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Date:   Wed, 23 Nov 2022 18:20:34 -0800
From:   Jakub Kicinski <kuba@kernel.org>
To:     Yang Yingliang <yangyingliang@huawei.com>
Cc:     Leon Romanovsky <leon@kernel.org>, <netdev@vger.kernel.org>,
        <jiri@nvidia.com>, <davem@davemloft.net>, <edumazet@google.com>,
        <pabeni@redhat.com>
Subject: Re: [PATCH net] net: devlink: fix UAF in
 devlink_compat_running_version()
Message-ID: <20221123182034.3914e03a@kernel.org>
In-Reply-To: <405f703b-b97e-afdd-8d5f-48b8f99d045d@huawei.com>
References: <20221122121048.776643-1-yangyingliang@huawei.com>
        <Y3zdaX1I0Y8rdSLn@unreal>
        <e311b567-8130-15de-8dbb-06878339c523@huawei.com>
        <Y30dPRzO045Od2FA@unreal>
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        <405f703b-b97e-afdd-8d5f-48b8f99d045d@huawei.com>
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On Wed, 23 Nov 2022 14:40:24 +0800 Yang Yingliang wrote:
> >   	if (err)
> > -		goto err_dl_unregister;
> > +		goto err_resource_unregister;
> >   	nsim_devlink_set_params_init_values(nsim_dev, devlink);
> >   
> > +	/* here, because params API still expect devlink to be unregistered */
> > +	devl_register(devlink);
> > +  
> devlink_set_features() called at last in probe() also needs devlink is 
> not registered.

You can move the devlink_set_features() up. It's also a leftover,
it was preventing reload from happening before probe has finished.
Now the instance is locked until probe is done so there is no race.