[PATCH 4.17 171/336] net: ethernet: ti: cpsw-phy-sel: check bus_find_device() ret value

[Greg Kroah-Hartman]

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

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

From: Grygorii Strashko <grygorii.strashko@xxxxxx>

[ Upstream commit c6213eb1aee308e67377fd1890d84f7284caf531 ]

This fixes klockworks warnings: Pointer 'dev' returned from call to
function 'bus_find_device' at line 179 may be NULL and will be dereferenced
at line 181.

    cpsw-phy-sel.c:179: 'dev' is assigned the return value from function 'bus_find_device'.
    bus.c:342: 'bus_find_device' explicitly returns a NULL value.
    cpsw-phy-sel.c:181: 'dev' is dereferenced by passing argument 1 to function 'dev_get_drvdata'.
    device.h:1024: 'dev' is passed to function 'dev_get_drvdata'.
    device.h:1026: 'dev' is explicitly dereferenced.

Signed-off-by: Grygorii Strashko <grygorii.strashko@xxxxxx>
[nsekhar@xxxxxx: add an error message, fix return path]
Signed-off-by: Sekhar Nori <nsekhar@xxxxxx>
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/ti/cpsw-phy-sel.c |    8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

--- a/drivers/net/ethernet/ti/cpsw-phy-sel.c
+++ b/drivers/net/ethernet/ti/cpsw-phy-sel.c
@@ -177,12 +177,18 @@ void cpsw_phy_sel(struct device *dev, ph
 	}
 
 	dev = bus_find_device(&platform_bus_type, NULL, node, match);
-	of_node_put(node);
+	if (!dev) {
+		dev_err(dev, "unable to find platform device for %pOF\n", node);
+		goto out;
+	}
+
 	priv = dev_get_drvdata(dev);
 
 	priv->cpsw_phy_sel(priv, phy_mode, slave);
 
 	put_device(dev);
+out:
+	of_node_put(node);
 }
 EXPORT_SYMBOL_GPL(cpsw_phy_sel);