CVE-2024-43869
Vulnérabilité non évaluée dans Linux (Linux)
Description
In the Linux kernel, the following vulnerability has been resolved: perf: Fix event leak upon exec and file release The perf pending task work is never waited upon the matching event release. In the case of a child event, released via free_event() directly, this can potentially result in a leaked event, such as in the following scenario that doesn't even require a weak IRQ work implementation to trigger: schedule() prepare_task_switch() =======> <NMI> perf_event_overflow() event->pending_sigtrap = ... irq_work_queue(&event->pending_irq) <======= </NMI> perf_event_task_sched_out() event_sched_out() event->pending_sigtrap = 0; atomic_long_inc_not_zero(&event->refcount) task_work_add(&event->pending_task) finish_lock_switch() =======> <IRQ> perf_pending_irq() //do nothing, rely on pending task work <======= </IRQ> begin_new_exec() perf_event_exit_task() perf_event_exit_event() // If is child event free_event() WARN(atomic_long_cmpxchg(&event->refcount, 1, 0) != 1) // event is leaked Similar scenarios can also happen with perf_event_remove_on_exec() or simply against concurrent perf_event_release(). Fix this with synchonizing against the possibly remaining pending task work while freeing the event, just like is done with remaining pending IRQ work. This means that the pending task callback neither need nor should hold a reference to the event, preventing it from ever beeing freed.
Gravité et risque d'exploitation
CVE-2024-43869 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 0.21 %, ce qui la place devant 10.8 % des CVE référencées.
Que faire ?
- Vérifiez si Linux (versions 6.10.3, <=6.1.*, 78e1317a174edbfd1182599bf76c092a2877672c, 6.1.103, 5.15.165, 0, <9ad46f1fef421d43cdab3a7d1744b2f43b54dae0, <f34d8307a73a18de5320fcc6f40403146d061891, 5.15.84, 8bffa95ac19ff27c8261904f89d36c7fcf215d59, <=6.6.*, <3a5465418f5fd970e86a86c7f4075be262682840, <ed2c202dac55423a52d7e2290f2888bf08b8ee99, <104e258a004037bc7dba9f6085c71dad6af57ad4, 6.0.14, 6.1, 6.11, <=*, <=5.15.*, 6.6.44, <5.15.165, <=6.10.*, 517e6a301f34613bff24a8e35b5455884f2d83d8, <6.1) 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/9ad46f1fef421d43cdab3a7d1744b2f43b54dae0
- https://git.kernel.org/stable/c/ed2c202dac55423a52d7e2290f2888bf08b8ee99
- https://git.kernel.org/stable/c/104e258a004037bc7dba9f6085c71dad6af57ad4
- https://git.kernel.org/stable/c/f34d8307a73a18de5320fcc6f40403146d061891
- https://git.kernel.org/stable/c/3a5465418f5fd970e86a86c7f4075be262682840