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

What is CVE-2026-64213?

CVE-2026-64213 is a medium-severity vulnerability in Linux kernel, published on 24 Jul 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: (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.

Which versions are affected by CVE-2026-64213?

It affects 1 product.

Products include Linux kernel.

How do I fix CVE-2026-64213?

Apply the vendor's patch.

Is CVE-2026-64213 being exploited?

There is no known exploitation of CVE-2026-64213 in the wild and no public exploit code.

Other vulnerabilities in Linux kernel

• CVE-2026-53266 Linux Kernel Out-of-Bounds Write Exploited High 8.8
• 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 AZL-93338, BELL-CVE-2026-64213, DEBIAN-CVE-2026-64213, GHSA-mf77-wwf7-m2ff, ROOT-OS-UBUNTU-2204-CVE-2026-64213, UBUNTU-CVE-2026-64213.