people can decide whether to backport the fix into
> their various kernels.
> 

OK, I'll resend with more details.