CVE-2026-68338

Description

In the Linux kernel, the following vulnerability has been resolved: net/packet: avoid fanout hook re-registration after unregister packet_set_ring() temporarily detaches a socket from packet delivery while reconfiguring its ring. It records the previous running state, clears po->num, unregisters the protocol hook when needed, drops po->bind_lock, and later restores po->num and re-registers the hook from the saved was_running value. That unlocked window can race with NETDEV_UNREGISTER. The notifier can observe the socket as not running, skip __unregister_prot_hook(), and invalidate the per-socket binding by setting po->ifindex to -1 and clearing po->prot_hook.dev. A one-member fanout group can still retain its shared fanout hook device pointer. When packet_set_ring() resumes, re-registering solely from the stale was_running state can re-add the fanout hook after the device has been unregistered. Treat po->ifindex == -1 as an invalidated binding after reacquiring po->bind_lock. This is distinct from ifindex 0, the normal unbound/wildcard state: ifindex -1 marks an existing device binding that was invalidated when the device was unregistered. Restore po->num as before, but do not re-register the hook if device unregister already detached the socket.

Gravité et risque d'exploitation

CVE-2026-68338 obtient un score CVSS de 7.8/10, soit une gravité élevée. Selon le modèle EPSS, la probabilité qu'elle soit exploitée dans les 30 prochains jours est de 0.18 %, ce qui la place devant 6.7 % des CVE référencées.

Que faire ?

• Vérifiez si Linux (versions <0a052e0808e015e68144a9877e6ef42b952c49fa, <=6.1.*, 7.2, <=6.12.*, <50aff80475abd3533eef4320477037e6fcc6b56e, 6.12.101, 0, <c820f4b7f2fa38f8769db0d0cefdd94e2721504d, 3.1, <=7.1.*, <1bc55c29cd85818e9052f17deb287d5a11fb817f, 5.15.216, <a885387dae7986a55bae5c77a15bdd447f64e9b9, <=5.10.*, <=6.6.*, <3.1, <4628efbdc7affd094181f5263e65c1062e31f15f, 6.18.42, 7.1.6, 6.1.183, <=6.18.*, <acb40ebfa5c4d62f84339fcbf713f2a9fd033a71, <=*, <=5.15.*, <80ec024d53a05c60ad1d08968dcf745f10c1665c, 5.10.265, 6.6.148, dc99f600698dcac69b8f56dda9a8a00d645c5ffc) 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/acb40ebfa5c4d62f84339fcbf713f2a9fd033a71
• https://git.kernel.org/stable/c/c820f4b7f2fa38f8769db0d0cefdd94e2721504d
• https://git.kernel.org/stable/c/4628efbdc7affd094181f5263e65c1062e31f15f
• https://git.kernel.org/stable/c/80ec024d53a05c60ad1d08968dcf745f10c1665c
• https://git.kernel.org/stable/c/0a052e0808e015e68144a9877e6ef42b952c49fa
• https://git.kernel.org/stable/c/1bc55c29cd85818e9052f17deb287d5a11fb817f
• https://git.kernel.org/stable/c/a885387dae7986a55bae5c77a15bdd447f64e9b9
• https://git.kernel.org/stable/c/50aff80475abd3533eef4320477037e6fcc6b56e