4.20-stable review patch. If anyone has any objections, please let me know.
------------------
[ Upstream commit c9c63915519b1def7043b184680f33c24cd49d7b ]
If lm80_read_value() fails, it returns a negative number instead of the correct read data. Therefore, we should avoid using the data if it fails.
The fix checks if lm80_read_value() fails, and if so, returns with the error number.
Signed-off-by: Kangjie Lu kjlu@umn.edu [groeck: One variable for return values is enough] Signed-off-by: Guenter Roeck linux@roeck-us.net Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/hwmon/lm80.c | 15 ++++++++++----- 1 file changed, 10 insertions(+), 5 deletions(-)
diff --git a/drivers/hwmon/lm80.c b/drivers/hwmon/lm80.c index 08e3945a6fbf..04f9df0d2341 100644 --- a/drivers/hwmon/lm80.c +++ b/drivers/hwmon/lm80.c @@ -360,9 +360,11 @@ static ssize_t set_fan_div(struct device *dev, struct device_attribute *attr, struct i2c_client *client = data->client; unsigned long min, val; u8 reg; - int err = kstrtoul(buf, 10, &val); - if (err < 0) - return err; + int rv; + + rv = kstrtoul(buf, 10, &val); + if (rv < 0) + return rv;
/* Save fan_min */ mutex_lock(&data->update_lock); @@ -390,8 +392,11 @@ static ssize_t set_fan_div(struct device *dev, struct device_attribute *attr, return -EINVAL; }
- reg = (lm80_read_value(client, LM80_REG_FANDIV) & - ~(3 << (2 * (nr + 1)))) | (data->fan_div[nr] << (2 * (nr + 1))); + rv = lm80_read_value(client, LM80_REG_FANDIV); + if (rv < 0) + return rv; + reg = (rv & ~(3 << (2 * (nr + 1)))) + | (data->fan_div[nr] << (2 * (nr + 1))); lm80_write_value(client, LM80_REG_FANDIV, reg);
/* Restore fan_min */