[PATCH AUTOSEL for-3.18 01/27] extcon: palmas: Check the parent instance to prevent the NULL

["Levin, Alexander (Sasha Levin)" <alexander.levin@one.verizon.com>]

From: Roger Quadros <rogerq@ti.com>

[ Upstream commit 9fe172b9be532acc23e35ba693700383ab775e66 ]

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>
Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>
Signed-off-by: Sasha Levin <alexander.levin@verizon.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 230e1220ce48..1cee9f4909db 100644
--- a/drivers/extcon/extcon-palmas.c
+++ b/drivers/extcon/extcon-palmas.c
@@ -150,6 +150,11 @@ static int palmas_usb_probe(struct platform_device *pdev)
 	struct palmas_usb *palmas_usb;
 	int status;
 
+	if (!palmas) {
+		dev_err(&pdev->dev, "failed to get valid parent\n");
+		return -EINVAL;
+	}
+
 	palmas_usb = devm_kzalloc(&pdev->dev, sizeof(*palmas_usb), GFP_KERNEL);
 	if (!palmas_usb)
 		return -ENOMEM;
-- 
2.11.0