netdev - Re: [PATCH v2 bpf-next 1/4] bpf: unprivileged BPF access via /dev/bpf

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Message-ID: <CACAyw9-YdqBYP7_vzDVH_AQ6Ko71XrDb5-+ZxkASMw-eHJa05A@mail.gmail.com>
Date:   Tue, 23 Jul 2019 11:45:45 +0100
From:   Lorenz Bauer <lmb@...udflare.com>
To:     Song Liu <songliubraving@...com>
Cc:     Andy Lutomirski <luto@...nel.org>,
        Kees Cook <keescook@...omium.org>,
        "linux-security@...r.kernel.org" <linux-security@...r.kernel.org>,
        Networking <netdev@...r.kernel.org>, bpf <bpf@...r.kernel.org>,
        Alexei Starovoitov <ast@...nel.org>,
        Daniel Borkmann <daniel@...earbox.net>,
        Kernel Team <Kernel-team@...com>, Jann Horn <jannh@...gle.com>,
        Greg KH <gregkh@...uxfoundation.org>,
        Linux API <linux-api@...r.kernel.org>
Subject: Re: [PATCH v2 bpf-next 1/4] bpf: unprivileged BPF access via /dev/bpf

On Mon, 22 Jul 2019 at 21:54, Song Liu <songliubraving@...com> wrote:
>
> Hi Andy, Lorenz, and all,
>
> With 5.3-rc1 out, I am back on this. :)
>
> How about we modify the set as:
>   1. Introduce sys_bpf_with_cap() that takes fd of /dev/bpf.
>   2. Better handling of capable() calls through bpf code. I guess the
>      biggest problem here is is_priv in verifier.c:bpf_check().
>
> With this approach, we will be able to pass the fd around, so it should
> also solve problem for Go.

Thanks for picking this up again. I need to figure out what the API
for this would
look like on the Go side, but I think it's a nice solution!

Lorenz

-- 
Lorenz Bauer  |  Systems Engineer
6th Floor, County Hall/The Riverside Building, SE1 7PB, UK

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