---
id: CVE-2026-64213
title: 'hwmon: (lm90) Add lock protection to lm90_alert'
summary: |-
  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 hardw…
severity: none
vendor: Linux
product: Linux
affected:
  - >-
    Linux >= 7a1d220ccb0cc2b808eb176fb05bf55a38179f3f <
    02b88fa993582b4fe228b4143b330b0bb9f28353
  - >-
    Linux >= 7a1d220ccb0cc2b808eb176fb05bf55a38179f3f <
    165ef777ec6f634a5e4b8d9b0dadca8ef91fa90e
  - >-
    Linux >= 7a1d220ccb0cc2b808eb176fb05bf55a38179f3f <
    bed1fc32e0eb653806fa98afcf55f9a311fc4ce2
  - >-
    Linux >= 7a1d220ccb0cc2b808eb176fb05bf55a38179f3f <
    b0b66aae8a94c3663d47e4000b0e81b89ce32186
  - >-
    Linux >= 7a1d220ccb0cc2b808eb176fb05bf55a38179f3f <
    873e919e3101063a7a75989510ccfc125a4391cf
  - Linux 5.3
published: '2026-07-24'
updated: '2026-10-21'
sourceUpdated: '2026-10-21T12:43:11.235Z'
source: CVEORG
sourceUrl: 'https://www.cve.org/CVERecord?id=CVE-2026-64213'
references:
  - url: 'https://git.kernel.org/stable/c/02b88fa993582b4fe228b4143b330b0bb9f28353'
  - url: 'https://git.kernel.org/stable/c/165ef777ec6f634a5e4b8d9b0dadca8ef91fa90e'
  - url: 'https://git.kernel.org/stable/c/bed1fc32e0eb653806fa98afcf55f9a311fc4ce2'
  - url: 'https://git.kernel.org/stable/c/b0b66aae8a94c3663d47e4000b0e81b89ce32186'
  - url: 'https://git.kernel.org/stable/c/873e919e3101063a7a75989510ccfc125a4391cf'
tags:
  - cve.org
epss: 0.00121
epssPercentile: 0.01753
ingestedAt: '2026-10-21T12:48:53.608Z'
---

## Overview

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

- `Linux >= 7a1d220ccb0cc2b808eb176fb05bf55a38179f3f < 02b88fa993582b4fe228b4143b330b0bb9f28353`
- `Linux >= 7a1d220ccb0cc2b808eb176fb05bf55a38179f3f < 165ef777ec6f634a5e4b8d9b0dadca8ef91fa90e`
- `Linux >= 7a1d220ccb0cc2b808eb176fb05bf55a38179f3f < bed1fc32e0eb653806fa98afcf55f9a311fc4ce2`
- `Linux >= 7a1d220ccb0cc2b808eb176fb05bf55a38179f3f < b0b66aae8a94c3663d47e4000b0e81b89ce32186`
- `Linux >= 7a1d220ccb0cc2b808eb176fb05bf55a38179f3f < 873e919e3101063a7a75989510ccfc125a4391cf`
- `Linux 5.3`

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.