Subject: Re: [PATCH net-next v2 1/2] hisilicon net: removes the once HANDEL_TX_MSG macro

From: Joe Perches <[email-masked]>
Date: Mon, 12 Oct 2015 09:12:54 -0700

On Mon, 2015-10-12 at 13:59 +0200, Arnd Bergmann wrote:
> On Monday 12 October 2015 11:23:44 huangdaode wrote:
> > +                       s += sprintf(s,
> > +                                   "\t\ttx_ring on %p:%u,%u,%u,%u,%u,%llu,%llu\n",
> > +                                   h->qs[i]->tx_ring.io_base,
[]
> There is actually a more significant problem with this code, which I
> failed to notice when doing the original bugfix: 
> 
> You have a sysfs interface here that exports internal data of the
> device that should not be visible like this. One problem is that
> the io_base is a kernel pointer that must not be visible to non-root
> users (so we don't easily create an attack surface for exploits).

Using %pK might have been appropriate.

> It would probably be better to completely remove that sysfs interface, and
> to use the ethtool netlink interface to export them.

But this would be better.