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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>
Jean Delvare 12 jaren geleden
bovenliggende
commit
45633fb370
1 gewijzigde bestanden met toevoegingen van 4 en 0 verwijderingen
  1. 4 0
      drivers/hwmon/w83627ehf.c

+ 4 - 0
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],