CVE-2026-23120

Description

In the Linux kernel, the following vulnerability has been resolved: l2tp: avoid one data-race in l2tp_tunnel_del_work() We should read sk->sk_socket only when dealing with kernel sockets. syzbot reported the following data-race: BUG: KCSAN: data-race in l2tp_tunnel_del_work / sk_common_release write to 0xffff88811c182b20 of 8 bytes by task 5365 on cpu 0: sk_set_socket include/net/sock.h:2092 [inline] sock_orphan include/net/sock.h:2118 [inline] sk_common_release+0xae/0x230 net/core/sock.c:4003 udp_lib_close+0x15/0x20 include/net/udp.h:325 inet_release+0xce/0xf0 net/ipv4/af_inet.c:437 __sock_release net/socket.c:662 [inline] sock_close+0x6b/0x150 net/socket.c:1455 __fput+0x29b/0x650 fs/file_table.c:468 ____fput+0x1c/0x30 fs/file_table.c:496 task_work_run+0x131/0x1a0 kernel/task_work.c:233 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline] __exit_to_user_mode_loop kernel/entry/common.c:44 [inline] exit_to_user_mode_loop+0x1fe/0x740 kernel/entry/common.c:75 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:226 [inline] syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:256 [inline] syscall_exit_to_user_mode_work include/linux/entry-common.h:159 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:194 [inline] do_syscall_64+0x1e1/0x2b0 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f read to 0xffff88811c182b20 of 8 bytes by task 827 on cpu 1: l2tp_tunnel_del_work+0x2f/0x1a0 net/l2tp/l2tp_core.c:1418 process_one_work kernel/workqueue.c:3257 [inline] process_scheduled_works+0x4ce/0x9d0 kernel/workqueue.c:3340 worker_thread+0x582/0x770 kernel/workqueue.c:3421 kthread+0x489/0x510 kernel/kthread.c:463 ret_from_fork+0x149/0x290 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246 value changed: 0xffff88811b818000 -> 0x0000000000000000

Gravité et risque d'exploitation

CVE-2026-23120 obtient un score CVSS de 0.0/10, soit une gravité non évaluée. Selon le modèle EPSS, la probabilité qu'elle soit exploitée dans les 30 prochains jours est de 0.13 %, ce qui la place devant 2.6 % des CVE référencées.

Que faire ?

• Vérifiez si Linux (versions <=6.1.*, <68e92085427c84e7679ddb53c0d68836d220b6e7, <=6.12.*, <4.16, 0, <7a29f6bf60f2590fe5e9c4decb451e19afad2bcf, <3d6d414b214ce31659bded2f8df50c93a3769474, 5.15.199, 18bdaefc715b4530b4b2fe670506bb47713664cc, 3.16.57, <=5.10.*, <=6.6.*, 4.15.8, 5.10.249, 6.18.8, <1f63ca44b4f419a1663d94d1bb0b4e2beb73fdb4, <32d417497b79efb403d75f4c185fe6fd9d64b94f, 6.1.162, <=6.18.*, <36c40a80109f1771d59558050b1a71e13c60c759, 6.12.68, 15df699fdc5af46a9fb15ae2d9326294852de5b5, d00fa9adc528c1b0e64d532556764852df8bd7b9, 4.16, <eae074dab764ea181bbed5e88626889319177498, <=*, <=5.15.*, 6.19, <3.17, 6.6.122) 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/1f63ca44b4f419a1663d94d1bb0b4e2beb73fdb4
• https://git.kernel.org/stable/c/36c40a80109f1771d59558050b1a71e13c60c759
• https://git.kernel.org/stable/c/eae074dab764ea181bbed5e88626889319177498
• https://git.kernel.org/stable/c/68e92085427c84e7679ddb53c0d68836d220b6e7
• https://git.kernel.org/stable/c/3d6d414b214ce31659bded2f8df50c93a3769474
• https://git.kernel.org/stable/c/32d417497b79efb403d75f4c185fe6fd9d64b94f
• https://git.kernel.org/stable/c/7a29f6bf60f2590fe5e9c4decb451e19afad2bcf