CVE-2026-68421

{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-68421", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-07-30T09:28:09.392Z", "datePublished": "2026-08-10T12:04:41.946Z", "dateUpdated": "2026-10-21T12:44:06.128Z"}, "containers": {"cna": {"providerMetadata": {"orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-10-21T12:44:06.128Z"}, "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."}], "affected": [{"product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": ["kernel/sched/ext/ext.c"], "versions": [{"version": "7c65ae81ea86a6ed8086e1a5651acd766187f19b", "lessThan": "6267ebee9f2f3e26f4968bf6dc29d350620fa320", "status": "affected", "versionType": "git"}, {"version": "7c65ae81ea86a6ed8086e1a5651acd766187f19b", "lessThan": "2907e9d0f05b506dfd58aec589a23042a56ef36b", "status": "affected", "versionType": "git"}, {"version": "7c65ae81ea86a6ed8086e1a5651acd766187f19b", "lessThan": "e2f188cdbf8312289532c36eb4e9eb1c9544d43a", "status": "affected", "versionType": "git"}, {"version": "7c65ae81ea86a6ed8086e1a5651acd766187f19b", "lessThan": "b7d9c359e5cf867f7eb23df3bb1c6b9e58af24da", "status": "affected", "versionType": "git"}]}, {"product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": ["kernel/sched/ext/ext.c"], "versions": [{"version": "6.12", "status": "affected"}, {"version": "0", "lessThan": "6.12", "status": "unaffected", "versionType": "semver"}, {"version": "6.12.114", "lessThanOrEqual": "6.12.*", "status": "unaffected", "versionType": "semver"}, {"version": "6.18.42", "lessThanOrEqual": "6.18.*", "status": "unaffected", "versionType": "semver"}, {"version": "7.1.6", "lessThanOrEqual": "7.1.*", "status": "unaffected", "versionType": "semver"}, {"version": "7.2", "lessThanOrEqual": "*", "status": "unaffected", "versionType": "original_commit_for_fix"}]}], "cpeApplicability": [{"nodes": [{"operator": "OR", "negate": false, "cpeMatch": [{"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.12", "versionEndExcluding": "6.12.114"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.12", "versionEndExcluding": "6.18.42"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.12", "versionEndExcluding": "7.1.6"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.12", "versionEndExcluding": "7.2"}]}]}], "references": [{"url": "https://git.kernel.org/stable/c/6267ebee9f2f3e26f4968bf6dc29d350620fa320"}, {"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"}}}}

{}

{"affected": [{"affectedData": [{"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": "6267ebee9f2f3e26f4968bf6dc29d350620fa320", "status": "affected", "version": "7c65ae81ea86a6ed8086e1a5651acd766187f19b", "versionType": "git"}, {"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": "6.12.*", "status": "unaffected", "version": "6.12.114", "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", "versionType": "original_commit_for_fix"}]}], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}], "cveTags": [], "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."}], "id": "CVE-2026-68421", "lastModified": "2026-10-21T13:19:30.430", "metrics": {}, "published": "2026-08-10T13:20:35.980", "references": [{"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/2907e9d0f05b506dfd58aec589a23042a56ef36b"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/6267ebee9f2f3e26f4968bf6dc29d350620fa320"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/b7d9c359e5cf867f7eb23df3bb1c6b9e58af24da"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/e2f188cdbf8312289532c36eb4e9eb1c9544d43a"}], "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "vulnStatus": "Received"}

