Subject: Re: [PATCH] cfg80211: Removed warning from cfg80211_send_rx_auth
From: Johannes Berg <johannes@sipsolutions.net>
To: Teemu Paasikivi <ext-teemu.3.paasikivi@nokia.com>
Cc: linville@tuxdriver.com, linux-wireless@vger.kernel.org
In-Reply-To: <1274870625-19712-1-git-send-email-ext-teemu.3.paasikivi@nokia.com>
References: <1274870625-19712-1-git-send-email-ext-teemu.3.paasikivi@nokia.com>
Content-Type: text/plain; charset="UTF-8"
Date: Wed, 26 May 2010 13:21:17 +0200
Message-ID: <1274872877.3658.4.camel@jlt3.sipsolutions.net>
Mime-Version: 1.0
Sender: linux-wireless-owner@vger.kernel.org

On Wed, 2010-05-26 at 13:43 +0300, Teemu Paasikivi wrote:
> In cfg80211_send_rx_auth function there was a warning if bssid of the received
> authentication message was not found from the authtry_bsses table.
> 
> During the beginning of the authentication there is a small time window, when
> handling of the received deauthentication message can cause information
> for the access point to be removed from the authtry_bsses table before
> authentication response is received. This triggers the warning. This has
> been seen happening with several access points occasionally. At least
> one of those (Asus) has been seen to send spurious deauthentication
> messages after deauthentication. Possibly this warning could be triggered also
> by forged deauthentication messages sent at a correct time.

This doesn't seem right. Why is mac80211 not preventing those messages
from bubbling up in that case?

FWIW, this check is there for a reason -- we want to avoid telling
userspace twice that we disconnected from a given AP, and we shouldn't
be processing it anyway.

johannes