{"schema":"threatline.record/2","record":{"id":"CVE-2026-98219","aliases":[],"summary":"sched_ext: Close the pre-enable ops error claim window","details":"In the Linux kernel, the following vulnerability has been resolved:\n\nsched_ext: Close the pre-enable ops error claim window\n\nscx_alloc_and_add_sched() publishes ops->priv before\nscx_root_enable_workfn() switches the state to SCX_ENABLING. An error\nclaimed via scx_bpf_error_bstr() from an associated BPF program in that\nwindow is consumed by scx_disable_workfn(), which takes the pre-enable\nshortcut in scx_root_disable(). The shortcut returns without any teardown\nand restores SCX_DISABLED with an unconditional scx_set_enable_state() xchg\nracing the enable workfn's own transition. The enable then completes with\nthe claim consumed: the scheduler stays up but can never be disabled again,\nand bpf_scx_unreg() frees it while still in use, resulting in a\nuse-after-free. Both WARN_ON_ONCE()s fire back to back:\n\n  WARNING: kernel/sched/ext/ext.c:7522 at\n  scx_root_enable_workfn+0xeec/0x1be0, CPU#3: scx_enable_help/276\n\n  WARNING: kernel/sched/ext/ext.c:6398 at scx_root_disable+0xb50/0xdb8,\n  CPU#0: sched_ext_helpe/664\n\nscx_root_enable_workfn() switches to SCX_ENABLING before the scheduler\nallocation, so ops->priv is never visible while SCX_DISABLED. The allocation\nfailure path restores SCX_DISABLED.","categories":["Operating systems"],"product":"Linux","vendor":"Linux","ecosystem":null,"affected_ranges":[{"source":"CVE List","source_url":"https://www.cve.org/CVERecord?id=CVE-2026-98219","source_modified_at":"2026-10-19T09:15:51.341Z","fetched_at":"2026-10-23T18:45:31.882637Z","product":"Linux","vendor":"Linux","versions":[{"version":"105dcd005be2ac1d5541921db8feb1d0f98d59d5","lessThan":"959c66dc4a915be306c35691095c787c61dc7df9","status":"affected","versionType":"git"},{"version":"105dcd005be2ac1d5541921db8feb1d0f98d59d5","lessThan":"c7a1c6e8004ab12a9c9bfdcb603f60f9bf4a3cee","status":"affected","versionType":"git"}],"defaultStatus":"unaffected"},{"source":"CVE List","source_url":"https://www.cve.org/CVERecord?id=CVE-2026-98219","source_modified_at":"2026-10-19T09:15:51.341Z","fetched_at":"2026-10-23T18:45:31.882637Z","product":"Linux","vendor":"Linux","versions":[{"version":"7.1","status":"affected"},{"version":"0","lessThan":"7.1","status":"unaffected","versionType":"semver"},{"version":"7.2.8","lessThanOrEqual":"7.2.*","status":"unaffected","versionType":"semver"},{"version":"7.3","lessThanOrEqual":"*","status":"unaffected","versionType":"original_commit_for_fix"}],"defaultStatus":"affected"}],"fixed_versions":[{"source":"CVE List","source_url":"https://www.cve.org/CVERecord?id=CVE-2026-98219","source_modified_at":"2026-10-19T09:15:51.341Z","fetched_at":"2026-10-23T18:45:31.882637Z","package":{"name":"Linux","ecosystem":null},"version":"959c66dc4a915be306c35691095c787c61dc7df9","basis":"first unaffected version stated in the CVE record"}],"cvss":null,"severity":null,"kev":{"listed":false},"epss":{"probability":0.00162,"percentile":0.05096,"score_date":"2026-10-23"},"published_at":"2026-10-06T08:44:54.943Z","modified_at":"2026-10-19T09:15:51.341Z","provenance":[{"source":"CVE List","url":"https://www.cve.org/CVERecord?id=CVE-2026-98219","fetched_at":"2026-10-23T18:45:31.882637Z","source_modified_at":"2026-10-19T09:15:51.341Z"},{"source":"EPSS","url":"https://api.first.org/data/v1/epss?cve=CVE-2026-98219","fetched_at":"2026-10-23T18:42:43.628194Z","source_modified_at":"2026-10-23"}],"sources":["CVE List","EPSS"],"references":[{"source":"CVE List","url":"https://git.kernel.org/stable/c/959c66dc4a915be306c35691095c787c61dc7df9"},{"source":"CVE List","url":"https://git.kernel.org/stable/c/c7a1c6e8004ab12a9c9bfdcb603f60f9bf4a3cee"}],"locations":[],"motoko_assessment":{"status":"requires_architecture_review","automatic_remediation":false},"cve_state":"PUBLISHED","classification":{"method":"product-first software-layer rules","rules_version":"2.1","matched_on":"product","confidence":"heuristic","reviewed":false},"change_timestamp":"2026-10-19T09:15:51.341Z","content_hash":"d0e0b0a959750cbd1fddafdffaebd7aed4bf18df23b7c5f312f85456cb22babf"}}