linux-kernel - Re: [RFC 2/2] initramfs with digital signature protection

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]

Date:	Tue, 5 Feb 2013 23:55:09 +0200
From:	"Kasatkin, Dmitry" <dmitry.kasatkin@...el.com>
To:	Vivek Goyal <vgoyal@...hat.com>
Cc:	Matthew Garrett <mjg59@...f.ucam.org>,
	linux-security-module@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: Re: [RFC 2/2] initramfs with digital signature protection

On Tue, Feb 5, 2013 at 8:34 PM, Vivek Goyal <vgoyal@...hat.com> wrote:
> On Tue, Feb 05, 2013 at 06:19:26PM +0000, Matthew Garrett wrote:
>> On Tue, Feb 05, 2013 at 02:34:50PM +0200, Dmitry Kasatkin wrote:
>>
>> > Digitally signed initramfs can be used to provide protected user-space
>> > environment for initialization purpose. For example, LSM, IMA/EVM can be
>> > securely initialized using such approach.
>>
>> What stops an attacker from simply removing the signed image from the
>> initramfs and running modified versions of the same tools from the
>> unsigned image?
>
> Looks like having signed initramfs image is mandatory otherwise system
> panics.
>
> +       if (sys_access(initramfs_img, 0))
> +               panic("signed initramfs image not found (INITRAMFS_SIG is
> +anabled)\n");
>
> Also I am assuming that from signed initramfs, keys will be loaded in
> appropriate keyrings and then keyring will be locked so that any
> tools from unsigned initramfs can not load additional keys.
>

Exactly like that.


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