Bluetooth: Fix SSP acceptor just-works confirmation without MITM

From the Bluetooth Core Specification 4.1 page 1958:

"if both devices have set the Authentication_Requirements parameter to
one of the MITM Protection Not Required options, authentication stage 1
shall function as if both devices set their IO capabilities to
DisplayOnly (e.g., Numeric comparison with automatic confirmation on
both devices)"

So far our implementation has done user confirmation for all just-works
cases regardless of the MITM requirements, however following the
specification to the word means that we should not be doing confirmation
when neither side has the MITM flag set.

Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Tested-by: Szymon Janc <szymon.janc@tieto.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Cc: stable@vger.kernel.org

diff --git a/net/bluetooth/hci_event.c b/net/bluetooth/hci_event.c
index 21e5913d12e03f4c8410a9464cd5794c9e5a0c70..ff11f4a1ada35b3a8405f1afae165b4519c2955e 100644 (file)
--- a/net/bluetooth/hci_event.c
+++ b/net/bluetooth/hci_event.c
@@ -3628,8 +3628,11 @@ static void hci_user_confirm_request_evt(struct hci_dev *hdev,
 
                /* If we're not the initiators request authorization to
                 * proceed from user space (mgmt_user_confirm with
-                * confirm_hint set to 1). */
-               if (!test_bit(HCI_CONN_AUTH_PEND, &conn->flags)) {
+                * confirm_hint set to 1). The exception is if neither
+                * side had MITM in which case we do auto-accept.
+                */
+               if (!test_bit(HCI_CONN_AUTH_PEND, &conn->flags) &&
+                   (loc_mitm || rem_mitm)) {
                        BT_DBG("Confirming auto-accept as acceptor");
                        confirm_hint = 1;
                        goto confirm;