power: supply: cpcap-battery: Fix use-after-free in power_supply_changed()

Summary

In the Linux kernel, the following vulnerability has been resolved: power: supply: cpcap-battery: 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.

Timeline

1. May 27, 2026, 12:16 PM UTCCVE published

Affected versions

• Linux Linux

  Version range not reported

• Linux Linux

  4.13

References 8