Re: [PATCH] nl80211: Reject disconnect commands except from conn_owner

[Johannes Berg <johannes@sipsolutions.net>]

On Tue, 2018-05-08 at 14:18 +0200, Arend van Spriel wrote:
> On 5/7/2018 9:19 PM, Johannes Berg wrote:
> > On Sun, 2018-04-29 at 20:30 +0200, Andrew Zaborowski wrote:
> > > On 28 April 2018 at 15:07, Kalle Valo <kvalo@codeaurora.org> wrote:
> > > > Andrew Zaborowski <andrew.zaborowski@intel.com> writes:
> > > > > Reject NL80211_CMD_DISCONNECT, NL80211_CMD_DISASSOCIATE,
> > > > > NL80211_CMD_DEAUTHENTICATE and NL80211_CMD_ASSOCIATE commands
> > > > > from clients other than the connection owner set in the connect,
> > > > > authenticate or associate commands, if it was set.
> > > > > 
> > > > > The main point of this check is to prevent chaos when two processes
> > > > > try to use nl80211 at the same time, it's not a security measure.
> > > > > The same thing should possibly be done for JOIN_IBSS/LEAVE_IBSS and
> > > > > START_AP/STOP_AP.
> > > > 
> > > > s-o-b missing.
> > > 
> > > True, thanks.  Also I was going to send this as an RFC.
> > > 
> > 
> > Looks fine to me, please resend if you want it in :)
> 
> Do we really want this? Is the referred chaos hypothetical or an actual 
> issue. Nothing stops me from doing an 'ifconfig down' so why should 'iw 
> disconnect' be any different. As far I can tell it does not affect my 
> testing environment, but particularly in such use-cases I can expect 
> issues adopting this change, which is also hypothetical of course ;-)

Yeah, it's a good question. But it might help with inadvertent issues,
like starting wpa_s which immediately disconnects if it finds something
connected. If that fails, perhaps you have a better chance of noticing
the error?

johannes