CVE-2026-89494

Full vulnerability record from the local CVENow database.

Description

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

CRITICAL

CVSS score

9.8 (v3.1)

Vulnerability status

Received

Source identifier

416baaa9-dc9f-4396-8d5f-8c081fb06d67

Published

2026-09-11 20:19:31.370000

Last modified

2026-10-19 09:17:43.363000

View original CVE JSON

{
  "id": "CVE-2026-89494",
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "published": "2026-09-11T20:19:31.370",
  "lastModified": "2026-10-19T09:17:43.363",
  "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->ml[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->lockname\nwith the unbounded lockname_len as a %.*s precision.  Reject the message\nunless lockname_len <= DLM_LOCKID_NAME_MAX, num_locks <=\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": "4a5798253212093b9ff7d90c6cfbe348bcda1594",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "6714d8e86bf443f6f7af50f9d432025649f091f5",
              "lessThan": "dce05b17db862f47ff60614017abe639b2e71cad",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "6714d8e86bf443f6f7af50f9d432025649f091f5",
              "lessThan": "0e999d56917f861f97adb961617b1828c9eb4733",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "6714d8e86bf443f6f7af50f9d432025649f091f5",
              "lessThan": "77686fa5bba135252d348e2dacf481fc19f60c41",
              "versionType": "git",
              "status": "affected"
            },
            {
              "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": "5.10.270",
              "lessThanOrEqual": "5.10.*",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "5.15.221",
              "lessThanOrEqual": "5.15.*",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "6.1.188",
              "lessThanOrEqual": "6.1.*",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "6.6.157",
              "lessThanOrEqual": "6.6.*",
              "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",
              "lessThanOrEqual": "*",
              "versionType": "original_commit_for_fix",
              "status": "unaffected"
            }
          ]
        }
      ]
    }
  ],
  "metrics": {
    "cvssMetricV31": [
      {
        "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "type": "Secondary",
        "cvssData": {
          "version": "3.1",
          "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
          "baseScore": 9.8,
          "baseSeverity": "CRITICAL",
          "attackVector": "NETWORK",
          "attackComplexity": "LOW",
          "privilegesRequired": "NONE",
          "userInteraction": "NONE",
          "scope": "UNCHANGED",
          "confidentialityImpact": "HIGH",
          "integrityImpact": "HIGH",
          "availabilityImpact": "HIGH"
        },
        "exploitabilityScore": 3.9,
        "impactScore": 5.9
      }
    ]
  },
  "references": [
    {
      "url": "https://git.kernel.org/stable/c/0e999d56917f861f97adb961617b1828c9eb4733",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/4a5798253212093b9ff7d90c6cfbe348bcda1594",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/50c4cc9183e11f83427efbf770f54851f4471c02",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/77686fa5bba135252d348e2dacf481fc19f60c41",
      "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/dce05b17db862f47ff60614017abe639b2e71cad",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/f33041906885f96e190cde54e61ddc69de39e3ee",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    }
  ]
}