svcrdma: wake sq waiters when the transport closes

{
  "id": "874825fe5461f82fbf1c6143cc020a8cdf806cbcd6ffd8fdb338326eb9736c8e",
  "url": "https://osv.dev/vulnerability/CVE-2026-64281",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "svcrdma: wake sq waiters when the transport closes",
    "summary": "In the Linux kernel, the following vulnerability has been resolved: svcrdma: wake sq waiters when the transport closes Threads parked in svc_rdma_sq_wait() on sc_sq_ticket_wait or sc_send_wait can hang indefinitely in TASK_UNINTERRUPTIBLE state across transport teardown, pinning svc_xprt references and blocking svc_rdma_free(). The close path sets XPT_CLOSE before invoking xpo_detach and both wait_event predicates include an XPT_CLOSE term, but the predicates are re-evaluated only on wakeup. sc_sq_ticket_wait has no completion-driven wake path; it is advanced solely by the chained ticket handoff inside svc_rdma_sq_wait() itself. Without an explicit wake at close, parked threads never observe XPT_CLOSE, hold their svc_xprt_get reference forever, and svc_rdma_free() blocks on xpt_ref dropping to zero. Two close entry points reach this transport. Local teardown runs svc_rdma_detach() from svc_handle_xprt() -> svc_delete_xprt() -> xpo_detach() on a worker thread. A remote disconnect arrives at svc_rdma_cma_handler(), which calls svc_xprt_deferred_close(): that sets XPT_CLOSE and enqueues the transport but does not access either RDMA waitqueue, so a worker already parked in svc_rdma_sq_wait() never re-evaluates its predicate. With every worker parked on this transport, no thread is available to run the local teardown either, and the wake site there is unreachable. Introduce svc_rdma_xprt_deferred_close(), a thin svcrdma wrapper that calls svc_xprt_deferred_close() and then wakes b",
    "evidence": "osv:CVE-2026-64281",
    "products": [
      {
        "name": {
          "value": "Kernel",
          "evidence": "/affected/1/package/name"
        },
        "prerequisites": [],
        "fixed_versions": [
          {
            "value": "7.1.4",
            "evidence": "/affected/1/ranges"
          }
        ],
        "affected_versions": []
      }
    ],
    "severity": "high",
    "structured": {
      "id": "CVE-2026-64281",
      "aliases": [
        "CVE-2026-64281"
      ],
      "metrics": [
        {
          "type": "CVSS_V3",
          "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H"
        }
      ],
      "affected": [
        {
          "ranges": [
            {
              "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
              "type": "GIT",
              "events": [
                {
                  "introduced": "ccc89b9d1ed233349cfe8d87b842e7351b74d8de"
                },
                {
                  "fixed": "40eedc4253dbda0b29b7961200534dfcecb48ace"
                },
                {
                  "fixed": "e5248a7426030db1e126363f72afdb3b71339a5c"
                }
              ]
            }
          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-64281.json"
          }
        },
        {
          "ranges": [
            {
              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "7.1.0"
                },
                {
                  "fixed": "7.1.4"
                }
              ]
            }
          ],
          "package": {
            "name": "Kernel",
            "ecosystem": "Linux"
          },
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-64281.json"
          }
        }
      ],
      "modified": "2026-10-28T02:30:27.117843043Z",
      "provider": "osv",
      "references": [
        "https://git.kernel.org/stable/c/40eedc4253dbda0b29b7961200534dfcecb48ace",
        "https://git.kernel.org/stable/c/e5248a7426030db1e126363f72afdb3b71339a5c",
        "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/64xxx/CVE-2026-64281.json",
        "https://nvd.nist.gov/vuln/detail/CVE-2026-64281",
        "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/2026/64xxx/CVE-2026-64281.json"
      }
    },
    "related_cves": [
      {
        "value": "CVE-2026-64281",
        "evidence": "/id"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
  },
  "source_id": "core-osv",
  "document_id": 493661,
  "published_at": "2026-07-25T08:49:24.399+00:00"
}