Re: [patch 0/7 v2] kexec kernel efi runtime support

From: Dave Young
Date: Sun Nov 10 2013 - 21:48:40 EST


On 11/10/13 at 06:21pm, H. Peter Anvin wrote:
> On 11/10/2013 06:13 PM, Dave Young wrote:
> >
> > Huang Ying <ying.huang@xxxxxxxxx> created the debugfs file for boot_params.
> > His first version patch tried sysfs, but sysfs is not designed for such
> > binary blobs so finally it go to debugfs.
> >
>
> That is a misunderstanding. Binary blobs can exist in sysfs as long as
> the blob is something that is inherently a blob. This is admittedly a
> corner case, but it is without any doubt a protocol-defined binary
> structure.

You are right. Greg objected that the whole structure being exported directly.

>
> The reason it was put in debugfs is that there was no non-debug user for
> it at the time.

Ok, I did not know this background.

>
> > Any idea for this is welcome, till now I have no better idea for such kind
> > of data. We should have another *fs instead of using debugfs.
>
> The problem with debugfs is that things go into debugfs with largely no
> auditing. As a result, mounting debugfs is very likely to mean that
> your system is exploitable one way or another.

Hmm, agree. Thanks for explaining about it.

Thanks
Dave
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