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Date:   Thu, 27 Jun 2019 11:23:50 -0400
From:   "J. Bruce Fields" <bfields@fieldses.org>
To:     Kees Cook <keescook@chromium.org>
Cc:     linux-nfs@vger.kernel.org, linux-kernel@vger.kernel.org,
        Rasmus Villemoes <linux@rasmusvillemoes.dk>
Subject: Re: [PATCH 08/16] nfsd: escape high characters in binary data
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On Wed, Jun 26, 2019 at 09:16:44PM -0700, Kees Cook wrote:
> Right -- any they're almost all logged surrounded by ' or " which means
> those would need to be escaped as well. The prism2 is leaking newlines
> too, as well as the thunderbolt sysfs printing.
> 
> So... seems like we should fix this. :P
...
> I think we need to make the default produce "loggable" output.
> non-ascii, non-printables, \, ', and " need to be escaped. Maybe " "
> too?

OK, so I think the first step is to take a closer look at the users of
the default %*pE.  If there are any that look like they'd be broken by a
change, we should make patches moving to something else, then we can
change the default.

Then we can also replace ESCAPE_ANY and ESCAPE_NP--that "don't escape
printable" logic is confusing and makes it hard to add more types of
escaping.  And it appears to only be used by %*pE.

--b