CVE-2026-64183

In the Linux kernel, the following vulnerability has been resolved:<br /> <br /> efi: Allocate runtime workqueue before ACPI init<br /> <br /> Since commit<br /> <br /> 5894cf571e14 ("acpi/prmt: Use EFI runtime sandbox to invoke PRM handlers")<br /> <br /> ACPI PRM calls are delegated to a workqueue which runs in a kernel<br /> thread, making it easier to detect and mitigate faulting memory accesses<br /> performed by the firmware.<br /> <br /> Rafael reports that such PRM accesses may occur before efisubsys_init()<br /> executes, which is where the workqueue is allocated, leading to NULL<br /> pointer dereferences. Since acpi_init() [which triggers the early PRM<br /> accesses] executes as a subsys_initcall() as well, and has its own<br /> dependencies that may be sensitive to initcall ordering, deferring<br /> acpi_init() is not an option.<br /> <br /> So instead, split off the workqueue allocation into its own postcore<br /> initcall, as this is the only missing piece to allow EFI runtime calls<br /> to be made. This ensures that EFI runtime call (including PRM calls) are<br /> accessible to all code running at subsys_initcall() level.