Re: [PATCH 4/4] xfs: validate v5 feature fields

Dave Chinner
2022-05-03T23:19:05Z

On Tue, May 03, 2022 at 03:59:18PM -0700, Darrick J. Wong wrote:
> On Mon, May 02, 2022 at 06:20:18PM +1000, Dave Chinner wrote:
> > From: Dave Chinner <dchinner@redhat.com>
> >
> > Because stupid dumb fuzzers.
>
> Dumb question: Should we make db_flds[] in db/sb.c (userspace) report
> each individual feature flag as a field_t?

Maybe, but we do already have the versionnum command that dumps the
feature bits in text/human readable format....

> I've been wondering why none
> of my fuzz tests ever found these problems, and it's probably because
> it never hit the magic bits that $scriptkiddie happened to hit.

Yeah, you've probably never cleared just the dirv2 bit. That one has
an assert on it these days because the kernel only supports v2-based
directory formats. In other cases, things still work but we
probably don't do the right thing for v5 formats :)

Cheers,

Dave.
--
Dave Chinner
david@fromorbit.com