[PATCH 4.4 105/190] net: freescale: fix potential null pointer dereference

[Greg Kroah-Hartman]

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

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

From: "Gustavo A. R. Silva" <garsilva@xxxxxxxxxxxxxx>


[ Upstream commit 06d2d6431bc8d41ef5ffd8bd4b52cea9f72aed22 ]

Add NULL check before dereferencing pointer _id_ in order to avoid
a potential NULL pointer dereference.

Addresses-Coverity-ID: 1397995
Signed-off-by: Gustavo A. R. Silva <garsilva@xxxxxxxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <alexander.levin@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
 drivers/net/ethernet/freescale/fsl_pq_mdio.c |    9 ++++++++-
 1 file changed, 8 insertions(+), 1 deletion(-)

--- a/drivers/net/ethernet/freescale/fsl_pq_mdio.c
+++ b/drivers/net/ethernet/freescale/fsl_pq_mdio.c
@@ -382,7 +382,7 @@ static int fsl_pq_mdio_probe(struct plat
 {
 	const struct of_device_id *id =
 		of_match_device(fsl_pq_mdio_match, &pdev->dev);
-	const struct fsl_pq_mdio_data *data = id->data;
+	const struct fsl_pq_mdio_data *data;
 	struct device_node *np = pdev->dev.of_node;
 	struct resource res;
 	struct device_node *tbi;
@@ -390,6 +390,13 @@ static int fsl_pq_mdio_probe(struct plat
 	struct mii_bus *new_bus;
 	int err;
 
+	if (!id) {
+		dev_err(&pdev->dev, "Failed to match device\n");
+		return -ENODEV;
+	}
+
+	data = id->data;
+
 	dev_dbg(&pdev->dev, "found %s compatible node\n", id->compatible);
 
 	new_bus = mdiobus_alloc_size(sizeof(*priv));