{"api_version":"1","generated_at":"2026-09-20T17:13:41+00:00","cve":"CVE-2026-80866","urls":{"html":"https://cve.report/CVE-2026-80866","api":"https://cve.report/api/cve/CVE-2026-80866.json","docs":"https://cve.report/api","cve_org":"https://www.cve.org/CVERecord?id=CVE-2026-80866","nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-80866"},"summary":{"title":"tipc: avoid busy looping in tipc_exit_net()","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.","state":"PUBLISHED","assigner":"Linux","published_at":"2026-09-04 17:16:58","updated_at":"2026-09-04 17:16:58"},"problem_types":[],"metrics":[],"references":[{"url":"https://git.kernel.org/stable/c/522d1d950b9e3b68190a6de7534827c8dccedb73","name":"https://git.kernel.org/stable/c/522d1d950b9e3b68190a6de7534827c8dccedb73","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/c1481c94e74c955e0448ddf46b8615a44d840c1e","name":"https://git.kernel.org/stable/c/c1481c94e74c955e0448ddf46b8615a44d840c1e","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-80866","name":"CVE Program record","refsource":"CVE.ORG","tags":["canonical"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-80866","name":"NVD vulnerability detail","refsource":"NVD","tags":["canonical","analysis"]}],"affected":[{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 04c26faa51d1e2fe71cf13c45791f5174c37f986 522d1d950b9e3b68190a6de7534827c8dccedb73 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 04c26faa51d1e2fe71cf13c45791f5174c37f986 c1481c94e74c955e0448ddf46b8615a44d840c1e git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected d1f76dfadaf8f47ed1753f97dbcbd41c16215ffa git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 5195ec5e365a2a9331bfeb585b613a6e94f98dba git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected b9f5b7ad4ac3af006443f535b1ce7bff1d130d7d git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 5.4.124 5.5 semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 5.10.42 5.11 semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 5.12.9 5.13 semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 5.13","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 5.13 semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 7.1.5 7.1.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 7.2 * original_commit_for_fix","platforms":[]}],"timeline":[],"solutions":[],"workarounds":[],"exploits":[],"credits":[],"nvd_cpes":[],"vendor_comments":[],"enrichments":{"kev":null,"epss":{"cve_year":"2026","cve_id":"80866","cve":"CVE-2026-80866","epss":"0.001450000","percentile":"0.040710000","score_date":"2026-09-07","updated_at":"2026-09-08 00:05:26"},"legacy_qids":[]},"source_records":{"cve_program":{"containers":{"cna":{"affected":[{"defaultStatus":"unaffected","product":"Linux","programFiles":["net/tipc/core.c","net/tipc/udp_media.c"],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","vendor":"Linux","versions":[{"lessThan":"522d1d950b9e3b68190a6de7534827c8dccedb73","status":"affected","version":"04c26faa51d1e2fe71cf13c45791f5174c37f986","versionType":"git"},{"lessThan":"c1481c94e74c955e0448ddf46b8615a44d840c1e","status":"affected","version":"04c26faa51d1e2fe71cf13c45791f5174c37f986","versionType":"git"},{"status":"affected","version":"d1f76dfadaf8f47ed1753f97dbcbd41c16215ffa","versionType":"git"},{"status":"affected","version":"5195ec5e365a2a9331bfeb585b613a6e94f98dba","versionType":"git"},{"status":"affected","version":"b9f5b7ad4ac3af006443f535b1ce7bff1d130d7d","versionType":"git"},{"lessThan":"5.5","status":"affected","version":"5.4.124","versionType":"semver"},{"lessThan":"5.11","status":"affected","version":"5.10.42","versionType":"semver"},{"lessThan":"5.13","status":"affected","version":"5.12.9","versionType":"semver"}]},{"defaultStatus":"affected","product":"Linux","programFiles":["net/tipc/core.c","net/tipc/udp_media.c"],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","vendor":"Linux","versions":[{"status":"affected","version":"5.13"},{"lessThan":"5.13","status":"unaffected","version":"0","versionType":"semver"},{"lessThanOrEqual":"7.1.*","status":"unaffected","version":"7.1.5","versionType":"semver"},{"lessThanOrEqual":"*","status":"unaffected","version":"7.2","versionType":"original_commit_for_fix"}]}],"cpeApplicability":[{"nodes":[{"cpeMatch":[{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"7.1.5","versionStartIncluding":"5.13","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"7.2","versionStartIncluding":"5.13","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.4.124","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.10.42","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.12.9","vulnerable":true}],"negate":false,"operator":"OR"}]}],"descriptions":[{"lang":"en","value":"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."}],"providerMetadata":{"dateUpdated":"2026-09-04T16:48:11.682Z","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","shortName":"Linux"},"references":[{"url":"https://git.kernel.org/stable/c/522d1d950b9e3b68190a6de7534827c8dccedb73"},{"url":"https://git.kernel.org/stable/c/c1481c94e74c955e0448ddf46b8615a44d840c1e"}],"title":"tipc: avoid busy looping in tipc_exit_net()","x_generator":{"engine":"bippy-1.2.0"}}},"cveMetadata":{"assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","assignerShortName":"Linux","cveId":"CVE-2026-80866","datePublished":"2026-09-04T16:48:11.682Z","dateReserved":"2026-08-26T14:34:25.798Z","dateUpdated":"2026-09-04T16:48:11.682Z","state":"PUBLISHED"},"dataType":"CVE_RECORD","dataVersion":"5.2"},"nvd":{"publishedDate":"2026-09-04 17:16:58","lastModifiedDate":"2026-09-04 17:16:58","problem_types":[],"metrics":[],"configurations":[]},"legacy_mitre":{"record":{"CveYear":"2026","CveId":"80866","Ordinal":"1","Title":"tipc: avoid busy looping in tipc_exit_net()","CVE":"CVE-2026-80866","Year":"2026"},"notes":[{"CveYear":"2026","CveId":"80866","Ordinal":"1","NoteData":"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.","Type":"Description","Title":"tipc: avoid busy looping in tipc_exit_net()"}]}}}