serial: sccnxp: Fix error handling in sccnxp_probe()

sccnxp_probe() returns result of regulator_disable() that may lead
to returning zero, while device is not properly initialized.
Also the driver enables clocks, but it does not disable it.

Found by Linux Driver Verification project (linuxtesting.org).

Signed-off-by: Alexey Khoroshilov <khoroshilov@ispras.ru>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

1 files changed, 11 insertions, 2 deletions

diff --git a/drivers/tty/serial/sccnxp.c b/drivers/tty/serial/sccnxp.c
index cdd2f942317c..b9c7a904c1ea 100644
--- a/drivers/tty/serial/sccnxp.c
+++ b/drivers/tty/serial/sccnxp.c
@@ -889,7 +889,16 @@ static int sccnxp_probe(struct platform_device *pdev)
                         goto err_out;
                 uartclk = 0;
         } else {
-                clk_prepare_enable(clk);
+                ret = clk_prepare_enable(clk);
+                if (ret)
+                        goto err_out;
+
+                ret = devm_add_action_or_reset(&pdev->dev,
+                                (void(*)(void *))clk_disable_unprepare,
+                                clk);
+                if (ret)
+                        goto err_out;
+
                 uartclk = clk_get_rate(clk);
         }
 
@@ -988,7 +997,7 @@ static int sccnxp_probe(struct platform_device *pdev)
         uart_unregister_driver(&s->uart);
 err_out:
         if (!IS_ERR(s->regulator))
-                return regulator_disable(s->regulator);
+                regulator_disable(s->regulator);
 
         return ret;
 }