[PATCH] extcon: palmas: Fail gracefully if invalid configuration

[Roger Quadros <rogerq@ti.com>]

extcon-palmas must be child of palmas and expects parent's
drvdata to be valid. Check for non NULL parent drvdata and
fail if it is NULL. Not doing so will result in a NULL
pointer dereference later in the probe() parent drvdata
is NULL (e.g. misplaced extcon-palmas node in device tree).

Signed-off-by: Roger Quadros <rogerq@ti.com>
---
 drivers/extcon/extcon-palmas.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/drivers/extcon/extcon-palmas.c b/drivers/extcon/extcon-palmas.c
index 634ba70..ec987ab 100644
--- a/drivers/extcon/extcon-palmas.c
+++ b/drivers/extcon/extcon-palmas.c
@@ -190,6 +190,11 @@ static int palmas_usb_probe(struct platform_device *pdev)
 	struct palmas_usb *palmas_usb;
 	int status;
 
+	if (!palmas) {
+		dev_err(&pdev->dev, "device has invalid parent\n");
+		return -EINVAL;
+	}
+
 	palmas_usb = devm_kzalloc(&pdev->dev, sizeof(*palmas_usb), GFP_KERNEL);
 	if (!palmas_usb)
 		return -ENOMEM;
-- 
2.7.4