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CVE-2026-46114

Vulnérabilité élevée dans Linux (Linux)

CVSS 7.5 · Élevée
EPSS 0.5%
Linux•Linux•Versions : <=7.0.*, 7.0.7, <=6.12.*, 0, <539cabb7b2d8ba70f55bba91db55faef11c2a6d7, <d415fce3fcde6d7aeea6c25362a395b905811452, 6.12.88, 034e285f8b99062a0cf29112e1232154a6a44aa5, <1114c87aa6f195cf07da55a27b2122ae26557b26, <=6.6.*, <105bf79a23b85cf3a761d18a4f3e10ce88526bc1, 7.1, <=6.18.*, <6.2, <7ec1ed4747f5f99f8b797bb438c5efd36079fad5, <=*, 6.6.140, 6.18.30, 6.2

Description

In the Linux kernel, the following vulnerability has been resolved: RDMA/rxe: Reject non-8-byte ATOMIC_WRITE payloads atomic_write_reply() at drivers/infiniband/sw/rxe/rxe_resp.c unconditionally dereferences 8 bytes at payload_addr(pkt): value = *(u64 *)payload_addr(pkt); check_rkey() previously accepted an ATOMIC_WRITE request with pktlen == resid == 0 because the length validation only compared pktlen against resid. A remote initiator that sets the RETH length to 0 therefore reaches atomic_write_reply() with a zero-byte logical payload, and the responder reads sizeof(u64) bytes from past the logical end of the packet into skb->head tailroom, then writes those 8 bytes into the attacker's MR via rxe_mr_do_atomic_write(). That is a remote disclosure of 4 bytes of kernel tailroom per probe (the other 4 bytes are the packet's own trailing ICRC). IBA oA19-28 defines ATOMIC_WRITE as exactly 8 bytes. Anything else is protocol-invalid. Hoist a strict length check into check_rkey() so the responder never reaches the unchecked dereference, and keep the existing WRITE-family length logic for the normal RDMA WRITE path. Reproduced on mainline with an unmodified rxe driver: a sustained zero-length ATOMIC_WRITE probe repeatedly leaks adjacent skb head-buffer bytes into the attacker's MR, including recognisable kernel strings and partial kernel-direct-map pointer words. With this patch applied the responder rejects the PDU and the MR stays all-zero.

Gravité et risque d'exploitation

CVE-2026-46114 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 0.47 %, ce qui la place devant 39.1 % des CVE référencées.

Que faire ?

  • Vérifiez si Linux (versions <=7.0.*, 7.0.7, <=6.12.*, 0, <539cabb7b2d8ba70f55bba91db55faef11c2a6d7, <d415fce3fcde6d7aeea6c25362a395b905811452, 6.12.88, 034e285f8b99062a0cf29112e1232154a6a44aa5, <1114c87aa6f195cf07da55a27b2122ae26557b26, <=6.6.*, <105bf79a23b85cf3a761d18a4f3e10ce88526bc1, 7.1, <=6.18.*, <6.2, <7ec1ed4747f5f99f8b797bb438c5efd36079fad5, <=*, 6.6.140, 6.18.30, 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

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