serial: core: fix potential NULL pointer dereference
The commit 761ed4a94582 ("tty: serial_core: convert uart_close to use
tty_port_close") refactored uart_close() to use tty_port_close(). At the same
time it introduced a potential NULL pointer dereference. Rearrange the code to
avoid kernel crash.
Fixes: 761ed4a94582 ("tty: serial_core: convert uart_close to use tty_port_close")
Cc: Rob Herring <robh@kernel.org>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff --git a/drivers/tty/serial/serial_core.c b/drivers/tty/serial/serial_core.c
index 6b7f857..6e4f636 100644
--- a/drivers/tty/serial/serial_core.c
+++ b/drivers/tty/serial/serial_core.c
@@ -1484,15 +1484,15 @@
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);
