CVE-2023-53310

In the Linux kernel, the following vulnerability has been resolved:

power: supply: axp288fuelgauge: Fix externalpowerchanged race

fuelgaugeexternalpowerchanged() dereferences info->bat, which gets sets in axp288fuelgauge_probe() like this:

info->bat = devmpowersupplyregister(dev, &fuelgaugedesc, &psycfg);

As soon as devmpowersupplyregister() has called deviceadd() the externalpowerchanged callback can get called. So there is a window where fuelgaugeexternalpowerchanged() may get called while info->bat has not been set yet leading to a NULL pointer dereference.

Fixing this is easy. The externalpowerchanged callback gets passed the powersupply which will eventually get stored in info->bat, so fuelgaugeexternalpower_changed() can simply directly use the passed in psy argument which is always valid.