{"id":"CVE-2026-98865","title":"sched_ext: Don't run ops.dequeue() with a DSQ lock held","summary":"In the Linux kernel, the following vulnerability has been resolved:\n\nsched_ext: Don't run ops.dequeue() with a DSQ lock held\n\nops.dequeue() is invoked with the source user DSQ's lock still held on\nthe consume and move paths (scx_consume_…","severity":"none","vendor":"Linux","product":"Linux","affected":["Linux >= ebf1ccff79c43f860cbd2f9d6cfab9a462d0cb2d < fe499ae9da46e297f578d4346c4c8e338c3118db","Linux >= ebf1ccff79c43f860cbd2f9d6cfab9a462d0cb2d < cb86607ada73185f321baa7f9d94a08a3a40bbf5","Linux 7.1"],"published":"2026-10-18","updated":"2026-10-18","sourceUpdated":"2026-10-18T15:51:26.449Z","source":"CVEORG","sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-98865","references":[{"url":"https://git.kernel.org/stable/c/fe499ae9da46e297f578d4346c4c8e338c3118db"},{"url":"https://git.kernel.org/stable/c/cb86607ada73185f321baa7f9d94a08a3a40bbf5"}],"tags":["cve.org"],"ingestedAt":"2026-10-18T16:47:32.460Z","slug":"CVE-2026-98865","body":"## Overview\n\nIn the Linux kernel, the following vulnerability has been resolved:\n\nsched_ext: Don't run ops.dequeue() with a DSQ lock held\n\nops.dequeue() is invoked with the source user DSQ's lock still held on\nthe consume and move paths (scx_consume_dispatch_q(),\nmove_task_between_dsqs()). A BPF scheduler which locks the source user\nDSQ from ops.dequeue() - e.g. by iterating it with bpf_iter_scx_dsq -\nself-deadlocks.\n\nops.dequeue() can only call the \"any\" kfuncs and none of them can lock a\nbuiltin DSQ, so the global and bypass paths can't deadlock; however,\nall DSQ locks share one lockdep class, so iterating any user DSQ from\nops.dequeue() on those paths trips the recursion check.\n\nMove the invocation after the DSQ unlock on all three paths.\nSCX_TASK_IN_CUSTODY is cleared under the lock serializing the transfer\nso that the callback is invoked exactly once.\n\n## Affected\n\n- `Linux >= ebf1ccff79c43f860cbd2f9d6cfab9a462d0cb2d < fe499ae9da46e297f578d4346c4c8e338c3118db`\n- `Linux >= ebf1ccff79c43f860cbd2f9d6cfab9a462d0cb2d < cb86607ada73185f321baa7f9d94a08a3a40bbf5`\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":[]}