CVE-2026-43086

Description

In the Linux kernel, the following vulnerability has been resolved: ipvs: fix NULL deref in ip_vs_add_service error path When ip_vs_bind_scheduler() succeeds in ip_vs_add_service(), the local variable sched is set to NULL. If ip_vs_start_estimator() subsequently fails, the out_err cleanup calls ip_vs_unbind_scheduler(svc, sched) with sched == NULL. ip_vs_unbind_scheduler() passes the cur_sched NULL check (because svc->scheduler was set by the successful bind) but then dereferences the NULL sched parameter at sched->done_service, causing a kernel panic at offset 0x30 from NULL. Oops: general protection fault, [..] [#1] PREEMPT SMP KASAN NOPTI KASAN: null-ptr-deref in range [0x0000000000000030-0x0000000000000037] RIP: 0010:ip_vs_unbind_scheduler (net/netfilter/ipvs/ip_vs_sched.c:69) Call Trace: <TASK> ip_vs_add_service.isra.0 (net/netfilter/ipvs/ip_vs_ctl.c:1500) do_ip_vs_set_ctl (net/netfilter/ipvs/ip_vs_ctl.c:2809) nf_setsockopt (net/netfilter/nf_sockopt.c:102) [..] Fix by simply not clearing the local sched variable after a successful bind. ip_vs_unbind_scheduler() already detects whether a scheduler is installed via svc->scheduler, and keeping sched non-NULL ensures the error path passes the correct pointer to both ip_vs_unbind_scheduler() and ip_vs_scheduler_put(). While the bug is older, the problem popups in more recent kernels (6.2), when the new error path is taken after the ip_vs_start_estimator() call.

Gravité et risque d'exploitation

CVE-2026-43086 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 0.16 %, ce qui la place devant 5.0 % des CVE référencées.

Que faire ?

• Vérifiez si Linux (versions <=6.12.*, 0, 6.12.83, 7.0, <4039959315008888dd53c37674d33351817a5166, <=6.6.*, <=6.19.*, 6.6.136, <a32dabacee111cea083ddd57a03635672e1bff29, <=6.18.*, <6.2, <c2ddbe577e2ebf63f2d8fb15cdc7503af70f3e94, <9a91797e61d286805ae10a92cc48959c30800556, 705dd34440812735ece298eb5bc153fde9544d42, <=*, 6.19.14, <730663352c9178f33fcf5929f4a37c1f1ca5a693, 6.18.24, 6.2) 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/730663352c9178f33fcf5929f4a37c1f1ca5a693
• https://git.kernel.org/stable/c/4039959315008888dd53c37674d33351817a5166
• https://git.kernel.org/stable/c/a32dabacee111cea083ddd57a03635672e1bff29
• https://git.kernel.org/stable/c/c2ddbe577e2ebf63f2d8fb15cdc7503af70f3e94
• https://git.kernel.org/stable/c/9a91797e61d286805ae10a92cc48959c30800556