{"api_version":"1","generated_at":"2026-08-14T21:48:21+00:00","cve":"CVE-2026-68421","urls":{"html":"https://cve.report/CVE-2026-68421","api":"https://cve.report/api/cve/CVE-2026-68421.json","docs":"https://cve.report/api","cve_org":"https://www.cve.org/CVERecord?id=CVE-2026-68421","nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-68421"},"summary":{"title":"sched_ext: Don't warn on core-sched forced idle in put_prev_task_scx()","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nsched_ext: Don't warn on core-sched forced idle in put_prev_task_scx()\n\nput_prev_task_scx() warns when a runnable task drops to a lower sched_class\nwithout SCX_OPS_ENQ_LAST, on the assumption that balance_one() would have\nkept it running. Core scheduling breaks that: a forced-idle SMT sibling\nreschedules through the core_pick fast path in pick_next_task(), which skips\npick_task_scx() and thus balance_one(), so a runnable task can drop to idle\nwith ENQ_LAST unset.\n\nGate the warning on sched_cpu_cookie_match(): a cookie mismatch means core\nscheduling forced the idle, while a match (or core scheduling off) still\ncatches a genuine missing-ENQ_LAST drop.","state":"PUBLISHED","assigner":"Linux","published_at":"2026-08-10 13:20:35","updated_at":"2026-08-10 13:20:35"},"problem_types":[],"metrics":[],"references":[{"url":"https://git.kernel.org/stable/c/e2f188cdbf8312289532c36eb4e9eb1c9544d43a","name":"https://git.kernel.org/stable/c/e2f188cdbf8312289532c36eb4e9eb1c9544d43a","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/2907e9d0f05b506dfd58aec589a23042a56ef36b","name":"https://git.kernel.org/stable/c/2907e9d0f05b506dfd58aec589a23042a56ef36b","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/b7d9c359e5cf867f7eb23df3bb1c6b9e58af24da","name":"https://git.kernel.org/stable/c/b7d9c359e5cf867f7eb23df3bb1c6b9e58af24da","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-68421","name":"CVE Program record","refsource":"CVE.ORG","tags":["canonical"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-68421","name":"NVD vulnerability detail","refsource":"NVD","tags":["canonical","analysis"]}],"affected":[{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 7c65ae81ea86a6ed8086e1a5651acd766187f19b 2907e9d0f05b506dfd58aec589a23042a56ef36b git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 7c65ae81ea86a6ed8086e1a5651acd766187f19b e2f188cdbf8312289532c36eb4e9eb1c9544d43a git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 7c65ae81ea86a6ed8086e1a5651acd766187f19b b7d9c359e5cf867f7eb23df3bb1c6b9e58af24da git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 6.12","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.12 semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.18.42 6.18.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 7.1.6 7.1.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 7.2-rc4 * 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":"2907e9d0f05b506dfd58aec589a23042a56ef36b","status":"affected","version":"7c65ae81ea86a6ed8086e1a5651acd766187f19b","versionType":"git"},{"lessThan":"e2f188cdbf8312289532c36eb4e9eb1c9544d43a","status":"affected","version":"7c65ae81ea86a6ed8086e1a5651acd766187f19b","versionType":"git"},{"lessThan":"b7d9c359e5cf867f7eb23df3bb1c6b9e58af24da","status":"affected","version":"7c65ae81ea86a6ed8086e1a5651acd766187f19b","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":"6.12"},{"lessThan":"6.12","status":"unaffected","version":"0","versionType":"semver"},{"lessThanOrEqual":"6.18.*","status":"unaffected","version":"6.18.42","versionType":"semver"},{"lessThanOrEqual":"7.1.*","status":"unaffected","version":"7.1.6","versionType":"semver"},{"lessThanOrEqual":"*","status":"unaffected","version":"7.2-rc4","versionType":"original_commit_for_fix"}]}],"cpeApplicability":[{"nodes":[{"cpeMatch":[{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.18.42","versionStartIncluding":"6.12","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"7.1.6","versionStartIncluding":"6.12","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"7.2-rc4","versionStartIncluding":"6.12","vulnerable":true}],"negate":false,"operator":"OR"}]}],"descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nsched_ext: Don't warn on core-sched forced idle in put_prev_task_scx()\n\nput_prev_task_scx() warns when a runnable task drops to a lower sched_class\nwithout SCX_OPS_ENQ_LAST, on the assumption that balance_one() would have\nkept it running. Core scheduling breaks that: a forced-idle SMT sibling\nreschedules through the core_pick fast path in pick_next_task(), which skips\npick_task_scx() and thus balance_one(), so a runnable task can drop to idle\nwith ENQ_LAST unset.\n\nGate the warning on sched_cpu_cookie_match(): a cookie mismatch means core\nscheduling forced the idle, while a match (or core scheduling off) still\ncatches a genuine missing-ENQ_LAST drop."}],"providerMetadata":{"dateUpdated":"2026-08-10T12:04:41.946Z","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","shortName":"Linux"},"references":[{"url":"https://git.kernel.org/stable/c/2907e9d0f05b506dfd58aec589a23042a56ef36b"},{"url":"https://git.kernel.org/stable/c/e2f188cdbf8312289532c36eb4e9eb1c9544d43a"},{"url":"https://git.kernel.org/stable/c/b7d9c359e5cf867f7eb23df3bb1c6b9e58af24da"}],"title":"sched_ext: Don't warn on core-sched forced idle in put_prev_task_scx()","x_generator":{"engine":"bippy-1.2.0"}}},"cveMetadata":{"assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","assignerShortName":"Linux","cveId":"CVE-2026-68421","datePublished":"2026-08-10T12:04:41.946Z","dateReserved":"2026-07-30T09:28:09.392Z","dateUpdated":"2026-08-10T12:04:41.946Z","state":"PUBLISHED"},"dataType":"CVE_RECORD","dataVersion":"5.2"},"nvd":{"publishedDate":"2026-08-10 13:20:35","lastModifiedDate":"2026-08-10 13:20:35","problem_types":[],"metrics":[],"configurations":[]},"legacy_mitre":{"record":{"CveYear":"2026","CveId":"68421","Ordinal":"1","Title":"sched_ext: Don't warn on core-sched forced idle in put_prev_task","CVE":"CVE-2026-68421","Year":"2026"},"notes":[{"CveYear":"2026","CveId":"68421","Ordinal":"1","NoteData":"In the Linux kernel, the following vulnerability has been resolved:\n\nsched_ext: Don't warn on core-sched forced idle in put_prev_task_scx()\n\nput_prev_task_scx() warns when a runnable task drops to a lower sched_class\nwithout SCX_OPS_ENQ_LAST, on the assumption that balance_one() would have\nkept it running. Core scheduling breaks that: a forced-idle SMT sibling\nreschedules through the core_pick fast path in pick_next_task(), which skips\npick_task_scx() and thus balance_one(), so a runnable task can drop to idle\nwith ENQ_LAST unset.\n\nGate the warning on sched_cpu_cookie_match(): a cookie mismatch means core\nscheduling forced the idle, while a match (or core scheduling off) still\ncatches a genuine missing-ENQ_LAST drop.","Type":"Description","Title":"sched_ext: Don't warn on core-sched forced idle in put_prev_task"}]}}}