net: phy: fixed_phy: fix use-after-free when checking link GPIO

If we fail to locate GPIO for any reason other than deferral or
not-found-GPIO, we try to print device tree node info, however if might
be freed already as we called of_node_put() on it.

Acked-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/drivers/net/phy/fixed_phy.c b/drivers/net/phy/fixed_phy.c
index 7c5265f..4190f9e 100644 (file)
--- a/drivers/net/phy/fixed_phy.c
+++ b/drivers/net/phy/fixed_phy.c
@@ -212,16 +212,13 @@ static struct gpio_desc *fixed_phy_get_gpiod(struct device_node *np)
         */
        gpiod = gpiod_get_from_of_node(fixed_link_node, "link-gpios", 0,
                                       GPIOD_IN, "mdio");
-       of_node_put(fixed_link_node);
-       if (IS_ERR(gpiod)) {
-               if (PTR_ERR(gpiod) == -EPROBE_DEFER)
-                       return gpiod;
-
+       if (IS_ERR(gpiod) && PTR_ERR(gpiod) != -EPROBE_DEFER) {
                if (PTR_ERR(gpiod) != -ENOENT)
                        pr_err("error getting GPIO for fixed link %pOF, proceed without\n",
                               fixed_link_node);
                gpiod = NULL;
        }
+       of_node_put(fixed_link_node);
 
        return gpiod;
 }