hwmon: (w83627ehf) Get rid of smatch warnings

The smatch static code analyzer complains:

drivers/hwmon/w83627ehf.c:911 w83627ehf_update_device() error: buffer overflow 'W83627EHF_REG_TEMP_OFFSET' 3 <= 8
drivers/hwmon/w83627ehf.c:909 w83627ehf_update_device() error: buffer overflow 'data->temp_offset' 3 <= 8
drivers/hwmon/w83627ehf.c:2672 w83627ehf_resume() error: buffer overflow 'W83627EHF_REG_TEMP_OFFSET' 3 <= 8
drivers/hwmon/w83627ehf.c:2673 w83627ehf_resume() error: buffer overflow 'data->temp_offset' 3 <= 8

A deeper analysis of the code shows that these are false positives, as
only the lower 3 bits of data->have_temp_offset can be set so the
write is never attempted with i >= 3. However this shows that the code
isn't very robust and future changes could easily introduce a buffer
overflow. So let's add a safety check to prevent that and make smatch
happy.

Signed-off-by: Jean Delvare <khali@linux-fr.org>
Cc: Peter Huewe <PeterHuewe@gmx.de>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>

1 files changed, 4 insertions, 0 deletions

diff --git a/drivers/hwmon/w83627ehf.c b/drivers/hwmon/w83627ehf.c
index 7fbd0ba0f26f..0e8ffd6059a0 100644
--- a/drivers/hwmon/w83627ehf.c
+++ b/drivers/hwmon/w83627ehf.c
@@ -905,6 +905,8 @@ static struct w83627ehf_data *w83627ehf_update_device(struct device *dev)
                                 data->temp_max_hyst[i]
                                   = w83627ehf_read_temp(data,
                                                 data->reg_temp_hyst[i]);
+                        if (i > 2)
+                                continue;
                         if (data->have_temp_offset & (1 << i))
                                 data->temp_offset[i]
                                   = w83627ehf_read_value(data,
@@ -2670,6 +2672,8 @@ static int w83627ehf_resume(struct device *dev)
                 if (data->reg_temp_hyst[i])
                         w83627ehf_write_temp(data, data->reg_temp_hyst[i],
                                              data->temp_max_hyst[i]);
+                if (i > 2)
+                        continue;
                 if (data->have_temp_offset & (1 << i))
                         w83627ehf_write_value(data,
                                               W83627EHF_REG_TEMP_OFFSET[i],