Medium 4.7Published Jan 14, 2026

CVE-2025-71111hwmon: (w83791d) Convert macros to functions to avoid TOCTOU

Updated under an hour ago (Oct 26, 2026, 2:30 PM ET)

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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: 4.7 MEDIUM (v3.1, NVD)CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H
Weakness (CWE): CWE-362
Known exploited: Not in CISA's KEV catalog
EPSS (exploitation in the next 30 days): Not loaded for this CVE
Assigned by: Linux
NVD analysis: Modified
Record last updated: Oct 19, 2026
First seen by InfoSec Signals: Oct 9, 2026

Affected products

Affected products

Linux Linux linux:linux (from the name)	9873964d6eb24bd0205394f9b791de9eddbcb855 builds before 3dceb68f6ad33156032ef4da21a93d84059cca6d; from 9873964d6eb24bd0205394f9b791de9eddbcb855 before bf5b03227f2e6d4360004886d268f9df8993ef8f; from 9873964d6eb24bd0205394f9b791de9eddbcb855 before f2b579a0c37c0df19603d719894a942a295f634a; from 9873964d6eb24bd0205394f9b791de9eddbcb855 before f94800fbc26ccf7c81eb791707b038a57aa39a18; from 9873964d6eb24bd0205394f9b791de9eddbcb855 before a9fb6e8835a22f5796c1182ed612daed3fd273af; from 9873964d6eb24bd0205394f9b791de9eddbcb855 before c8cf0c2bdcccc6634b6915ff793b844e12436680; 9873964d6eb24bd0205394f9b791de9eddbcb855 builds before 670d7ef945d3a84683594429aea6ab2cdfa5ceb4	CNA record
linux linux_kernel linux:linux_kernel	from 2.6.18.1 before 5.10.248; from 5.11 before 5.15.198; from 5.16 before 6.1.160; from 6.2 before 6.6.120; from 6.7 before 6.12.64; from 6.13 before 6.18.3; 2.6.18; 6.19; and 7 more ranges	NVD

References

References

https://git.kernel.org/stable/c/3dceb68f6ad33156032ef4da21a93d84059cca6d	patch
https://git.kernel.org/stable/c/bf5b03227f2e6d4360004886d268f9df8993ef8f	patch
https://git.kernel.org/stable/c/f2b579a0c37c0df19603d719894a942a295f634a	patch
https://git.kernel.org/stable/c/f94800fbc26ccf7c81eb791707b038a57aa39a18	patch
https://git.kernel.org/stable/c/a9fb6e8835a22f5796c1182ed612daed3fd273af	patch
https://git.kernel.org/stable/c/c8cf0c2bdcccc6634b6915ff793b844e12436680	patch
https://git.kernel.org/stable/c/670d7ef945d3a84683594429aea6ab2cdfa5ceb4	patch

The CVE record on cve.org NVD's entry

The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.