{"id":"CVE-2026-80866","title":"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   …","summary":"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   …","severity":"none","vendor":"Linux","product":"Linux","affected":["Linux >= 04c26faa51d1e2fe71cf13c45791f5174c37f986 < 7672973957e3e20780afe5937a9fec70b72bc060","Linux >= 04c26faa51d1e2fe71cf13c45791f5174c37f986 < 522d1d950b9e3b68190a6de7534827c8dccedb73","Linux >= 04c26faa51d1e2fe71cf13c45791f5174c37f986 < c1481c94e74c955e0448ddf46b8615a44d840c1e","Linux d1f76dfadaf8f47ed1753f97dbcbd41c16215ffa","Linux 5195ec5e365a2a9331bfeb585b613a6e94f98dba","Linux b9f5b7ad4ac3af006443f535b1ce7bff1d130d7d","Linux >= 5.4.124 < 5.5","Linux >= 5.10.42 < 5.11","Linux >= 5.12.9 < 5.13","Linux 5.13"],"published":"2026-09-04","updated":"2026-10-15","sourceUpdated":"2026-10-15T11:17:52.417","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-80866","references":[{"url":"https://git.kernel.org/stable/c/522d1d950b9e3b68190a6de7534827c8dccedb73","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/7672973957e3e20780afe5937a9fec70b72bc060","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/c1481c94e74c955e0448ddf46b8615a44d840c1e","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"}],"tags":["nvd","cve.org"],"epss":0.00198,"epssPercentile":0.08906,"ingestedAt":"2026-10-15T11:00:41.661Z","slug":"CVE-2026-80866","body":"## Overview\n\nIn 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.\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"sunlit","depthScore":3,"depthScoreParts":{"impact":2.8,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[]}