CVE Catalog

CVE-2025-71111

MediumCVSS 4.7
Published: Updated: Translated: NVD NIST

Exploitation Probability (EPSS)

Low risk
0.11%

1th percentile - higher than 1% of all known CVEs

Summary

In the Linux kernel hwmon w83791d driver, the FAN_FROM_REG macro evaluated its arguments multiple times, leading to Time-of-Check to Time-of-Use (TOCTOU) race conditions in lockless contexts and potential divide-by-zero errors. The fix converts the macro to a static function and moves the minimum limit calculation inside the update lock.

Risk Assessment

This can cause divide-by-zero errors and system instability when reading hardware sensor data. Exploitation requires specific race conditions but results in a kernel crash.

Recommendation

Update the Linux kernel to a version containing the fix that converts the macro to a static function and moves calculations into the critical section.

Related vulnerabilities

Original NVD description (English source)

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.

Vulnerability data from NVD (NIST) · CISA KEV · EPSS