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    Subject[PATCH 5.15 331/667] Bluetooth: use hdev lock for accept_list and reject_list in conn req
    Date
    From: Niels Dossche <dossche.niels@gmail.com>

    [ Upstream commit fb048cae51bacdfbbda2954af3c213fdb1d484f4 ]

    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>
    Signed-off-by: Sasha Levin <sashal@kernel.org>
    ---
    net/bluetooth/hci_event.c | 15 +++++++++------
    1 file changed, 9 insertions(+), 6 deletions(-)

    diff --git a/net/bluetooth/hci_event.c b/net/bluetooth/hci_event.c
    index e984a8b4b914..5ac3aca6deeb 100644
    --- a/net/bluetooth/hci_event.c
    +++ b/net/bluetooth/hci_event.c
    @@ -2790,10 +2790,12 @@ static void hci_conn_request_evt(struct hci_dev *hdev, struct sk_buff *skb)
    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
    @@ -2805,13 +2807,11 @@ static void hci_conn_request_evt(struct hci_dev *hdev, struct sk_buff *skb)
    !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);
    @@ -2823,8 +2823,7 @@ static void hci_conn_request_evt(struct hci_dev *hdev, struct sk_buff *skb)
    HCI_ROLE_SLAVE);
    if (!conn) {
    bt_dev_err(hdev, "no memory for new connection");
    - hci_dev_unlock(hdev);
    - return;
    + goto unlock;
    }
    }

    @@ -2864,6 +2863,10 @@ static void hci_conn_request_evt(struct hci_dev *hdev, struct sk_buff *skb)
    conn->state = BT_CONNECT2;
    hci_connect_cfm(conn, 0);
    }
    +
    + return;
    +unlock:
    + hci_dev_unlock(hdev);
    }

    static u8 hci_to_mgmt_reason(u8 err)
    --
    2.35.1


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