CVE-2026-99269 (GCVE-0-2026-99269)

Vulnerability from cvelistv5 – Published: 2026-11-03 11:48 – Updated: 2026-11-03 19:14
VLAI
Title
sched_ext: Wait for SCX_OPSS_DISPATCHING before moving tasks off DSQs
Summary
In the Linux kernel, the following vulnerability has been resolved: sched_ext: Wait for SCX_OPSS_DISPATCHING before moving tasks off DSQs A task can be found on a non-local DSQ while the CPU which dispatched it is still running ops.dequeue() and hasn't cleared SCX_OPSS_DISPATCHING. The DSQ consume and move paths don't wait for the dispatch to finish and can operate on the task concurrently with the dispatcher. Call scx_wait_dispatching() in scx_move_local_task_to_local_dsq(), unlink_dsq_and_switch_rq_lock() and move_task_between_dsqs() before they operate on the task. In scx_move_local_task_to_local_dsq(), wait before scx_resolve_local_dsq() as it may update p->scx.flags.
Severity
7.8 (High)
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Assigner
Linux CNA under the mitre root
CNA scorecard D 53/100 over 6637 records in the last 180 days details
References
Impacted products
Vendor Product Version CPE status
Linux Linux Affected: ebf1ccff79c43f860cbd2f9d6cfab9a462d0cb2d , < cc2839946328c1618b3870d521b32bb9483d49d0 (git)
Affected: ebf1ccff79c43f860cbd2f9d6cfab9a462d0cb2d , < 2935062be77113c1c4565ca9d0c72180449aafee (git)
guessed Create a notification for this product.
Linux Linux Affected: 7.1
Unaffected: 0 , < 7.1 (semver)
Unaffected: 7.2.14 , ≤ 7.2.* (semver)
Unaffected: 7.3 , ≤ * (original_commit_for_fix)
guessed Create a notification for this product.
Show details on NVD website
To clipboard 

