Return-path: Received: from mail-yw0-f46.google.com ([209.85.213.46]:59997 "EHLO mail-yw0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751422Ab2GIROk (ORCPT ); Mon, 9 Jul 2012 13:14:40 -0400 Received: by yhmm54 with SMTP id m54so11112192yhm.19 for ; Mon, 09 Jul 2012 10:14:39 -0700 (PDT) MIME-Version: 1.0 In-Reply-To: <1341853775.4455.53.camel@jlt3.sipsolutions.net> References: <1341853048-12150-1-git-send-email-arik@wizery.com> <1341853186.4455.52.camel@jlt3.sipsolutions.net> <1341853775.4455.53.camel@jlt3.sipsolutions.net> From: Arik Nemtsov Date: Mon, 9 Jul 2012 20:14:24 +0300 Message-ID: (sfid-20120709_191443_871920_1C5394CD) Subject: Re: [PATCH v2] mac80211: fix invalid band deref building preq IEs To: Johannes Berg Cc: linux-wireless@vger.kernel.org Content-Type: text/plain; charset=ISO-8859-1 Sender: linux-wireless-owner@vger.kernel.org List-ID: On Mon, Jul 9, 2012 at 8:09 PM, Johannes Berg wrote: > On Mon, 2012-07-09 at 20:04 +0300, Arik Nemtsov wrote: >> On Mon, Jul 9, 2012 at 7:59 PM, Johannes Berg wrote: >> > On Mon, 2012-07-09 at 19:57 +0300, Arik Nemtsov wrote: >> >> The function building probe-request IEs does not validate the band is >> >> supported before dereferencing it. This can result in a panic when >> >> all bands are traversed, as done during sched-scan start. >> >> >> >> Warn when this happens and return an empty probe request. Also fix >> >> sched-scan to not waste memory on unsupported bands. >> >> >> >> Signed-off-by: Arik Nemtsov >> >> --- >> >> better? :) >> > >> > Yeah I'll apply this :-) >> > >> > I do wonder though why we even bother building probe request IEs for a >> > band if no channels from it are listed in the sched scan request. >> >> It's a bit complicated to know this, because of how the request is >> structured (have to traverse all the channels etc). >> The memory waste is not so bad anyway I guess. > > Yeah but we could just iterate all the channels and build the probe > request IEs for each channel's band unless we did before? Anyway, it > doesn't matter, something for another day maybe :) Yea that's a possibility I guess. For another day :)