[PATCH 4.4 23/65] i2c-dev: dont get i2c adapter via i2c_dev

[Greg Kroah-Hartman]

From: viresh kumar <viresh.kumar@xxxxxxxxxx>

commit 5136ed4fcb05cd4981cc6034a11e66370ed84789 upstream.

There is no code protecting i2c_dev to be freed after it is returned
from i2c_dev_get_by_minor() and using it to access the value which we
already have (minor) isn't safe really.

Avoid using it and get the adapter directly from 'minor'.

Signed-off-by: Viresh Kumar <viresh.kumar@xxxxxxxxxx>
Reviewed-by: Jean Delvare <jdelvare@xxxxxxx>
Tested-by: Jean Delvare <jdelvare@xxxxxxx>
Signed-off-by: Wolfram Sang <wsa@xxxxxxxxxxxxx>
Signed-off-by: Ben Hutchings <ben.hutchings@xxxxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
 drivers/i2c/i2c-dev.c | 7 +------
 1 file changed, 1 insertion(+), 6 deletions(-)

diff --git a/drivers/i2c/i2c-dev.c b/drivers/i2c/i2c-dev.c
index e5cd307ebfc9..5543b49e2e05 100644
--- a/drivers/i2c/i2c-dev.c
+++ b/drivers/i2c/i2c-dev.c
@@ -492,13 +492,8 @@ static int i2cdev_open(struct inode *inode, struct file *file)
 	unsigned int minor = iminor(inode);
 	struct i2c_client *client;
 	struct i2c_adapter *adap;
-	struct i2c_dev *i2c_dev;
-
-	i2c_dev = i2c_dev_get_by_minor(minor);
-	if (!i2c_dev)
-		return -ENODEV;
 
-	adap = i2c_get_adapter(i2c_dev->adap->nr);
+	adap = i2c_get_adapter(minor);
 	if (!adap)
 		return -ENODEV;
 
-- 
2.25.1