GCVE Workshop - 22 September 2026 (14:00-18:00), Luxembourg Before The Vulnopticon Conference - Registration

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

Vulnerability from cvelistv5 – Published: 2026-09-11 19:43 – Updated: 2026-09-11 19:43
VLAI
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
References
Impacted products
Vendor Product Version CPE status
Linux Linux Affected: 84b1a0ea0b7c23dec240783a592e480780efe459 , < c480961a1e790b46ffd8c20c4b6754d65ec6572d (git)
Affected: 84b1a0ea0b7c23dec240783a592e480780efe459 , < 8d8dd8ae89eaa78b37fc85528e926029f5facbdf (git)
guessed Create a notification for this product.
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)
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": "c480961a1e790b46ffd8c20c4b6754d65ec6572d",
              "status": "affected",
              "version": "84b1a0ea0b7c23dec240783a592e480780efe459",
              "versionType": "git"
            },
            {
              "lessThan": "8d8dd8ae89eaa78b37fc85528e926029f5facbdf",
              "status": "affected",
              "version": "84b1a0ea0b7c23dec240783a592e480780efe459",
              "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": "7.2.4",
              "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": "7.1",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.3-rc1",
                  "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: 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."
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-09-11T19:43:59.941Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
      },
      "references": [
        {
          "url": "https://git.kernel.org/stable/c/c480961a1e790b46ffd8c20c4b6754d65ec6572d"
        },
        {
          "url": "https://git.kernel.org/stable/c/8d8dd8ae89eaa78b37fc85528e926029f5facbdf"
        }
      ],
      "title": "sched_ext: Don\u0027t BUG_ON a destroyed DSQ in process_deferred_reenq_users",
      "x_generator": {
        "engine": "bippy-1.2.0"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
    "assignerShortName": "Linux",
    "cveId": "CVE-2026-89516",
    "datePublished": "2026-09-11T19:43:59.941Z",
    "dateReserved": "2026-09-11T19:38:34.717Z",
    "dateUpdated": "2026-09-11T19:43:59.941Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2",
  "vulnerability-lookup:meta": {
    "epss": {
      "cve": "CVE-2026-89516",
      "date": "2026-09-17",
      "epss": "0.00162",
      "percentile": "0.05853"
    },
    "nvd": "{\"cve\":{\"id\":\"CVE-2026-89516\",\"sourceIdentifier\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\",\"published\":\"2026-09-11T20:19:34.170\",\"lastModified\":\"2026-09-11T20:19:34.170\",\"vulnStatus\":\"Received\",\"cveTags\":[],\"descriptions\":[{\"lang\":\"en\",\"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.\"}],\"affected\":[{\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\",\"affectedData\":[{\"vendor\":\"Linux\",\"product\":\"Linux\",\"defaultStatus\":\"unaffected\",\"programFiles\":[\"kernel/sched/ext/ext.c\"],\"repo\":\"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\",\"versions\":[{\"version\":\"84b1a0ea0b7c23dec240783a592e480780efe459\",\"lessThan\":\"c480961a1e790b46ffd8c20c4b6754d65ec6572d\",\"versionType\":\"git\",\"status\":\"affected\"},{\"version\":\"84b1a0ea0b7c23dec240783a592e480780efe459\",\"lessThan\":\"8d8dd8ae89eaa78b37fc85528e926029f5facbdf\",\"versionType\":\"git\",\"status\":\"affected\"}]},{\"vendor\":\"Linux\",\"product\":\"Linux\",\"defaultStatus\":\"affected\",\"programFiles\":[\"kernel/sched/ext/ext.c\"],\"repo\":\"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\",\"versions\":[{\"version\":\"7.1\",\"status\":\"affected\"},{\"version\":\"0\",\"lessThan\":\"7.1\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"7.2.4\",\"lessThanOrEqual\":\"7.2.*\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"7.3-rc1\",\"lessThanOrEqual\":\"*\",\"versionType\":\"original_commit_for_fix\",\"status\":\"unaffected\"}]}]}],\"metrics\":{},\"references\":[{\"url\":\"https://git.kernel.org/stable/c/8d8dd8ae89eaa78b37fc85528e926029f5facbdf\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"},{\"url\":\"https://git.kernel.org/stable/c/c480961a1e790b46ffd8c20c4b6754d65ec6572d\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"}]}}",
    "redhat_vex": {
      "aggregate_severity": "Moderate",
      "current_release_date": "2026-09-11T21:28:54+00:00",
      "cve": "CVE-2026-89516",
      "id": "CVE-2026-89516",
      "initial_release_date": "2026-09-11T19:43:59.941000+00:00",
      "product_status:known_affected": "2",
      "source": "Red Hat CSAF VEX",
      "status": "final",
      "title": "kernel: Linux Kernel: Denial of Service due to use-after-free in sched_ext",
      "url": "https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-89516.json",
      "version": "3"
    },
    "suse_vex": {
      "aggregate_severity": "moderate",
      "current_release_date": "2026-09-16T00:02:24Z",
      "cve": "CVE-2026-89516",
      "id": "CVE-2026-89516",
      "initial_release_date": "2026-09-12T16:27:06Z",
      "product_status:known_not_affected": "353",
      "source": "SUSE CSAF VEX",
      "status": "interim",
      "title": "SUSE CVE CVE-2026-89516",
      "url": "https://ftp.suse.com/pub/projects/security/csaf-vex/cve-2026-89516.json",
      "version": "3"
    }
  }
}



Log in or create an account to share your comment.




Tags
Taxonomy of the tags.





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.


Detection rules are retrieved from Rulezet.


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.