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Subject: Re: [PATCH 04/11] wil6210: fix PTK re-key race
To:     Alexander Wetzel <alexander@wetzel-home.de>,
        Kalle Valo <kvalo@codeaurora.org>,
        Maya Erez <merez@codeaurora.org>
Cc:     Ahmad Masri <amasri@codeaurora.org>,
        linux-wireless@vger.kernel.org, wil6210@qti.qualcomm.com
References: <1567931575-27984-5-git-send-email-merez@codeaurora.org>
 <20190910132315.D7AC7602F2@smtp.codeaurora.org>
 <7b636313-fa4a-5ee4-935a-ba2ed5dde1e5@wetzel-home.de>
From:   Denis Kenzior <denkenz@gmail.com>
Message-ID: <2c6bc637-62c2-020c-ab83-d2e1677d96b2@gmail.com>
Date:   Thu, 12 Sep 2019 12:39:37 -0500
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Hi Alexander,

> I don't know anything about the driver here but in mac80211 the idea to 
> avoid the race is to simply flush the queues prior deleting the outgoing 
> key.

Maybe a silly question, but what does flushing the queue mean in this 
context?  Is it waiting for all the packets to be sent or dropping them 
on the floor?

> 
> Now wpa_supplicant is not yet bypassing qdisks, but adding the socket 
> parameter PACKET_QDISC_BYPASS is basically a one-liner in wpa_supplicant 
> and should allow a generic way for drivers to avoid the race with a 
> simple queue flush...

Can you expand on this actually?  What would the sequence of events be?

Also, how would this be made to work with CONTROL_PORT over NL80211 ?

Regards,
-Denis