CVE-2026-98773
Vulnérabilité non évaluée dans Linux (Linux)
Description
In the Linux kernel, the following vulnerability has been resolved: USB: cdc-acm: skip URB restart in port_shutdown if disconnected acm_port_shutdown() is called from the tty-port machinery whenever the last user closes the port. acm_disconnect() sets acm->disconnected and calls tty_port_tty_vhangup(), which eventually triggers port_shutdown(). At that point acm_disconnect() has already called acm_poison_urbs() and is about to free the control and read URBs. However, acm_port_shutdown() unconditionally calls acm_unpoison_urbs() and, when the ALWAYS_POLL_CTRL quirk is set, immediately re-submits the ctrlurb and all read URBs. If the concurrent acm_disconnect() then frees those URBs and their DMA buffers while they are in-flight, the result is a use-after-free in acm_ctrl_irq() or acm_read_bulk_callback() accessing the freed DMA memory. Fix by checking acm->disconnected after draining the delayed anchor and returning early: if we are in a disconnect path the URBs must remain poisoned and must not be resubmitted. The early return is placed after the delayed-anchor drain loop because that loop only cancels write-side accounting (wb->use = false and autopm counter) and does not touch the hardware path.
Gravité et risque d'exploitation
CVE-2026-98773 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 0.17 %, ce qui la place devant 5.7 % des CVE référencées.
Que faire ?
- Vérifiez si Linux (versions <420ca35af891d33522cc08504768ccd60a4c450a, <=6.12.*, <6.12.113, <a0ed07b5bbb2d8fcef86810453216070691816e7, 6.12.83, 7.0.1, 0, 7.2.10, <7.1, 6.1.175, 6.6.136, <6.18.56, <6.20, 603d5a7110832e10165d21f9a1486399457177de, f77f10bc76c2da86b4248269472f6d971e37828b, 7.1, <=6.18.*, <6.2, <=7.2.*, <6.7, f58752ebcb35e156c85cd1a82d6579c7af3b9023, 6.12.113, d826061aa64cb28089bf4c73e301dd7928662b84, <=*, 6.19.14, 8fb82e3555a7d56a05d8ef0edee9859f889c0860, 6.18.56, 6.18.24, <dc614d6bc991740d41d5a99ac7765c4b675dda88, 5d29d7ff8679e5a525f22da467ba33c042e8029b, <9742905d9ed5bf23ebe4c100dec80b6bc50fb522, 283f8162cc3c82086537cbc7dc01870dbeb07a91, 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.