SOC status:Duty analyst on shift

UK Cyber Defence
VulnerabilityModified

CVE-2025-71111

In the Linux kernel, the following vulnerability has been resolved: hwmon: (w83791d) Convert macros to functions to avoid TOCTOU The macro FAN_FROM_REG evaluates its arguments multiple times.

MEDIUM 4.7EPSS 0.10%

Does this matter?

Lower severity and a low EPSS score (0.10%). Track it; it rarely justifies an emergency change on its own.

Description

In the Linux kernel, the following vulnerability has been resolved: hwmon: (w83791d) Convert macros to functions to avoid TOCTOU The macro FAN_FROM_REG evaluates its arguments multiple times. When used in lockless contexts involving shared driver data, this leads to Time-of-Check to Time-of-Use (TOCTOU) race conditions, potentially causing divide-by-zero errors. Convert the macro to a static function. This guarantees that arguments are evaluated only once (pass-by-value), preventing the race conditions. Additionally, in store_fan_div, move the calculation of the minimum limit inside the update lock. This ensures that the read-modify-write sequence operates on consistent data. Adhere to the principle of minimal changes by only converting macros that evaluate arguments multiple times and are used in lockless contexts.

CVSS 3.1
4.7 MEDIUMCVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H
EPSS
0.10% probability · 1th percentile
Public exploits
None in Exploit-DB
CISA KEV
Not listed
Weakness
CWE-367, CWE-362
Affected
linux/linux kernel
Source
416baaa9-dc9f-4396-8d5f-8c081fb06d67
EPSS trend
0%3%5%27 October 2026: 0.10%27 October 202627 October 2026

EPSS 0.1% since 27 October 2026; no change recorded yet. Points are recorded when the score first appears and whenever it moves by a percentage point or more.

Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.