From: "Jérémy Jean" <jeremy.jean@oss.cyber.gouv.fr>
To: Alexei Starovoitov <alexei.starovoitov@gmail.com>
Cc: Daniel Borkmann <daniel@iogearbox.net>,
Andrii Nakryiko <andrii@kernel.org>,
Eduard Zingerman <eddyz87@gmail.com>,
Kumar Kartikeya Dwivedi <memxor@gmail.com>,
bpf@vger.kernel.org, linux-kernel@vger.kernel.org,
stable@vger.kernel.org
Subject: Re: [PATCH] bpf: netns: require CAP_NET_ADMIN for link targets
Date: Mon, 02 Nov 2026 23:35:03 +0100 [thread overview]
Message-ID: <d984ed03fbd7b6c12b88f1a18d7762f6@oss.cyber.gouv.fr> (raw)
In-Reply-To: <DML2GFI6LWXU.3ODKDXNQDBYYA@gmail.com>
On 2026-11-02 23:08, Alexei Starovoitov wrote:
> On Mon, Nov 02, 2026 at 12:29 PM Jérémy Jean
> <Jeremy.Jean@oss.cyber.gouv.fr> wrote:
>> BPF tokens allow a process to load BPF programs using CAP_NET_ADMIN in
>> a userns, however, netns_bpf_link_create() does not check for
>> CAP_NET_ADMIN in the target netns. Consequently, a token can be used
>> to attach a BPF program to a netns it does not control.
>
> That's not a gap. The prog FD and the netns FD are the permission.
>
> pw-bot: cr
Thanks for the reply, yet I feel that I misunderstood something.
At first, it seemed to me that there was a security boundary issue,
but digging more with your feedback and Sashiko's one, I believe I was
wrong,
that there is no issue and that this patch should instead simply be
dropped.
Am I right? Or do you believe that there are still things to fix?
Regards,
Jérémy
prev parent reply other threads:[~2026-11-02 22:35 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-11-02 20:29 Jérémy Jean
2026-11-02 20:53 ` bot+bpf-ci
2026-11-02 22:08 ` Alexei Starovoitov
2026-11-02 22:35 ` Jérémy Jean [this message]
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