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Subject: Re: [PATCH 1/2] mac80211: Remove connected MPP table entries with
 MPath
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>
Date: Tue, 26 Jan 2016 22:31:29 +0100
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On Tue, 2016-01-26 at 16:22 -0500, Bob Copeland wrote:
> 
> void mesh_path_flush_by_nexthop(struct sta_info *sta)
> {
>     [...]
> 	rhashtable_walk_start(&iter);

It seems you need to check the return value here?

> 	while ((mpath = rhashtable_walk_next(&iter))) {
> 		if (IS_ERR(mpath) && PTR_ERR(mpath) == -EAGAIN)
> 			continue;
> 		if (IS_ERR(mpath))
> 			break;
> 
> 		if (rcu_access_pointer(mpath->next_hop) == sta)
> 			__mesh_path_del(tbl, mpath);
> 	}
> 	rhashtable_walk_stop(&iter);
>     [...]
> }
> 
> ...this still relies on the rcu read lock inside _walk_start and
> _walk_stop, though.

At least that's kinda hidden in walk_start/stop though ;-)

johannes