CVE-2026-89569
Vulnérabilité élevée dans Linux (Linux)
Description
In the Linux kernel, the following vulnerability has been resolved: Bluetooth: RFCOMM: serialize security confirmation handling rfcomm_security_cfm() looks up a session on session_list and then walks its DLC list without holding rfcomm_mutex. Since RFCOMM session teardown uses rfcomm_mutex, krfcommd can close and free the same session and DLCs concurrently: hci_rx_work krfcommd ----------- --------- rfcomm_session_get() rfcomm_lock() rfcomm_session_close() rfcomm_dlc_unlink() rfcomm_session_del() kfree(s) rfcomm_unlock() walk s->dlcs The callback can then read a freed session list head and touch freed DLCs while updating their flags or timers. Serialize the session lookup and DLC traversal in rfcomm_security_cfm() with rfcomm_mutex. This matches the existing RFCOMM session lifetime rules and prevents concurrent rfcomm_session_del() / rfcomm_dlc_unlink() from tearing the objects down while the callback is using them. KASAN reported: BUG: KASAN: slab-use-after-free in rfcomm_security_cfm+0x41c/0x440 Read of size 8 at addr ffff888111fb3960 by task kworker/u17:1/89 Workqueue: hci0 hci_rx_work Call Trace: rfcomm_security_cfm+0x41c/0x440 hci_encrypt_cfm+0x139/0x590 hci_encrypt_change_evt+0x37b/0xc40 hci_event_packet+0x71b/0xb20 hci_rx_work+0x293/0x730 Allocated by task 69: rfcomm_session_add+0x9e/0x2f0 rfcomm_run+0x44b/0x41e0 Freed by task 69: kfree+0x131/0x3c0 rfcomm_session_del+0x188/0x220 rfcomm_run+0x1985/0x41e0
Gravité et risque d'exploitation
CVE-2026-89569 obtient un score CVSS de 8.8/10, soit une gravité élevée. Selon le modèle EPSS, la probabilité qu'elle soit exploitée dans les 30 prochains jours est de 0.34 %, ce qui la place devant 26.5 % des CVE référencées.
Que faire ?
- Vérifiez si Linux (versions <=6.1.*, <946d76db77ee5f922968ce558629ae47b381e3fc, <=6.12.*, <62ce8b33eb238cf18c15207332fbdc26d858f592, 5.15.221, 5.10.270, 0, 7.2.4, <1b7841ffad08e911e8c4b9470f3fa08423568940, 6.1.188, 08c30aca9e698faddebd34f81e1196295f9dc063, <82425b14f0fb22e46cfddc56d6465570f5ed0ce6, <fbf7961964a6e93360179f64712320ae9a1e9577, <759c185d0bbdb131357408f50b8735e04ed3caff, <3.10, <=5.10.*, <=6.6.*, 6.6.157, <=6.18.*, <=7.2.*, <7ded3264106418c6456ccceaafd9fda596ce12c3, <=*, <3873f3449701b3dc98cba577923be6493598e7a1, <=5.15.*, 3.10, 6.18.50, 6.12.109, 7.3) 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/62ce8b33eb238cf18c15207332fbdc26d858f592
- https://git.kernel.org/stable/c/3873f3449701b3dc98cba577923be6493598e7a1
- https://git.kernel.org/stable/c/7ded3264106418c6456ccceaafd9fda596ce12c3
- https://git.kernel.org/stable/c/82425b14f0fb22e46cfddc56d6465570f5ed0ce6
- https://git.kernel.org/stable/c/1b7841ffad08e911e8c4b9470f3fa08423568940
- https://git.kernel.org/stable/c/946d76db77ee5f922968ce558629ae47b381e3fc
- https://git.kernel.org/stable/c/fbf7961964a6e93360179f64712320ae9a1e9577
- https://git.kernel.org/stable/c/759c185d0bbdb131357408f50b8735e04ed3caff
