{
  "affected": [
    {
      "ranges": [
        {
          "events": [
            {
              "introduced": "21a091b970cdbcf3e8ff829234b51be6f9192766"
            },
            {
              "fixed": "e22f4494cc9487d326e5e3067f33dea7c1e442b2"
            },
            {
              "fixed": "b6bb334b0e9348887e3e55e1f494b0c3b8fbf59f"
            },
            {
              "fixed": "40b6ccf68731809ceb85c6e9f0f8f2ed61c7aa5a"
            },
            {
              "fixed": "cd305ee3633a45fcf5f3a5d83f99f3cb77d87b6e"
            }
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "type": "GIT"
        }
      ]
    },
    {
      "package": {
        "ecosystem": "Linux",
        "name": "Kernel"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "6.1.0"
            },
            {
              "fixed": "6.18.49"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "6.19.0"
            },
            {
              "fixed": "7.1.11"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "7.2.0"
            },
            {
              "fixed": "7.2.1"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "database_specific": {
    "cna_assigner": "Linux",
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/80xxx/CVE-2026-80920.json"
  },
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nio_uring: defer eventfd signaling when queued from a wakeup handler\n\nio_req_local_work_add() signals the CQ ring eventfd inline when it is the\none to push the first entry onto -\u003ework_list. For DEFER_TASKRUN rings that\nadd is frequently done from a waitqueue wakeup handler, where an\narbitrary waitqueue lock is held.\n\neventfd_signal_mask() only refuses to recurse when current-\u003ein_eventfd\nis set, but that bit is set by eventfd_signal_mask() itself. If the wake\nchain starts somewhere else, signal goes out inline and can feed back\ninto epoll.\n\nAdd IOU_F_TWQ_IN_WAKE, set it on the task_work add done from the three\nwaitqueue callbacks, and use it to force io_eventfd_signal() down the\nexisting call_rcu_hurry() deferral instead of signaling inline.",
  "id": "CVE-2026-80920",
  "modified": "2026-09-11T03:30:34.754120606Z",
  "published": "2026-09-09T16:13:17.023Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/40b6ccf68731809ceb85c6e9f0f8f2ed61c7aa5a"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/b6bb334b0e9348887e3e55e1f494b0c3b8fbf59f"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/cd305ee3633a45fcf5f3a5d83f99f3cb77d87b6e"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/e22f4494cc9487d326e5e3067f33dea7c1e442b2"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/80xxx/CVE-2026-80920.json"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-80920"
    },
    {
      "type": "PACKAGE",
      "url": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"
    }
  ],
  "schema_version": "1.9.0",
  "summary": "io_uring: defer eventfd signaling when queued from a wakeup handler"
}