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.
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
- CISA KEV
- Not listed
- Weakness
- CWE-367
- Affected
- linux/linux kernel
- Source
- 416baaa9-dc9f-4396-8d5f-8c081fb06d67
References
- https://git.kernel.org/stable/c/3dceb68f6ad33156032ef4da21a93d84059cca6dPatch
- https://git.kernel.org/stable/c/670d7ef945d3a84683594429aea6ab2cdfa5ceb4Patch
- https://git.kernel.org/stable/c/a9fb6e8835a22f5796c1182ed612daed3fd273afPatch
- https://git.kernel.org/stable/c/bf5b03227f2e6d4360004886d268f9df8993ef8fPatch
- https://git.kernel.org/stable/c/c8cf0c2bdcccc6634b6915ff793b844e12436680Patch
- https://git.kernel.org/stable/c/f2b579a0c37c0df19603d719894a942a295f634aPatch
- https://git.kernel.org/stable/c/f94800fbc26ccf7c81eb791707b038a57aa39a18Patch
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.