From: Johannes Berg <johannes@sipsolutions.net>
To: Bob Copeland <me@bobcopeland.com>
Cc: Henning Rogge <hrogge@gmail.com>,
linux-wireless@vger.kernel.org,
"David S. Miller" <davem@davemloft.net>,
Henning Rogge <henning.rogge@fkie.fraunhofer.de>
Subject: Re: [PATCH 1/2] mac80211: Remove connected MPP table entries with MPath
Date: Tue, 26 Jan 2016 21:53:33 +0100 [thread overview]
Message-ID: <1453841613.2759.77.camel@sipsolutions.net> (raw)
In-Reply-To: <20160126183628.GA30183@localhost> (sfid-20160126_193634_459896_87BDC3FE)
On Tue, 2016-01-26 at 13:36 -0500, Bob Copeland wrote:
> On Tue, Jan 26, 2016 at 12:41:25PM +0100, Johannes Berg wrote:
> > > + mpp = node->mpath;
> > > + if (ether_addr_equal(mpp->mpp, proxy)) {
> > > + spin_lock(&tbl->hashwlock[i]);
> > > + __mesh_path_del(tbl, node);
> > > + spin_unlock(&tbl->hashwlock[i]);
> >
> > It also doesn't seem like for_each_mesh_entry() can deal with
> > "node"
> > getting deleted from underneath it? It accesses it through
> > hlist_next_rcu() after the deletion, so you have a use-after-free
> > here
> > afaict.
>
> But __mesh_path_del() doesn't free it immediately: it does:
>
> hlist_del_rcu(&node->list);
> call_rcu(&node->rcu, mesh_path_node_reclaim);
>
> ...so this should be ok if in an rcu read-side critical section,
> right?
Oh. Interesting. Yeah, I guess that should be OK then.
It's not *nice*, since that's pretty much unexpected, and you then do
need the rcu_read_lock() ... hmm.
johannes
next prev parent reply other threads:[~2016-01-26 20:53 UTC|newest]
Thread overview: 21+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-01-19 8:04 [PATCH 0/2] mac80211: add cleanup path for MPP table entries Henning Rogge
2016-01-19 8:04 ` [PATCH 1/2] mac80211: Remove connected MPP table entries with MPath Henning Rogge
2016-01-26 11:41 ` Johannes Berg
2016-01-26 18:36 ` Bob Copeland
2016-01-26 19:04 ` Henning Rogge
2016-01-26 20:53 ` Johannes Berg [this message]
2016-01-26 21:22 ` Bob Copeland
2016-01-26 21:31 ` Johannes Berg
2016-01-26 21:32 ` Johannes Berg
2016-01-26 21:44 ` Bob Copeland
2016-01-19 8:04 ` [PATCH 2/2] mac80211: let unused MPP table entries timeout Henning Rogge
2016-01-22 20:30 ` Bob Copeland
2016-01-23 9:39 ` Henning Rogge
2016-01-23 15:15 ` Bob Copeland
2016-01-24 17:53 ` Henning Rogge
2016-01-26 11:44 ` Johannes Berg
2016-01-26 19:54 ` Henning Rogge
2016-01-26 23:17 ` Bob Copeland
2016-01-28 13:44 ` [PATCH 0/2] mac80211: add cleanup path for MPP table entries Bob Copeland
2016-01-28 15:07 ` Henning Rogge
2016-01-28 15:12 ` Bob Copeland
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