Re: [PATCH 05/12] usb: feed USB device information to the /dev/random driver

Hi,

Theodore Ts'o wrote:

On Fri, Jul 06, 2012 at 06:02:18PM -0500, Jonathan Nieder wrote:

quoted

Why cc: stable@?  Does this fix a build error, oops, hang, data
corruption, real security issue, or other critical "oh, that's not
good" bug?

All of the /dev/random patches in this patch series that were marked
for the stable backports are to address a security issue.  See:
https://factorable.net/

Thanks for explaining.  If there's occasion for a reroll (I'm guessing
there won't be) then it would be nice to mention this in the commit
messages.

[...]

While these patches are designed to do as much as we can without
assuming any fixes in userspace, and the weak kea vulnerabilities are
much more obviously detectable in embedded devices with close to zero
available entropy, ideally there are improvements that can and should
be done in upstream userspace packages as well as in the packaging and
installation scripts for more general-purpose server and workstation
distributions.

For example, ssh key generation should happen as late as possible;
ideally, some time *after* the networking has been brought up.

[...]

              The same is true for the generation of remote
administration keys for ntpd and bind.

Very much agreed.  These patches look like an improvement but on
diskless systems without a hardware RNG it still seems possible for
someone with knowledge of the hardware configuration to predict the
generator state.

Except that patch 2 improves matters a lot.

Thanks for your work and kindness,
Jonathan