xprtrdma: Fix ep kref imbalance on ADDR_CHANGE
Summary
| CVE | CVE-2026-72469 |
|---|---|
| State | PUBLISHED |
| Assigner | Linux |
| Source Priority | CVE Program / NVD first with legacy fallback |
| Published | 2026-08-15 06:22:20 UTC |
| Updated | 2026-08-15 06:22:20 UTC |
| 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. |
Risk And Classification
EPSS: 0.002090000 probability, percentile 0.113110000 (date 2026-08-15)
Vendor Declared Affected Products
| Source | Vendor | Product | Version | Platforms |
|---|---|---|---|---|
| CNA | Linux | Linux | affected 2acc5cae292355f5f18ad377a2a966e7f03c8fec cfd1bab66b042da7a778786685125656c695931b git | Not specified |
| CNA | Linux | Linux | affected 2acc5cae292355f5f18ad377a2a966e7f03c8fec d0479c2b12974aa188b10d221a5770126b118b6d git | Not specified |
| CNA | Linux | Linux | affected 2acc5cae292355f5f18ad377a2a966e7f03c8fec ffc07790539736a5d029f6a3c966b46c529f93a8 git | Not specified |
| CNA | Linux | Linux | affected 2acc5cae292355f5f18ad377a2a966e7f03c8fec af9b65b29af341932625c4283dc7a23cdb62688a git | Not specified |
| CNA | Linux | Linux | affected 2fcbf07a4f23174a45e015b62a8e42ddbc2e53ef git | Not specified |
| CNA | Linux | Linux | affected 5.7.9 5.8 semver | Not specified |
| CNA | Linux | Linux | affected 5.8 | Not specified |
| CNA | Linux | Linux | unaffected 5.8 semver | Not specified |
| CNA | Linux | Linux | unaffected 6.12.97 6.12.* semver | Not specified |
| CNA | Linux | Linux | unaffected 6.18.40 6.18.* semver | Not specified |
| CNA | Linux | Linux | unaffected 7.1.5 7.1.* semver | Not specified |
| CNA | Linux | Linux | unaffected 7.2-rc1 * original_commit_for_fix | Not specified |
References
| Reference | Source | Link | Tags |
|---|---|---|---|
| git.kernel.org/stable/c/cfd1bab66b042da7a778786685125656c695931b | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | git.kernel.org | |
| git.kernel.org/stable/c/af9b65b29af341932625c4283dc7a23cdb62688a | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | git.kernel.org | |
| git.kernel.org/stable/c/ffc07790539736a5d029f6a3c966b46c529f93a8 | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | git.kernel.org | |
| git.kernel.org/stable/c/d0479c2b12974aa188b10d221a5770126b118b6d | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | git.kernel.org | |
| CVE Program record | CVE.ORG | www.cve.org | canonical |
| NVD vulnerability detail | NVD | nvd.nist.gov | canonical, analysis |
No vendor comments have been submitted for this CVE.
There are currently no legacy QID mappings associated with this CVE.