From 871b5a5a3be968a2412e11b98fe402dcbc2f0d0a Mon Sep 17 00:00:00 2001
From: Wolfram Sang <wsa+renesas@sang-engineering.com>
Date: Sat, 25 Jul 2020 21:50:53 +0200
Subject: [PATCH] i2c: slave: add sanity check when unregistering

[ Upstream commit 8808981baf96e1b3dea1f08461e4d958aa0dbde1 ]

Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Reviewed-by: Alain Volmat <alain.volmat@st.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/i2c/i2c-core-slave.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/i2c/i2c-core-slave.c b/drivers/i2c/i2c-core-slave.c
index 549751347e6c..1589179d5eb9 100644
--- a/drivers/i2c/i2c-core-slave.c
+++ b/drivers/i2c/i2c-core-slave.c
@@ -58,6 +58,9 @@ int i2c_slave_unregister(struct i2c_client *client)
 {
 	int ret;
 
+	if (IS_ERR_OR_NULL(client))
+		return -EINVAL;
+
 	if (!client->adapter->algo->unreg_slave) {
 		dev_err(&client->dev, "%s: not supported by adapter\n", __func__);
 		return -EOPNOTSUPP;