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From: Matthew Garrett <mjg59@google.com>
Date: Tue, 9 Oct 2018 14:32:15 -0700
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Subject: Re: Allow FUSE filesystems to provide out-of-band hashes to IMA
To: zohar@linux.ibm.com
Cc: linux-integrity <linux-integrity@vger.kernel.org>,
        Dmitry Kasatkin <dmitry.kasatkin@gmail.com>, miklos@szeredi.hu,
        linux-fsdevel@vger.kernel.org,
        Alexander Viro <viro@zeniv.linux.org.uk>,
        chuck.lever@oracle.com
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On Tue, Oct 9, 2018 at 1:52 PM Mimi Zohar <zohar@linux.ibm.com> wrote:
>
> > The performance hit is more noticeable over remote filesystems, but we
> > have large binaries that take several seconds to hash even on local
> > filesystems. Would it be helpful to try to define the assumptions that
> > IMA makes in terms of whether or not it produces trustworthy results?
> > It feels like it's be easier to talk about this if we have a more
> > formal set of conditions to take into consideration.
>
> [Cc'ing Chuck Lever]
>
> Integrity of files on remote filesystems should probably be discussed
> in the context of fs-verity, not FUSE filesystems.

Hm. We /could/ fake up fs-verity style behaviour, but we're not
talking about files that are expected to be immutable so it would seem
like there might be mismatched semantics there.

> Do you want to continue the discussion here or perhaps as an LSS-EU
> BoF?

This is something that's causing us pain at the moment, so if there's
any chance we can reach a resolution over the next couple of weeks
then I'd like to continue discussing it :)