From: Christian Brauner <christian.brauner@ubuntu.com>
To: Lorenz Bauer <lmb@cloudflare.com>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>,
"David S. Miller" <davem@davemloft.net>,
Jakub Kicinski <kuba@kernel.org>,
Alexei Starovoitov <ast@kernel.org>,
Daniel Borkmann <daniel@iogearbox.net>,
Andrii Nakryiko <andrii@kernel.org>,
kernel-team <kernel-team@cloudflare.com>,
Linux API <linux-api@vger.kernel.org>,
linux-fsdevel@vger.kernel.org,
LKML <linux-kernel@vger.kernel.org>,
Networking <netdev@vger.kernel.org>, bpf <bpf@vger.kernel.org>
Subject: Re: [PATCH bpf 2/4] nsfs: add an ioctl to discover the network namespace cookie
Date: Tue, 2 Mar 2021 11:14:04 +0100 [thread overview]
Message-ID: <20210302101404.ns3t7oow4a565l7a@wittgenstein> (raw)
In-Reply-To: <CACAyw9_P0o36edN9RiimJBQqBupMWwvq746+Mp1_a=YO3ctfgw@mail.gmail.com>
On Tue, Mar 02, 2021 at 09:47:10AM +0000, Lorenz Bauer wrote:
> On Mon, 1 Mar 2021 at 10:04, Christian Brauner
> <christian.brauner@ubuntu.com> wrote:
> >
> > Hey Lorenz,
> >
> > Just to make sure: is it intentional that any user can retrieve the
> > cookie associated with any network namespace, i.e. you don't require any
> > form of permission checking in the owning user namespace of the network
> > namespace?
> >
> > Christian
>
> Hi Christian,
>
> I've decided to drop the patch set for now, but that was my intention, yes. Is
> there a downside I'm not aware of?
It depends on whether this cookie is in any way security or at least
information sensitive. For example, would leaking it between
unprivileged containers with different user+network namespace pairs
allow one container to gain access to information about the other
container that it shouldn't.
Christian
prev parent reply other threads:[~2021-03-02 12:06 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-02-10 12:04 [PATCH bpf 0/4] Expose network namespace cookies to user space Lorenz Bauer
2021-02-10 12:04 ` [PATCH bpf 2/4] nsfs: add an ioctl to discover the network namespace cookie Lorenz Bauer
2021-03-01 10:04 ` Christian Brauner
2021-03-02 9:47 ` Lorenz Bauer
2021-03-02 10:14 ` Christian Brauner [this message]
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