Vulnerability-Lookup

GHSA-99WV-M4HP-R266

Vulnerability from github – Published: 2026-09-11 21:31 – Updated: 2026-09-11 21:31

Details

In the Linux kernel, the following vulnerability has been resolved:

sched_ext: Don't BUG_ON a destroyed DSQ in process_deferred_reenq_users

scx_bpf_dsq_reenq() queues a deferred reenq (dru) that runs from run_deferred(), not ops.dispatch(). If the DSQ is destroyed before the dru runs, process_deferred_reenq_users() sees dsq->id == SCX_DSQ_INVALID and hits the BUG_ON. destroy_dsq() doesn't flush pending drus, so just skip.

tj: Read dsq->id once with READ_ONCE(). Reading it separately in the INVALID check and the BUG_ON would leave a window where destroy_dsq() can invalidate the id between the two reads and still trigger the BUG_ON.

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{
  "affected": [],
  "aliases": [
    "CVE-2026-89516"
  ],
  "database_specific": {
    "cwe_ids": [],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2026-09-11T20:19:34Z",
    "severity": null
  },
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nsched_ext: Don\u0027t BUG_ON a destroyed DSQ in process_deferred_reenq_users\n\nscx_bpf_dsq_reenq() queues a deferred reenq (dru) that runs from\nrun_deferred(), not ops.dispatch(). If the DSQ is destroyed before the dru\nruns, process_deferred_reenq_users() sees dsq-\u003eid == SCX_DSQ_INVALID and\nhits the BUG_ON. destroy_dsq() doesn\u0027t flush pending drus, so just skip.\n\ntj: Read dsq-\u003eid once with READ_ONCE(). Reading it separately in the INVALID\n    check and the BUG_ON would leave a window where destroy_dsq() can\n    invalidate the id between the two reads and still trigger the BUG_ON.",
  "id": "GHSA-99wv-m4hp-r266",
  "modified": "2026-09-11T21:31:30Z",
  "published": "2026-09-11T21:31:30Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-89516"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/8d8dd8ae89eaa78b37fc85528e926029f5facbdf"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/c480961a1e790b46ffd8c20c4b6754d65ec6572d"
    }
  ],
  "schema_version": "1.4.0",
  "severity": []
}

CVE-2026-89516 (GCVE-0-2026-89516)

Vulnerability from cvelistv5 – Published: 2026-09-11 19:43 – Updated: 2026-09-11 19:43

Title

sched_ext: Don't BUG_ON a destroyed DSQ in process_deferred_reenq_users

Summary

In the Linux kernel, the following vulnerability has been resolved: sched_ext: Don't BUG_ON a destroyed DSQ in process_deferred_reenq_users scx_bpf_dsq_reenq() queues a deferred reenq (dru) that runs from run_deferred(), not ops.dispatch(). If the DSQ is destroyed before the dru runs, process_deferred_reenq_users() sees dsq->id == SCX_DSQ_INVALID and hits the BUG_ON. destroy_dsq() doesn't flush pending drus, so just skip. tj: Read dsq->id once with READ_ONCE(). Reading it separately in the INVALID check and the BUG_ON would leave a window where destroy_dsq() can invalidate the id between the two reads and still trigger the BUG_ON.

Severity

No CVSS data available.

Assigner

Linux mitre root

References

2 references

URL	Tags
https://git.kernel.org/stable/c/c480961a1e790b46f…
https://git.kernel.org/stable/c/8d8dd8ae89eaa78b3…

Impacted products

2 products

Vendor	Product	Version
Linux	Linux	Affected: 84b1a0ea0b7c23dec240783a592e480780efe459 , < c480961a1e790b46ffd8c20c4b6754d65ec6572d (git) Affected: 84b1a0ea0b7c23dec240783a592e480780efe459 , < 8d8dd8ae89eaa78b37fc85528e926029f5facbdf (git)
Linux	Linux	Affected: 7.1 Unaffected: 0 , < 7.1 (semver) Unaffected: 7.2.4 , ≤ 7.2.* (semver) Unaffected: 7.3-rc1 , ≤ * (original_commit_for_fix)

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          "vendor": "Linux",
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              "versionType": "original_commit_for_fix"
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          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nsched_ext: Don\u0027t BUG_ON a destroyed DSQ in process_deferred_reenq_users\n\nscx_bpf_dsq_reenq() queues a deferred reenq (dru) that runs from\nrun_deferred(), not ops.dispatch(). If the DSQ is destroyed before the dru\nruns, process_deferred_reenq_users() sees dsq-\u003eid == SCX_DSQ_INVALID and\nhits the BUG_ON. destroy_dsq() doesn\u0027t flush pending drus, so just skip.\n\ntj: Read dsq-\u003eid once with READ_ONCE(). Reading it separately in the INVALID\n    check and the BUG_ON would leave a window where destroy_dsq() can\n    invalidate the id between the two reads and still trigger the BUG_ON."
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        "dateUpdated": "2026-09-11T19:43:59.941Z",
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    "datePublished": "2026-09-11T19:43:59.941Z",
    "dateReserved": "2026-09-11T19:38:34.717Z",
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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.
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