[PATCH 6/9] net: bcmgenet: fix OF child-node lookup

From: Johan Hovold
Date: Wed Aug 22 2018 - 06:57:51 EST


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 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: aa09677cba42 ("net: bcmgenet: add MDIO routines")
Cc: stable <stable@xxxxxxxxxxxxxxx> # 3.15
Cc: Florian Fainelli <f.fainelli@xxxxxxxxx>
Cc: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Johan Hovold <johan@xxxxxxxxxx>
---
drivers/net/ethernet/broadcom/genet/bcmmii.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/net/ethernet/broadcom/genet/bcmmii.c b/drivers/net/ethernet/broadcom/genet/bcmmii.c
index 5333274a283c..87fc65560ceb 100644
--- 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");
--
2.18.0