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From: Johannes Berg <johannes@sipsolutions.net>
To: Emmanuel Grumbach <egrumbach@gmail.com>,
	voncken <cedric.voncken@acksys.fr>
Cc: linux-wireless <linux-wireless@vger.kernel.org>
Subject: Re: Mac80211 : Wpa rekeying issue
Date: Thu, 07 Jan 2016 22:15:08 +0100	[thread overview]
Message-ID: <1452201308.3141.25.camel@sipsolutions.net> (raw)
In-Reply-To: <CANUX_P2pF_He3mruTxMU_poBXzZpa9rXA7AgYV_RQ4BJ9wS6Mg@mail.gmail.com> (sfid-20151231_094154_715579_53F875A2)

On Thu, 2015-12-31 at 10:41 +0200, Emmanuel Grumbach wrote:
> 
> So essentially, this is a bug in the TX'ing side. Fixing it requires
> to hit the performance which is not something people are willing to
> do, when the bug is really in the spec.
> 

I wonder if, for most devices, this is really true?

We could, after all, remove the key from hardware acceleration before
we replace it logically in software, avoiding the problem [1], like
this:

https://p.sipsolutions.net/a71aa559c27998c7.txt
(completely untested!)

This would slightly increase the window of time in which devices like
ath10k that require hardware crypto drop the frame entirely, but that
seems quite reasonable?


[1] assuming the driver doesn't return from the set_key() method while
it still has frames that might have been decrypted with that key; which
again is clearly true for iwlwifi due to the combined data/firmware
command design, but maybe not fully guaranteed for ath9k

  parent reply	other threads:[~2016-01-07 21:15 UTC|newest]

Thread overview: 16+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2015-12-29 13:01 Mac80211 : Wpa rekeying issue Cedric VONCKEN
2015-12-29 14:19 ` Emmanuel Grumbach
2015-12-29 15:23   ` voncken
2015-12-31  8:12     ` voncken
2015-12-31  8:41       ` Emmanuel Grumbach
2015-12-31 10:15         ` voncken
2015-12-31 15:25           ` Ben Greear
2016-01-05  9:19         ` Johannes Berg
2016-01-05  9:47         ` Matthias May
2016-01-05  9:58           ` Johannes Berg
2016-01-05 10:54             ` Matthias May
2016-01-05 15:50               ` Johannes Berg
2016-01-06  9:09                 ` Matthias May
2016-01-07 21:06                   ` Johannes Berg
2016-01-07 21:15         ` Johannes Berg [this message]
2016-01-12 11:38           ` Emmanuel Grumbach

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