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CVE-2026-74493

Vulnérabilité critique dans Linux (Linux)

CVSS 9.8 · Critique
EPSS 0.5%
Linux•Linux•Versions : <=6.1.*, <=6.12.*, <bea8dc14de2d56aca749d368563e6888217710a5, 0, 69318b5215f2dc32c345a3d65b98b4b1bf29c007, <=7.1.*, 5.15.216, 6.12.103, <=5.10.*, <=6.6.*, 6.1.183, <281c103a8eaed59001ce952f231df1b07674215a, <f0541a775d04c88e90ba448e35ce0d743512822a, <5.5, <=6.18.*, <f621d6ebeebb6374342571e4ddf45fdbc420f6cd, <5a42f162b857019a4c10ff687dc3bcdf51831865, 5.5, <9fb17c95b8f0683570fca1fb2792264147af937a, <=*, <ff44f2df57fb5560bdc75eb977867643e764a262, <=5.15.*, <f807a63d0d95680c34f677700da9148a07d7c78f, 7.1.8, 6.18.44, 6.6.151, 5.10.265, 7.2

Description

In the Linux kernel, the following vulnerability has been resolved: net/smc: fix socket use-after-free during link group termination __smc_lgr_terminate() drops conns_lock after finding a connection in lgr->conns_all, but before taking a reference on its socket. The connection is embedded in the socket, and its registration reference protects it only while the connection remains in the tree. A concurrent close can unregister the connection and drop that reference, freeing the socket before the termination worker reaches sock_hold(). The race is reachable when close overlaps link group termination. Local stress testing reproduced the use-after-free and KASAN reported: BUG: KASAN: slab-use-after-free in __smc_lgr_terminate.part.0 [smc] Write of size 4 by task kworker/3:3 Workqueue: events smc_lgr_terminate_work [smc] __smc_lgr_terminate.part.0 [smc] The socket was allocated by smc_create(), freed through slab_free_after_rcu_debug(), and was followed by: refcount_t: addition on 0; use-after-free. __smc_lgr_terminate.part.0 [smc] Take the socket reference while conns_lock still protects the tree entry. The unregister path then cannot drop the last reference until termination has finished using the socket.

Gravité et risque d'exploitation

CVE-2026-74493 obtient un score CVSS de 9.8/10, soit une gravité critique. Selon le modèle EPSS, la probabilité qu'elle soit exploitée dans les 30 prochains jours est de 0.50 %, ce qui la place devant 41.6 % des CVE référencées.

Que faire ?

  • Vérifiez si Linux (versions <=6.1.*, <=6.12.*, <bea8dc14de2d56aca749d368563e6888217710a5, 0, 69318b5215f2dc32c345a3d65b98b4b1bf29c007, <=7.1.*, 5.15.216, 6.12.103, <=5.10.*, <=6.6.*, 6.1.183, <281c103a8eaed59001ce952f231df1b07674215a, <f0541a775d04c88e90ba448e35ce0d743512822a, <5.5, <=6.18.*, <f621d6ebeebb6374342571e4ddf45fdbc420f6cd, <5a42f162b857019a4c10ff687dc3bcdf51831865, 5.5, <9fb17c95b8f0683570fca1fb2792264147af937a, <=*, <ff44f2df57fb5560bdc75eb977867643e764a262, <=5.15.*, <f807a63d0d95680c34f677700da9148a07d7c78f, 7.1.8, 6.18.44, 6.6.151, 5.10.265, 7.2) 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

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