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Date:   Tue, 1 May 2018 20:56:04 -0400
From:   "Theodore Y. Ts'o" <tytso@mit.edu>
To:     Sultan Alsawaf <sultanxda@gmail.com>
Cc:     Justin Forbes <jmforbes@linuxtx.org>,
        Jeremy Cline <jeremy@jcline.org>, Pavel Machek <pavel@ucw.cz>,
        LKML <linux-kernel@vger.kernel.org>, Jann Horn <jannh@google.com>
Subject: Re: Linux messages full of `random: get_random_u32 called from`
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        Sultan Alsawaf <sultanxda@gmail.com>,
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        Jeremy Cline <jeremy@jcline.org>, Pavel Machek <pavel@ucw.cz>,
        LKML <linux-kernel@vger.kernel.org>, Jann Horn <jannh@google.com>
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On Tue, May 01, 2018 at 05:43:17PM -0700, Sultan Alsawaf wrote:
> 
> I've attached what I think is a reasonable stopgap solution until this is
> actually fixed. If you're willing to revert the CVE-2018-1108 patches
> completely, then I don't think you'll mind using this patch in the meantime.

I would put it slightly differently; reverting the CVE-2018-1108
patches is less dangerous than what you are proposing in your attached
patch.

Again, I think the right answer is to fix userspace to not require
cryptographic grade entropy during early system startup, and for
people to *think* about what they are doing.  I've looked at the
systemd's use of hmac in journal-authenticate, and as near as I can
tell, there isn't any kind of explanation about why it was necessary,
or what threat it was trying to protect against.

						- Ted