CVE-2026-45885power: supply: cpcap-battery: Fix use-after-free in power_supply_changed()

Official description

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.

Affected packages & fixed versions

Affected products (as reported)

References

• https://git.kernel.org/stable/c/c549dd3de4b3f6e726d1b8386d40ccf7d3abdbe4
• https://git.kernel.org/stable/c/3ff75cba1c98349a23a8f9333981deba1972cc11
• https://git.kernel.org/stable/c/2ce2334be155bd8bad6377e99984246ce4dbd08c
• https://git.kernel.org/stable/c/cbb9b07f88a9ef6518934c41eb3e8cf840d657d5
• https://git.kernel.org/stable/c/f3fbe309c9bfe1aac1e2b26543e9dc4829f3275a
• https://git.kernel.org/stable/c/2841bbb5a35c4449c0a0458e8e476b2a62f95147
• https://git.kernel.org/stable/c/e261be6f18929f2397cd54cd583a2df624c129c1
• https://git.kernel.org/stable/c/642f33e34b969eedec334738fd5df95d2dc42742