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@xxxxxxxxxxxxxxx>.
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@xxxxxxxxxx>
> 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@xxxxxxxxxxxxxxx> # 3.15
> Cc: David S. Miller <davem@xxxxxxxxxxxxx>
> Reviewed-by: Florian Fainelli <f.fainelli@xxxxxxxxx>
> Signed-off-by: Johan Hovold <johan@xxxxxxxxxx>
> Signed-off-by: Rob Herring <robh@xxxxxxxxxx>
>
> 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");
>
