{"id":"CVE-2026-98864","title":"sched_ext: Wait for SCX_OPSS_DISPATCHING before reenqueueing a task","summary":"In the Linux kernel, the following vulnerability has been resolved:\n\nsched_ext: Wait for SCX_OPSS_DISPATCHING before reenqueueing a task\n\nebf1ccff79c4 (\"sched_ext: Fix ops.dequeue() semantics\") moved the final\nops_state store in scx_disp…","severity":"none","vendor":"Linux","product":"Linux","affected":["Linux >= ebf1ccff79c43f860cbd2f9d6cfab9a462d0cb2d < 43457bf6550044c40bd6d3fcdf9ea66f5a55d139","Linux >= ebf1ccff79c43f860cbd2f9d6cfab9a462d0cb2d < 7de9a6fb44eae4f05e68c805d58b9c618815adfa","Linux 7.1"],"published":"2026-10-18","updated":"2026-10-18","sourceUpdated":"2026-10-18T15:51:25.532Z","source":"CVEORG","sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-98864","references":[{"url":"https://git.kernel.org/stable/c/43457bf6550044c40bd6d3fcdf9ea66f5a55d139"},{"url":"https://git.kernel.org/stable/c/7de9a6fb44eae4f05e68c805d58b9c618815adfa"}],"tags":["cve.org"],"ingestedAt":"2026-10-18T16:47:32.459Z","slug":"CVE-2026-98864","body":"## Overview\n\nIn the Linux kernel, the following vulnerability has been resolved:\n\nsched_ext: Wait for SCX_OPSS_DISPATCHING before reenqueueing a task\n\nebf1ccff79c4 (\"sched_ext: Fix ops.dequeue() semantics\") moved the final\nops_state store in scx_dispatch_enqueue() after the DSQ unlock so that the\ncustody update and ops.dequeue() precede it. A task can thus be found on a\nDSQ while still SCX_OPSS_DISPATCHING.\n\nThe dequeue and core-sched pick paths wait for the state to clear in\nops_dequeue() but the reenqueue paths don't. A reenqueue in that window runs\nops.enqueue() and sets SCX_OPSS_QUEUED before the dispatch has completed.\nThe dispatcher's final store then overwrites it with SCX_OPSS_NONE and\nfinish_dispatch() drops every later dispatch of the task.\n\nWait for SCX_OPSS_DISPATCHING to clear before dequeueing a task for\nreenqueue, the same way ops_dequeue() does.\n\n## Affected\n\n- `Linux >= ebf1ccff79c43f860cbd2f9d6cfab9a462d0cb2d < 43457bf6550044c40bd6d3fcdf9ea66f5a55d139`\n- `Linux >= ebf1ccff79c43f860cbd2f9d6cfab9a462d0cb2d < 7de9a6fb44eae4f05e68c805d58b9c618815adfa`\n- `Linux 7.1`\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"sunlit","depthScore":3,"depthScoreParts":{"impact":2.8,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[]}