linux-kernel - Re: [PATCH] Revert "hwrng: core - zeroize buffers with random data"

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Message-ID: <CA+55aFwBdG42kk8J0t2tufHE=OUk4qWXEkFyySNgU3Ru2TA-tQ@mail.gmail.com>
Date:   Wed, 8 Feb 2017 17:57:23 -0800
From:   Linus Torvalds <torvalds@...ux-foundation.org>
To:     David Daney <david.daney@...ium.com>
Cc:     Linux Crypto Mailing List <linux-crypto@...r.kernel.org>,
        Matt Mackall <mpm@...enic.com>,
        Herbert Xu <herbert@...dor.apana.org.au>,
        Stephan Mueller <smueller@...onox.de>,
        Linux Kernel Mailing List <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH] Revert "hwrng: core - zeroize buffers with random data"

Stephan, Herbert? The zeroes in /dev/hwrng output are obviously
complete crap, so there's something badly wrong somewhere.

The locking, for example, is completely buggered. There's even a
comment about it, but that comment makes the correct observation of
"but y'know: randomness". But the memset() also being outside the lock
makes a complete joke of the whole thing.

Is the hwrng thing even worth maintaining? Compared to something like
/dev/urandom, it clearly does not do a very good job.

So I'm inclined to take the revert, but I'm also somewhat inclined to
simply mark this crud broken when we have other things that clearly do
a lot better.

              Linus

On Tue, Feb 7, 2017 at 4:23 PM, David Daney <david.daney@...ium.com> wrote:
> This reverts commit 2cc751545854d7bd7eedf4d7e377bb52e176cd07.