Re: [PATCH 0/10] Add additional security checks when module loadingis restricted

[Lenny Szubowicz]

----- Original Message -----
> From: "Matthew Garrett" <matthew.garrett@xxxxxxxxxx>
> To: "Lenny Szubowicz" <lszubowi@xxxxxxxxxx>
> Cc: linux-kernel@xxxxxxxxxxxxxxx, linux-efi@xxxxxxxxxxxxxxx, jwboyer@xxxxxxxxxx, keescook@xxxxxxxxxxxx
> Sent: Wednesday, August 28, 2013 6:41:55 PM
> Subject: Re: [PATCH 0/10] Add additional security checks when module loading is restricted
> 
> On Wed, 2013-08-28 at 18:37 -0400, Lenny Szubowicz wrote:
> 
> > Did you purposely exclude similar checks for hibernate that were covered
> > by earlier versions of your patch set?
> 
> Yes, I think it's worth tying it in with the encrypted hibernation
> support. The local attack is significantly harder in the hibernation
> case - in the face of unknown hardware it basically involves a
> pre-generated memory image corresponding to your system or the ability
> to force a reboot into an untrusted environment. I think it's probably
> more workable to just add a configuration option for forcing encrypted
> hibernation when secure boot is in use.
> 
> --
> Matthew Garrett <matthew.garrett@xxxxxxxxxx>

I'm root. So I can write anything I want to the swap file that looks
like a valid hibernate image but is code of my choosing. I can read
anything I need from /dev/mem or /dev/kmem to help me do that.
I can then immediately initiate a reboot.

                               -Lenny.
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/