CVE-2026-74748
Vulnérabilité élevée dans Linux (Linux)
Description
In the Linux kernel, the following vulnerability has been resolved: netfilter: ipset: fix refcount race between list:set GC and swap __ip_set_put_byindex() resolved the index to a set pointer under RCU, then took ip_set_ref_lock in __ip_set_put() to decrement set->ref. ip_set_swap() holds that same lock while swapping both the ip_set_list slots and the two sets' ref counters, so it can interleave between the dereference and the lock acquisition, leaving the caller to decrement a set whose reference already moved to the other index and hit BUG_ON(set->ref == 0). list_set_gc() reaches this from timer softirq, which the nfnl mutex does not serialize against swap: an expiring list:set member calls list_set_del() -> ip_set_put_byindex() while IPSET_CMD_SWAP runs on the referenced sets. Resolve the index and decrement under ip_set_ref_lock, as ip_set_swap() already does, keeping the refcount tied to the index rather than to a stale set pointer. kernel BUG at net/netfilter/ipset/ip_set_core.c:685! Oops: invalid opcode: 0000 [#1] SMP KASAN NOPTI RIP: 0010:ip_set_put_byindex (net/netfilter/ipset/ip_set_core.c:870) Call Trace: <IRQ> list_set_del (net/netfilter/ipset/ip_set_list_set.c:159) set_cleanup_entries (net/netfilter/ipset/ip_set_list_set.c:181) list_set_gc (net/netfilter/ipset/ip_set_list_set.c:578) call_timer_fn (kernel/time/timer.c:1748) __run_timers (kernel/time/timer.c:1799 kernel/time/timer.c:2374) run_timer_softirq (kernel/time/timer.c:2405) </IRQ> Kernel panic - not syncing: Fatal exception in interrupt
Gravité et risque d'exploitation
CVE-2026-74748 obtient un score CVSS de 7.8/10, soit une gravité élevée. Selon le modèle EPSS, la probabilité qu'elle soit exploitée dans les 30 prochains jours est de 0.14 %, ce qui la place devant 2.9 % des CVE référencées.
Que faire ?
- Vérifiez si Linux (versions <=6.1.*, <=6.12.*, 5.15.217, <b891e7a6bb06e0f6560e5932665ac660acd12225, 0, <=7.1.*, <20cb13a523f0a05cb2d0a7d72abae687683712e0, <24ffcb1e1688c55fd2a505f064295cd28eac546d, <=5.10.*, <=6.6.*, 3.8, 5.10.266, <0c88868271653537ed443272dd8e7d13634d214b, 9076aea76538556224e7d73ab718f8841330818a, <=6.18.*, 6.1.184, <97a01de0c6321b7210d30d0a4d60f10f561097c7, 7.1.10, <3.8, <c21afc7c216a4d257a4f3f300e0791890bc846b9, <cb20da33839f28f590c99f16bafaa6151451c0e8, <=*, <=5.15.*, 6.6.153, 6.12.105, 6.18.46, 7.2, <b0aab9dd1a348b99d75ff52765719d0cc2050630) 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/97a01de0c6321b7210d30d0a4d60f10f561097c7
- https://git.kernel.org/stable/c/c21afc7c216a4d257a4f3f300e0791890bc846b9
- https://git.kernel.org/stable/c/b0aab9dd1a348b99d75ff52765719d0cc2050630
- https://git.kernel.org/stable/c/b891e7a6bb06e0f6560e5932665ac660acd12225
- https://git.kernel.org/stable/c/20cb13a523f0a05cb2d0a7d72abae687683712e0
- https://git.kernel.org/stable/c/cb20da33839f28f590c99f16bafaa6151451c0e8
- https://git.kernel.org/stable/c/24ffcb1e1688c55fd2a505f064295cd28eac546d
- https://git.kernel.org/stable/c/0c88868271653537ed443272dd8e7d13634d214b
