DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 66D4720843
Date:   Wed, 26 Sep 2018 14:28:01 +0300
From:   Johan Hedberg <johan.hedberg@gmail.com>
To:     fabien dvlt <fabiendvlt@gmail.com>
Cc:     linux-bluetooth@vger.kernel.org
Subject: Re: Security block and Bluez - connection issue with Android
Message-ID: <20180926112801.GA8013@x1c.lan>
Mail-Followup-To: fabien dvlt <fabiendvlt@gmail.com>,
        linux-bluetooth@vger.kernel.org
References: <CAOiLkfOuenvh5ZLQD_k-yi7mL1Epr+gGJZ65zr2Fcp2SzE9F7w@mail.gmail.com>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <CAOiLkfOuenvh5ZLQD_k-yi7mL1Epr+gGJZ65zr2Fcp2SzE9F7w@mail.gmail.com>
User-Agent: Mutt/1.10.1 (2018-07-13)
Sender: linux-bluetooth-owner@vger.kernel.org
Precedence: bulk

Hi Fabien,

On Tue, Sep 25, 2018, fabien dvlt wrote:
> > ACL Data RX: Handle 13 flags 0x02 dlen 12           #198 [hci0] 21.813116
>       L2CAP: Connection Request (0x02) ident 7 len 4
>         PSM: 25 (0x0019)
>         Source CID: 75
> > HCI Event: Encryption Change (0x08) plen 4          #199 [hci0] 21.813155
>         Status: Success (0x00)
>         Handle: 13
>         Encryption: Enabled with AES-CCM (0x02)
> < ACL Data TX: Handle 13 flags 0x00 dlen 16           #200 [hci0]
>       L2CAP: Connection Response (0x03) ident 7 len 8
>         Destination CID: 0
>         Source CID: 75
>         Result: Connection refused - security block (0x0003)
>         Status: No further information available (0x0000)

This looks like the well-known race condition for ACL data and HCI
events on USB where the two come through different endpoints. From the
host perspective there's not much we can do since we can't make
assumptions that the connection request was sent over an encrypted
connection if we haven't seen the encryption change request at that
point.

Johan