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From:   Kees Cook <keescook@chromium.org>
Date:   Thu, 11 Apr 2019 13:36:37 -0700
Message-ID: <CAGXu5jJo0jXhB5Xy0fryrYPy7zN2RhSsMb0r0DPQ91dNR0zPCA@mail.gmail.com>
Subject: Re: crypto: Kernel memory overwrite attempt detected to spans
 multiple pages
To:     Eric Biggers <ebiggers@kernel.org>
Cc:     Dmitry Vyukov <dvyukov@google.com>,
        Geert Uytterhoeven <geert@linux-m68k.org>,
        Herbert Xu <herbert@gondor.apana.org.au>,
        linux-security-module <linux-security-module@vger.kernel.org>,
        Linux ARM <linux-arm-kernel@lists.infradead.org>,
        Linux Crypto Mailing List <linux-crypto@vger.kernel.org>,
        Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
        Laura Abbott <labbott@redhat.com>,
        Rik van Riel <riel@surriel.com>
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On Thu, Apr 11, 2019 at 12:26 PM Eric Biggers <ebiggers@kernel.org> wrote:
> Well, I guess I'll just add __GFP_COMP so I at least don't get spammed with
> useless bug reports.

Thanks, I appreciate it.

> But I don't think it's in any way acceptable to change the semantics of the
> kernel's page allocator but only under some obscure config option, don't
> document it anywhere, ignore the known problems for years, say that the option
> is broken anyway so it shouldn't be used, and have to exchange 15 emails to get
> anything resembling an explanation.

I understand what you mean, yeah. I'm sorry I wasn't clear about it
earlier. What do you think might help the situation as far as
documentation?

-- 
Kees Cook