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Date:   Sun, 23 Jul 2023 06:02:16 -0400
From:   "Michael S. Tsirkin" <mst@redhat.com>
To:     Lin Ma <linma@zju.edu.cn>
Cc:     jasowang@redhat.com, xuanzhuo@linux.alibaba.com,
        virtualization@lists.linux-foundation.org,
        linux-kernel@vger.kernel.org, Parav Pandit <parav@nvidia.com>,
        Eli Cohen <elic@nvidia.com>
Subject: Re: [PATCH v1] vdpa: Complement vdpa_nl_policy for nlattr length
 check
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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 is 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 = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_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.

-- 
MST