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From: Jonathan Corbet <corbet@lwn.net>
To: Petr =?utf-8?B?VGVzYcWZw61r?= <petr@tesarici.cz>, Dave Hansen
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Subject: Re: [RFC 0/8] PGP key parser using SandBox Mode
In-Reply-To: <20240216170805.0d0decd5@meshulam.tesarici.cz>
References: <fb4a40c7-af9a-406a-95ab-406595f3ffe5@intel.com>
 <20240216152435.1575-1-petrtesarik@huaweicloud.com>
 <c65eb8f1-2903-4043-a3ab-945d880043b5@intel.com>
 <20240216170805.0d0decd5@meshulam.tesarici.cz>
Date: Fri, 16 Feb 2024 10:21:43 -0700
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Petr Tesa=C5=99=C3=ADk <petr@tesarici.cz> writes:

> On Fri, 16 Feb 2024 07:38:30 -0800
> Dave Hansen <dave.hansen@intel.com> wrote:
>> I'm confused by this.  The kernel doesn't (appear to) have a PGP parser
>> today.  So are you saying that it *should* have one and it's only
>> feasible if its confined in a sandbox?
>
> I'm sorry if this is confusing. Yes, your understanding is correct.
> This patch series demonstrates that SBM (even in the initial version
> that was submitted) allows to write a PGP parser which can survive
> memory safety bugs withoug compromising the rest of the kernel.

So I have a different question: some years ago we added the "usermode
blob" feature for just this kind of use case - parsing firewall rules at
the time.  It has never been used for that, but it's still there in
kernel/usermode_driver.c.  Is there a reason why this existing
functionality can't be used for tasks like PGP parsing as well?

Thanks,

jon