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

From: Greg Kroah-Hartman
Date: Wed Apr 11 2018 - 16:31:15 EST


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));