CVE-2026-89643
Vulnérabilité critique dans Linux (Linux)
Description
In the Linux kernel, the following vulnerability has been resolved: audit: avoid dropping live tree ref on fsnotify rule autoremove audit_del_rule() is used for both netlink deletion templates and internal fsnotify autoremove. The former passes a parsed template which owns a temporary tree reference; the latter passes the installed entry itself. The unconditional audit_put_tree() at the end of audit_del_rule() assumes the template case. For mixed AUDIT_DIR plus AUDIT_EXE rules, an fsnotify autoremove event therefore drops the installed rule's live tree reference. Repeating this across rules sharing the same tree can free the tree while another rule still references it, and a later autoremove dereferences the freed pathname while comparing rules. Move the temporary-tree put to audit_rule_change(), the caller that owns deletion templates. Keep it in the AUDIT_DEL_RULE cleanup so both successful deletion and -ENOENT still release the parser-owned tree. [PM: dropped unnecessary comment for line length reasons]
Gravité et risque d'exploitation
CVE-2026-89643 obtient un score CVSS de 9.8/10, soit une gravité critique. Selon le modèle EPSS, la probabilité qu'elle soit exploitée dans les 30 prochains jours est de 0.71 %, ce qui la place devant 52.8 % des CVE référencées.
Que faire ?
- Vérifiez si Linux (versions <4.3, <=6.1.*, <b322cc7adcd2e6ec1594d187533a126506ab545c, <=6.12.*, <636a99bab36ba27515363d325866c0273ac83b3e, 5.15.221, 5.10.270, 0, <cf37b61b5420fd4600fe78cf8c24da6e4d9bfe28, 7.2.4, 6.1.188, <583cf579b32d99e3fe4e9c8ecc4d852e3708fbec, <783f0f0974c156aca630f4ffff248671082a098d, <=5.10.*, <=6.6.*, 6.6.157, <01b0ec8c397be65ff710777c97017ca1de56ef8e, <=6.18.*, <=7.2.*, 4.3, <695c85dc345a4e0292739f004c261bedef3f27e6, <=*, 34d99af52ad40bd498ba66970579a5bc1fb1a3bc, <=5.15.*, <9cac21f8eb82675ed19fb955b8bbb9dd14cc3d58, 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/9cac21f8eb82675ed19fb955b8bbb9dd14cc3d58
- https://git.kernel.org/stable/c/b322cc7adcd2e6ec1594d187533a126506ab545c
- https://git.kernel.org/stable/c/695c85dc345a4e0292739f004c261bedef3f27e6
- https://git.kernel.org/stable/c/01b0ec8c397be65ff710777c97017ca1de56ef8e
- https://git.kernel.org/stable/c/cf37b61b5420fd4600fe78cf8c24da6e4d9bfe28
- https://git.kernel.org/stable/c/636a99bab36ba27515363d325866c0273ac83b3e
- https://git.kernel.org/stable/c/583cf579b32d99e3fe4e9c8ecc4d852e3708fbec
- https://git.kernel.org/stable/c/783f0f0974c156aca630f4ffff248671082a098d