[PATCH 3.11 04/93] net: cpsw: fix null dereference at probe

[Luis Henriques]

3.11.10.12 -stable review patch.  If anyone has any objections, please let me know.

------------------

From: Johan Hovold <jhovold at gmail.com>

commit 6954cc1f238199e971ec905c5cc87120806ac981 upstream.

Fix null-pointer dereference at probe when the mdio platform device is
missing (e.g. when it has been disabled in DT).

Signed-off-by: Johan Hovold <jhovold at gmail.com>
Signed-off-by: David S. Miller <davem at davemloft.net>
Signed-off-by: Luis Henriques <luis.henriques at canonical.com>
---
 drivers/net/ethernet/ti/cpsw.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/drivers/net/ethernet/ti/cpsw.c b/drivers/net/ethernet/ti/cpsw.c
index 22a7a4336211..04b39c155c6a 100644
--- a/drivers/net/ethernet/ti/cpsw.c
+++ b/drivers/net/ethernet/ti/cpsw.c
@@ -1548,6 +1548,10 @@ static int cpsw_probe_dt(struct cpsw_platform_data *data,
 		mdio_node = of_find_node_by_phandle(be32_to_cpup(parp));
 		phyid = be32_to_cpup(parp+1);
 		mdio = of_find_device_by_node(mdio_node);
+		if (!mdio) {
+			pr_err("Missing mdio platform device\n");
+			return -EINVAL;
+		}
 		snprintf(slave_data->phy_id, sizeof(slave_data->phy_id),
 			 PHY_ID_FMT, mdio->name, phyid);
 
-- 
1.9.1