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Date:   Thu, 18 May 2023 13:11:58 -0400
Message-ID: <2a3b77fc369dd3b3e611db00c992060d.paul@paul-moore.com>
From:   Paul Moore <paul@paul-moore.com>
To:     Matthieu Baerts <matthieu.baerts@tessares.net>,
        James Morris <jmorris@namei.org>,
        "Serge E. Hallyn" <serge@hallyn.com>,
        Stephen Smalley <stephen.smalley.work@gmail.com>,
        Eric Paris <eparis@parisplace.org>
Cc:     Paolo Abeni <pabeni@redhat.com>,
        "David S. Miller" <davem@davemloft.net>,
        Eric Dumazet <edumazet@google.com>,
        Jakub Kicinski <kuba@kernel.org>,
        Ondrej Mosnacek <omosnace@redhat.com>, mptcp@lists.linux.dev,
        linux-kernel@vger.kernel.org, netdev@vger.kernel.org,
        linux-security-module@vger.kernel.org, selinux@vger.kernel.org,
        Matthieu Baerts <matthieu.baerts@tessares.net>
Subject: Re: [PATCH v2 1/2] security, lsm: Introduce  security_mptcp_add_subflow()
References: <20230419-upstream-lsm-next-20230419-mptcp-sublows-user-ctx-v2-1-e7a3c8c15676@tessares.net>
In-Reply-To: <20230419-upstream-lsm-next-20230419-mptcp-sublows-user-ctx-v2-1-e7a3c8c15676@tessares.net>
Precedence: bulk

On Apr 20, 2023 Matthieu Baerts <matthieu.baerts@tessares.net> wrote:
> 
> MPTCP can create subflows in kernel context, and later indirectly
> expose them to user-space, via the owning MPTCP socket.
> 
> As discussed in the reported link, the above causes unexpected failures
> for server, MPTCP-enabled applications.
> 
> Let's introduce a new LSM hook to allow the security module to relabel
> the subflow according to the owning user-space process, via the MPTCP
> socket owning the subflow.
> 
> Note that the new hook requires both the MPTCP socket and the new
> subflow. This could allow future extensions, e.g. explicitly validating
> the MPTCP <-> subflow linkage.
> 
> Link: https://lore.kernel.org/mptcp/CAHC9VhTNh-YwiyTds=P1e3rixEDqbRTFj22bpya=+qJqfcaMfg@mail.gmail.com/
> Signed-off-by: Paolo Abeni <pabeni@redhat.com>
> Acked-by: Matthieu Baerts <matthieu.baerts@tessares.net>
> Signed-off-by: Matthieu Baerts <matthieu.baerts@tessares.net>
> ---
> v2:
>  - Address Paul's comments:
>    - clarification around "the owning process" in the commit message
>    - making it clear the hook has to be called after the sk init part
>    - consistent capitalization of "MPTCP"
> ---
>  include/linux/lsm_hook_defs.h |  1 +
>  include/linux/security.h      |  6 ++++++
>  net/mptcp/subflow.c           |  6 ++++++
>  security/security.c           | 17 +++++++++++++++++
>  4 files changed, 30 insertions(+)

This looks good to me, merged into selinux/next - thank you for all
the work that went into this!

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