{
  "affected": [
    {
      "ranges": [
        {
          "events": [
            {
              "introduced": "04c26faa51d1e2fe71cf13c45791f5174c37f986"
            },
            {
              "fixed": "522d1d950b9e3b68190a6de7534827c8dccedb73"
            },
            {
              "fixed": "c1481c94e74c955e0448ddf46b8615a44d840c1e"
            }
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "type": "GIT"
        },
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "last_affected": "d1f76dfadaf8f47ed1753f97dbcbd41c16215ffa"
            },
            {
              "last_affected": "5195ec5e365a2a9331bfeb585b613a6e94f98dba"
            },
            {
              "last_affected": "b9f5b7ad4ac3af006443f535b1ce7bff1d130d7d"
            }
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "type": "GIT"
        },
        {
          "events": [
            {
              "introduced": "5.4.124"
            },
            {
              "fixed": "5.5"
            }
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "type": "GIT"
        },
        {
          "events": [
            {
              "introduced": "5.10.42"
            },
            {
              "fixed": "5.11"
            }
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "type": "GIT"
        },
        {
          "events": [
            {
              "introduced": "5.12.9"
            },
            {
              "fixed": "5.13"
            }
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "type": "GIT"
        }
      ]
    },
    {
      "package": {
        "ecosystem": "Linux",
        "name": "Kernel"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "5.13.0"
            },
            {
              "fixed": "7.1.5"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "database_specific": {
    "cna_assigner": "Linux",
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/80xxx/CVE-2026-80866.json"
  },
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\ntipc: avoid busy looping in tipc_exit_net()\n\nBlamed commit introduced a busy-wait loop in tipc_exit_net()\nto wait for pending UDP bearer cleanup works to complete:\n\n       while (atomic_read(\u0026tn-\u003ewq_count))\n               cond_resched();\n\nThis loop can busy-wait for a long time if cond_resched() is a NOP. This\ntypically happens if the netns exit is executed by a high priority task,\nor under kernels configured without preemption (CONFIG_PREEMPT_NONE). In\nsuch cases, it wastes CPU cycles and can lead to soft lockups.\n\nFix this by replacing the busy loop with wait_var_event(), allowing the\nthread to sleep properly until the work queue count reaches zero.\n\nAccordingly, update cleanup_bearer() to use atomic_dec_and_test() and\nwake_up_var() to wake up the waiter when the count drops to zero.\n\nThis uses the global wait queue hash table, avoiding the need to bloat\nstruct tipc_net with a wait_queue_head_t. The atomic_dec_and_test()\nprovides the necessary memory barrier to ensure the wakeup is not missed.",
  "id": "CVE-2026-80866",
  "modified": "2026-09-06T03:30:42.947034799Z",
  "published": "2026-09-04T16:48:11.682Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/522d1d950b9e3b68190a6de7534827c8dccedb73"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/c1481c94e74c955e0448ddf46b8615a44d840c1e"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/80xxx/CVE-2026-80866.json"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-80866"
    },
    {
      "type": "PACKAGE",
      "url": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"
    }
  ],
  "schema_version": "1.9.0",
  "summary": "tipc: avoid busy looping in tipc_exit_net()"
}