Re: [GIT PULL] Asymmetric keys and module signing

From: Josh Boyer
Date: Mon Oct 01 2012 - 16:55:13 EST


On Sat, Sep 29, 2012 at 08:13:25AM +0100, David Howells wrote:
> Rusty Russell <rusty@xxxxxxxxxxxxxxx> wrote:
>
> > [ 2.808075] Loading module verification certificates
> > [ 2.809331] X.509: Cert 6e03943da0f3b015ba6ed7f5e0cac4fe48680994 has expired
> > [ 2.810500] MODSIGN: Problem loading in-kernel X.509 certificate (-127)
>
> Hmmm... Other people have seen that.
>
> Ahhhhh!
>
> I wonder if the problem is that the certificate is valid for 100 years....
> That might well cause an overflow on a 32-bit system.

That does seem quite plausible. The comparisons are done with time_t,
which boils down to 'long' and 100 years in seconds would overflow
LONG_MAX.

> Could you try changing the '36500' in kernel/Makefile to something shorter,
> like 365?

I tried two values today. One close to LONG_MAX (24800 or ~68 years),
and 10 years (3650). The former still seemed to overflow, but
specifying a 10yr lifetime appears to have worked.

josh
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