---
id: CVE-2026-74546
title: 'hwmon: (adt7470) Fix divide-by-zero TOCTOU crash in fan speed read'
summary: |-
  In the Linux kernel, the following vulnerability has been resolved:

  hwmon: (adt7470) Fix divide-by-zero TOCTOU crash in fan speed read

  If the fan data becomes 0 between the FAN_DATA_VALID() check and the
  FAN_PERIOD_TO_RPM() conversion,…
severity: none
vendor: Linux
product: Linux
affected:
  - >-
    Linux >= fc958a61ff6d34a0ec42744d3ff524ee202b2e9f <
    689a2ea75434131d0af58aeb7d51fde40e858b4d
  - >-
    Linux >= fc958a61ff6d34a0ec42744d3ff524ee202b2e9f <
    009240d057e26831cc925feaba4c490209c1d0ba
  - >-
    Linux >= fc958a61ff6d34a0ec42744d3ff524ee202b2e9f <
    d328175045176f85c15c369bd21dc551351e7935
  - >-
    Linux >= fc958a61ff6d34a0ec42744d3ff524ee202b2e9f <
    832069bec79cf6f903441c5769d3cdba95d0af33
  - >-
    Linux >= fc958a61ff6d34a0ec42744d3ff524ee202b2e9f <
    96ad57d31763559d376416cdf3bf5ae79bbbebec
  - >-
    Linux >= fc958a61ff6d34a0ec42744d3ff524ee202b2e9f <
    76963b04b2d1c648d69949d8dd521e1ff7f40b51
  - >-
    Linux >= fc958a61ff6d34a0ec42744d3ff524ee202b2e9f <
    1b46fe9dc8f8de59310f37e6c5e5c0e05ded46c3
  - Linux 5.15
ssvc:
  exploitation: none
  automatable: 'no'
  technicalImpact: partial
  timestamp: '2026-11-06T16:59:29.110410Z'
published: '2026-08-15'
updated: '2026-11-06'
sourceUpdated: '2026-11-06T17:05:48.081Z'
source: CVEORG
sourceUrl: 'https://www.cve.org/CVERecord?id=CVE-2026-74546'
references:
  - url: 'https://git.kernel.org/stable/c/689a2ea75434131d0af58aeb7d51fde40e858b4d'
  - url: 'https://git.kernel.org/stable/c/009240d057e26831cc925feaba4c490209c1d0ba'
  - url: 'https://git.kernel.org/stable/c/d328175045176f85c15c369bd21dc551351e7935'
  - url: 'https://git.kernel.org/stable/c/832069bec79cf6f903441c5769d3cdba95d0af33'
  - url: 'https://git.kernel.org/stable/c/96ad57d31763559d376416cdf3bf5ae79bbbebec'
  - url: 'https://git.kernel.org/stable/c/76963b04b2d1c648d69949d8dd521e1ff7f40b51'
  - url: 'https://git.kernel.org/stable/c/1b46fe9dc8f8de59310f37e6c5e5c0e05ded46c3'
tags:
  - cve.org
epss: 0.00173
epssPercentile: 0.06688
ingestedAt: '2026-11-06T18:00:12.548Z'
---

## Overview

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

hwmon: (adt7470) Fix divide-by-zero TOCTOU crash in fan speed read

If the fan data becomes 0 between the FAN_DATA_VALID() check and the
FAN_PERIOD_TO_RPM() conversion, it will result in a divide-by-zero crash
due to a race with a concurrent update of the cached fan value.

Fix a TOCTOU issue by reading fan data once.

## Affected

- `Linux >= fc958a61ff6d34a0ec42744d3ff524ee202b2e9f < 689a2ea75434131d0af58aeb7d51fde40e858b4d`
- `Linux >= fc958a61ff6d34a0ec42744d3ff524ee202b2e9f < 009240d057e26831cc925feaba4c490209c1d0ba`
- `Linux >= fc958a61ff6d34a0ec42744d3ff524ee202b2e9f < d328175045176f85c15c369bd21dc551351e7935`
- `Linux >= fc958a61ff6d34a0ec42744d3ff524ee202b2e9f < 832069bec79cf6f903441c5769d3cdba95d0af33`
- `Linux >= fc958a61ff6d34a0ec42744d3ff524ee202b2e9f < 96ad57d31763559d376416cdf3bf5ae79bbbebec`
- `Linux >= fc958a61ff6d34a0ec42744d3ff524ee202b2e9f < 76963b04b2d1c648d69949d8dd521e1ff7f40b51`
- `Linux >= fc958a61ff6d34a0ec42744d3ff524ee202b2e9f < 1b46fe9dc8f8de59310f37e6c5e5c0e05ded46c3`
- `Linux 5.15`

## Remediation

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