diff options
| author | Gui-Dong Han <hanguidong02@gmail.com> | 2025-11-28 20:47:09 +0800 |
|---|---|---|
| committer | Guenter Roeck <linux@roeck-us.net> | 2025-11-28 08:36:25 -0800 |
| commit | b8d5acdcf525f44e521ca4ef51dce4dac403dab4 (patch) | |
| tree | 06815fba754ba7b4ed87ce99cbe45203399edd17 | |
| parent | 07272e883fc61574b8367d44de48917f622cdd83 (diff) | |
hwmon: (max16065) Use local variable to avoid TOCTOU
In max16065_current_show, data->curr_sense is read twice: once for the
error check and again for the calculation. Since
i2c_smbus_read_byte_data returns negative error codes on failure, if the
data changes to an error code between the check and the use, ADC_TO_CURR
results in an incorrect calculation.
Read data->curr_sense into a local variable to ensure consistency. Note
that data->curr_gain is constant and safe to access directly.
This aligns max16065_current_show with max16065_input_show, which
already uses a local variable for the same reason.
Link: https://lore.kernel.org/all/CALbr=LYJ_ehtp53HXEVkSpYoub+XYSTU8Rg=o1xxMJ8=5z8B-g@mail.gmail.com/
Fixes: f5bae2642e3d ("hwmon: Driver for MAX16065 System Manager and compatibles")
Cc: stable@vger.kernel.org
Signed-off-by: Gui-Dong Han <hanguidong02@gmail.com>
Link: https://lore.kernel.org/r/20251128124709.3876-1-hanguidong02@gmail.com
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
| -rw-r--r-- | drivers/hwmon/max16065.c | 7 |
1 files changed, 4 insertions, 3 deletions
diff --git a/drivers/hwmon/max16065.c b/drivers/hwmon/max16065.c index 0ccb5eb596fc..4c9e7892a73c 100644 --- a/drivers/hwmon/max16065.c +++ b/drivers/hwmon/max16065.c @@ -216,12 +216,13 @@ static ssize_t max16065_current_show(struct device *dev, struct device_attribute *da, char *buf) { struct max16065_data *data = max16065_update_device(dev); + int curr_sense = data->curr_sense; - if (unlikely(data->curr_sense < 0)) - return data->curr_sense; + if (unlikely(curr_sense < 0)) + return curr_sense; return sysfs_emit(buf, "%d\n", - ADC_TO_CURR(data->curr_sense, data->curr_gain)); + ADC_TO_CURR(curr_sense, data->curr_gain)); } static ssize_t max16065_limit_store(struct device *dev, |