| Message ID | 20220121115543.GA25292@kili (mailing list archive) |
|---|---|
| State | Accepted |
| Headers | show |
| Series | [v2] hwmon: (adt7470) Prevent divide by zero in adt7470_fan_write() | expand |
On Fri, Jan 21, 2022 at 02:55:43PM +0300, Dan Carpenter wrote: > 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@oracle.com> Applied. Thanks, Guenter > --- > drivers/hwmon/adt7470.c | 3 +++ > 1 file changed, 3 insertions(+) > > diff --git a/drivers/hwmon/adt7470.c b/drivers/hwmon/adt7470.c > index d519aca4a9d6..fb6d14d213a1 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); > > -- > 2.20.1 >
diff --git a/drivers/hwmon/adt7470.c b/drivers/hwmon/adt7470.c index d519aca4a9d6..fb6d14d213a1 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);
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@oracle.com> --- drivers/hwmon/adt7470.c | 3 +++ 1 file changed, 3 insertions(+)