extcon: palmas: Check the parent instance to prevent the NULL

[ 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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/extcon/extcon-palmas.c b/drivers/extcon/extcon-palmas.c
index 230e1220ce48bc49ef24bd5683ca1c074e94202e..1cee9f4909db079a7fcafcf425a4caa4e6e1fc42 100644 (file)
--- 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;