Re: [PATCH net-next v11 07/23] ovpn: introduce the ovpn_socket object

[Sergey Ryazanov <ryazanov.s.a@xxxxxxxxx>]

On 19.11.2024 15:44, Antonio Quartulli wrote:
> On 15/11/2024 15:28, Antonio Quartulli wrote:
> [...]
> > > > +}
> > > > +
> > > > +static struct ovpn_socket *ovpn_socket_get(struct socket *sock)
> > > > +{
> > > > +    struct ovpn_socket *ovpn_sock;
> > > > +
> > > > +    rcu_read_lock();
> > > > +    ovpn_sock = rcu_dereference_sk_user_data(sock->sk);
> > > > +    if (!ovpn_socket_hold(ovpn_sock)) {
> > > > +        pr_warn("%s: found ovpn_socket with ref = 0\n", __func__);
> > >
> > > Should we be more specific here and print warning with 
> > > netdev_warn(ovpn_sock->ovpn->dev, ...)?
> >
> > ACK must be an unnoticed leftover
>
> I take this back.
> If refcounter is zero, I'd avoid accessing any field of the ovpn_sock 
> object, thus the pr_warn() without any reference to the device.

If it's such unlikely scenario, then should it be:

if (WARN_ON(!ovpn_socket_hold(ovpn_sock)))
    ovpn_sock = NULL;

?

--
Sergey