CVE-2026-72469
Vulnérabilité élevée dans Linux (Linux)
Description
In the Linux kernel, the following vulnerability has been resolved: xprtrdma: Fix ep kref imbalance on ADDR_CHANGE rpcrdma_cm_event_handler() falls through to the disconnected: label on RDMA_CM_EVENT_ADDR_CHANGE and calls rpcrdma_ep_put() with no matching get when the event arrives before RDMA_CM_EVENT_ESTABLISHED. The kref then underflows during connect teardown and rpcrdma_xprt_disconnect() operates on a freed ep. Reference counts across a normal connection lifecycle: rpcrdma_ep_create() kref_init ->1 rpcrdma_xprt_connect() ep_get ->2 (before post_recvs) RDMA_CM_EVENT_ESTABLISHED ep_get ->3 RDMA_CM_EVENT_DISCONNECTED ep_put ->2 rpcrdma_xprt_drain() ep_put ->1 rpcrdma_xprt_disconnect() tail ep_put ->0 (ep_destroy) The connect-time get in rpcrdma_xprt_connect(), taken just before rpcrdma_post_recvs() "while there are outstanding Receives," is balanced by rpcrdma_xprt_drain. ADDR_CHANGE before ESTABLISHED has no get to consume, so its put drops the count to 1 and the drain put then frees the ep while rpcrdma_xprt_disconnect() still holds a pointer to it. Fix by dispatching on the prior re_connect_status via xchg(): for prev == 0 (pre-ESTABLISHED) wake the connect waiter and return with no put; for prev == 1 call rpcrdma_force_disconnect() and return. The case-1 arm relies on the subsequent RDMA_CM_EVENT_DISCONNECTED event -- reliably delivered when rdma_disconnect() is called on a still-connected cm_id -- to balance the ESTABLISHED get; rpcrdma_xprt_drain() continues to balance only that connect-time get. Any other prior value means teardown is already in flight.
Gravité et risque d'exploitation
CVE-2026-72469 obtient un score CVSS de 8.8/10, soit une gravité élevée. Selon le modèle EPSS, la probabilité qu'elle soit exploitée dans les 30 prochains jours est de 0.38 %, ce qui la place devant 30.4 % des CVE référencées.
Que faire ?
- Vérifiez si Linux (versions 7.1.5, 6.18.40, <=6.12.*, <d0479c2b12974aa188b10d221a5770126b118b6d, 2acc5cae292355f5f18ad377a2a966e7f03c8fec, <=*, <af9b65b29af341932625c4283dc7a23cdb62688a, 2fcbf07a4f23174a45e015b62a8e42ddbc2e53ef, <ffc07790539736a5d029f6a3c966b46c529f93a8, <=6.18.*, 6.12.97, 5.8, 0, 7.2, <cfd1bab66b042da7a778786685125656c695931b, <5.8, <=7.1.*, 5.7.9) 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.