In the Linux kernel, the following vulnerability has been resolved: ACPI: processor: Update cpuidle driver check in __acpi_processor_start() Commit 7a8c994cbb2d ("ACPI: processor: idle: Optimize ACPI idle driver registration") moved the ACPI idle driver registration to acpi_processor_driver_init() and acpi_processor_power_init() does not register an idle driver any more. Accordingly, the cpuidle driver check in __acpi_processor_start() needs to be updated to avoid calling acpi_processor_power_init() without a cpuidle driver, in which case the registration of the cpuidle device in that function would lead to a NULL pointer dereference in __cpuidle_register_device().
https://git.kernel.org/stable/c/6cfed39c2ce64ac024bbde458a9727105e0b8c66
https://git.kernel.org/stable/c/68f38f648e4b5bed2aeadd2f711e25302e6490f8
https://git.kernel.org/stable/c/0089ce1c056aee547115bdc25c223f8f88c08498