CVE-2026-64183

CVE-2026-64183 · efi: Allocate runtime workqueue before ACPI init

CVSS 5.5 · Medium · EPSS 0.1% · Fix available

dpkg-query -W -f='${source:Package} ${binary:Package} ${Version}\n' | awk '$1=="linux"'

dpkg-query -W -f='${source:Package} ${binary:Package} ${Version}\n' | awk '$1=="linux-hwe-edge"'

curl -fsSL https://patchfirst.dev/check.sh | sh

This page contains facts from public vulnerability sources. Check the original advisory before updating.

This page shows selected source facts. See the linked advisories for the complete description and affected versions.

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

Published

2026-07-19T15:41:05.896Z

Updated

2026-07-19T15:41:05.896Z

Stack: system

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