FKIE_CVE-2026-74401

Vulnerability from fkie_nvd - Published: 2026-08-15 06:22 - Updated: 2026-10-16 20:17
Severity
9.8 (Critical) - CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Summary
In the Linux kernel, the following vulnerability has been resolved: dlm: fix add msg handle in send_queue ordered In a benchmark scenario triggering a lot of requests that triggers a lot of DLM messages on the network it can be that the mh->seq is not ordered according the oldest seq number. This ordering is required by dlm_receive_ack as "before(mh->seq, seq)" will stop to check for older sequence numbers that are ordered in the tail of "node->send_queue". The side effects of not having it correct ordered regarding "before(mh->seq, seq)" are refcounting issues and use-after free. I only was able to reproduce this issue in a experimental DLM branch and a user space DLM benchmark that uses io_uring. After changing this I don't experienced any refcounting with the sending buffer issues anymore.
References
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/4d45250b1d22960f86d83245be188b16e456218b
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/6369619f1b665f12d8c99cc6ff733c64eb08b22e
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/712714f818d83373847874ab0f8e426be79296cf
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/ae9e534e502a0f48c12baf83608c5de0ff0eab11
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/d2248cb70c070f8f04762872772e155b59016f17
Impacted products
Vendor Product Version
To clipboard 

{
  "affected": [
    {
      "affectedData": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "fs/dlm/midcomms.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "ae9e534e502a0f48c12baf83608c5de0ff0eab11",
              "status": "affected",
              "version": "489d8e559c6596eb08e16447d9830bc39afbe54e",
              "versionType": "git"
            },
            {
              "lessThan": "6369619f1b665f12d8c99cc6ff733c64eb08b22e",
              "status": "affected",
              "version": "489d8e559c6596eb08e16447d9830bc39afbe54e",
              "versionType": "git"
            },
            {
              "lessThan": "712714f818d83373847874ab0f8e426be79296cf",
              "status": "affected",
              "version": "489d8e559c6596eb08e16447d9830bc39afbe54e",
              "versionType": "git"
            },
            {
              "lessThan": "4d45250b1d22960f86d83245be188b16e456218b",
              "status": "affected",
              "version": "489d8e559c6596eb08e16447d9830bc39afbe54e",
              "versionType": "git"
            },
            {
              "lessThan": "d2248cb70c070f8f04762872772e155b59016f17",
              "status": "affected",
              "version": "489d8e559c6596eb08e16447d9830bc39afbe54e",
              "versionType": "git"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "fs/dlm/midcomms.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "5.14"
            },
            {
              "lessThan": "5.14",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.6.*",
              "status": "unaffected",
              "version": "6.6.145",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.12.*",
              "status": "unaffected",
              "version": "6.12.97",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.18.*",
              "status": "unaffected",
              "version": "6.18.40",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "7.1.*",
              "status": "unaffected",
              "version": "7.1.5",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "7.2",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    }
  ],
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\ndlm: fix add msg handle in send_queue ordered\n\nIn a benchmark scenario triggering a lot of requests that triggers a lot\nof DLM messages on the network it can be that the mh-\u003eseq is not ordered\naccording the oldest seq number. This ordering is required by\ndlm_receive_ack as \"before(mh-\u003eseq, seq)\" will stop to check for older\nsequence numbers that are ordered in the tail of \"node-\u003esend_queue\".\n\nThe side effects of not having it correct ordered regarding\n\"before(mh-\u003eseq, seq)\" are refcounting issues and use-after free.\n\nI only was able to reproduce this issue in a experimental DLM branch\nand a user space DLM benchmark that uses io_uring. After changing this I\ndon\u0027t experienced any refcounting with the sending buffer issues anymore."
    }
  ],
  "id": "CVE-2026-74401",
  "lastModified": "2026-10-16T20:17:25.567",
  "metrics": {
    "cvssMetricV31": [
      {
        "cvssData": {
          "attackComplexity": "LOW",
          "attackVector": "NETWORK",
          "availabilityImpact": "HIGH",
          "baseScore": 9.8,
          "baseSeverity": "CRITICAL",
          "confidentialityImpact": "HIGH",
          "integrityImpact": "HIGH",
          "privilegesRequired": "NONE",
          "scope": "UNCHANGED",
          "userInteraction": "NONE",
          "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
          "version": "3.1"
        },
        "exploitabilityScore": 3.9,
        "impactScore": 5.9,
        "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "type": "Secondary"
      }
    ],
    "ssvcV203": [
      {
        "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
        "ssvcData": {
          "id": "CVE-2026-74401",
          "options": [
            {
              "exploitation": "none"
            },
            {
              "automatable": "yes"
            },
            {
              "technicalImpact": "total"
            }
          ],
          "role": "CISA Coordinator",
          "timestamp": "2026-10-16T18:55:33.158512Z",
          "version": "2.0.3"
        }
      }
    ]
  },
  "published": "2026-08-15T06:22:42.120",
  "references": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/4d45250b1d22960f86d83245be188b16e456218b"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/6369619f1b665f12d8c99cc6ff733c64eb08b22e"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/712714f818d83373847874ab0f8e426be79296cf"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/ae9e534e502a0f48c12baf83608c5de0ff0eab11"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/d2248cb70c070f8f04762872772e155b59016f17"
    }
  ],
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "vulnStatus": "Received"
}



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