net: bcmgenet: fix OF child-node lookup

jhovold · robherring · commit d397dbe60612 · 2018-10-23T13:28:52.000-05:00
Use the new of_get_compatible_child() helper to lookup the mdio child node instead of using of_find_compatible_node(), which searches the entire tree from a given start node and thus can return an unrelated (i.e. non-child) node. This also addresses a potential use-after-free (e.g. after probe deferral) as the tree-wide helper drops a reference to its first argument (i.e. the node of the device being probed). Fixes: aa09677 ("net: bcmgenet: add MDIO routines") Cc: stable <stable@vger.kernel.org> # 3.15 Cc: David S. Miller <davem@davemloft.net> Reviewed-by: Florian Fainelli <f.fainelli@gmail.com> Signed-off-by: Johan Hovold <johan@kernel.org> Signed-off-by: Rob Herring <robh@kernel.org>
diff --git a/drivers/net/ethernet/broadcom/genet/bcmmii.c b/drivers/net/ethernet/broadcom/genet/bcmmii.c
@@ -333,7 +333,7 @@ static struct device_node *bcmgenet_mii_of_find_mdio(struct bcmgenet_priv *priv)
 	if (!compat)
 		return NULL;
 
-	priv->mdio_dn = of_find_compatible_node(dn, NULL, compat);
+	priv->mdio_dn = of_get_compatible_child(dn, compat);
 	kfree(compat);
 	if (!priv->mdio_dn) {
 		dev_err(kdev, "unable to find MDIO bus node\n");
