CVE-2026-31486

Description

In the Linux kernel, the following vulnerability has been resolved: hwmon: (pmbus/core) Protect regulator operations with mutex The regulator operations pmbus_regulator_get_voltage(), pmbus_regulator_set_voltage(), and pmbus_regulator_list_voltage() access PMBus registers and shared data but were not protected by the update_lock mutex. This could lead to race conditions. However, adding mutex protection directly to these functions causes a deadlock because pmbus_regulator_notify() (which calls regulator_notifier_call_chain()) is often called with the mutex already held (e.g., from pmbus_fault_handler()). If a regulator callback then calls one of the now-protected voltage functions, it will attempt to acquire the same mutex. Rework pmbus_regulator_notify() to utilize a worker function to send notifications outside of the mutex protection. Events are stored as atomics in a per-page bitmask and processed by the worker. Initialize the worker and its associated data during regulator registration, and ensure it is cancelled on device removal using devm_add_action_or_reset(). While at it, remove the unnecessary include of linux/of.h.

Gravité et risque d'exploitation

CVE-2026-31486 obtient un score CVSS de 7.1/10, soit une gravité élevée. Selon le modèle EPSS, la probabilité qu'elle soit exploitée dans les 30 prochains jours est de 0.10 %, ce qui la place devant 0.8 % des CVE référencées.

Que faire ?

• Vérifiez si Linux (versions <=6.12.*, <2c77ae315f3ce9d2c8e1609be74c9358c1fe4e07, 3.19, <754bd2b4a084b90b5e7b630e1f423061a9b9b761, 0, 7.0, 6.12.92, <4e9d723d9f198b86f6882a84c501ba1f39e8d055, <=6.6.*, 6.19.11, <=6.19.*, <=6.18.*, <b26849cffaa7c43355b82e9bef3725e786973a1a, ddbb4db4ced1ba784fcd3500179a7291b6c5d7b7, <acf04e2863132f6d9222f71f3a76fb9782cbe061, <=*, <3.19, 6.6.143, 6.18.21) est présent sur votre parc.
• Appliquez le correctif ou la version corrigée indiqués dans les références de l'éditeur.
• À défaut de correctif, limitez l'exposition (filtrage réseau, désactivation du composant).
• Automatisez la détection : les agents CVE Heimdall (gratuits, open source) corrèlent l'inventaire de vos serveurs avec la base CVE.

Références

• https://git.kernel.org/stable/c/b26849cffaa7c43355b82e9bef3725e786973a1a
• https://git.kernel.org/stable/c/acf04e2863132f6d9222f71f3a76fb9782cbe061
• https://git.kernel.org/stable/c/4e9d723d9f198b86f6882a84c501ba1f39e8d055
• https://git.kernel.org/stable/c/2c77ae315f3ce9d2c8e1609be74c9358c1fe4e07
• https://git.kernel.org/stable/c/754bd2b4a084b90b5e7b630e1f423061a9b9b761