5.4-stable review patch. If anyone has any objections, please let me know.
------------------
From: Hui Wang hui.wang@canonical.com
commit c569242cd49287d53b73a94233db40097d838535 upstream.
We have a BT headset (Lenovo Thinkplus XT99), the pairing and connecting has no problem, once this headset is paired, bluez will remember this device and will auto re-connect it whenever the device is powered on. The auto re-connecting works well with Windows and Android, but with Linux, it always fails. Through debugging, we found at the rfcomm connection stage, the bluetooth stack reports "Connection refused - security block (0x0003)".
For this device, the re-connecting negotiation process is different from other BT headsets, it sends the Link_KEY_REQUEST command before the CONNECT_REQUEST completes, and it doesn't send ENCRYPT_CHANGE command during the negotiation. When the device sends the "connect complete" to hci, the ev->encr_mode is 1.
So here in the conn_complete_evt(), if ev->encr_mode is 1, link type is ACL and HCI_CONN_ENCRYPT is not set, we set HCI_CONN_ENCRYPT to this conn, and update conn->enc_key_size accordingly.
After this change, this BT headset could re-connect with Linux successfully. This is the btmon log after applying the patch, after receiving the "Connect Complete" with "Encryption: Enabled", will send the command to read encryption key size:
HCI Event: Connect Request (0x04) plen 10
Address: 8C:3C:AA:D8:11:67 (OUI 8C-3C-AA) Class: 0x240404 Major class: Audio/Video (headset, speaker, stereo, video, vcr) Minor class: Wearable Headset Device Rendering (Printing, Speaker) Audio (Speaker, Microphone, Headset) Link type: ACL (0x01) ...
HCI Event: Link Key Request (0x17) plen 6
Address: 8C:3C:AA:D8:11:67 (OUI 8C-3C-AA) < HCI Command: Link Key Request Reply (0x01|0x000b) plen 22 Address: 8C:3C:AA:D8:11:67 (OUI 8C-3C-AA) Link key: ${32-hex-digits-key} ...
HCI Event: Connect Complete (0x03) plen 11
Status: Success (0x00) Handle: 256 Address: 8C:3C:AA:D8:11:67 (OUI 8C-3C-AA) Link type: ACL (0x01) Encryption: Enabled (0x01) < HCI Command: Read Encryption Key... (0x05|0x0008) plen 2 Handle: 256 < ACL Data TX: Handle 256 flags 0x00 dlen 10 L2CAP: Information Request (0x0a) ident 1 len 2 Type: Extended features supported (0x0002)
HCI Event: Command Complete (0x0e) plen 7
Read Encryption Key Size (0x05|0x0008) ncmd 1 Status: Success (0x00) Handle: 256 Key size: 16
Cc: stable@vger.kernel.org Link: https://github.com/bluez/bluez/issues/704 Reviewed-by: Paul Menzel pmenzel@molgen.mpg.de Reviewed-by: Luiz Augusto von Dentz luiz.dentz@gmail.com Signed-off-by: Hui Wang hui.wang@canonical.com Signed-off-by: Luiz Augusto von Dentz luiz.von.dentz@intel.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- net/bluetooth/hci_event.c | 25 +++++++++++++++++++++++++ 1 file changed, 25 insertions(+)
--- a/net/bluetooth/hci_event.c +++ b/net/bluetooth/hci_event.c @@ -2537,6 +2537,31 @@ static void hci_conn_complete_evt(struct if (test_bit(HCI_ENCRYPT, &hdev->flags)) set_bit(HCI_CONN_ENCRYPT, &conn->flags);
+ /* "Link key request" completed ahead of "connect request" completes */ + if (ev->encr_mode == 1 && !test_bit(HCI_CONN_ENCRYPT, &conn->flags) && + ev->link_type == ACL_LINK) { + struct link_key *key; + struct hci_cp_read_enc_key_size cp; + + key = hci_find_link_key(hdev, &ev->bdaddr); + if (key) { + set_bit(HCI_CONN_ENCRYPT, &conn->flags); + + if (!(hdev->commands[20] & 0x10)) { + conn->enc_key_size = HCI_LINK_KEY_SIZE; + } else { + cp.handle = cpu_to_le16(conn->handle); + if (hci_send_cmd(hdev, HCI_OP_READ_ENC_KEY_SIZE, + sizeof(cp), &cp)) { + bt_dev_err(hdev, "sending read key size failed"); + conn->enc_key_size = HCI_LINK_KEY_SIZE; + } + } + + hci_encrypt_cfm(conn, ev->status); + } + } + /* Get remote features */ if (conn->type == ACL_LINK) { struct hci_cp_read_remote_features cp;