Bluetooth: use hdev lock for accept_list and reject_list in conn req

All accesses (both reads and modifications) to
hdev->{accept,reject}_list are protected by hdev lock,
except the ones in hci_conn_request_evt. This can cause a race
condition in the form of a list corruption.
The solution is to protect these lists in hci_conn_request_evt as well.

I was unable to find the exact commit that introduced the issue for the
reject list, I was only able to find it for the accept list.

Fixes: a55bd29d5227 ("Bluetooth: Add white list lookup for incoming connection requests")
Signed-off-by: Niels Dossche <dossche.niels@gmail.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

diff --git a/net/bluetooth/hci_event.c b/net/bluetooth/hci_event.c
index 6645166..a835ce6 100644 (file)
--- a/net/bluetooth/hci_event.c
+++ b/net/bluetooth/hci_event.c
@@ -3225,10 +3225,12 @@ static void hci_conn_request_evt(struct hci_dev *hdev, void *data,
                return;
        }
 
+       hci_dev_lock(hdev);
+
        if (hci_bdaddr_list_lookup(&hdev->reject_list, &ev->bdaddr,
                                   BDADDR_BREDR)) {
                hci_reject_conn(hdev, &ev->bdaddr);
-               return;
+               goto unlock;
        }
 
        /* Require HCI_CONNECTABLE or an accept list entry to accept the
@@ -3240,13 +3242,11 @@ static void hci_conn_request_evt(struct hci_dev *hdev, void *data,
            !hci_bdaddr_list_lookup_with_flags(&hdev->accept_list, &ev->bdaddr,
                                               BDADDR_BREDR)) {
                hci_reject_conn(hdev, &ev->bdaddr);
-               return;
+               goto unlock;
        }
 
        /* Connection accepted */
 
-       hci_dev_lock(hdev);
-
        ie = hci_inquiry_cache_lookup(hdev, &ev->bdaddr);
        if (ie)
                memcpy(ie->data.dev_class, ev->dev_class, 3);
@@ -3258,8 +3258,7 @@ static void hci_conn_request_evt(struct hci_dev *hdev, void *data,
                                    HCI_ROLE_SLAVE);
                if (!conn) {
                        bt_dev_err(hdev, "no memory for new connection");
-                       hci_dev_unlock(hdev);
-                       return;
+                       goto unlock;
                }
        }
 
@@ -3299,6 +3298,10 @@ static void hci_conn_request_evt(struct hci_dev *hdev, void *data,
                conn->state = BT_CONNECT2;
                hci_connect_cfm(conn, 0);
        }
+
+       return;
+unlock:
+       hci_dev_unlock(hdev);
 }
 
 static u8 hci_to_mgmt_reason(u8 err)