GHSA-W6WR-JW44-5F3C
Vulnerability from github – Published: 2026-08-15 06:32 – Updated: 2026-08-17 06:33In 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.
{
"affected": [],
"aliases": [
"CVE-2026-72469"
],
"database_specific": {
"cwe_ids": [],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2026-08-15T06:22:20Z",
"severity": "HIGH"
},
"details": "In the Linux kernel, the following vulnerability has been resolved:\n\nxprtrdma: Fix ep kref imbalance on ADDR_CHANGE\n\nrpcrdma_cm_event_handler() falls through to the disconnected: label\non RDMA_CM_EVENT_ADDR_CHANGE and calls rpcrdma_ep_put() with no\nmatching get when the event arrives before RDMA_CM_EVENT_ESTABLISHED.\nThe kref then underflows during connect teardown and\nrpcrdma_xprt_disconnect() operates on a freed ep.\n\nReference counts across a normal connection lifecycle:\n\n rpcrdma_ep_create() kref_init -\u003e1\n rpcrdma_xprt_connect() ep_get -\u003e2 (before post_recvs)\n RDMA_CM_EVENT_ESTABLISHED ep_get -\u003e3\n RDMA_CM_EVENT_DISCONNECTED ep_put -\u003e2\n rpcrdma_xprt_drain() ep_put -\u003e1\n rpcrdma_xprt_disconnect() tail ep_put -\u003e0 (ep_destroy)\n\nThe connect-time get in rpcrdma_xprt_connect(), taken just before\nrpcrdma_post_recvs() \"while there are outstanding Receives,\" is\nbalanced by rpcrdma_xprt_drain. ADDR_CHANGE before ESTABLISHED has\nno get to consume, so its put drops the count to 1 and the drain\nput then frees the ep while rpcrdma_xprt_disconnect() still holds a\npointer to it.\n\nFix by dispatching on the prior re_connect_status via xchg(): for\nprev == 0 (pre-ESTABLISHED) wake the connect waiter and return with\nno put; for prev == 1 call rpcrdma_force_disconnect() and return.\nThe case-1 arm relies on the subsequent RDMA_CM_EVENT_DISCONNECTED\nevent -- reliably delivered when rdma_disconnect() is called on a\nstill-connected cm_id -- to balance the ESTABLISHED get;\nrpcrdma_xprt_drain() continues to balance only that connect-time\nget. Any other prior value means teardown is already in flight.",
"id": "GHSA-w6wr-jw44-5f3c",
"modified": "2026-08-17T06:33:31Z",
"published": "2026-08-15T06:32:25Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2026-72469"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/af9b65b29af341932625c4283dc7a23cdb62688a"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/cfd1bab66b042da7a778786685125656c695931b"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/d0479c2b12974aa188b10d221a5770126b118b6d"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/ffc07790539736a5d029f6a3c966b46c529f93a8"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
"type": "CVSS_V3"
}
]
}
Sightings
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