Vulnerability-Lookup

FKIE_CVE-2026-89518

Vulnerability from fkie_nvd - Published: 2026-09-11 20:19 - Updated: 2026-09-11 20:19

Severity

Summary

In the Linux kernel, the following vulnerability has been resolved: sched_ext: Fix this_rq() assumptions in dispatch kfuncs Under core scheduling, dispatch runs from within the core-wide pick and can target a sibling rq, so ops.dispatch() may execute on a CPU different from the dispatched rq's. Several kfunc paths assumed the two always coincide: - scx_dsq_move() decided whether an rq lock is held by testing this_rq()'s rq flags and lock-danced accordingly. A dispatch for a sibling took the unlocked-context branch and acquired the source rq lock on top of the already held dispatched rq lock which could deadlock. - scx_bpf_sub_dispatch() dispatched this_rq() with its stashed sub_dispatch_prev, which is NULL when dispatching for a sibling. - finish_dispatch(), scx_bpf_dsq_reenq() and scx_bpf_dsq_nr_queued() resolved SCX_DSQ_LOCAL to this CPU's local DSQ rather than the dispatched rq's. The latter two are callable from other rq-locked operations too, where SCX_DSQ_LOCAL now likewise resolves to the op's rq. This changes behavior also without core scheduling, e.g. for ops.enqueue() running a remote wakeup on the waking CPU, and is intended: which CPU happens to execute an operation is incidental, the op's rq is what it is operating on, and the resolution now matches the insert side where SCX_DSQ_LOCAL dispatches land on the task's rq. Use the rq tracked by scx_locked_rq(), which is set to the dispatched rq around ops invocations and NULL in unlocked contexts.

References

	URL	Tags
	416baaa9-dc9f-4396-8d5f-8c081fb06d67	https://git.kernel.org/stable/c/3dd52416e44a70bc993adb96d2e0d71b9ea21359
	416baaa9-dc9f-4396-8d5f-8c081fb06d67	https://git.kernel.org/stable/c/6d1890d3c6137ab523799765ae2de62cc05f116d

Impacted products

	Vendor	Product	Version

JSON

To clipboard

{
  "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": "6d1890d3c6137ab523799765ae2de62cc05f116d",
              "status": "affected",
              "version": "4c95380701f58b8112f0b891de8d160e4199e19d",
              "versionType": "git"
            },
            {
              "lessThan": "3dd52416e44a70bc993adb96d2e0d71b9ea21359",
              "status": "affected",
              "version": "4c95380701f58b8112f0b891de8d160e4199e19d",
              "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": "6.19"
            },
            {
              "lessThan": "6.19",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "7.2.*",
              "status": "unaffected",
              "version": "7.2.4",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "7.3-rc1",
              "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: Fix this_rq() assumptions in dispatch kfuncs\n\nUnder core scheduling, dispatch runs from within the core-wide pick and can\ntarget a sibling rq, so ops.dispatch() may execute on a CPU different from\nthe dispatched rq\u0027s. Several kfunc paths assumed the two always coincide:\n\n- scx_dsq_move() decided whether an rq lock is held by testing this_rq()\u0027s\n  rq flags and lock-danced accordingly. A dispatch for a sibling took the\n  unlocked-context branch and acquired the source rq lock on top of the\n  already held dispatched rq lock which could deadlock.\n\n- scx_bpf_sub_dispatch() dispatched this_rq() with its stashed\n  sub_dispatch_prev, which is NULL when dispatching for a sibling.\n\n- finish_dispatch(), scx_bpf_dsq_reenq() and scx_bpf_dsq_nr_queued()\n  resolved SCX_DSQ_LOCAL to this CPU\u0027s local DSQ rather than the dispatched\n  rq\u0027s. The latter two are callable from other rq-locked operations too,\n  where SCX_DSQ_LOCAL now likewise resolves to the op\u0027s rq. This changes\n  behavior also without core scheduling, e.g. for ops.enqueue() running a\n  remote wakeup on the waking CPU, and is intended: which CPU happens to\n  execute an operation is incidental, the op\u0027s rq is what it is operating\n  on, and the resolution now matches the insert side where SCX_DSQ_LOCAL\n  dispatches land on the task\u0027s rq.\n\nUse the rq tracked by scx_locked_rq(), which is set to the dispatched rq\naround ops invocations and NULL in unlocked contexts."
    }
  ],
  "id": "CVE-2026-89518",
  "lastModified": "2026-09-11T20:19:34.417",
  "metrics": {},
  "published": "2026-09-11T20:19:34.417",
  "references": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/3dd52416e44a70bc993adb96d2e0d71b9ea21359"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/6d1890d3c6137ab523799765ae2de62cc05f116d"
    }
  ],
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "vulnStatus": "Received"
}

CVE-2026-89518 (GCVE-0-2026-89518)

Vulnerability from cvelistv5 – Published: 2026-09-11 19:44 – Updated: 2026-09-11 19:44

Title

sched_ext: Fix this_rq() assumptions in dispatch kfuncs

Summary

Severity

No CVSS data available.

