CVE-2026-23186 hwmon: (acpi_power_meter) Fix deadlocks related to acpi_power_meter_notify()

What is CVE-2026-23186?

CVE-2026-23186 is a medium-severity vulnerability in Linux kernel, published on 14 Feb 2026. It can only be exploited from the same machine or local network, with no action from the victim.

Official description

In the Linux kernel, the following vulnerability has been resolved:

hwmon: (acpi_power_meter) Fix deadlocks related to acpi_power_meter_notify()

The acpi_power_meter driver's .notify() callback function, acpi_power_meter_notify(), calls hwmon_device_unregister() under a lock that is also acquired by callbacks in sysfs attributes of the device being unregistered which is prone to deadlocks between sysfs access and device removal.

Address this by moving the hwmon device removal in acpi_power_meter_notify() outside the lock in question, but notice that doing it alone is not sufficient because two concurrent METER_NOTIFY_CONFIG notifications may be attempting to remove the same device at the same time. To prevent that from happening, add a new lock serializing the execution of the switch () statement in acpi_power_meter_notify(). For simplicity, it is a static mutex which should not be a problem from the performance perspective.

The new lock also allows the hwmon_device_register_with_info() in acpi_power_meter_notify() to be called outside the inner lock because it prevents the other notifications handled by that function from manipulating the "resource" object while the hwmon device based on it is being registered. The sending of ACPI netlink messages from acpi_power_meter_notify() is serialized by the new lock too which generally helps to ensure that the order of handling firmware notifications is the same as the order of sending netlink messages related to them.

In addition, notice that hwmon_device_register_with_info() may fail in which case resource->hwmon_dev will become an error pointer, so add checks to avoid attempting to unregister the hwmon device pointer to by it in that case to acpi_power_meter_notify() and acpi_power_meter_remove().

Weakness: CWE-667

Which versions are affected by CVE-2026-23186?

It affects 1 product.

Products include Linux kernel.

How do I fix CVE-2026-23186?

Apply the vendor's patch.

Is CVE-2026-23186 being exploited?

There is no known exploitation of CVE-2026-23186 in the wild and no public exploit code.

Other vulnerabilities in Linux kernel

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• CVE-2013-6282 Linux Kernel Improper Input Validation Exploited High 8.8
• CVE-2022-0185 Linux Kernel Heap-Based Buffer Overflow Exploited High 8.4
• CVE-2013-2094 Linux Kernel Privilege Escalation Exploited High 8.4
• CVE-2026-53362 Linux Kernel Unspecified Exploited High 7.8

All Linux kernel vulnerabilities

Sources

• CVE record
• NVD
• OSV
• GitHub advisory
• How this page is made

Also known as BELL-CVE-2026-23186, DEBIAN-CVE-2026-23186, GHSA-2m65-7fpj-78p9, UBUNTU-CVE-2026-23186.