{
  "containers": {
    "cna": {
      "affected": [
        {
          "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": "cc2839946328c1618b3870d521b32bb9483d49d0",
              "status": "affected",
              "version": "ebf1ccff79c43f860cbd2f9d6cfab9a462d0cb2d",
              "versionType": "git"
            },
            {
              "lessThan": "2935062be77113c1c4565ca9d0c72180449aafee",
              "status": "affected",
              "version": "ebf1ccff79c43f860cbd2f9d6cfab9a462d0cb2d",
              "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": "7.1"
            },
            {
              "lessThan": "7.1",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "7.2.*",
              "status": "unaffected",
              "version": "7.2.14",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "7.3",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
      "cpeApplicability": [
        {
          "nodes": [
            {
              "cpeMatch": [
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.2.14",
                  "versionStartIncluding": "7.1",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.3",
                  "versionStartIncluding": "7.1",
                  "vulnerable": true
                }
              ],
              "negate": false,
              "operator": "OR"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nsched_ext: Wait for SCX_OPSS_DISPATCHING before moving tasks off DSQs\n\nA task can be found on a non-local DSQ while the CPU which dispatched it\nis still running ops.dequeue() and hasn\u0027t cleared SCX_OPSS_DISPATCHING.\nThe DSQ consume and move paths don\u0027t wait for the dispatch to finish and\ncan operate on the task concurrently with the dispatcher.\n\nCall scx_wait_dispatching() in scx_move_local_task_to_local_dsq(),\nunlink_dsq_and_switch_rq_lock() and move_task_between_dsqs() before they\noperate on the task. In scx_move_local_task_to_local_dsq(), wait before\nscx_resolve_local_dsq() as it may update p-\u003escx.flags."
        }
      ],
      "metrics": [
        {
          "cvssV3_1": {
            "baseScore": 7.8,
            "baseSeverity": "HIGH",
            "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
            "version": "3.1"
          },
          "scenarios": [
            {
              "lang": "en",
              "value": "AV:L - The race is in scx_dispatch_enqueue() versus scx_move_local_task_to_local_dsq(), unlink_dsq_and_switch_rq_lock() and move_task_between_dsqs() in kernel/sched/ext/ext.c, reached locally by bpf(BPF_LINK_CREATE)-\u003ebpf_scx_reg() then scx_bpf_dsq_insert()/scx_bpf_dsq_move[_to_local](), or by __schedule()-\u003epick_task_scx()-\u003escx_dispatch_sched()-\u003econsume_global_dsq(); no remote protocol supplies the triggering state.\nAC:L - A loaded sched_ext program inserts a task onto a non-local DSQ so scx_dispatch_enqueue() drops dsq-\u003elock while ops_state is still SCX_OPSS_DISPATCHING and runs ops.dequeue(), while another CPU consumes or moves that same task via scx_bpf_dsq_move_to_local()/scx_bpf_dsq_move() or consume_global_dsq(); the attacker drives both sides and can retry.\nPR:L - Enabling the scheduler takes bpf() BPF_PROG_LOAD of BPF_PROG_TYPE_STRUCT_OPS, which is_perfmon_prog_type() gates on bpf_token_capable(CAP_BPF) and CAP_PERFMON, then BPF_LINK_CREATE into bpf_scx_reg(); those capabilities are delegable into a user namespace with a BPF token, so this is not init-namespace root.\nUI:N - The attacker attaches their own sched_ext_ops, has scx_bpf_dsq_insert() place a task on a non-local DSQ, and consumes or moves it from another CPU; no victim mount, file open, or other user action is required.\nS:U - The concurrent updates of p-\u003escx.flags, p-\u003escx.ops_state and p-\u003escx.dsq_list stay inside the host kernel sched_ext hot path; this is same-authority kernel memory corruption, not a VM, IOMMU, or guest-to-host escape.\nC:H - scx_move_local_task_to_local_dsq() and move_task_between_dsqs() unlink and re-link p-\u003escx.dsq_list and RMW p-\u003escx.flags (scx_resolve_local_dsq() may clear SCX_TASK_IMMED) while scx_dispatch_enqueue() still holds SCX_OPSS_DISPATCHING; a lost SCX_TASK_QUEUED bit or a second list_add of the live node corrupts kernel list state, a disclosure-capable memory-corruption primitive.\nI:H - The same unsynchronized DSQ unlink/insert and non-atomic p-\u003escx.flags RMW, plus scx_dispatch_enqueue()\u0027s later SCX_ENQ_CLEAR_OPSS store overwriting a new QUEUEING/QUEUED ops_state, can double-link a task or clobber scheduler ownership and yield kernel list corruption and control-flow corruption on the sched_ext path.\nA:H - Consuming or moving a task found on a non-local DSQ while scx_dispatch_enqueue() is still in ops.dequeue() with SCX_OPSS_DISPATCHING set hits WARN_ON_ONCE() in the enqueue/dispatch paths, can strand the task when CLEAR_OPSS overwrites QUEUED so later finish_dispatch() drops it, and can oops on a corrupted dsq_list, causing a kernel hang or panic."
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-11-03T19:14:42.052Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
      },
      "references": [
        {
          "url": "https://git.kernel.org/stable/c/cc2839946328c1618b3870d521b32bb9483d49d0"
        },
        {
          "url": "https://git.kernel.org/stable/c/2935062be77113c1c4565ca9d0c72180449aafee"
        }
      ],
      "title": "sched_ext: Wait for SCX_OPSS_DISPATCHING before moving tasks off DSQs",
      "x_generator": {
        "engine": "bippy-1.2.0"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
    "assignerShortName": "Linux",
    "cveId": "CVE-2026-99269",
    "datePublished": "2026-11-03T11:48:18.333Z",
    "dateReserved": "2026-09-25T10:25:14.404Z",
    "dateUpdated": "2026-11-03T19:14:42.052Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2",
  "vulnerability-lookup:meta": {
    "epss": {
      "cve": "CVE-2026-99269",
      "date": "2026-11-04",
      "epss": "0.00146",
      "percentile": "0.03862"
    },
    "nvd": {
      "cve": {
        "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": "cc2839946328c1618b3870d521b32bb9483d49d0",
                    "status": "affected",
                    "version": "ebf1ccff79c43f860cbd2f9d6cfab9a462d0cb2d",
                    "versionType": "git"
                  },
                  {
                    "lessThan": "2935062be77113c1c4565ca9d0c72180449aafee",
                    "status": "affected",
                    "version": "ebf1ccff79c43f860cbd2f9d6cfab9a462d0cb2d",
                    "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": "7.1"
                  },
                  {
                    "lessThan": "7.1",
                    "status": "unaffected",
                    "version": "0",
                    "versionType": "semver"
                  },
                  {
                    "lessThanOrEqual": "7.2.*",
                    "status": "unaffected",
                    "version": "7.2.14",
                    "versionType": "semver"
                  },
                  {
                    "lessThanOrEqual": "*",
                    "status": "unaffected",
                    "version": "7.3",
                    "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: Wait for SCX_OPSS_DISPATCHING before moving tasks off DSQs\n\nA task can be found on a non-local DSQ while the CPU which dispatched it\nis still running ops.dequeue() and hasn\u0027t cleared SCX_OPSS_DISPATCHING.\nThe DSQ consume and move paths don\u0027t wait for the dispatch to finish and\ncan operate on the task concurrently with the dispatcher.\n\nCall scx_wait_dispatching() in scx_move_local_task_to_local_dsq(),\nunlink_dsq_and_switch_rq_lock() and move_task_between_dsqs() before they\noperate on the task. In scx_move_local_task_to_local_dsq(), wait before\nscx_resolve_local_dsq() as it may update p-\u003escx.flags."
          }
        ],
        "id": "CVE-2026-99269",
        "lastModified": "2026-11-03T20:18:32.627",
        "metrics": {
          "cvssMetricV31": [
            {
              "cvssData": {
                "attackComplexity": "LOW",
                "attackVector": "LOCAL",
                "availabilityImpact": "HIGH",
                "baseScore": 7.8,
                "baseSeverity": "HIGH",
                "confidentialityImpact": "HIGH",
                "integrityImpact": "HIGH",
                "privilegesRequired": "LOW",
                "scope": "UNCHANGED",
                "userInteraction": "NONE",
                "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
                "version": "3.1"
              },
              "exploitabilityScore": 1.8,
              "impactScore": 5.9,
              "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
              "type": "Secondary"
            }
          ]
        },
        "published": "2026-11-03T12:17:34.117",
        "references": [
          {
            "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
            "url": "https://git.kernel.org/stable/c/2935062be77113c1c4565ca9d0c72180449aafee"
          },
          {
            "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
            "url": "https://git.kernel.org/stable/c/cc2839946328c1618b3870d521b32bb9483d49d0"
          }
        ],
        "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "vulnStatus": "Received"
      }
    },
    "suse_vex": {
      "aggregate_severity": "moderate",
      "current_release_date": "2026-11-04T15:58:22Z",
      "cve": "CVE-2026-99269",
      "id": "CVE-2026-99269",
      "initial_release_date": "2026-11-04T00:37:56Z",
      "product_status:known_not_affected": "345",
      "source": "SUSE CSAF VEX",
      "status": "interim",
      "title": "SUSE CVE CVE-2026-99269",
      "url": "https://ftp.suse.com/pub/projects/security/csaf-vex/2026/cve-2026-99269.json",
      "version": "3"
    }
  }
}



