From 7f8a294b5707fb8a6769125f3366e1f38ae7bcec Mon Sep 17 00:00:00 2001 From: Sonny Sasaka Date: Wed, 6 May 2020 12:55:03 -0700 Subject: [PATCH] Bluetooth: Handle Inquiry Cancel error after Inquiry Complete [ Upstream commit adf1d6926444029396861413aba8a0f2a805742a ] After sending Inquiry Cancel command to the controller, it is possible that Inquiry Complete event comes before Inquiry Cancel command complete event. In this case the Inquiry Cancel command will have status of Command Disallowed since there is no Inquiry session to be cancelled. This case should not be treated as error, otherwise we can reach an inconsistent state. Example of a btmon trace when this happened: < HCI Command: Inquiry Cancel (0x01|0x0002) plen 0 > HCI Event: Inquiry Complete (0x01) plen 1 Status: Success (0x00) > HCI Event: Command Complete (0x0e) plen 4 Inquiry Cancel (0x01|0x0002) ncmd 1 Status: Command Disallowed (0x0c) Signed-off-by: Sonny Sasaka Signed-off-by: Marcel Holtmann Signed-off-by: Sasha Levin --- net/bluetooth/hci_event.c | 19 +++++++++++++++++-- 1 file changed, 17 insertions(+), 2 deletions(-) diff --git a/net/bluetooth/hci_event.c b/net/bluetooth/hci_event.c index 700a2eb16149..d6da119f5082 100644 --- a/net/bluetooth/hci_event.c +++ b/net/bluetooth/hci_event.c @@ -41,12 +41,27 @@ /* Handle HCI Event packets */ -static void hci_cc_inquiry_cancel(struct hci_dev *hdev, struct sk_buff *skb) +static void hci_cc_inquiry_cancel(struct hci_dev *hdev, struct sk_buff *skb, + u8 *new_status) { __u8 status = *((__u8 *) skb->data); BT_DBG("%s status 0x%2.2x", hdev->name, status); + /* It is possible that we receive Inquiry Complete event right + * before we receive Inquiry Cancel Command Complete event, in + * which case the latter event should have status of Command + * Disallowed (0x0c). This should not be treated as error, since + * we actually achieve what Inquiry Cancel wants to achieve, + * which is to end the last Inquiry session. + */ + if (status == 0x0c && !test_bit(HCI_INQUIRY, &hdev->flags)) { + bt_dev_warn(hdev, "Ignoring error of Inquiry Cancel command"); + status = 0x00; + } + + *new_status = status; + if (status) return; @@ -2772,7 +2787,7 @@ static void hci_cmd_complete_evt(struct hci_dev *hdev, struct sk_buff *skb, switch (*opcode) { case HCI_OP_INQUIRY_CANCEL: - hci_cc_inquiry_cancel(hdev, skb); + hci_cc_inquiry_cancel(hdev, skb, status); break; case HCI_OP_PERIODIC_INQ: -- 2.20.1