{"id":"CVE-2026-80866","summary":"tipc: avoid busy looping in tipc_exit_net()","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(&tn-\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.","modified":"2026-10-22T02:49:13.917744058Z","published":"2026-09-04T16:48:11.682Z","database_specific":{"osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/80xxx/CVE-2026-80866.json","cna_assigner":"Linux"},"references":[{"type":"WEB","url":"https://git.kernel.org/stable/c/110bb16d37bdba03213156c0df37e7119c190936"},{"type":"WEB","url":"https://git.kernel.org/stable/c/522d1d950b9e3b68190a6de7534827c8dccedb73"},{"type":"WEB","url":"https://git.kernel.org/stable/c/7672973957e3e20780afe5937a9fec70b72bc060"},{"type":"WEB","url":"https://git.kernel.org/stable/c/99b82c8452887408ea908fdfa5df33c4a5dfa88f"},{"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"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","events":[{"introduced":"04c26faa51d1e2fe71cf13c45791f5174c37f986"},{"fixed":"99b82c8452887408ea908fdfa5df33c4a5dfa88f"},{"fixed":"110bb16d37bdba03213156c0df37e7119c190936"},{"fixed":"7672973957e3e20780afe5937a9fec70b72bc060"},{"fixed":"522d1d950b9e3b68190a6de7534827c8dccedb73"},{"fixed":"c1481c94e74c955e0448ddf46b8615a44d840c1e"}]},{"type":"GIT","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","events":[{"introduced":"5.4.124"},{"fixed":"5.5"}]},{"type":"GIT","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","events":[{"introduced":"5.10.42"},{"fixed":"5.11"}]},{"type":"GIT","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","events":[{"introduced":"5.12.9"},{"fixed":"5.13"}]},{"type":"GIT","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","events":[{"introduced":"d1f76dfadaf8f47ed1753f97dbcbd41c16215ffa"}]},{"type":"GIT","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","events":[{"introduced":"5195ec5e365a2a9331bfeb585b613a6e94f98dba"}]},{"type":"GIT","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","events":[{"introduced":"b9f5b7ad4ac3af006443f535b1ce7bff1d130d7d"}]}],"versions":["v5.4.302","v5.4.301","v5.4.300","v5.4.299","v5.4.298","v5.4.297","v5.4.296","v5.4.295","v5.4.294","v5.4.293","v5.4.292","v5.4.291","v5.4.290","v5.4.289","v5.4.288","v5.4.287","v5.4.286","v5.4.285","v5.4.284","v5.4.283","v5.4.282","v5.4.281","v5.4.280","v5.4.279","v5.4.278","v5.4.277","v5.4.276","v5.4.275","v5.4.274","v5.4.273","v5.4.272","v5.4.271","v5.4.270","v5.4.269","v5.4.268","v5.4.267","v5.4.266","v5.4.265","v5.4.264","v5.4.263","v5.4.262","v5.4.261","v5.4.260","v5.4.259","v5.4.258","v5.4.257","v5.4.256","v5.4.255","v5.4.254","v5.4.253","v5.4.252","v5.4.251","v5.4.250","v5.4.249","v5.4.248","v5.4.247","v5.4.246","v5.4.245","v5.4.244","v5.4.243","v5.4.242","v5.4.241","v5.4.240","v5.4.239","v5.4.238","v5.4.237","v5.4.236","v5.4.235","v5.4.234","v5.4.233","v5.4.232","v5.4.231","v5.4.230","v5.4.229","v5.4.228","v5.4.227","v5.4.226","v5.4.225","v5.4.224","v5.4.223","v5.4.222","v5.4.221","v5.4.220","v5.4.219","v5.4.218","v5.4.217","v5.4.216","v5.4.215","v5.4.214","v5.4.213","v5.4.212","v5.4.211","v5.4.210","v5.4.209","v5.4.208","v5.4.207","v5.4.206","v5.4.205","v5.4.204","v5.4.203","v5.4.202","v5.4.201","v5.4.200","v5.4.199","v5.4.198","v5.4.197","v5.4.196","v5.4.195","v5.4.194","v5.4.193","v5.4.192","v5.4.191","v5.4.190","v5.4.189","v5.4.188","v5.4.187","v5.4.186","v5.4.185","v5.4.184","v5.4.183","v5.4.182","v5.4.181","v5.4.180","v5.4.179","v5.4.178","v5.4.177","v5.4.176","v5.4.175","v5.4.174","v5.4.173","v5.4.172","v5.4.171","v5.4.170","v5.4.169","v5.4.168","v5.4.167","v5.4.166","v5.4.165","v5.4.164","v5.4.163","v5.4.162","v5.4.161","v5.4.160","v5.4.159","v5.4.158","v5.4.157","v5.4.156","v5.4.155","v5.4.154","v5.4.153","v5.4.152","v5.4.151","v5.4.150","v5.4.149","v5.4.148","v5.4.147","v5.4.146","v5.4.145","v5.4.144","v5.4.143","v5.4.142","v5.4.141","v5.4.140","v5.4.139","v5.4.138","v5.4.137","v5.4.136","v5.4.135","v5.4.134","v5.4.133","v5.4.132","v5.4.131","v5.4.130","v5.4.129","v5.4.128","v5.4.127","v5.4.126","v5.4.125","v5.4.124","v5.10.272","v5.10.271","v5.10.270","v5.10.269","v5.10.268","v5.10.267","v5.10.266","v5.10.265","v5.10.264","v5.10.263","v5.10.262","v5.10.261","v5.10.260","v5.10.259","v5.10.258","v5.10.257","v5.10.256","v5.10.255","v5.10.254","v5.10.253","v5.10.252","v5.10.251","v5.10.250","v5.10.249","v5.10.248","v5.10.247","v5.10.246","v5.10.245","v5.10.244","v5.10.243","v5.10.242","v5.10.241","v5.10.240","v5.10.239","v5.10.238","v5.10.237","v5.10.236","v5.10.235","v5.10.234","v5.10.233","v5.10.232","v5.10.231","v5.10.230","v5.10.229","v5.10.228","v5.10.227","v5.10.226","v5.10.225","v5.10.224","v5.10.223","v5.10.222","v5.10.221","v5.10.220","v5.10.219","v5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