Re: [PATCH cover letter] Bluetooth: Revert: Fix L2CAP connection ...

[Gustavo Padovan <padovan@profusion.mobi>]

Hi Arek,

* Arkadiusz.Lichwa@tieto.com <Arkadiusz.Lichwa@tieto.com> [2011-11-22 15:27:17 +0200]:

> Hi Gustavo
> 
> >-----Original Message-----
> >From: Gustavo F. Padovan [mailto:pao@profusion.mobi] On Behalf Of Gustavo
> >Padovan
> >Sent: Monday, November 07, 2011 7:54 PM
> >To: Lichwa Arkadiusz
> >Cc: linux-bluetooth@vger.kernel.org; iliak@ti.com; ulrik.lauren@stericsson.com
> >Subject: Re: [PATCH cover letter] Bluetooth: Revert: Fix L2CAP connection ...
> >
> >
> >* Arkadiusz.Lichwa@tieto.com <Arkadiusz.Lichwa@tieto.com> [2011-11-07
> >12:06:32 +0200]:
> >
> >>
> >> >From: Gustavo F. Padovan [mailto:pao@profusion.mobi] On Behalf Of Gustavo
> >> >Padovan
> >> >Sent: Friday, November 04, 2011 6:18 PM
> >> >To: Lichwa Arkadiusz
> >> >Cc: linux-bluetooth@vger.kernel.org; iliak@ti.com; ulrik.lauren@stericsson.com
> >> >Subject: Re: [PATCH cover letter] Bluetooth: Revert: Fix L2CAP connection ...
> >> >
> >> >Hi Arek,
> >> >
> >> >* Arkadiusz.Lichwa@tieto.com <Arkadiusz.Lichwa@tieto.com> [2011-11-02
> >> >09:53:10 +0200]:
> >> >
> >> >>
> >> >> Hi Gustavo
> >> >>
> >> >> >From: Gustavo F. Padovan [mailto:pao@profusion.mobi] On Behalf Of
> >Gustavo
> >> >> >Padovan
> >> >> >Sent: Monday, October 31, 2011 8:01 PM
> >> >> >To: Lichwa Arkadiusz
> >> >> >Cc: linux-bluetooth@vger.kernel.org; iliak@ti.com;
> >ulrik.lauren@stericsson.com
> >> >> >Subject: Re: [PATCH cover letter] Bluetooth: Revert: Fix L2CAP connection ...
> >> >> >
> >> >> >Hi Arek,
> >> >> >
> >> >> >* Arek Lichwa <arkadiusz.lichwa@tieto.com> [2011-10-26 11:23:21 +0200]:
> >> >> >
> >> >> >> Hi
> >> >> >>
> >> >> >> We found during testing problem when setting rfcomm (SPP) channel
> >between
> >> >> >> two 2.1 devices.
> >> >> >> The test case always failed mostly saying security block on l2cap level
> >> >> >> but sometimes the fail root cause was 'Command not understood' on l2cap
> >> >> >> as well.
> >> >> >> Analyzing security block issue, I found that there's unencrypted link when
> >> >> >> l2cap command 'connection request' is sent to remote.
> >> >> >> The second issue with 'command not understood' has turn out to be related
> >to
> >> >> >> expiration of l2cap timer and its implications.
> >> >> >>
> >> >> >> Solution that I found to fix the problem seems to be related to old commit
> >> >> >> 330605423ca6eafafb8dcc27502bce1c585d1b06 made by Ilia Kolomisnky.
> >> >When
> >> >> >there's
> >> >> >> authentication ongoing, 'encryption pending' should be turn on, otherwise
> >> >> >> there're situations when link stays unencrypted.
> >> >> >> The issue with timer expiration is related to Andrzej Kaczmarek's patch
> >> >> >> sent to community a couple days ago (~ 2011/10/20).
> >> >> >> This patch actually recalculates (repairs) timer values on l2cap which were
> >> >> >> wrongly converted before.
> >> >> >> With this patch the expiration issue disappears during the test case
> >> >> >> I've made, otherwise just reverting
> >> >> >330605423ca6eafafb8dcc27502bce1c585d1b06
> >> >> >> is not enough, since timer issue blocks very often passing the test case.
> >> >> >
> >> >> >Are you saying that Andrzej's patch together with revert of 330605423 fixes
> >> >> >the problem? and are you sure that we are not creating any new regression?
> >> >> >
> >> >> >	Gustavo
> >> >>
> >> >> Yes, that's right, it fixes.
> >> >> About potencial new regression, I don't think so since previous code before Ilia
> >> >made change was stable and verified. Did you asked Ilia about regression report
> >> >that time?
> >> >
> >> >So did you test this in many different cases? with and without SSP, in all
> >> >security levels, with and without MITM protection and so on?
> >>
> >> Hi Gustavo,
> >>
> >> Should't such scenarios to be run/verified on bluez community's
> >> common security regression test framework/set ?
> >> Looks like now everyone (I hope) verify against his own and it's not trustable.
> >>
> >> To your questions, yes, I did, do you belive me ? :)
> >
> >Ok, I'm applying this one to the bluetooth tree (aka linux 3.2). Thanks.
> >
> >Also I verified the need of this patch while developing the security patches I
> >just sent to the mailing list, it only works if I revert this patch.
> >
> >	Gustavo
> 
> Looks like the patch got to be reverted. 
> More thorough / manual tests showed the problem on setting up subsequent
> l2cap channels with legacy devices.

What goes wrong? security block? Why does it happen?

	Gustavo