CVE-2026-80784
Vulnérabilité non évaluée dans Linux (Linux)
Description
In the Linux kernel, the following vulnerability has been resolved: mptcp: pm: fix memory leak from alloc-during-teardown race mptcp_pm_destroy() empties msk->pm.anno_list and msk->pm.userspace_pm_local_addr_list under msk->pm.lock during socket teardown, dropping the lock between the two. A concurrent userspace PM genl ANNOUNCE on the same msk holds a sock reference via mptcp_token_get_sock() and, in mptcp_pm_nl_announce_doit(), calls mptcp_userspace_pm_append_new_local_addr() and mptcp_pm_announced_alloc(). Both take msk->pm.lock briefly to add to their respective lists. Because the genl handler holds a sock reference, mptcp_pm_destroy() may run on the same msk via mptcp_disconnect(), which invokes mptcp_destroy_common() without dropping the sock refcount, before the handler completes. If the lock acquisitions interleave such that mptcp_pm_destroy() empties a list first, the later alloc adds its entry to a list head that nothing else iterates for this msk, and the entry leaks. kmemleak reports both mptcp_pm_add_addr objects (from mptcp_pm_announced_alloc()) and mptcp_pm_addr_entry objects (from mptcp_userspace_pm_append_new_local_addr()) under sustained concurrent ANNOUNCE + close load against the userspace PM. Add an MPTCP_PM_DESTROYING bit in msk->pm.status, set by mptcp_pm_destroy() under pm.lock before the lists are emptied and checked under pm.lock by the alloc paths. Either the alloc takes pm.lock first, in which case its entry is on the list when mptcp_pm_destroy() frees it; or mptcp_pm_destroy() takes pm.lock first, in which case the later alloc observes the bit and refuses. Found by an MPTCP protocol-flow harness extending BRF (arXiv:2305.08782).
Gravité et risque d'exploitation
CVE-2026-80784 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 6.2 % des CVE référencées.
Que faire ?
- Vérifiez si Linux (versions <=6.1.*, 7.1.11, <=6.12.*, 6.12.106, 0, <=7.1.*, 5.19, 6.6.154, <f48341830e4202db3fe884b819b2db6740f0537d, <=6.6.*, <6c290915a03fc8228b473641025cf762b256dbd2, <efc33b5102ff859bacd390a5f30112d8e0c084c0, <9fe5eebb664ecdba88f3fde18062d94b1d1c465f, <=6.18.*, 6.18.47, <5.19, <=*, 9ab4807c84a4aacfc9b4f79cc81254035e0ec361, <b2a0b55bf613bd3e81ed26a847b0f6b8e6b7f804, <bb32e9a6a9a9f99eeda16c4efe443400f3e43892, 7.2, 6.1.187) 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/f48341830e4202db3fe884b819b2db6740f0537d
- https://git.kernel.org/stable/c/bb32e9a6a9a9f99eeda16c4efe443400f3e43892
- https://git.kernel.org/stable/c/b2a0b55bf613bd3e81ed26a847b0f6b8e6b7f804
- https://git.kernel.org/stable/c/9fe5eebb664ecdba88f3fde18062d94b1d1c465f
- https://git.kernel.org/stable/c/6c290915a03fc8228b473641025cf762b256dbd2
- https://git.kernel.org/stable/c/efc33b5102ff859bacd390a5f30112d8e0c084c0