Heimdall Security Logo

CVE-2024-26923

Vulnérabilité élevée dans Linux (Linux)

CVSS 7.8 · Élevée
EPSS 0.2%
Linux•Linux•Versions : 6.9, <=6.1.*, <e76c2678228f6aec74b305ae30c9374cc2f28a51, 6.6.28, 0, 5.10.216, <507cc232ffe53a352847893f8177d276c3b532a9, 2.6.23, <343c5372d5e17b306db5f8f3c895539b06e3177f, 4.19.314, <=5.10.*, <=6.6.*, 1fd05ba5a2f2aa8e7b9b52ef55df850e2e7d54c9, <2e2a03787f4f0abc0072350654ab0ef3324d9db3, 6.8.7, <b75722be422c276b699200de90527d01c602ea7c, <2.6.23, 5.4.275, <=5.4.*, <=4.19.*, <dbdf7bec5c920200077d693193f989cb1513f009, <=6.8.*, <47d8ac011fe1c9251070e1bd64cb10b48193ec51, <=*, 6.1.87, <=5.15.*, <a36ae0ec2353015f0f6762e59f4c2dbc0c906423, 5.15.156

Description

In the Linux kernel, the following vulnerability has been resolved: af_unix: Fix garbage collector racing against connect() Garbage collector does not take into account the risk of embryo getting enqueued during the garbage collection. If such embryo has a peer that carries SCM_RIGHTS, two consecutive passes of scan_children() may see a different set of children. Leading to an incorrectly elevated inflight count, and then a dangling pointer within the gc_inflight_list. sockets are AF_UNIX/SOCK_STREAM S is an unconnected socket L is a listening in-flight socket bound to addr, not in fdtable V's fd will be passed via sendmsg(), gets inflight count bumped connect(S, addr) sendmsg(S, [V]); close(V) __unix_gc() ---------------- ------------------------- ----------- NS = unix_create1() skb1 = sock_wmalloc(NS) L = unix_find_other(addr) unix_state_lock(L) unix_peer(S) = NS // V count=1 inflight=0 NS = unix_peer(S) skb2 = sock_alloc() skb_queue_tail(NS, skb2[V]) // V became in-flight // V count=2 inflight=1 close(V) // V count=1 inflight=1 // GC candidate condition met for u in gc_inflight_list: if (total_refs == inflight_refs) add u to gc_candidates // gc_candidates={L, V} for u in gc_candidates: scan_children(u, dec_inflight) // embryo (skb1) was not // reachable from L yet, so V's // inflight remains unchanged __skb_queue_tail(L, skb1) unix_state_unlock(L) for u in gc_candidates: if (u.inflight) scan_children(u, inc_inflight_move_tail) // V count=1 inflight=2 (!) If there is a GC-candidate listening socket, lock/unlock its state. This makes GC wait until the end of any ongoing connect() to that socket. After flipping the lock, a possibly SCM-laden embryo is already enqueued. And if there is another embryo coming, it can not possibly carry SCM_RIGHTS. At this point, unix_inflight() can not happen because unix_gc_lock is already taken. Inflight graph remains unaffected.

Gravité et risque d'exploitation

CVE-2024-26923 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 0.21 %, ce qui la place devant 10.2 % des CVE référencées.

Que faire ?

  • Vérifiez si Linux (versions 6.9, <=6.1.*, <e76c2678228f6aec74b305ae30c9374cc2f28a51, 6.6.28, 0, 5.10.216, <507cc232ffe53a352847893f8177d276c3b532a9, 2.6.23, <343c5372d5e17b306db5f8f3c895539b06e3177f, 4.19.314, <=5.10.*, <=6.6.*, 1fd05ba5a2f2aa8e7b9b52ef55df850e2e7d54c9, <2e2a03787f4f0abc0072350654ab0ef3324d9db3, 6.8.7, <b75722be422c276b699200de90527d01c602ea7c, <2.6.23, 5.4.275, <=5.4.*, <=4.19.*, <dbdf7bec5c920200077d693193f989cb1513f009, <=6.8.*, <47d8ac011fe1c9251070e1bd64cb10b48193ec51, <=*, 6.1.87, <=5.15.*, <a36ae0ec2353015f0f6762e59f4c2dbc0c906423, 5.15.156) 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

Rechercher une autre CVE