From 6c53823ae0e10e723131055e1e65dd6a328a228e Mon Sep 17 00:00:00 2001 From: Johan Hedberg Date: Fri, 11 Jul 2014 15:32:23 +0300 Subject: [PATCH] Bluetooth: Fix tracking local SSP authentication requirement When we need to make the decision whether to perform just-works or real user confirmation we need to know the exact local authentication requirement that was passed to the controller. So far conn->auth_type (the local requirement) wasn't in one case updated appropriately in fear of the user confirmation being rejected later. The real problem however was not really that conn->auth_type couldn't represent the true value but that we were checking the local MITM requirement in an incorrect way. It's perfectly fine to let auth_type follow what we tell the controller since we're still tracking the target security level with conn->pending_sec_level. This patch updates the check for local MITM requirement in the hci_user_confirm_request_evt function to use the locally requested security level and ensures that auth_type always represents what we tell the controller. All other code in hci_user_confirm_request_evt still uses the auth_type instead of pending_sec_level for determining whether to do just-works or not, since that's the only value that's in sync with what the remote device knows. Signed-off-by: Johan Hedberg Tested-by: Szymon Janc Signed-off-by: Marcel Holtmann Cc: stable@vger.kernel.org # 3.16 --- net/bluetooth/hci_event.c | 17 ++++++++--------- 1 file changed, 8 insertions(+), 9 deletions(-) diff --git a/net/bluetooth/hci_event.c b/net/bluetooth/hci_event.c index f0f220057f21..8980bd24b8c0 100644 --- a/net/bluetooth/hci_event.c +++ b/net/bluetooth/hci_event.c @@ -3664,18 +3664,14 @@ static void hci_io_capa_request_evt(struct hci_dev *hdev, struct sk_buff *skb) /* If we are initiators, there is no remote information yet */ if (conn->remote_auth == 0xff) { - cp.authentication = conn->auth_type; - /* Request MITM protection if our IO caps allow it * except for the no-bonding case. - * conn->auth_type is not updated here since - * that might cause the user confirmation to be - * rejected in case the remote doesn't have the - * IO capabilities for MITM. */ if (conn->io_capability != HCI_IO_NO_INPUT_OUTPUT && cp.authentication != HCI_AT_NO_BONDING) - cp.authentication |= 0x01; + conn->auth_type |= 0x01; + + cp.authentication = conn->auth_type; } else { conn->auth_type = hci_get_auth_req(conn); cp.authentication = conn->auth_type; @@ -3747,9 +3743,12 @@ static void hci_user_confirm_request_evt(struct hci_dev *hdev, rem_mitm = (conn->remote_auth & 0x01); /* If we require MITM but the remote device can't provide that - * (it has NoInputNoOutput) then reject the confirmation request + * (it has NoInputNoOutput) then reject the confirmation + * request. We check the security level here since it doesn't + * necessarily match conn->auth_type. */ - if (loc_mitm && conn->remote_cap == HCI_IO_NO_INPUT_OUTPUT) { + if (conn->pending_sec_level > BT_SECURITY_MEDIUM && + conn->remote_cap == HCI_IO_NO_INPUT_OUTPUT) { BT_DBG("Rejecting request: remote device can't provide MITM"); hci_send_cmd(hdev, HCI_OP_USER_CONFIRM_NEG_REPLY, sizeof(ev->bdaddr), &ev->bdaddr); -- 2.11.0