Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20;
MIME-Version: 1.0
References: <20230723080507.3716924-1-linma@zju.edu.cn> <20230723050656-mutt-send-email-mst@kernel.org>
 <729f5c17.e4079.18982192866.Coremail.linma@zju.edu.cn> <8ecec51.e40ad.1898226c545.Coremail.linma@zju.edu.cn>
 <20230723055820-mutt-send-email-mst@kernel.org>
In-Reply-To: <20230723055820-mutt-send-email-mst@kernel.org>
From:   Jason Wang <jasowang@redhat.com>
Date:   Mon, 24 Jul 2023 15:11:55 +0800
Message-ID: <CACGkMEuGHMu6te3jRfEhhwTrWR1mpqp3hbVhDKQiXK9tgwz3qw@mail.gmail.com>
Subject: Re: [PATCH v1] vdpa: Complement vdpa_nl_policy for nlattr length check
To:     "Michael S. Tsirkin" <mst@redhat.com>
Cc:     Lin Ma <linma@zju.edu.cn>, xuanzhuo@linux.alibaba.com,
        virtualization@lists.linux-foundation.org,
        linux-kernel@vger.kernel.org, Parav Pandit <parav@nvidia.com>,
        Eli Cohen <elic@nvidia.com>,
        Dragos Tatulea <dtatulea@nvidia.com>
Content-Type: text/plain; charset="UTF-8"
Content-Transfer-Encoding: quoted-printable
Precedence: bulk

On Sun, Jul 23, 2023 at 6:02=E2=80=AFPM Michael S. Tsirkin <mst@redhat.com>=
 wrote:
>
> On Sun, Jul 23, 2023 at 05:48:46PM +0800, Lin Ma wrote:
> >
> > > Sure, that is another undergoing task I'm working on. If the nlattr i=
s parsed with
> > > NL_VALIDATE_UNSPEC, any forgotten nlattr will be rejected, therefore =
(which is the default
> > > for modern nla_parse).
> >
> > For the general netlink interface, the deciding flag should be genl_ops=
.validate defined in
> > each ops. The default validate flag is strict, while the developer can =
overwrite the flag
> > with GENL_DONT_VALIDATE_STRICT to ease the validation. That is to say, =
safer code should
> > enforce NL_VALIDATE_STRICT by not overwriting the validate flag.
> >
> > Regrads
> > Lin
>
>
> Oh I see.
>
> It started here:
>
> commit 33b347503f014ebf76257327cbc7001c6b721956
> Author: Parav Pandit <parav@nvidia.com>
> Date:   Tue Jan 5 12:32:00 2021 +0200
>
>     vdpa: Define vdpa mgmt device, ops and a netlink interface
>
> which did:
>
> +               .validate =3D GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALID=
ATE_DUMP,
>
>
> which was most likely just a copy paste from somewhere, right Parav?
>
> and then everyone kept copying this around.
>
> Parav, Eli can we drop these? There's a tiny chance of breaking something
> but I feel there aren't that many users outside mlx5 yet, so if you
> guys can test on mlx5 and confirm no breakage, I think we are good.

Adding Dragos.

Thanks

>
> --
> MST
>