SB20260816180 - Time-of-check Time-of-use (TOCTOU) Race Condition in Linux kernel hwmon driver

Description

This security bulletin contains information about 1 vulnerability.

1) Time-of-check Time-of-use (TOCTOU) Race Condition (CVE-ID: CVE-2026-74546)

CWE-ID: CWE-367 - Time-of-check Time-of-use (TOCTOU) Race Condition

CVSSv4: 6.8 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N]

The vulnerability allows a local user to cause a denial of service.

The vulnerability exists due to a time-of-check time-of-use race condition in the adt7470 fan speed read handler when reading cached fan data during fan speed conversion. A local user can trigger concurrent updates of the cached fan value to cause a denial of service.

The issue can lead to a divide-by-zero crash if the fan data changes to 0 between the validity check and the RPM conversion.

Remediation

Install update from vendor's website.

References

• https://git.kernel.org/stable/c/1b46fe9dc8f8de59310f37e6c5e5c0e05ded46c3
• https://git.kernel.org/stable/c/76963b04b2d1c648d69949d8dd521e1ff7f40b51
• https://git.kernel.org/stable/c/832069bec79cf6f903441c5769d3cdba95d0af33
• https://git.kernel.org/stable/c/96ad57d31763559d376416cdf3bf5ae79bbbebec
• https://git.kernel.org/stable/c/d328175045176f85c15c369bd21dc551351e7935