Commit 45633fb3 authored Dec 19, 2012 by Jean Delvare Committed by Jean Delvare Dec 19, 2012

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>

parent 8f3c7c54

drivers/hwmon/w83627ehf.c

+4 −0

Original line number	Diff line number	Diff line
		@@ -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],