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CVE-2026-89494 (GCVE-0-2026-89494)

Vulnerability from cvelistv5 – Published: 2026-09-11 19:43 – Updated: 2026-09-11 19:43
VLAI
Title
ocfs2: validate lengths in dlm_mig_lockres_handler
Summary
In the Linux kernel, the following vulnerability has been resolved: ocfs2: validate lengths in dlm_mig_lockres_handler A node receiving a DLM_MIG_LOCKRES message trusts several fields of the peer-supplied dlm_migratable_lockres without validation. num_locks and lockname_len are bounded only on the sending side, and the message is never checked to actually carry num_locks migratable_lock entries. As a result dlm_process_recovery_data() walks mres->ml[0..num_locks) past the kmalloc(data_len) copy of the message (an out-of-bounds read that ends in a BUG_ON panic), and dlm_init_lockres() copies lockname_len bytes into the fixed 32-byte o2dlm_lockname slab object (a heap out-of-bounds write). Both are reachable by any node in the domain. Validate these fields right after dlm_grab(), before anything uses them -- including the not-joined error path, which already prints mres->lockname with the unbounded lockname_len as a %.*s precision. Reject the message unless lockname_len <= DLM_LOCKID_NAME_MAX, num_locks <= DLM_MAX_MIGRATABLE_LOCKS (the bound the sender already asserts), and the payload is large enough to hold the claimed locks. Conforming recovery and migration messages are unaffected.
Severity
No CVSS data available.
Impacted products
Vendor Product Version CPE status
Linux Linux Affected: 6714d8e86bf443f6f7af50f9d432025649f091f5 , < f33041906885f96e190cde54e61ddc69de39e3ee (git)
Affected: 6714d8e86bf443f6f7af50f9d432025649f091f5 , < 50c4cc9183e11f83427efbf770f54851f4471c02 (git)
Affected: 6714d8e86bf443f6f7af50f9d432025649f091f5 , < a8facb1670b4a0612183198e758d9539ef628ed9 (git)
Affected: 6714d8e86bf443f6f7af50f9d432025649f091f5 , < b54e03d9b3697d25f4a0063cf717d459c5e3ad94 (git)
guessed Create a notification for this product.
Linux Linux Affected: 2.6.16
Unaffected: 0 , < 2.6.16 (semver)
Unaffected: 6.12.109 , ≤ 6.12.* (semver)
Unaffected: 6.18.50 , ≤ 6.18.* (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

