Date: Wed, 20 Mar 2013 08:30:29 +0100
From: Stanislaw Gruszka <sgruszka@redhat.com>
To: greearb@candelatech.com
Cc: linux-wireless@vger.kernel.org
Subject: Re: [PATCH v3] mac80211:  Don't restart sta-timer if not associated.
Message-ID: <20130320073028.GC1761@redhat.com> (sfid-20130320_082953_024251_C5540681)
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On Tue, Mar 19, 2013 at 05:50:50PM -0700, greearb@candelatech.com wrote:
> From: Ben Greear <greearb@candelatech.com>
> 
> I found another crash when deleting lots of virtual stations
> in a congested environment.  I think the problem is that
> the ieee80211_mlme_notify_scan_completed could call
> ieee80211_restart_sta_timer for a stopped interface
> that was about to be deleted.
> 
> With the following patch I am unable to reproduce the
> crash.
> 
> Signed-off-by: Ben Greear <greearb@candelatech.com>
> ---
> v3:  Just check for sdata-is-running once at top of method
>   instead of worrying about if it is associated or not.
> 
> :100644 100644 aec786d... 74a8c5f... M	net/mac80211/mlme.c
>  net/mac80211/mlme.c |    3 +++
>  1 files changed, 3 insertions(+), 0 deletions(-)
> 
> diff --git a/net/mac80211/mlme.c b/net/mac80211/mlme.c
> index aec786d..74a8c5f 100644
> --- a/net/mac80211/mlme.c
> +++ b/net/mac80211/mlme.c
> @@ -2933,6 +2933,9 @@ static void ieee80211_restart_sta_timer(struct ieee80211_sub_if_data *sdata)
>  {
>  	u32 flags;
>  
> +	if (!ieee80211_sdata_running(sdata))
> +		return;
> +

I think this check should go to ieee80211_mlme_notify_scan_completed(),
and another one to ieee80211_mesh_notify_scan_completed(), IBSS already
has it.

Stanislaw