CVE-2026-64213: hwmon: (lm90) Add lock protection to lm90_alert

Severity: medium (CVSS 5.5 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.1% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-07-24 · updated 2026-10-30

Description

In the Linux kernel, the following vulnerability has been resolved: hwmon: (lm90) Add lock protection to lm90_alert Sashiko reports: lm90_alert() executes in the smbus alert context and calls lm90_update_confreg() to disable the hardware alert line, without acquiring hwmon_lock. Concurrently, sysfs write operations (such as lm90_write_convrate) hold the hwmon_lock, temporarily modify data->config, and then restore it. If an alert interrupt occurs concurrently with a sysfs write, the sysfs path will overwrite the alert handler's modifications to data->config and the hardware register. This unintentionally re-enables the hardware alert line while the alarm is still active, causing an interrupt storm. Add the missing lock to lm90_alert() to solve the problem.

Affected products

Linux kernel: from 5.3 before 6.18.34; from 6.19 before 7.0.11; 7.1-rc1, 7.1-rc2, 7.1-rc3 — fixed in 6.18.34, 7.0.11
Linux: 5.3 — fixed in 7.1

How to fix

Upgrade to a fixed version: Linux kernel 6.18.34, 7.0.11; Linux 7.1. Check the vendor advisory for mitigations.

References

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