Commits
Guenter Roeck committed c793279c770
hwmon: (nct6775) Fix access to fan pulse registers
Not all fans have a fan pulse register. This can result in reading
beyond the end of REG_FAN_PULSES and FAN_PULSE_SHIFT arrays,
and was reported by smatch as possible error.
1672 for (i = 0; i < ARRAY_SIZE(data->rpm); i++) {
^^^^^^^^^^^^^^^^^^^^^^^^
This is a 7 element array.
...
1685 data->fan_pulses[i] =
1686 (nct6775_read_value(data, data->REG_FAN_PULSES[i])
1687 >> data->FAN_PULSE_SHIFT[i]) & 0x03;
^^^^^^^^^^^^^^^^^^^^^^^^
FAN_PULSE_SHIFT is either 5 or 6
elements.
To fix the problem, we have to ensure that all REG_FAN_PULSES and
FAN_PULSE_SHIFT have the appropriate length, and that REG_FAN_PULSES
is only read if the register actually exists.
Fixes: 6c009501ff200 ("hwmon: (nct6775) Add support for NCT6102D/6106D")
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>