{"api_version":"1","generated_at":"2026-08-22T17:47:28+00:00","cve":"CVE-2026-74731","urls":{"html":"https://cve.report/CVE-2026-74731","api":"https://cve.report/api/cve/CVE-2026-74731.json","docs":"https://cve.report/api","cve_org":"https://www.cve.org/CVERecord?id=CVE-2026-74731","nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-74731"},"summary":{"title":"sched_ext: Skip sub-disable teardown for never-linked sub-schedulers","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nsched_ext: Skip sub-disable teardown for never-linked sub-schedulers\n\nA sub-scheduler enable can fail before scx_link_sched() links the sched into\nthe hierarchy, e.g. when the parent is already being disabled, and cleanup\nstill runs the full scx_sub_disable().\n\nThat is racy against root disable: drain_descendants() is the only ordering\nbetween a sub's disable-time task walk and root disable's all-task teardown,\nand an unlinked sub is invisible to it. Root's teardown can thus run between\nthe never-linked sub's drain and its walk, exiting every task to no\nscheduler.\n\nThe walk then trips the membership WARN and re-homes the exited tasks onto\nthe dying hierarchy, a use-after-free.\n\nSkip the cgroup ownership reset and the task walk if @sch was never linked,\nindicated by the empty ->sibling as unlinking only happens later in the same\nfunction. The membership WARN remains valid: a linked sub is always waited\non by an ancestor's drain.","state":"PUBLISHED","assigner":"Linux","published_at":"2026-08-22 16:16:48","updated_at":"2026-08-22 16:16:48"},"problem_types":[],"metrics":[],"references":[{"url":"https://git.kernel.org/stable/c/6428093a4a986c38c9089b5eb32b56d914ef437a","name":"https://git.kernel.org/stable/c/6428093a4a986c38c9089b5eb32b56d914ef437a","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/8c13364db9c9a43ed286f3a8d0fb9477b1adc43c","name":"https://git.kernel.org/stable/c/8c13364db9c9a43ed286f3a8d0fb9477b1adc43c","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-74731","name":"CVE Program record","refsource":"CVE.ORG","tags":["canonical"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-74731","name":"NVD vulnerability detail","refsource":"NVD","tags":["canonical","analysis"]}],"affected":[{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 337ec00b1d9c676f637651c2cefddb8612b867ee 6428093a4a986c38c9089b5eb32b56d914ef437a git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 337ec00b1d9c676f637651c2cefddb8612b867ee 8c13364db9c9a43ed286f3a8d0fb9477b1adc43c git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 7.1","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 7.1 semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 7.1.9 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":null,"legacy_qids":[]},"source_records":{"cve_program":{"containers":{"cna":{"affected":[{"defaultStatus":"unaffected","product":"Linux","programFiles":["kernel/sched/ext/ext.c"],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","vendor":"Linux","versions":[{"lessThan":"6428093a4a986c38c9089b5eb32b56d914ef437a","status":"affected","version":"337ec00b1d9c676f637651c2cefddb8612b867ee","versionType":"git"},{"lessThan":"8c13364db9c9a43ed286f3a8d0fb9477b1adc43c","status":"affected","version":"337ec00b1d9c676f637651c2cefddb8612b867ee","versionType":"git"}]},{"defaultStatus":"affected","product":"Linux","programFiles":["kernel/sched/ext/ext.c"],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","vendor":"Linux","versions":[{"status":"affected","version":"7.1"},{"lessThan":"7.1","status":"unaffected","version":"0","versionType":"semver"},{"lessThanOrEqual":"7.1.*","status":"unaffected","version":"7.1.9","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":"7.1.9","versionStartIncluding":"7.1","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"7.2","versionStartIncluding":"7.1","vulnerable":true}],"negate":false,"operator":"OR"}]}],"descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nsched_ext: Skip sub-disable teardown for never-linked sub-schedulers\n\nA sub-scheduler enable can fail before scx_link_sched() links the sched into\nthe hierarchy, e.g. when the parent is already being disabled, and cleanup\nstill runs the full scx_sub_disable().\n\nThat is racy against root disable: drain_descendants() is the only ordering\nbetween a sub's disable-time task walk and root disable's all-task teardown,\nand an unlinked sub is invisible to it. Root's teardown can thus run between\nthe never-linked sub's drain and its walk, exiting every task to no\nscheduler.\n\nThe walk then trips the membership WARN and re-homes the exited tasks onto\nthe dying hierarchy, a use-after-free.\n\nSkip the cgroup ownership reset and the task walk if @sch was never linked,\nindicated by the empty ->sibling as unlinking only happens later in the same\nfunction. The membership WARN remains valid: a linked sub is always waited\non by an ancestor's drain."}],"providerMetadata":{"dateUpdated":"2026-08-22T15:33:20.294Z","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","shortName":"Linux"},"references":[{"url":"https://git.kernel.org/stable/c/6428093a4a986c38c9089b5eb32b56d914ef437a"},{"url":"https://git.kernel.org/stable/c/8c13364db9c9a43ed286f3a8d0fb9477b1adc43c"}],"title":"sched_ext: Skip sub-disable teardown for never-linked sub-schedulers","x_generator":{"engine":"bippy-1.2.0"}}},"cveMetadata":{"assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","assignerShortName":"Linux","cveId":"CVE-2026-74731","datePublished":"2026-08-22T15:33:20.294Z","dateReserved":"2026-08-15T05:44:03.930Z","dateUpdated":"2026-08-22T15:33:20.294Z","state":"PUBLISHED"},"dataType":"CVE_RECORD","dataVersion":"5.2"},"nvd":{"publishedDate":"2026-08-22 16:16:48","lastModifiedDate":"2026-08-22 16:16:48","problem_types":[],"metrics":[],"configurations":[]},"legacy_mitre":{"record":{"CveYear":"2026","CveId":"74731","Ordinal":"1","Title":"sched_ext: Skip sub-disable teardown for never-linked sub-schedu","CVE":"CVE-2026-74731","Year":"2026"},"notes":[{"CveYear":"2026","CveId":"74731","Ordinal":"1","NoteData":"In the Linux kernel, the following vulnerability has been resolved:\n\nsched_ext: Skip sub-disable teardown for never-linked sub-schedulers\n\nA sub-scheduler enable can fail before scx_link_sched() links the sched into\nthe hierarchy, e.g. when the parent is already being disabled, and cleanup\nstill runs the full scx_sub_disable().\n\nThat is racy against root disable: drain_descendants() is the only ordering\nbetween a sub's disable-time task walk and root disable's all-task teardown,\nand an unlinked sub is invisible to it. Root's teardown can thus run between\nthe never-linked sub's drain and its walk, exiting every task to no\nscheduler.\n\nThe walk then trips the membership WARN and re-homes the exited tasks onto\nthe dying hierarchy, a use-after-free.\n\nSkip the cgroup ownership reset and the task walk if @sch was never linked,\nindicated by the empty ->sibling as unlinking only happens later in the same\nfunction. The membership WARN remains valid: a linked sub is always waited\non by an ancestor's drain.","Type":"Description","Title":"sched_ext: Skip sub-disable teardown for never-linked sub-schedu"}]}}}