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.
| Date Added | Due Date | Vulnerability Name | Required Action |
|---|---|---|---|
| N/A |
| Type | Version | Base score | Base severity | Vector |
|---|---|---|---|---|
| Primary | 3.1 | 4.7 | MEDIUM | CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H |
| Hyperlink | Source | Resource |
|---|---|---|
| https://git.kernel.org/stable/c/3dceb68f6ad33156032ef4da21a93d84059cca6d | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | Patch |
| https://git.kernel.org/stable/c/670d7ef945d3a84683594429aea6ab2cdfa5ceb4 | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | Patch |
| https://git.kernel.org/stable/c/a9fb6e8835a22f5796c1182ed612daed3fd273af | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | Patch |
| https://git.kernel.org/stable/c/bf5b03227f2e6d4360004886d268f9df8993ef8f | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | Patch |
| https://git.kernel.org/stable/c/c8cf0c2bdcccc6634b6915ff793b844e12436680 | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | Patch |
| https://git.kernel.org/stable/c/f2b579a0c37c0df19603d719894a942a295f634a | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | Patch |
| https://git.kernel.org/stable/c/f94800fbc26ccf7c81eb791707b038a57aa39a18 | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | Patch |