Re: [PATCH v1 2/5] connector/cn_proc: Add filtering to fix some bugs

[Anjali Kulkarni <anjali.k.kulkarni@oracle.com>]

________________________________________
From: Christian Brauner <brauner@kernel.org>
Sent: Tuesday, March 14, 2023 1:38 AM
To: Jakub Kicinski
Cc: Anjali Kulkarni; davem@davemloft.net; edumazet@google.com; pabeni@redhat.com; zbr@ioremap.net; johannes@sipsolutions.net; ecree.xilinx@gmail.com; leon@kernel.org; keescook@chromium.org; socketcan@hartkopp.net; petrm@nvidia.com; linux-kernel@vger.kernel.org; netdev@vger.kernel.org
Subject: Re: [PATCH v1 2/5] connector/cn_proc: Add filtering to fix some bugs

On Mon, Mar 13, 2023 at 05:24:41PM -0700, Jakub Kicinski wrote:
> On Fri, 10 Mar 2023 14:15:44 -0800 Anjali Kulkarni wrote:
> > diff --git a/include/linux/connector.h b/include/linux/connector.h
> > index 487350bb19c3..1336a5e7dd2f 100644
> > --- a/include/linux/connector.h
> > +++ b/include/linux/connector.h
> > @@ -96,7 +96,11 @@ void cn_del_callback(const struct cb_id *id);
> >   *
> >   * If there are no listeners for given group %-ESRCH can be returned.
> >   */
> > -int cn_netlink_send_mult(struct cn_msg *msg, u16 len, u32 portid, u32 group, gfp_t gfp_mask);
> > +int cn_netlink_send_mult(struct cn_msg *msg, u16 len, u32 portid,
> > +                    u32 group, gfp_t gfp_mask,
> > +                    int (*filter)(struct sock *dsk, struct sk_buff *skb,
> > +                                  void *data),
> > +                    void *filter_data);
>
> kdoc needs to be extended

just a thought from my side. I think giving access to unprivileged users
will require a little thought as that's potentially sensitive.

If possible I would think that the patches that don't lead to a
behavioral change should go in completely independently and then we can
discuss the non-root access change.
ANJALI> That sounds fine. I can send the non-root change as the last patch 
in the series. I can also add a change to allow the sensitive content only if
the user ID or parent ID matches etc. I know the exit status needs more
discussion..