Assigner

Linux mitre root

References

2 references

URL	Tags
https://git.kernel.org/stable/c/6d1890d3c6137ab52…
https://git.kernel.org/stable/c/3dd52416e44a70bc9…

Impacted products

2 products

Vendor	Product	Version
Linux	Linux	Affected: 4c95380701f58b8112f0b891de8d160e4199e19d , < 6d1890d3c6137ab523799765ae2de62cc05f116d (git) Affected: 4c95380701f58b8112f0b891de8d160e4199e19d , < 3dd52416e44a70bc993adb96d2e0d71b9ea21359 (git)
Linux	Linux	Affected: 6.19 Unaffected: 0 , < 6.19 (semver) Unaffected: 7.2.4 , ≤ 7.2.* (semver) Unaffected: 7.3-rc1 , ≤ * (original_commit_for_fix)

Show details on NVD website

JSON

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": "6d1890d3c6137ab523799765ae2de62cc05f116d",
              "status": "affected",
              "version": "4c95380701f58b8112f0b891de8d160e4199e19d",
              "versionType": "git"
            },
            {
              "lessThan": "3dd52416e44a70bc993adb96d2e0d71b9ea21359",
              "status": "affected",
              "version": "4c95380701f58b8112f0b891de8d160e4199e19d",
              "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": "6.19"
            },
            {
              "lessThan": "6.19",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "7.2.*",
              "status": "unaffected",
              "version": "7.2.4",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "7.3-rc1",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
      "cpeApplicability": [
        {
          "nodes": [
            {
              "cpeMatch": [
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.2.4",
                  "versionStartIncluding": "6.19",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.3-rc1",
                  "versionStartIncluding": "6.19",
                  "vulnerable": true
                }
              ],
              "negate": false,
              "operator": "OR"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nsched_ext: Fix this_rq() assumptions in dispatch kfuncs\n\nUnder core scheduling, dispatch runs from within the core-wide pick and can\ntarget a sibling rq, so ops.dispatch() may execute on a CPU different from\nthe dispatched rq\u0027s. Several kfunc paths assumed the two always coincide:\n\n- scx_dsq_move() decided whether an rq lock is held by testing this_rq()\u0027s\n  rq flags and lock-danced accordingly. A dispatch for a sibling took the\n  unlocked-context branch and acquired the source rq lock on top of the\n  already held dispatched rq lock which could deadlock.\n\n- scx_bpf_sub_dispatch() dispatched this_rq() with its stashed\n  sub_dispatch_prev, which is NULL when dispatching for a sibling.\n\n- finish_dispatch(), scx_bpf_dsq_reenq() and scx_bpf_dsq_nr_queued()\n  resolved SCX_DSQ_LOCAL to this CPU\u0027s local DSQ rather than the dispatched\n  rq\u0027s. The latter two are callable from other rq-locked operations too,\n  where SCX_DSQ_LOCAL now likewise resolves to the op\u0027s rq. This changes\n  behavior also without core scheduling, e.g. for ops.enqueue() running a\n  remote wakeup on the waking CPU, and is intended: which CPU happens to\n  execute an operation is incidental, the op\u0027s rq is what it is operating\n  on, and the resolution now matches the insert side where SCX_DSQ_LOCAL\n  dispatches land on the task\u0027s rq.\n\nUse the rq tracked by scx_locked_rq(), which is set to the dispatched rq\naround ops invocations and NULL in unlocked contexts."
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-09-11T19:44:01.222Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
      },
      "references": [
        {
          "url": "https://git.kernel.org/stable/c/6d1890d3c6137ab523799765ae2de62cc05f116d"
        },
        {
          "url": "https://git.kernel.org/stable/c/3dd52416e44a70bc993adb96d2e0d71b9ea21359"
        }
      ],
      "title": "sched_ext: Fix this_rq() assumptions in dispatch kfuncs",
      "x_generator": {
        "engine": "bippy-1.2.0"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
    "assignerShortName": "Linux",
    "cveId": "CVE-2026-89518",
    "datePublished": "2026-09-11T19:44:01.222Z",
    "dateReserved": "2026-09-11T19:38:34.718Z",
    "dateUpdated": "2026-09-11T19:44:01.222Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}

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.

Detection rules are retrieved from Rulezet.

The MITRE ATT&CK techniques below are AI-generated suggestions, inferred from the description of the vulnerability by the CIRCL/vulnerability-attack-technique-classification-roberta-base model, served locally by ML-Gateway. They have not been verified by an analyst and are provided for guidance only.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
Browse all ATT&CK techniques and the vulnerabilities related to each.

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