{"cve":"CVE-2026-80866","nvd":{"published":"2026-09-04T17:16:58.390","modified":"2026-10-21T13:20:00.710","status":"Received","description":"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(&tn->wq_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.","cvss_v4":null,"cvss_v3":null,"cwes":[],"references":["https://git.kernel.org/stable/c/110bb16d37bdba03213156c0df37e7119c190936","https://git.kernel.org/stable/c/522d1d950b9e3b68190a6de7534827c8dccedb73","https://git.kernel.org/stable/c/7672973957e3e20780afe5937a9fec70b72bc060","https://git.kernel.org/stable/c/99b82c8452887408ea908fdfa5df33c4a5dfa88f","https://git.kernel.org/stable/c/c1481c94e74c955e0448ddf46b8615a44d840c1e"],"products":[],"source":"nvd","synced_at":"2026-10-22T16:41:11.231219466+00:00"},"epss":{"cve":"CVE-2026-80866","score":0.00209,"percentile":0.10915,"date":"2026-10-25"},"kev":null,"osv":[],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}