CVE-2024-42245
Vulnérabilité non évaluée dans Linux (Linux)
Description
In the Linux kernel, the following vulnerability has been resolved: Revert "sched/fair: Make sure to try to detach at least one movable task" This reverts commit b0defa7ae03ecf91b8bfd10ede430cff12fcbd06. b0defa7ae03ec changed the load balancing logic to ignore env.max_loop if all tasks examined to that point were pinned. The goal of the patch was to make it more likely to be able to detach a task buried in a long list of pinned tasks. However, this has the unfortunate side effect of creating an O(n) iteration in detach_tasks(), as we now must fully iterate every task on a cpu if all or most are pinned. Since this load balance code is done with rq lock held, and often in softirq context, it is very easy to trigger hard lockups. We observed such hard lockups with a user who affined O(10k) threads to a single cpu. When I discussed this with Vincent he initially suggested that we keep the limit on the number of tasks to detach, but increase the number of tasks we can search. However, after some back and forth on the mailing list, he recommended we instead revert the original patch, as it seems likely no one was actually getting hit by the original issue.
Gravité et risque d'exploitation
CVE-2024-42245 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 5.4 % des CVE référencées.
Que faire ?
- Vérifiez si Linux (versions <=6.1.*, 6.9.10, <=*, <1e116c18e32b035a2d1bd460800072c8bf96bc44, 6.10, <d467194018dd536fe6c65a2fd3aedfcdb1424903, <2feab2492deb2f14f9675dd6388e9e2bf669c27a, 6.1.100, <=6.6.*, <0fa6dcbfa2e2b97c1e6febbea561badf0931a38b, 0, b0defa7ae03ecf91b8bfd10ede430cff12fcbd06, 6.1, <=6.9.*, <6.1, 6.6.41) 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.