CVE-2026-46111

Description

In the Linux kernel, the following vulnerability has been resolved: Bluetooth: hci_conn: fix potential UAF in create_big_sync Add hci_conn_valid() check in create_big_sync() to detect stale connections before proceeding with BIG creation. Handle the resulting -ECANCELED in create_big_complete() and re-validate the connection under hci_dev_lock() before dereferencing, matching the pattern used by create_le_conn_complete() and create_pa_complete(). Keep the hci_conn object alive across the async boundary by taking a reference via hci_conn_get() when queueing create_big_sync(), and dropping it in the completion callback. The refcount and the lock are complementary: the refcount keeps the object allocated, while hci_dev_lock() serializes hci_conn_hash_del()'s list_del_rcu() on hdev->conn_hash, as required by hci_conn_del(). hci_conn_put() is called outside hci_dev_unlock() so the final put (which resolves to kfree() via bt_link_release) does not run under hdev->lock, though the release path would be safe either way. Without this, create_big_complete() would unconditionally dereference the conn pointer on error, causing a use-after-free via hci_connect_cfm() and hci_conn_del().

Gravité et risque d'exploitation

CVE-2026-46111 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 0.17 %, ce qui la place devant 6.0 % des CVE référencées.

Que faire ?

• Vérifiez si Linux (versions <f8eaf92c57ad99358dd372580d5ff87623343a72, <=6.1.*, 7.0.7, eca0ae4aea66914515e5e3098ea051b518ee5316, <=6.12.*, <=7.0.*, <1750a2df0eab61dc421a7afae74abdd239a44b85, 0, <=6.6.*, 6.0, <d41093723e47255d7d74df86e2736711c1b8486e, <6.0, 6.1.183, <dc34f8d8240f25dd137dc2758ebbcc75e3779142, 7.1, 6.18.32, <=6.18.*, <=*, <6823f730bf195fc296d9edd09e2ca94bc1ff5584, 6.6.140, 6.12.90, <0beddb0c380bed5f5b8e61ddbe14635bb73d0b41) 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/d41093723e47255d7d74df86e2736711c1b8486e
• https://git.kernel.org/stable/c/6823f730bf195fc296d9edd09e2ca94bc1ff5584
• https://git.kernel.org/stable/c/1750a2df0eab61dc421a7afae74abdd239a44b85
• https://git.kernel.org/stable/c/dc34f8d8240f25dd137dc2758ebbcc75e3779142
• https://git.kernel.org/stable/c/f8eaf92c57ad99358dd372580d5ff87623343a72
• https://git.kernel.org/stable/c/0beddb0c380bed5f5b8e61ddbe14635bb73d0b41