linux-kernel - Re: Linux messages full of `random: get_random

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <20180502162653.GB3461@thunk.org>
Date:   Wed, 2 May 2018 12:26:53 -0400
From:   "Theodore Y. Ts'o" <tytso@....edu>
To:     Justin Forbes <jmforbes@...uxtx.org>
Cc:     Jeremy Cline <jeremy@...ine.org>,
        Sultan Alsawaf <sultanxda@...il.com>,
        Pavel Machek <pavel@....cz>,
        LKML <linux-kernel@...r.kernel.org>, Jann Horn <jannh@...gle.com>
Subject: Re: Linux messages full of `random: get_random_u32 called from`

On Wed, May 02, 2018 at 07:09:11AM -0500, Justin Forbes wrote:
> Yes, Fedora libgcrypt is carrying a patch which makes it particularly
> painful for us, we have reached out to the libgcrypt maintainer to
> follow up on that end. But as I said before, even without that code
> path (no dracut-fips) we are seeing some instances of 4 minute boots.
> This is not really a workable user experience.  And are you sure that
> every cloud platform and VM platform offers, makes it possible to
> config virtio-rng?

Unfortunately, the answer is no.  Google Compute Engine, alas, does
not currently support virtio-rng.  With my Google hat on, I can't
comment on future product features.  With my upstream developer hat
on, I'll give you three guesses what I have been advocating and
pushing for internally, and the first two don't count.  :-)

That being said, I just booted a Debian 9 (Stable, aka Stretch)
standard kernel, and then installed 4.17-rc3 (which has the
CVE-2018-1108 patches).  The crng_init=2 message doesn't appear
immediately, and it does appear quite a bit later comapred to
the standard 4.9.0-6-amd64 Debian 9 kernel.  However, the lack of a
fully initialized random pool doesn't prevent the standard Debian 9
image from booting:

May  2 15:33:42 localhost kernel: [    0.000000] Linux version 4.17.0-rc3-xfstests (tytso@...c) (gcc version 7.3.0 (Debian 7.3.0-16)) #169 SMP Wed May 2 11:28:17 EDT 2018
May  2 15:33:42 localhost kernel: [    1.456883] random: fast init done
May  2 15:33:46 rng-testing systemd[1]: Startup finished in 3.202s (kernel) + 5.963s (userspace) = 9.166s.
May  2 15:33:46 rng-testing google-accounts: INFO Starting Google Accounts daemon.
May  2 15:44:39 rng-testing kernel: [  661.436664] random: crng init done

So it really does appear to be something going on with Fedora's
userspace; can you help try to track down what it is?

Thanks,

						- Ted