CVE-2026-43392
Vulnérabilité non évaluée dans Linux (Linux)
Description
In the Linux kernel, the following vulnerability has been resolved: sched_ext: Fix starvation of scx_enable() under fair-class saturation During scx_enable(), the READY -> ENABLED task switching loop changes the calling thread's sched_class from fair to ext. Since fair has higher priority than ext, saturating fair-class workloads can indefinitely starve the enable thread, hanging the system. This was introduced when the enable path switched from preempt_disable() to scx_bypass() which doesn't protect against fair-class starvation. Note that the original preempt_disable() protection wasn't complete either - in partial switch modes, the calling thread could still be starved after preempt_enable() as it may have been switched to ext class. Fix it by offloading the enable body to a dedicated system-wide RT (SCHED_FIFO) kthread which cannot be starved by either fair or ext class tasks. scx_enable() lazily creates the kthread on first use and passes the ops pointer through a struct scx_enable_cmd containing the kthread_work, then synchronously waits for completion. The workfn runs on a different kthread from sch->helper (which runs disable_work), so it can safely flush disable_work on the error path without deadlock.
Gravité et risque d'exploitation
CVE-2026-43392 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 <05ab9ec5dc24f234e0a2fecf3e6ff937c68f7d81, 6.12, <e0b14bf06393be137d3efb6a3b7cd5b4b9810a6b, <=6.12.*, <=*, 6.19.9, <c44198f25fdfecc0ec0fe366bf8a47fe17d8e229, 6.12.78, <=6.18.*, 8c2090c504e998c8f34ec870bae71dafcc96a6e0, 0, <=6.19.*, <6.12, 7.0, 6.18.20, <b06ccbabe2506fd70b9167a644978b049150224a) 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.