CVE-2026-45879

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

power: supply: bq25980: 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.

Weakness

The product reuses or references memory after it has been freed. At some point afterward, the memory may be allocated again and saved in another pointer, while the original pointer references a location somewhere within the new allocation. Any operations using the original pointer are no longer valid because the memory “belongs” to the code that operates on the new pointer.

Affected Software

Potential Mitigations

References

• https://git.kernel.org/stable/c/03d1e4ee4e6aa6d2966e883e4ca0e5be73bf1b7c
• https://git.kernel.org/stable/c/0560a4b09c92e2ecaa883965cf6f9ca51c158ff9
• https://git.kernel.org/stable/c/0de95d29d847c6217b7d5845e24a71a4aee7b359
• https://git.kernel.org/stable/c/16875e3b7bc9e59bfa0acaf1e43f275a6f42a30f
• https://git.kernel.org/stable/c/4aeaf03c17260415c2fdd55992f9ad4188d5455a
• https://git.kernel.org/stable/c/5f0b1cb41906e86b64bf69f5ededb83b0d757c27
• https://git.kernel.org/stable/c/86f93dfb23f5bf4f285c4256a7e909d222f7de56
• https://git.kernel.org/stable/c/abea607ff2f62f4c0a5fb29f7fbdaaab163276a4