From: Myungho Jung <[email protected]> commit e20a2e9c42c9e4002d9e338d74e7819e88d77162 upstream.
When releasing socket, it is possible to enter hci_sock_release() and hci_sock_dev_event(HCI_DEV_UNREG) at the same time in different thread. The reference count of hdev should be decremented only once from one of them but if storing hdev to local variable in hci_sock_release() before detached from socket and setting to NULL in hci_sock_dev_event(), hci_dev_put(hdev) is unexpectedly called twice. This is resolved by referencing hdev from socket after bt_sock_unlink() in hci_sock_release(). Reported-by: [email protected] Signed-off-by: Myungho Jung <[email protected]> Signed-off-by: Marcel Holtmann <[email protected]> Signed-off-by: Zubin Mithra <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]> --- net/bluetooth/hci_sock.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) --- a/net/bluetooth/hci_sock.c +++ b/net/bluetooth/hci_sock.c @@ -558,13 +558,12 @@ static int hci_sock_release(struct socke if (!sk) return 0; - hdev = hci_pi(sk)->hdev; - if (hci_pi(sk)->channel == HCI_CHANNEL_MONITOR) atomic_dec(&monitor_promisc); bt_sock_unlink(&hci_sk_list, sk); + hdev = hci_pi(sk)->hdev; if (hdev) { if (hci_pi(sk)->channel == HCI_CHANNEL_USER) { /* When releasing an user channel exclusive access,
