rpcrdma: arm rn_done before publishing the notification

{
  "id": "5535edfeb57fe279cd165ecebfe72da784fa73aaddbcf58bcd4e2c88cec04a55",
  "url": "https://osv.dev/vulnerability/CVE-2026-89798",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "rpcrdma: arm rn_done before publishing the notification",
    "summary": "In the Linux kernel, the following vulnerability has been resolved: rpcrdma: arm rn_done before publishing the notification rpcrdma_rn_register() inserts @rn into rd_xa with xa_alloc() before storing the caller's callback in rn->rn_done. The xarray makes @rn reachable to rpcrdma_remove_one(), which walks rd_xa and invokes rn->rn_done(rn) for every registered notification. A device removal that races a fresh registration can therefore observe @rn with rn_done still NULL, because the notification objects are zero allocated by their owners, and call through a NULL function pointer. Store rn->rn_done before xa_alloc() publishes @rn. The xarray's store-side and load-side ordering then guarantees that any CPU which finds @rn in rd_xa also observes the armed callback. rpcrdma_rn_unregister() treats a non-NULL rn_done as the sentinel for a completed registration, so the early store must not survive a failed registration. Clear rn_done again when xa_alloc() fails. Were it left set, the failed-accept cleanup path would call rpcrdma_rn_unregister() on an @rn that was never inserted, erasing an unrelated rd_xa slot and underflowing rd_kref.",
    "evidence": "osv:CVE-2026-89798",
    "products": [
      {
        "name": {
          "value": "Kernel",
          "evidence": "/affected/1/package/name"
        },
        "prerequisites": [],
        "fixed_versions": [
          {
            "value": "6.12.111",
            "evidence": "/affected/1/ranges"
          },
          {
            "value": "6.18.51",
            "evidence": "/affected/1/ranges"
          },
          {
            "value": "7.2.5",
            "evidence": "/affected/1/ranges"
          }
        ],
        "affected_versions": []
      }
    ],
    "severity": "unknown",
    "structured": {
      "id": "CVE-2026-89798",
      "aliases": [
        "CVE-2026-89798"
      ],
      "affected": [
        {
          "ranges": [
            {
              "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
              "type": "GIT",
              "events": [
                {
                  "introduced": "7e86845a0346efc95fddaa97ce5cd6a8bda8c71c"
                },
                {
                  "fixed": "f9fe3cad43c42d874a388583552b39b411d886eb"
                },
                {
                  "fixed": "3c97b8e76ca2bba9e8770571413aed694068e78e"
                },
                {
                  "fixed": "ea0408273ccf5df1fb52d9a1b9db4d31600dcb36"
                },
                {
                  "fixed": "5b06f706374c37375bdff9d21cc10e61df925a92"
                }
              ]
            }
          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-89798.json"
          }
        },
        {
          "ranges": [
            {
              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "6.11.0"
                },
                {
                  "fixed": "6.12.111"
                }
              ]
            },
            {
              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "6.13.0"
                },
                {
                  "fixed": "6.18.51"
                }
              ]
            },
            {
              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "6.19.0"
                },
                {
                  "fixed": "7.2.5"
                }
              ]
            }
          ],
          "package": {
            "name": "Kernel",
            "ecosystem": "Linux"
          },
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-89798.json"
          }
        }
      ],
      "modified": "2026-10-28T02:30:34.711974213Z",
      "provider": "osv",
      "references": [
        "https://git.kernel.org/stable/c/3c97b8e76ca2bba9e8770571413aed694068e78e",
        "https://git.kernel.org/stable/c/5b06f706374c37375bdff9d21cc10e61df925a92",
        "https://git.kernel.org/stable/c/ea0408273ccf5df1fb52d9a1b9db4d31600dcb36",
        "https://git.kernel.org/stable/c/f9fe3cad43c42d874a388583552b39b411d886eb",
        "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/89xxx/CVE-2026-89798.json",
        "https://nvd.nist.gov/vuln/detail/CVE-2026-89798",
        "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"
      ],
      "provider_metadata": {
        "cna_assigner": "Linux",
        "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/89xxx/CVE-2026-89798.json"
      }
    },
    "related_cves": [
      {
        "value": "CVE-2026-89798",
        "evidence": "/id"
      }
    ],
    "security_relevant": true,
    "severity_evidence": null
  },
  "source_id": "core-osv",
  "document_id": 502098,
  "published_at": "2026-09-16T10:30:29.93+00:00"
}