drivers: watchdog: exar_wdt.c fix use after free

fix use after free by storing the result of PTR_ERR(n->pdev)
to a local variable before returning.

Signed-off-by: Manank Patel <pmanank200502@gmail.com>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Link: https://lore.kernel.org/r/20221013095258.1424967-1-pmanank200502@gmail.com
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Wim Van Sebroeck <wim@linux-watchdog.org>

diff --git a/drivers/watchdog/exar_wdt.c b/drivers/watchdog/exar_wdt.c
index 35058d8..7c61ff3 100644 (file)
--- a/drivers/watchdog/exar_wdt.c
+++ b/drivers/watchdog/exar_wdt.c
@@ -355,8 +355,10 @@ static int __init exar_wdt_register(struct wdt_priv *priv, const int idx)
                                                    &priv->wdt_res, 1,
                                                    priv, sizeof(*priv));
        if (IS_ERR(n->pdev)) {
+               int err = PTR_ERR(n->pdev);
+
                kfree(n);
-               return PTR_ERR(n->pdev);
+               return err;
        }
 
        list_add_tail(&n->list, &pdev_list);