6.6-stable review patch. If anyone has any objections, please let me know.
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From: Gui-Dong Han hanguidong02@gmail.com
commit 07272e883fc61574b8367d44de48917f622cdd83 upstream.
The macros FAN_FROM_REG and TEMP_FROM_REG evaluate their arguments multiple times. When used in lockless contexts involving shared driver data, this causes Time-of-Check to Time-of-Use (TOCTOU) race conditions.
Convert the macros to static functions. This guarantees that arguments are evaluated only once (pass-by-value), preventing the race conditions.
Adhere to the principle of minimal changes by only converting macros that evaluate arguments multiple times and are used in lockless contexts.
Link: https://lore.kernel.org/all/CALbr=LYJ_ehtp53HXEVkSpYoub+XYSTU8Rg=o1xxMJ8=5z8... Fixes: 85f03bccd6e0 ("hwmon: Add support for Winbond W83L786NG/NR") Cc: stable@vger.kernel.org Signed-off-by: Gui-Dong Han hanguidong02@gmail.com Link: https://lore.kernel.org/r/20251128123816.3670-1-hanguidong02@gmail.com Signed-off-by: Guenter Roeck linux@roeck-us.net Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/hwmon/w83l786ng.c | 26 ++++++++++++++++++-------- 1 file changed, 18 insertions(+), 8 deletions(-)
--- a/drivers/hwmon/w83l786ng.c +++ b/drivers/hwmon/w83l786ng.c @@ -76,15 +76,25 @@ FAN_TO_REG(long rpm, int div) return clamp_val((1350000 + rpm * div / 2) / (rpm * div), 1, 254); }
-#define FAN_FROM_REG(val, div) ((val) == 0 ? -1 : \ - ((val) == 255 ? 0 : \ - 1350000 / ((val) * (div)))) +static int fan_from_reg(int val, int div) +{ + if (val == 0) + return -1; + if (val == 255) + return 0; + return 1350000 / (val * div); +}
/* for temp */ #define TEMP_TO_REG(val) (clamp_val(((val) < 0 ? (val) + 0x100 * 1000 \ : (val)) / 1000, 0, 0xff)) -#define TEMP_FROM_REG(val) (((val) & 0x80 ? \ - (val) - 0x100 : (val)) * 1000) + +static int temp_from_reg(int val) +{ + if (val & 0x80) + return (val - 0x100) * 1000; + return val * 1000; +}
/* * The analog voltage inputs have 8mV LSB. Since the sysfs output is @@ -280,7 +290,7 @@ static ssize_t show_##reg(struct device int nr = to_sensor_dev_attr(attr)->index; \ struct w83l786ng_data *data = w83l786ng_update_device(dev); \ return sprintf(buf, "%d\n", \ - FAN_FROM_REG(data->reg[nr], DIV_FROM_REG(data->fan_div[nr]))); \ + fan_from_reg(data->reg[nr], DIV_FROM_REG(data->fan_div[nr]))); \ }
show_fan_reg(fan); @@ -347,7 +357,7 @@ store_fan_div(struct device *dev, struct
/* Save fan_min */ mutex_lock(&data->update_lock); - min = FAN_FROM_REG(data->fan_min[nr], DIV_FROM_REG(data->fan_div[nr])); + min = fan_from_reg(data->fan_min[nr], DIV_FROM_REG(data->fan_div[nr]));
data->fan_div[nr] = DIV_TO_REG(val);
@@ -409,7 +419,7 @@ show_temp(struct device *dev, struct dev int nr = sensor_attr->nr; int index = sensor_attr->index; struct w83l786ng_data *data = w83l786ng_update_device(dev); - return sprintf(buf, "%d\n", TEMP_FROM_REG(data->temp[nr][index])); + return sprintf(buf, "%d\n", temp_from_reg(data->temp[nr][index])); }
static ssize_t