Skip to content
Fencer Vulns
medium 5.5

CVE-2026-23186 json

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

published 2026-02-14 8 mo ago modified 2026-11-05 3 d ago also EUVD-2026-5856

cvss
5.5
version 3.1, NVD
cisa kev
Not listed
not in CISA's catalog
epss
0.1%
EPSS 0.1% chance of exploitation in 30 days, percentile 0%
public exploits
0
none known

Summary

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().

Patch / fix

  • Linux Linux 6.18.10, 6.19
  • linux Debian 14 6.18.10-1

debian advisories DEBIAN-CVE-2026-23186

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2026-23186 updated cvss 5.5

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

  • Red Hat Enterprise Linux 9 rv, perf, rtla, kernel, bpftool, libperf, +83 more Red Hat Enterprise Linux 10 kernel
    affected: workaround, no fix available “Fix deferred”
  • Red Hat Enterprise Linux 6 perf, kernel, python-perf, kernel-kdump, kernel-firmware, kernel-bootwrapper, +1 more Red Hat Enterprise Linux 7 perf, kernel, bpftool, kernel-rt, python-perf, kernel-kdump, +8 more Red Hat Enterprise Linux 8 perf, kernel, bpftool, kernel-rt, kernel-core, kernel-tools, +29 more
    not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

CISA SSVC

Exploitation
none
Automatable
no
Technical impact
partial
Assessed
3 d ago

Exploit prediction

0.10% chance of exploitation in the next 30 days, higher than 0% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
NVD 3.1 5.5 CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

Affected products

  • Linux Linux

Classification

Weakness
Technology feeds

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.