[PATCH 5.4 105/408] Bluetooth: hci_uart: Cancel init work before unregistering

[Greg Kroah-Hartman]

From: Samuel Holland <sam...@sholland.org>

[ Upstream commit 3b799254cf6f481460719023d7a18f46651e5e7f ]

If hci_uart_tty_close() or hci_uart_unregister_device() is called while
hu->init_ready is scheduled, hci_register_dev() could be called after
the hci_uart is torn down. Avoid this by ensuring the work is complete
or canceled before checking the HCI_UART_REGISTERED flag.

Fixes: 9f2aee848fe6 ("Bluetooth: Add delayed init sequence support for UART 
controllers")
Signed-off-by: Samuel Holland <sam...@sholland.org>
Signed-off-by: Marcel Holtmann <mar...@holtmann.org>
Signed-off-by: Sasha Levin <sas...@kernel.org>
---
 drivers/bluetooth/hci_ldisc.c  | 1 +
 drivers/bluetooth/hci_serdev.c | 2 ++
 2 files changed, 3 insertions(+)

diff --git a/drivers/bluetooth/hci_ldisc.c b/drivers/bluetooth/hci_ldisc.c
index 85a30fb9177bb..f83d67eafc9f0 100644
--- a/drivers/bluetooth/hci_ldisc.c
+++ b/drivers/bluetooth/hci_ldisc.c
@@ -538,6 +538,7 @@ static void hci_uart_tty_close(struct tty_struct *tty)
                clear_bit(HCI_UART_PROTO_READY, &hu->flags);
                percpu_up_write(&hu->proto_lock);
 
+               cancel_work_sync(&hu->init_ready);
                cancel_work_sync(&hu->write_work);
 
                if (hdev) {
diff --git a/drivers/bluetooth/hci_serdev.c b/drivers/bluetooth/hci_serdev.c
index ad2f26cb2622e..5b9aa73ff2b7f 100644
--- a/drivers/bluetooth/hci_serdev.c
+++ b/drivers/bluetooth/hci_serdev.c
@@ -357,6 +357,8 @@ void hci_uart_unregister_device(struct hci_uart *hu)
        struct hci_dev *hdev = hu->hdev;
 
        clear_bit(HCI_UART_PROTO_READY, &hu->flags);
+
+       cancel_work_sync(&hu->init_ready);
        if (test_bit(HCI_UART_REGISTERED, &hu->flags))
                hci_unregister_dev(hdev);
        hci_free_dev(hdev);
-- 
2.25.1