From: John Stultz <john.stultz@linaro.org>
To: "Maciej Żenczykowski" <zenczykowski@gmail.com>
Cc: Alexei Starovoitov <alexei.starovoitov@gmail.com>,
BPF Mailing List <bpf@vger.kernel.org>,
Alexei Starovoitov <ast@kernel.org>,
Daniel Borkmann <daniel@iogearbox.net>,
Amit Pundir <amit.pundir@linaro.org>
Subject: Re: capable_bpf_net_admin()
Date: Thu, 18 Jun 2020 12:03:32 -0700 [thread overview]
Message-ID: <CALAqxLXgnqSM16=a3O1NyqYae1n_rMyw4_hcx5APm9s-h3TBtQ@mail.gmail.com> (raw)
In-Reply-To: <CAHo-Ooz4smKgTDTit4NAnaasUDLJLkX7iRcYouv4KY=AG5SUaA@mail.gmail.com>
On Thu, Jun 18, 2020 at 3:20 AM Maciej Żenczykowski
<zenczykowski@gmail.com> wrote:
>
> John has all the details. I'm just guessing.
>
> But having actually looked at the code, commit 2c78ee898d8f1 ie.
>
> kernel/bpf/syscall.c: bpf_prog_load()
> + if (is_net_admin_prog_type(type) && !capable(CAP_NET_ADMIN))
> + return -EPERM;
>
> looks fishy, since our bpfloader only has CHOWN SYS_ADMIN, and the
> maps/programs it creates/loads are used by netd which only has
> NET_ADMIN (but not SYS_ADMIN). Furthermore I don't really want to
> grant it NET_ADMIN.
>
> I think this should again be either NET_ADMIN or SYS_ADMIN.
Just to confirm, reverting 2c78ee898d8f1 (which doesn't revert
perfectly cleanly) seems to avoid the failure I was seeing.
And specifically in the chunk Maciej pointed out above, if we just
switch the check to CAP_SYS_ADMIN it also avoids the problem.
Let me know if there is anything folks would like me to test!
thanks
-john
next prev parent reply other threads:[~2020-06-18 19:03 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-06-18 6:43 capable_bpf_net_admin() Maciej Żenczykowski
2020-06-18 7:01 ` capable_bpf_net_admin() Alexei Starovoitov
2020-06-18 10:19 ` capable_bpf_net_admin() Maciej Żenczykowski
2020-06-18 19:03 ` John Stultz [this message]
2020-06-18 19:21 ` capable_bpf_net_admin() Maciej Żenczykowski
2020-06-18 19:59 ` [PATCH] restore behaviour of CAP_SYS_ADMIN allowing the loading of net bpf program Maciej Żenczykowski
2020-06-18 21:02 ` Alexei Starovoitov
2020-06-20 21:26 ` [PATCH bpf v2] restore behaviour of CAP_SYS_ADMIN allowing the loading of networking bpf programs Maciej Żenczykowski
2020-06-22 19:44 ` John Stultz
2020-06-24 0:54 ` Alexei Starovoitov
2020-07-06 20:11 ` John Stultz
2020-07-06 20:15 ` Daniel Borkmann
2020-07-06 20:36 ` John Stultz
2020-06-20 1:59 ` capable_bpf_net_admin() John Stultz
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