In the Linux kernel, the following vulnerability has been resolved: power: supply: bq256xx: Fix use-after-free in power_supply_changed() Using the devm_ variant for requesting IRQ _before_ the devm_ variant for allocating/registering the power_supply handle, means that the power_supply handle will be deallocated/unregistered _before_ the interrupt handler (since devm_ naturally deallocates in reverse allocation order). This means that during removal, there is a race condition where an interrupt can fire just _after_ the power_supply handle has been freed, but just _before_ the corresponding unregistration of the IRQ handler has run. This will lead to the IRQ handler calling power_supply_changed() with a freed power_supply handle. Which usually crashes the system or otherwise silently corrupts the memory... Note that there is a similar situation which can also happen during probe().

the possibility of an interrupt firing _before_ registering the power_supply handle. This would then lead to the nasty situation of using the power_supply handle uninitialized in power_supply_changed(). Fix this racy use-after-free by making sure the IRQ is requested _after_ the registration of the power_supply handle.