Re: [PATCH] syscalls: Document OCI seccomp filter interactions & workaround

From: Florian Weimer <fweimer@redhat.com>
To: Christoph Hellwig <hch@infradead.org>
Cc: linux-api@vger.kernel.org, linux-doc@vger.kernel.org,
	linux-kernel@vger.kernel.org, dev@opencontainers.org,
	corbet@lwn.net, Carlos O'Donell <carlos@redhat.com>
Subject: Re: [PATCH] syscalls: Document OCI seccomp filter interactions & workaround
Date: Tue, 24 Nov 2020 15:08:09 +0100	[thread overview]
Message-ID: <87k0ua26gm.fsf@oldenburg2.str.redhat.com> (raw)
In-Reply-To: <20201124133719.GA30896@infradead.org> (Christoph Hellwig's message of "Tue, 24 Nov 2020 13:37:19 +0000")

* Christoph Hellwig:

> On Tue, Nov 24, 2020 at 01:08:20PM +0100, Florian Weimer wrote:
>> This documents a way to safely use new security-related system calls
>> while preserving compatibility with container runtimes that require
>> insecure emulation (because they filter the system call by default).
>> Admittedly, it is somewhat hackish, but it can be implemented by
>> userspace today, for existing system calls such as faccessat2,
>> without kernel or container runtime changes.
>
> I think this is completely insane.  Tell the OCI folks to fix their
> completely broken specification instead.

Do you categorically reject the general advice, or specific instances as
well?  Like this workaround for faccessat that follows the pattern I
outlined:

<https://sourceware.org/pipermail/libc-alpha/2020-November/119955.html>

I value your feedback and want to make sure I capture it accurately.

Thanks,
Florian
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