Re: [PATCHv6 2/6] cfg80211: check radar interface combinations

Luciano Coelho
2013-01-30T17:21:48Z

On Wed, 2013-01-30 at 17:56 +0100, Simon Wunderlich wrote:
> On Wed, Jan 30, 2013 at 06:34:48PM +0200, Luciano Coelho wrote:
> > > + switch (iftype) {
> > > + case NL80211_IFTYPE_ADHOC:
> > > + case NL80211_IFTYPE_AP:
> > > + case NL80211_IFTYPE_AP_VLAN:
> > > + case NL80211_IFTYPE_MESH_POINT:
> > > + case NL80211_IFTYPE_P2P_GO:
> > > + radar_required = !!(chan->flags & IEEE80211_CHAN_RADAR);
> > > + break;
> >
> > This code is causing an oops with the wl18xx driver in AP mode. The
> > problem is that cfg80211_can_change_interface() calls
> > cfg80211_can_use_iftype_chan() with chan == NULL. This code doesn't
> > check if chan is NULL, so this dereference causes the oops.
>
> Sorry about that - I believe you've found the same bug I've posted a patch
> for a few days ago. Johannes already has this in mac80211-next, but it is
> not yet in wireless-testing:
>
> http://article.gmane.org/gmane.linux.kernel.wireless.general/102836/match=simon
> http://git.kernel.org/?p=linux/kernel/git/jberg/mac80211-next.git;a=commit;h=683d41ae6755e6ae297ec09603c229795ab9566e

Ah, thanks. I should have read the list more carefully. :)

> > I don't have the time right now to fix this, but I'll look into it
> > tomorrow (unless someone comes with a fix before that :P).
>
> Please have a look at the patch posted above (both links for the same patch).

I'll apply that and try it out. Thanks for pointing it out so promptly!

--
Cheers,
Luca.