hwmon: (nct6775) Check array index when accessing temp_offset

smatch complains about a potential out-of-bounds access to the
temp_offset array. That doesn't happen in practice, but it doesn't
hurt to add an explicit check either. This prevents potential problems
in the future (for example if the number of 'fixed' temperature
sensors is increased to add support for another chip).

Signed-off-by: Guenter Roeck <linux@roeck-us.net>

diff --git a/drivers/hwmon/nct6775.c b/drivers/hwmon/nct6775.c
index de57e0d60d230fa51ea3e195c826d8b94e041a87..b82fad48777794e9775ce29f55817263508d2a81 100644 (file)
--- a/drivers/hwmon/nct6775.c
+++ b/drivers/hwmon/nct6775.c
@@ -1457,7 +1457,8 @@ static struct nct6775_data *nct6775_update_device(struct device *dev)
                                          = nct6775_read_temp(data,
                                                data->reg_temp[j][i]);
                        }
-                       if (!(data->have_temp_fixed & (1 << i)))
+                       if (i >= NUM_TEMP_FIXED ||
+                           !(data->have_temp_fixed & (1 << i)))
                                continue;
                        data->temp_offset[i]
                          = nct6775_read_value(data, data->REG_TEMP_OFFSET[i]);