{"bugzilla": {"description": "kernel: Linux kernel sched_ext: Incorrect warning during core scheduling", "id": "2513236", "url": "https://bugzilla.redhat.com/show_bug.cgi?id=2513236"}, "csaw": false, "cvss3": {"cvss3_base_score": "0.0", "cvss3_scoring_vector": "CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:N", "status": "draft"}, "cwe": "CWE-1288", "details": ["In the Linux kernel, the following vulnerability has been resolved:\nsched_ext: Don't warn on core-sched forced idle in put_prev_task_scx()\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.\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.", "A flaw was found in the Linux kernel's `sched_ext` component. The `put_prev_task_scx()` function incorrectly issues a warning when a runnable task transitions to an idle state due to core scheduling. This occurs because the core scheduling mechanism bypasses certain checks, leading to a misleading warning."], "name": "CVE-2026-68421", "package_state": [{"cpe": "cpe:/o:redhat:enterprise_linux:10", "fix_state": "Fix deferred", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 10"}, {"cpe": "cpe:/o:redhat:enterprise_linux:6", "fix_state": "Not affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 6"}, {"cpe": "cpe:/o:redhat:enterprise_linux:7", "fix_state": "Not affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 7"}, {"cpe": "cpe:/o:redhat:enterprise_linux:7", "fix_state": "Not affected", "package_name": "kernel-rt", "product_name": "Red Hat Enterprise Linux 7"}, {"cpe": "cpe:/o:redhat:enterprise_linux:8", "fix_state": "Not affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 8"}, {"cpe": "cpe:/o:redhat:enterprise_linux:8", "fix_state": "Not affected", "package_name": "kernel-rt", "product_name": "Red Hat Enterprise Linux 8"}, {"cpe": "cpe:/o:redhat:enterprise_linux:9", "fix_state": "Not affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 9"}, {"cpe": "cpe:/o:redhat:enterprise_linux:9", "fix_state": "Not affected", "package_name": "kernel-rt", "product_name": "Red Hat Enterprise Linux 9"}, {"cpe": "cpe:/a:redhat:enterprise_linux_nvidia:", "fix_state": "Out of support scope", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux for NVIDIA 26"}, {"cpe": "cpe:/a:redhat:openshift:4", "fix_state": "Not affected", "package_name": "rhcos", "product_name": "Red Hat OpenShift Container Platform 4"}], "public_date": "2026-08-10T12:04:41Z", "references": ["https://www.cve.org/CVERecord?id=CVE-2026-68421\nhttps://nvd.nist.gov/vuln/detail/CVE-2026-68421\nhttps://git.kernel.org/stable/c/2907e9d0f05b506dfd58aec589a23042a56ef36b\nhttps://git.kernel.org/stable/c/b7d9c359e5cf867f7eb23df3bb1c6b9e58af24da\nhttps://git.kernel.org/stable/c/e2f188cdbf8312289532c36eb4e9eb1c9544d43a"], "threat_severity": "Low"}

{"affected": [{"configurations": [{"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[7c65ae81ea86a6ed8086e1a5651acd766187f19b,2907e9d0f05b506dfd58aec589a23042a56ef36b)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[7c65ae81ea86a6ed8086e1a5651acd766187f19b,e2f188cdbf8312289532c36eb4e9eb1c9544d43a)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[7c65ae81ea86a6ed8086e1a5651acd766187f19b,b7d9c359e5cf867f7eb23df3bb1c6b9e58af24da)"}}], "enrichment": {"confidence": 99.0, "confidence_source": "inferred", "scores": [{"score": 99.0, "source": "inferred"}, {"score": 100.0, "source": "matching"}]}, "original": {"product": "Linux", "source": "cna", "vendor": "Linux"}, "product": "linux_kernel", "vendor": "linux"}, {"configurations": [{"platform": null, "status": "affected", "versions": {"scheme": "generic", "value": "6.12"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "generic", "value": "[0,6.12)"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "semver", "value": "[6.18.42,6.19.0)"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "semver", "value": "[7.1.6,7.2.0)"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "generic", "value": "[7.2-rc4,*]"}}], "enrichment": {"confidence": 99.0, "confidence_source": "inferred", "scores": [{"score": 99.0, "source": "inferred"}, {"score": 100.0, "source": "matching"}]}, "original": {"product": "Linux", "source": "cna", "vendor": "Linux"}, "product": "linux_kernel", "vendor": "linux"}], "created": "2026-08-10T18:15:11.380695+00:00", "updated": "2026-08-13T03:15:12.153147+00:00", "vendors": ["linux", "linux$PRODUCT$linux_kernel"]}