On Sun, Nov 11, 2018 at 06:32:23AM -0800, Greg Kroah-Hartman wrote:

The patch below does not apply to the 4.4-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to stable@vger.kernel.org.

This one also depends on

36156f9241cb ("of: add helper to lookup compatible child node")

Johan

------------------ original commit in Linus's tree ------------------

From d397dbe606120a1ea1b11b0020c3f7a3852da5ac Mon Sep 17 00:00:00 2001 From: Johan Hovold johan@kernel.org Date: Mon, 27 Aug 2018 10:21:50 +0200 Subject: [PATCH] net: bcmgenet: fix OF child-node lookup

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: aa09677cba42 ("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 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");