{
  "containers": {
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "fs/ocfs2/dlm/dlmrecovery.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
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              "versionType": "git"
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              "versionType": "git"
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          "product": "Linux",
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          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
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              "version": "2.6.16"
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              "version": "0",
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              "version": "6.12.109",
              "versionType": "semver"
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              "lessThanOrEqual": "6.18.*",
              "status": "unaffected",
              "version": "6.18.50",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "7.2.*",
              "status": "unaffected",
              "version": "7.2.4",
              "versionType": "semver"
            },
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              "status": "unaffected",
              "version": "7.3-rc1",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
      "cpeApplicability": [
        {
          "nodes": [
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              "cpeMatch": [
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                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.12.109",
                  "versionStartIncluding": "2.6.16",
                  "vulnerable": true
                },
                {
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                  "versionEndExcluding": "6.18.50",
                  "versionStartIncluding": "2.6.16",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
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                  "vulnerable": true
                },
                {
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                  "versionEndExcluding": "7.3-rc1",
                  "versionStartIncluding": "2.6.16",
                  "vulnerable": true
                }
              ],
              "negate": false,
              "operator": "OR"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nocfs2: validate lengths in dlm_mig_lockres_handler\n\nA node receiving a DLM_MIG_LOCKRES message trusts several fields of the\npeer-supplied dlm_migratable_lockres without validation.  num_locks and\nlockname_len are bounded only on the sending side, and the message is\nnever checked to actually carry num_locks migratable_lock entries.  As a\nresult dlm_process_recovery_data() walks mres-\u003eml[0..num_locks) past the\nkmalloc(data_len) copy of the message (an out-of-bounds read that ends in\na BUG_ON panic), and dlm_init_lockres() copies lockname_len bytes into the\nfixed 32-byte o2dlm_lockname slab object (a heap out-of-bounds write). \nBoth are reachable by any node in the domain.\n\nValidate these fields right after dlm_grab(), before anything uses them --\nincluding the not-joined error path, which already prints mres-\u003elockname\nwith the unbounded lockname_len as a %.*s precision.  Reject the message\nunless lockname_len \u003c= DLM_LOCKID_NAME_MAX, num_locks \u003c=\nDLM_MAX_MIGRATABLE_LOCKS (the bound the sender already asserts), and the\npayload is large enough to hold the claimed locks.  Conforming recovery\nand migration messages are unaffected."
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-09-11T19:43:45.455Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
      },
      "references": [
        {
          "url": "https://git.kernel.org/stable/c/f33041906885f96e190cde54e61ddc69de39e3ee"
        },
        {
          "url": "https://git.kernel.org/stable/c/50c4cc9183e11f83427efbf770f54851f4471c02"
        },
        {
          "url": "https://git.kernel.org/stable/c/a8facb1670b4a0612183198e758d9539ef628ed9"
        },
        {
          "url": "https://git.kernel.org/stable/c/b54e03d9b3697d25f4a0063cf717d459c5e3ad94"
        }
      ],
      "title": "ocfs2: validate lengths in dlm_mig_lockres_handler",
      "x_generator": {
        "engine": "bippy-1.2.0"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
    "assignerShortName": "Linux",
    "cveId": "CVE-2026-89494",
    "datePublished": "2026-09-11T19:43:45.455Z",
    "dateReserved": "2026-09-11T19:38:34.714Z",
    "dateUpdated": "2026-09-11T19:43:45.455Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2",
  "vulnerability-lookup:meta": {
    "epss": {
      "cve": "CVE-2026-89494",
      "date": "2026-09-12",
      "epss": "0.002",
      "percentile": "0.09962"
    },
    "nvd": "{\"cve\":{\"id\":\"CVE-2026-89494\",\"sourceIdentifier\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\",\"published\":\"2026-09-11T20:19:31.370\",\"lastModified\":\"2026-09-11T20:19:31.370\",\"vulnStatus\":\"Received\",\"cveTags\":[],\"descriptions\":[{\"lang\":\"en\",\"value\":\"In the Linux kernel, the following vulnerability has been resolved:\\n\\nocfs2: validate lengths in dlm_mig_lockres_handler\\n\\nA node receiving a DLM_MIG_LOCKRES message trusts several fields of the\\npeer-supplied dlm_migratable_lockres without validation.  num_locks and\\nlockname_len are bounded only on the sending side, and the message is\\nnever checked to actually carry num_locks migratable_lock entries.  As a\\nresult dlm_process_recovery_data() walks mres-\u003eml[0..num_locks) past the\\nkmalloc(data_len) copy of the message (an out-of-bounds read that ends in\\na BUG_ON panic), and dlm_init_lockres() copies lockname_len bytes into the\\nfixed 32-byte o2dlm_lockname slab object (a heap out-of-bounds write). \\nBoth are reachable by any node in the domain.\\n\\nValidate these fields right after dlm_grab(), before anything uses them --\\nincluding the not-joined error path, which already prints mres-\u003elockname\\nwith the unbounded lockname_len as a %.*s precision.  Reject the message\\nunless lockname_len \u003c= DLM_LOCKID_NAME_MAX, num_locks \u003c=\\nDLM_MAX_MIGRATABLE_LOCKS (the bound the sender already asserts), and the\\npayload is large enough to hold the claimed locks.  Conforming recovery\\nand migration messages are unaffected.\"}],\"affected\":[{\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\",\"affectedData\":[{\"vendor\":\"Linux\",\"product\":\"Linux\",\"defaultStatus\":\"unaffected\",\"programFiles\":[\"fs/ocfs2/dlm/dlmrecovery.c\"],\"repo\":\"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\",\"versions\":[{\"version\":\"6714d8e86bf443f6f7af50f9d432025649f091f5\",\"lessThan\":\"f33041906885f96e190cde54e61ddc69de39e3ee\",\"versionType\":\"git\",\"status\":\"affected\"},{\"version\":\"6714d8e86bf443f6f7af50f9d432025649f091f5\",\"lessThan\":\"50c4cc9183e11f83427efbf770f54851f4471c02\",\"versionType\":\"git\",\"status\":\"affected\"},{\"version\":\"6714d8e86bf443f6f7af50f9d432025649f091f5\",\"lessThan\":\"a8facb1670b4a0612183198e758d9539ef628ed9\",\"versionType\":\"git\",\"status\":\"affected\"},{\"version\":\"6714d8e86bf443f6f7af50f9d432025649f091f5\",\"lessThan\":\"b54e03d9b3697d25f4a0063cf717d459c5e3ad94\",\"versionType\":\"git\",\"status\":\"affected\"}]},{\"vendor\":\"Linux\",\"product\":\"Linux\",\"defaultStatus\":\"affected\",\"programFiles\":[\"fs/ocfs2/dlm/dlmrecovery.c\"],\"repo\":\"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\",\"versions\":[{\"version\":\"2.6.16\",\"status\":\"affected\"},{\"version\":\"0\",\"lessThan\":\"2.6.16\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"6.12.109\",\"lessThanOrEqual\":\"6.12.*\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"6.18.50\",\"lessThanOrEqual\":\"6.18.*\",\"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/50c4cc9183e11f83427efbf770f54851f4471c02\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"},{\"url\":\"https://git.kernel.org/stable/c/a8facb1670b4a0612183198e758d9539ef628ed9\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"},{\"url\":\"https://git.kernel.org/stable/c/b54e03d9b3697d25f4a0063cf717d459c5e3ad94\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"},{\"url\":\"https://git.kernel.org/stable/c/f33041906885f96e190cde54e61ddc69de39e3ee\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"}]}}",
    "redhat_vex": {
      "aggregate_severity": "Important",
      "current_release_date": "2026-09-11T20:51:56+00:00",
      "cve": "CVE-2026-89494",
      "id": "CVE-2026-89494",
      "initial_release_date": "2026-09-11T19:43:45.455000+00:00",
      "product_status:known_affected": "2",
      "source": "Red Hat CSAF VEX",
      "status": "final",
      "title": "kernel: ocfs2: Arbitrary Code Execution via DLM migration message handling",
      "url": "https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-89494.json",
      "version": "3"
    }
  }
}



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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.

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Detection rules are retrieved from Rulezet.

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