Not possible to connect to Ubuntu from remote device

[Konrad Zapałowicz]

The Ubuntu is not letting the remote device in in case when the remote device is the initiator of the connection request. It drops connection request on the L2CAP level with 'security block' error code.

The step-by-step example:

1. Ubuntu pairs & connects to remote device
2. Ubuntu disconnects
3. Remote device tries to reconnect

It is seen from the HCI trace that the root cause is the problem in finding the agent that could carry the auth process on. In this case however the agent has been registered previously.

The HCI trace:

> ACL Data RX: Handle 12 flags 0x02 dlen 12 [hci0] 941.214394
      L2CAP: Connection Request (0x02) ident 38 len 4
        PSM: 25 (0x0019)
        Source CID: 65
< ACL Data TX: Handle 12 flags 0x00 dlen 16 [hci0] 941.214473
      L2CAP: Connection Response (0x03) ident 38 len 8
        Destination CID: 64
        Source CID: 65
        Result: Connection pending (0x0001)
        Status: Authorization pending (0x0002)
= bluetoothd: Authentication attempt without agent [hci0] 941.214871
= bluetoothd: Access denied: org.bluez.Error.Rejected 941.214921
< ACL Data TX: Handle 12 flags 0x00 dlen 16 [hci0] 941.214916
      L2CAP: Connection Response (0x03) ident 38 len 8
        Destination CID: 64
        Source CID: 65
        Result: Connection refused - security block (0x0003)
        Status: No further information available (0x0000)

[Launchpad Janitor (janitor)]

Status changed to 'Confirmed' because the bug affects multiple users.