Re: [PATCH v1] vdpa: Complement vdpa_nl_policy for nlattr length check

Michael S. Tsirkin
2023-07-23T10:03:06Z

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