From 5f54a85db5df67df8161739a4b2f9c2b7ab219fe Mon Sep 17 00:00:00 2001
From: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Date: Wed, 12 Jun 2019 17:15:40 +0300
Subject: [PATCH] usb: typec: Make sure an alt mode exist before getting its
 partner

Adding check to typec_altmode_get_partner() to prevent
potential NULL pointer dereference.

Reported-by: Vladimir Yerilov <openmindead@gmail.com>
Fixes: ad74b8649bea ("usb: typec: ucsi: Preliminary support for alternate modes")
Signed-off-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 drivers/usb/typec/bus.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/usb/typec/bus.c b/drivers/usb/typec/bus.c
index 76299b6ff06d..74cb3c2ecb34 100644
--- a/drivers/usb/typec/bus.c
+++ b/drivers/usb/typec/bus.c
@@ -192,7 +192,7 @@ EXPORT_SYMBOL_GPL(typec_altmode_vdm);
 const struct typec_altmode *
 typec_altmode_get_partner(struct typec_altmode *adev)
 {
-	return &to_altmode(adev)->partner->adev;
+	return adev ? &to_altmode(adev)->partner->adev : NULL;
 }
 EXPORT_SYMBOL_GPL(typec_altmode_get_partner);