CVE-2026-98865 (GCVE-0-2026-98865)

Vulnerability from cvelistv5 – Published: 2026-10-18 15:51 – Updated: 2026-10-19 09:26
VLAI
Title
sched_ext: Don't run ops.dequeue() with a DSQ lock held
Summary
In the Linux kernel, the following vulnerability has been resolved: sched_ext: Don't run ops.dequeue() with a DSQ lock held ops.dequeue() is invoked with the source user DSQ's lock still held on the consume and move paths (scx_consume_dispatch_q(), move_task_between_dsqs()). A BPF scheduler which locks the source user DSQ from ops.dequeue() - e.g. by iterating it with bpf_iter_scx_dsq - self-deadlocks. ops.dequeue() can only call the "any" kfuncs and none of them can lock a builtin DSQ, so the global and bypass paths can't deadlock; however, all DSQ locks share one lockdep class, so iterating any user DSQ from ops.dequeue() on those paths trips the recursion check. Move the invocation after the DSQ unlock on all three paths. SCX_TASK_IN_CUSTODY is cleared under the lock serializing the transfer so that the callback is invoked exactly once.
Severity
No CVSS data available.
Assigner
Linux CNA under the mitre root
CNA scorecard D 53/100 over 6996 records in the last 180 days details
References
Impacted products
Vendor Product Version CPE status
Linux Linux Affected: ebf1ccff79c43f860cbd2f9d6cfab9a462d0cb2d , < fe499ae9da46e297f578d4346c4c8e338c3118db (git)
Affected: ebf1ccff79c43f860cbd2f9d6cfab9a462d0cb2d , < cb86607ada73185f321baa7f9d94a08a3a40bbf5 (git)
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Linux Linux Affected: 7.1
Unaffected: 0 , < 7.1 (semver)
Unaffected: 7.2.10 , ≤ 7.2.* (semver)
Unaffected: 7.3 , ≤ * (original_commit_for_fix)
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          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nsched_ext: Don\u0027t run ops.dequeue() with a DSQ lock held\n\nops.dequeue() is invoked with the source user DSQ\u0027s 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\u0027t 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."
        }
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      "providerMetadata": {
        "dateUpdated": "2026-10-19T09:26:59.604Z",
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        "shortName": "Linux"
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    "cveId": "CVE-2026-98865",
    "datePublished": "2026-10-18T15:51:26.449Z",
    "dateReserved": "2026-09-25T10:25:14.377Z",
    "dateUpdated": "2026-10-19T09:26:59.604Z",
    "state": "PUBLISHED"
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        "descriptions": [
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            "lang": "en",
            "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nsched_ext: Don\u0027t run ops.dequeue() with a DSQ lock held\n\nops.dequeue() is invoked with the source user DSQ\u0027s 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\u0027t 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."
          }
        ],
        "id": "CVE-2026-98865",
        "lastModified": "2026-10-19T10:19:50.563",
        "metrics": {},
        "published": "2026-10-18T16:17:40.973",
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        "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "vulnStatus": "Received"
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}



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