| Message ID | b09c4396-1578-45bb-b1fb-23c1f91cabe7@kylinos.cn (mailing list archive) |
|---|---|
| State | Changes Requested |
| Headers | show |
| Series | [RFC] hwmon: (nct6775-core) Fix overflows seen when writing limit attributes | expand |
On 11/11/24 00:36, Pei Xiao wrote: > hi Guenter Roeck, > Excuse me, may I ask a question? > When I see this commit (Fixes: 0403e10bf082 ("hwmon: (nct6775-core) Fix underflows seen when writing limit attributes")), I found an issue, > DIV_ROUND_CLOSEST() after kstrtoul() results in an overflow if a large > number such as 18446744073709551615 is provided by the user. > Fix it by reordering clamp_val() and DIV_ROUND_CLOSEST() operations. > > If the issue described above does indeed exist, I will send an formal patch. > Yes, and good find, but please fix the calculations. Thanks, Guenter > > diff --git a/drivers/hwmon/nct6775-core.c b/drivers/hwmon/nct6775-core.c > index 934fed3dd586..12ee2ca4a6d6 100644 > --- a/drivers/hwmon/nct6775-core.c > +++ b/drivers/hwmon/nct6775-core.c > @@ -2878,8 +2878,7 @@ store_target_temp(struct device *dev, struct device_attribute *attr, > if (err < 0) > return err; > > - val = clamp_val(DIV_ROUND_CLOSEST(val, 1000), 0, > - data->target_temp_mask); > + val = DIV_ROUND_CLOSEST(clamp_val(val, 0, data->tolerance_mask * 1000), 1000); > data->target_temp_mask > mutex_lock(&data->update_lock); > data->target_temp[nr] = val; > @@ -2959,7 +2958,7 @@ store_temp_tolerance(struct device *dev, struct device_attribute *attr, > return err; > > /* Limit tolerance as needed */ > - val = clamp_val(DIV_ROUND_CLOSEST(val, 1000), 0, data->tolerance_mask); > + val = DIV_ROUND_CLOSEST(clamp_val(val, 0, data->tolerance_mask * 1000), 1000); > > mutex_lock(&data->update_lock); > data->temp_tolerance[index][nr] = val; > @@ -3085,7 +3084,7 @@ store_weight_temp(struct device *dev, struct device_attribute *attr, > if (err < 0) > return err; > > - val = clamp_val(DIV_ROUND_CLOSEST(val, 1000), 0, 255); > + val = DIV_ROUND_CLOSEST(clamp_val(val, 0, 25500), 1000); 255000 > > mutex_lock(&data->update_lock); > data->weight_temp[index][nr] = val; > > Thanks!
diff --git a/drivers/hwmon/nct6775-core.c b/drivers/hwmon/nct6775-core.c index 934fed3dd586..12ee2ca4a6d6 100644 --- a/drivers/hwmon/nct6775-core.c +++ b/drivers/hwmon/nct6775-core.c @@ -2878,8 +2878,7 @@ store_target_temp(struct device *dev, struct device_attribute *attr, if (err < 0) return err; - val = clamp_val(DIV_ROUND_CLOSEST(val, 1000), 0, - data->target_temp_mask); + val = DIV_ROUND_CLOSEST(clamp_val(val, 0, data->tolerance_mask * 1000), 1000);
hi Guenter Roeck, Excuse me, may I ask a question? When I see this commit (Fixes: 0403e10bf082 ("hwmon: (nct6775-core) Fix underflows seen when writing limit attributes")), I found an issue, DIV_ROUND_CLOSEST() after kstrtoul() results in an overflow if a large number such as 18446744073709551615 is provided by the user. Fix it by reordering clamp_val() and DIV_ROUND_CLOSEST() operations. If the issue described above does indeed exist, I will send an formal patch. mutex_lock(&data->update_lock); data->target_temp[nr] = val; @@ -2959,7 +2958,7 @@ store_temp_tolerance(struct device *dev, struct device_attribute *attr, return err; /* Limit tolerance as needed */ - val = clamp_val(DIV_ROUND_CLOSEST(val, 1000), 0, data->tolerance_mask); + val = DIV_ROUND_CLOSEST(clamp_val(val, 0, data->tolerance_mask * 1000), 1000); mutex_lock(&data->update_lock); data->temp_tolerance[index][nr] = val; @@ -3085,7 +3084,7 @@ store_weight_temp(struct device *dev, struct device_attribute *attr, if (err < 0) return err; - val = clamp_val(DIV_ROUND_CLOSEST(val, 1000), 0, 255); + val = DIV_ROUND_CLOSEST(clamp_val(val, 0, 25500), 1000); mutex_lock(&data->update_lock); data->weight_temp[index][nr] = val; Thanks!