[BUG] power: supply: 88pm860x_battery: possible uninitialized-variable access in measure_vbatt()

From: Li Tuo
Date: Wed Jul 28 2021 - 06:24:19 EST


Hello,

Our static analysis tool finds a possible uninitialized-variable access in the 88pm860x_battery driver in Linux 5.14.0-rc3:

In calc_soc():
369:    int ocv;
376:    switch (state) {
380:    case OCV_MODE_SLEEP:
381:        ret = measure_vbatt(info, OCV_MODE_SLEEP, &ocv);

In measure_vbatt(struct pm860x_battery_info *info, int state, int *data)
176:    switch (state) {
184:    case OCV_MODE_SLEEP:
201:        *data = ((*data & 0xff) * 27 * 25) >> 9;

If the variable state is OCV_MODE_SLEEP, the function measure_vbatt() is called with the argument &ocv,
and the corresponding parameter is data. Thus *data is uninitialized but it is used at line 201.

I am not quite sure whether this possible uninitialized-variable access is real and how to fix it if it is real.
Any feedback would be appreciated, thanks!

Reported-by: TOTE Robot <oslab@xxxxxxxxxxxxxxx>

Best wishes,
Tuo Li