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authorDmitry Osipenko <digetx@gmail.com>2021-06-23 07:22:30 +0300
committerGuenter Roeck <linux@roeck-us.net>2021-06-24 07:14:27 -0700
commitb50aa49638c7e12abf4ecc483f4e928c5cccc1b0 (patch)
tree2fa4452247143bf21e425a0937ed54a9e0f90bd1 /drivers/hwmon
parent4c7f85a321a1ac265159c22a6998ef4f2a60c21d (diff)
hwmon: (lm90) Prevent integer underflows of temperature calculations
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> Link: https://lore.kernel.org/r/20210623042231.16008-2-digetx@gmail.com Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Diffstat (limited to 'drivers/hwmon')
-rw-r--r--drivers/hwmon/lm90.c13
1 files 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);