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CVE-2026-64141

Vulnérabilité élevée dans Linux (Linux)

CVSS 7.5 · Élevée
EPSS 0.6%
Linux•Linux•Versions : 6.9, <=7.0.*, <=6.12.*, 0, <4b83cbc4c15f09b000cc06f033f64b0824b6dc87, 8df4bcdb0a4232192b2445256c39b787d58ef14d, <cd5c1b75d2f454f625d7dc55bd3ae21d0855f6ad, c8efcc786146a951091588e5fa7e3c754850cb3c, 6.12.92, 6.6.142, <=6.6.*, 6.18.34, 7.1, <=6.18.*, 7.0.11, <e43cb36d4d7827710cfcd48e95e29a507f0d87be, <af86896ca3239e25a6bd7d352213371265073d38, <=*, <6.6.142, <6.9, <0836081b394ca074d1b910f2b990ff7b4b4404c7, 6.6.32

Description

In the Linux kernel, the following vulnerability has been resolved: ksmbd: fix null pointer dereference in compare_guid_key() session_fd_check() walks the per-inode m_op_list during durable-handle session teardown and sets op->conn = NULL for every opinfo whose conn matched the closing session's connection. The matching opinfo, however, stays linked in its per-ClientGuid lease_table_list entry's lb->lease_list because destroy_lease_table() only runs on full TCP-connection teardown, not on SESSION_LOGOFF. If the same TCP connection then negotiates a fresh session with the same ClientGuid (ClientGuid is bound to NEGOTIATE, not the session, and is unchanged across LOGOFF + SETUP) and issues a SMB2 CREATE with a lease context on a different inode, find_same_lease_key() walks lb->lease_list, reaches the stale opinfo, and calls compare_guid_key(), which unconditionally dereferences opinfo->conn->ClientGUID. The conn pointer is NULL and the kernel panics. Reproducer requires only a successful SMB2 SESSION_SETUP and a share configured with 'durable handles = yes'. KASAN report on mainline 70390501d194: general protection fault, probably for non-canonical address 0xdffffc0000000069: 0000 [#1] SMP KASAN PTI KASAN: null-ptr-deref in range [0x0000000000000348-0x000000000000034f] Workqueue: ksmbd-io handle_ksmbd_work RIP: 0010:bcmp+0x5b/0x230 Call Trace: compare_guid_key+0x4b/0xd0 find_same_lease_key+0x324/0x690 smb2_open+0x6aea/0x8e60 handle_ksmbd_work+0x796/0xee0 ... Faulting address 0x348 is the offset of ClientGUID within struct ksmbd_conn, confirming opinfo->conn was NULL. Read opinfo->conn once and bail out if it has been cleared by a concurrent session_fd_check(). A half-detached opinfo cannot be the owner of an active lease, so returning 0 is the correct match result.

Gravité et risque d'exploitation

CVE-2026-64141 obtient un score CVSS de 7.5/10, soit une gravité élevée. Selon le modèle EPSS, la probabilité qu'elle soit exploitée dans les 30 prochains jours est de 0.63 %, ce qui la place devant 49.1 % des CVE référencées.

Que faire ?

  • Vérifiez si Linux (versions 6.9, <=7.0.*, <=6.12.*, 0, <4b83cbc4c15f09b000cc06f033f64b0824b6dc87, 8df4bcdb0a4232192b2445256c39b787d58ef14d, <cd5c1b75d2f454f625d7dc55bd3ae21d0855f6ad, c8efcc786146a951091588e5fa7e3c754850cb3c, 6.12.92, 6.6.142, <=6.6.*, 6.18.34, 7.1, <=6.18.*, 7.0.11, <e43cb36d4d7827710cfcd48e95e29a507f0d87be, <af86896ca3239e25a6bd7d352213371265073d38, <=*, <6.6.142, <6.9, <0836081b394ca074d1b910f2b990ff7b4b4404c7, 6.6.32) 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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