Log in or create an account to share your comment.




Tags
Taxonomy of the tags.




Drag nodes to arrange them. Double-click a related vulnerability to open it, or a source to visit its link. The Physics button on the left tunes the layout and the simulation; the legend at the bottom left hides or shows nodes by kind and by sighting type.

Forecast uses a logistic model when the trend is rising, or an exponential decay model when the trend is falling. Fitted via linearized least squares.

Sightings

Author Source Type Date Other

Nomenclature

  • Seen: The vulnerability was mentioned, discussed, or observed by the user.
  • Confirmed: The vulnerability has been validated from an analyst's perspective.
  • Published Proof of Concept: A public proof of concept is available for this vulnerability.
  • Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
  • Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
  • Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
  • Not confirmed: The user expressed doubt about the validity of the vulnerability.
  • Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.
Vulnerability timeline

Sightings and recorded dates, grouped by day · UTC

JSON
How durations are calculated

Following the VTEM framework (Black Hat USA 2015), time to patch starts when the vendor or a coordinator was informed, total time to patch at discovery, and disclosure to patch at public disclosure; vendor response time runs from the report to its acknowledgement. Time to exploit and time unpatched start at the earliest discovery or report, falling back to public disclosure. Unpatched time ends at the first recorded patch, or the calculation time when no patch is recorded. Exploitation to patch shows the interval between those two events; a published proof of concept is a public exploit, not exploitation.

Each result shows its source dates. A negative interval means the end event came first; when date-only inputs leave the order open, the result says so. Date-only inputs are approximate. The earliest evidence wins: KEV report dates and sightings are labelled as such. Records describing another vulnerability are listed but never calculated from, and a PoC alone does not establish exploitation. Missing patch evidence does not prove that no patch exists. Filters below change the event list only.

Loading timeline…




    Related by attack behaviour

    Vulnerabilities whose description is nearest to this one in the vector space of the CIRCL/vulnerability-attack-technique-biencoder model. This is a similarity search over the bi-encoder space (plain cosine), not a classification, and it has no measured accuracy.