serial: core: fix potential NULL pointer dereference

[cascardo/linux.git] / drivers / tty / serial / serial_core.c

diff --git a/drivers/tty/serial/serial_core.c b/drivers/tty/serial/serial_core.c
index 6b7f857..6e4f636 100644 (file)
--- a/drivers/tty/serial/serial_core.c
+++ b/drivers/tty/serial/serial_core.c
@@ -1484,15 +1484,15 @@ static void uart_tty_port_shutdown(struct tty_port *port)
        struct uart_state *state = container_of(port, struct uart_state, port);
        struct uart_port *uport = uart_port_check(state);
 
-       spin_lock_irq(&uport->lock);
        /*
         * At this point, we stop accepting input.  To do this, we
         * disable the receive line status interrupts.
         */
-       WARN(!uport, "detached port still initialized!\n");
+       if (WARN(!uport, "detached port still initialized!\n"))
+               return;
 
+       spin_lock_irq(&uport->lock);
        uport->ops->stop_rx(uport);
-
        spin_unlock_irq(&uport->lock);
 
        uart_port_shutdown(port);