CVE-2026-99144 (GCVE-0-2026-99144)

Vulnerability from cvelistv5 – Published: 2026-10-28 10:35 – Updated: 2026-10-28 10:35
VLAI
Title
sched_ext: Fix use-after-free of a destroyed user DSQ by a deferred reenqueue
Summary
In the Linux kernel, the following vulnerability has been resolved: sched_ext: Fix use-after-free of a destroyed user DSQ by a deferred reenqueue A deferred reenqueue can read a freed user DSQ. The request stays on its CPU's deferred list until run_deferred() takes it, and the RCU callback that frees the DSQ assumes that the grace period has flushed it, so exit_dsq() checks the per-CPU node without the deferred list lock. A grace period waits for readers in flight, not for a pending run_deferred(). A run_deferred() which starts after the grace period began can detach the request right before the callback looks and then read the freed DSQ's id. Cancel the pending requests before the grace period instead. The irq work that frees the DSQ unlinks every CPU's request under the per-CPU deferred list lock, and schedule_dsq_reenq() ignores a new request under the same lock once the id is invalid. Only a run_deferred() that started before the grace period can hold a request, and it runs with IRQs disabled, so the grace period waits for it and nothing touches the DSQ after the callback.
Severity
No CVSS data available.
Assigner
Linux CNA under the mitre root
CNA scorecard D 53/100 over 6642 records in the last 180 days details
References
Impacted products
Vendor Product Version CPE status
Linux Linux Affected: 84b1a0ea0b7c23dec240783a592e480780efe459 , < 633f586329bfd9843bf8acf86c95353f4c16e22d (git)
Affected: 84b1a0ea0b7c23dec240783a592e480780efe459 , < 069403dff337feb192bfc70fb28ddc8a171e20c1 (git)
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Linux Linux Affected: 7.1
Unaffected: 0 , < 7.1 (semver)
Unaffected: 7.2.13 , ≤ 7.2.* (semver)
Unaffected: 7.3 , ≤ * (original_commit_for_fix)
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Show details on NVD website
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          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nsched_ext: Fix use-after-free of a destroyed user DSQ by a deferred reenqueue\n\nA deferred reenqueue can read a freed user DSQ. The request stays on its\nCPU\u0027s deferred list until run_deferred() takes it, and the RCU callback that\nfrees the DSQ assumes that the grace period has flushed it, so exit_dsq()\nchecks the per-CPU node without the deferred list lock. A grace period waits\nfor readers in flight, not for a pending run_deferred(). A run_deferred()\nwhich starts after the grace period began can detach the request right\nbefore the callback looks and then read the freed DSQ\u0027s id.\n\nCancel the pending requests before the grace period instead. The irq work\nthat frees the DSQ unlinks every CPU\u0027s request under the per-CPU deferred\nlist lock, and schedule_dsq_reenq() ignores a new request under the same\nlock once the id is invalid. Only a run_deferred() that started before the\ngrace period can hold a request, and it runs with IRQs disabled, so the\ngrace period waits for it and nothing touches the DSQ after the callback."
        }
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      "providerMetadata": {
        "dateUpdated": "2026-10-28T10:35:00.602Z",
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        "shortName": "Linux"
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    "datePublished": "2026-10-28T10:35:00.602Z",
    "dateReserved": "2026-09-25T10:25:14.395Z",
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    "state": "PUBLISHED"
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            "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nsched_ext: Fix use-after-free of a destroyed user DSQ by a deferred reenqueue\n\nA deferred reenqueue can read a freed user DSQ. The request stays on its\nCPU\u0027s deferred list until run_deferred() takes it, and the RCU callback that\nfrees the DSQ assumes that the grace period has flushed it, so exit_dsq()\nchecks the per-CPU node without the deferred list lock. A grace period waits\nfor readers in flight, not for a pending run_deferred(). A run_deferred()\nwhich starts after the grace period began can detach the request right\nbefore the callback looks and then read the freed DSQ\u0027s id.\n\nCancel the pending requests before the grace period instead. The irq work\nthat frees the DSQ unlinks every CPU\u0027s request under the per-CPU deferred\nlist lock, and schedule_dsq_reenq() ignores a new request under the same\nlock once the id is invalid. Only a run_deferred() that started before the\ngrace period can hold a request, and it runs with IRQs disabled, so the\ngrace period waits for it and nothing touches the DSQ after the callback."
          }
        ],
        "id": "CVE-2026-99144",
        "lastModified": "2026-10-28T11:17:34.433",
        "metrics": {},
        "published": "2026-10-28T11:17:34.433",
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      "source": "Red Hat CSAF VEX",
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      "title": "kernel: kernel: Denial of service via use-after-free in sched_ext",
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      "cve": "CVE-2026-99144",
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      "source": "SUSE CSAF VEX",
      "status": "interim",
      "title": "SUSE CVE CVE-2026-99144",
      "url": "https://ftp.suse.com/pub/projects/security/csaf-vex/2026/cve-2026-99144.json",
      "version": "5"
    }
  }
}



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