This is a note to let you know that I've just added the patch titled
hwmon: (adt7470) Prevent divide by zero in adt7470_fan_write()
to the 5.16-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
hwmon-adt7470-prevent-divide-by-zero-in-adt7470_fan_.patch
and it can be found in the queue-5.16 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit c4eb88d6023f55e38cfa8abd9bc9fe92143568b2
Author: Dan Carpenter <dan.carpenter@xxxxxxxxxx>
Date: Fri Jan 21 14:55:43 2022 +0300
hwmon: (adt7470) Prevent divide by zero in adt7470_fan_write()
[ Upstream commit c1ec0cabc36718efc7fe8b4157d41b82d08ec1d2 ]
The "val" variable is controlled by the user and comes from
hwmon_attr_store(). The FAN_RPM_TO_PERIOD() macro divides by "val"
so a zero will crash the system. Check for that and return -EINVAL.
Negatives are also invalid so return -EINVAL for those too.
Fixes: fc958a61ff6d ("hwmon: (adt7470) Convert to devm_hwmon_device_register_with_info API")
Signed-off-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx>
Signed-off-by: Guenter Roeck <linux@xxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/drivers/hwmon/adt7470.c b/drivers/hwmon/adt7470.c
index d519aca4a9d64..fb6d14d213a18 100644
--- a/drivers/hwmon/adt7470.c
+++ b/drivers/hwmon/adt7470.c
@@ -662,6 +662,9 @@ static int adt7470_fan_write(struct device *dev, u32 attr, int channel, long val
struct adt7470_data *data = dev_get_drvdata(dev);
int err;
+ if (val <= 0)
+ return -EINVAL;
+
val = FAN_RPM_TO_PERIOD(val);
val = clamp_val(val, 1, 65534);
