| Message ID | 20210623042231.16008-2-digetx@gmail.com |
|---|---|
| State | Accepted |
| Commit | b50aa49638c7e12abf4ecc483f4e928c5cccc1b0 |
| Headers | show |
| Series | [v5,1/2] hwmon: (lm90) Prevent integer underflows of temperature calculations | expand |
On Wed, Jun 23, 2021 at 07:22:30AM +0300, Dmitry Osipenko wrote: > The min/max/crit and all other temperature values that are passed to > the driver are unlimited and value that is close to INT_MIN results in > integer underflow of the temperature calculations made by the driver > for LM99 sensor. Temperature hysteresis is among those values that need > to be limited, but limiting of hysteresis is independent from the sensor > version. Add the missing limits. > > Signed-off-by: Dmitry Osipenko <digetx@gmail.com> Applied. Thanks, Guenter > --- > drivers/hwmon/lm90.c | 13 +++++++++++-- > 1 file changed, 11 insertions(+), 2 deletions(-) > > diff --git a/drivers/hwmon/lm90.c b/drivers/hwmon/lm90.c > index b53f17511b05..567b7c521f38 100644 > --- a/drivers/hwmon/lm90.c > +++ b/drivers/hwmon/lm90.c > @@ -1029,8 +1029,11 @@ static int lm90_set_temp11(struct lm90_data *data, int index, long val) > int err; > > /* +16 degrees offset for temp2 for the LM99 */ > - if (data->kind == lm99 && index <= 2) > + if (data->kind == lm99 && index <= 2) { > + /* prevent integer underflow */ > + val = max(val, -128000l); > val -= 16000; > + } > > if (data->kind == adt7461 || data->kind == tmp451) > data->temp11[index] = temp_to_u16_adt7461(data, val); > @@ -1089,8 +1092,11 @@ static int lm90_set_temp8(struct lm90_data *data, int index, long val) > int err; > > /* +16 degrees offset for temp2 for the LM99 */ > - if (data->kind == lm99 && index == 3) > + if (data->kind == lm99 && index == 3) { > + /* prevent integer underflow */ > + val = max(val, -128000l); > val -= 16000; > + } > > if (data->kind == adt7461 || data->kind == tmp451) > data->temp8[index] = temp_to_u8_adt7461(data, val); > @@ -1137,6 +1143,9 @@ static int lm90_set_temphyst(struct lm90_data *data, long val) > else > temp = temp_from_s8(data->temp8[LOCAL_CRIT]); > > + /* prevent integer underflow */ > + val = max(val, -128000l); > + > data->temp_hyst = hyst_to_reg(temp - val); > err = i2c_smbus_write_byte_data(client, LM90_REG_W_TCRIT_HYST, > data->temp_hyst);
diff --git a/drivers/hwmon/lm90.c b/drivers/hwmon/lm90.c index b53f17511b05..567b7c521f38 100644 --- a/drivers/hwmon/lm90.c +++ b/drivers/hwmon/lm90.c @@ -1029,8 +1029,11 @@ static int lm90_set_temp11(struct lm90_data *data, int index, long val) int err; /* +16 degrees offset for temp2 for the LM99 */ - if (data->kind == lm99 && index <= 2) + if (data->kind == lm99 && index <= 2) { + /* prevent integer underflow */ + val = max(val, -128000l); val -= 16000; + } if (data->kind == adt7461 || data->kind == tmp451) data->temp11[index] = temp_to_u16_adt7461(data, val); @@ -1089,8 +1092,11 @@ static int lm90_set_temp8(struct lm90_data *data, int index, long val) int err; /* +16 degrees offset for temp2 for the LM99 */ - if (data->kind == lm99 && index == 3) + if (data->kind == lm99 && index == 3) { + /* prevent integer underflow */ + val = max(val, -128000l); val -= 16000; + } if (data->kind == adt7461 || data->kind == tmp451) data->temp8[index] = temp_to_u8_adt7461(data, val); @@ -1137,6 +1143,9 @@ static int lm90_set_temphyst(struct lm90_data *data, long val) else temp = temp_from_s8(data->temp8[LOCAL_CRIT]); + /* prevent integer underflow */ + val = max(val, -128000l); + data->temp_hyst = hyst_to_reg(temp - val); err = i2c_smbus_write_byte_data(client, LM90_REG_W_TCRIT_HYST, data->temp_hyst);
The min/max/crit and all other temperature values that are passed to the driver are unlimited and value that is close to INT_MIN results in integer underflow of the temperature calculations made by the driver for LM99 sensor. Temperature hysteresis is among those values that need to be limited, but limiting of hysteresis is independent from the sensor version. Add the missing limits. Signed-off-by: Dmitry Osipenko <digetx@gmail.com> --- drivers/hwmon/lm90.c | 13 +++++++++++-- 1 file changed, 11 insertions(+), 2 deletions(-)