{"id":"CVE-2026-68421","revision":"607a8af7c02748d19816575c48b0b53e","records":[{"revision":"607a8af7c02748d19816575c48b0b53e","observedAt":"2026-10-23T15:48:27.903+00:00","statement":{"source":"cve-program","id":"CVE-2026-68421","aliases":[],"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":0,"publishedAt":"2026-08-10T12:04:41.946+00:00","modifiedAt":"2026-10-21T12:44:06.128+00:00","affected":[{"ecosystem":"Vendor product","name":"Linux","ranges":[],"versions":[],"rawVersionEvidence":"{\n                    \"product\": \"Linux\",\n                    \"vendor\": \"Linux\",\n                    \"defaultStatus\": \"unaffected\",\n                    \"repo\": \"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\",\n                    \"programFiles\": [\n                        \"kernel/sched/ext/ext.c\"\n                    ],\n                    \"versions\": [\n                        {\n                            \"version\": \"7c65ae81ea86a6ed8086e1a5651acd766187f19b\",\n                            \"lessThan\": \"6267ebee9f2f3e26f4968bf6dc29d350620fa320\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"7c65ae81ea86a6ed8086e1a5651acd766187f19b\",\n                            \"lessThan\": \"2907e9d0f05b506dfd58aec589a23042a56ef36b\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"7c65ae81ea86a6ed8086e1a5651acd766187f19b\",\n                            \"lessThan\": \"e2f188cdbf8312289532c36eb4e9eb1c9544d43a\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"7c65ae81ea86a6ed8086e1a5651acd766187f19b\",\n                            \"lessThan\": \"b7d9c359e5cf867f7eb23df3bb1c6b9e58af24da\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        }\n                    ]\n                }"},{"ecosystem":"Vendor product","name":"Linux","ranges":[],"versions":[],"rawVersionEvidence":"{\n                    \"product\": \"Linux\",\n                    \"vendor\": \"Linux\",\n                    \"defaultStatus\": \"affected\",\n                    \"repo\": \"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\",\n                    \"programFiles\": [\n                        \"kernel/sched/ext/ext.c\"\n                    ],\n                    \"versions\": [\n                        {\n                            \"version\": \"6.12\",\n                            \"status\": \"affected\"\n                        },\n                        {\n                            \"version\": \"0\",\n                            \"lessThan\": \"6.12\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"6.12.114\",\n                            \"lessThanOrEqual\": \"6.12.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"6.18.42\",\n                            \"lessThanOrEqual\": \"6.18.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"7.1.6\",\n                            \"lessThanOrEqual\": \"7.1.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"7.2\",\n                            \"lessThanOrEqual\": \"*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"original_commit_for_fix\"\n                        }\n                    ]\n                }"}],"metrics":[],"references":["https://git.kernel.org/stable/c/6267ebee9f2f3e26f4968bf6dc29d350620fa320","https://git.kernel.org/stable/c/2907e9d0f05b506dfd58aec589a23042a56ef36b","https://git.kernel.org/stable/c/e2f188cdbf8312289532c36eb4e9eb1c9544d43a","https://git.kernel.org/stable/c/b7d9c359e5cf867f7eb23df3bb1c6b9e58af24da"],"sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-68421","license":"CVE Program Terms of Use","key":"cve-program:CVE-2026-68421","identifiers":["CVE-2026-68421"]},"retained":false,"historicalAffected":[]}],"coverage":[]}