[PATCH] usb: typec: fix null-pointer-dereference in wcove_typec_probe()

[Jeffin Philip]

dev_get_drvdata() on the parent device can return NULL if we attempt to
bind our device as a root device with no parent. This causes a null pointer
dereference when accessing pmic->regmap later as pmic uses the parent
struct. Fix this by adding a NULL check for pmic and returning -ENODEV
if to_platform_device() returns NULL for pmic.

Reported-by: syzbot+1a01783ea233350598b5@xxxxxxxxxxxxxxxxxxxxxxxxx
Closes: https://syzkaller.appspot.com/bug?extid=1a01783ea233350598b5
Fixes: d2061f9cc32d ("usb: typec: add driver for Intel Whiskey Cove PMIC USB Type-C PHY")
Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Jeffin Philip <jeffinphilip14@xxxxxxxxx>
---
 drivers/usb/typec/tcpm/wcove.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/drivers/usb/typec/tcpm/wcove.c b/drivers/usb/typec/tcpm/wcove.c
index 0e5a3e277c3e..80bca8edeba6 100644
--- a/drivers/usb/typec/tcpm/wcove.c
+++ b/drivers/usb/typec/tcpm/wcove.c
@@ -612,6 +612,10 @@ static int wcove_typec_probe(struct platform_device *pdev)
 	int irq;
 	int ret;
 
+	/* check if we have a parent device first */
+	if (!pmic)
+		return -ENODEV;
+
 	wcove = devm_kzalloc(&pdev->dev, sizeof(*wcove), GFP_KERNEL);
 	if (!wcove)
 		return -ENOMEM;
-- 
2.55.0