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HighFix available

ksmbd: transport_ipc: validate payload size before reading handle

Type: advisorySources: OSV

In the Linux kernel, the following vulnerability has been resolved: ksmbd: transport_ipc: validate payload size before reading handle handle_response() dereferences the payload as a 4-byte handle without verifying that the declared payload size is at least 4 bytes. A malformed or truncated message from ksmbd.mountd can lead to a 4-byte read past the declared payload size. Validate the size before dereferencing. This is a minimal fix to guard the initial handle read.

Products
Kernel
Affected versions
Not specified
Fixed versions
6.1.158, 6.12.56, 6.17.6, 6.6.115
CVEs
CVE-2025-40084
Confirmed fixed CVEs
Not specified
Updated in this feed
5 Nov 2026, 16:57 UTC · Revision 1

Source evidence

ksmbd: transport_ipc: validate payload size before reading handle

core-osv · Original source

Published 29 Oct 2025, 13:37 UTC

In the Linux kernel, the following vulnerability has been resolved: ksmbd: transport_ipc: validate payload size before reading handle handle_response() dereferences the payload as a 4-byte handle without verifying that the declared payload size is at least 4 bytes. A malformed or truncated message from ksmbd.mountd can lead to a 4-byte read past the declared payload size. Validate the size before dereferencing. This is a minimal fix to guard the initial handle read.

osv:CVE-2025-40084

Kernel

Fixed versions: 6.1.158, 6.6.115, 6.12.56, 6.17.6

Complete source record
{
  "id": "95a1d0c2916f79cac0e1d9b96bbd7eed5112656055e01937b49214af50da61fc",
  "url": "https://osv.dev/vulnerability/CVE-2025-40084",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "ksmbd: transport_ipc: validate payload size before reading handle",
    "summary": "In the Linux kernel, the following vulnerability has been resolved: ksmbd: transport_ipc: validate payload size before reading handle handle_response() dereferences the payload as a 4-byte handle without verifying that the declared payload size is at least 4 bytes. A malformed or truncated message from ksmbd.mountd can lead to a 4-byte read past the declared payload size. Validate the size before dereferencing. This is a minimal fix to guard the initial handle read.",
    "evidence": "osv:CVE-2025-40084",
    "products": [
      {
        "name": {
          "value": "Kernel",
          "evidence": "/affected/1/package/name"
        },
        "prerequisites": [],
        "fixed_versions": [
          {
            "value": "6.1.158",
            "evidence": "/affected/1/ranges"
          },
          {
            "value": "6.6.115",
            "evidence": "/affected/1/ranges"
          },
          {
            "value": "6.12.56",
            "evidence": "/affected/1/ranges"
          },
          {
            "value": "6.17.6",
            "evidence": "/affected/1/ranges"
          }
        ],
        "affected_versions": []
      }
    ],
    "severity": "high",
    "structured": {
      "id": "CVE-2025-40084",
      "aliases": [
        "CVE-2025-40084"
      ],
      "metrics": [
        {
          "type": "CVSS_V3",
          "score": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H"
        }
      ],
      "affected": [
        {
          "ranges": [
            {
              "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
              "type": "GIT",
              "events": [
                {
                  "introduced": "0626e6641f6b467447c81dd7678a69c66f7746cf"
                },
                {
                  "fixed": "a02e432d5130da4c723aabe1205bac805889fdb2"
                },
                {
                  "fixed": "2dc125f5da134c0915a840b62565c60a595673dd"
                },
                {
                  "fixed": "898d527ed94c19980a4d848f10057f1fed578ffb"
                },
                {
                  "fixed": "867ffd9d67285612da3f0498ca618297f8e41f01"
                },
                {
                  "fixed": "6f40e50ceb99fc8ef37e5c56e2ec1d162733fef0"
                }
              ]
            }
          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2025-40084.json"
          }
        },
        {
          "ranges": [
            {
              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "5.15.0"
                },
                {
                  "fixed": "6.1.158"
                }
              ]
            },
            {
              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "6.2.0"
                },
                {
                  "fixed": "6.6.115"
                }
              ]
            },
            {
              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "6.7.0"
                },
                {
                  "fixed": "6.12.56"
                }
              ]
            },
            {
              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "6.13.0"
                },
                {
                  "fixed": "6.17.6"
                }
              ]
            }
          ],
          "package": {
            "name": "Kernel",
            "ecosystem": "Linux"
          },
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2025-40084.json"
          }
        }
      ],
      "modified": "2026-10-28T02:30:44.498451789Z",
      "provider": "osv",
      "references": [
        "https://git.kernel.org/stable/c/2dc125f5da134c0915a840b62565c60a595673dd",
        "https://git.kernel.org/stable/c/6f40e50ceb99fc8ef37e5c56e2ec1d162733fef0",
        "https://git.kernel.org/stable/c/867ffd9d67285612da3f0498ca618297f8e41f01",
        "https://git.kernel.org/stable/c/898d527ed94c19980a4d848f10057f1fed578ffb",
        "https://git.kernel.org/stable/c/a02e432d5130da4c723aabe1205bac805889fdb2",
        "https://github.com/CVEProject/cvelistV5/tree/main/cves/2025/40xxx/CVE-2025-40084.json",
        "https://nvd.nist.gov/vuln/detail/CVE-2025-40084",
        "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"
      ],
      "provider_metadata": {
        "cna_assigner": "Linux",
        "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2025/40xxx/CVE-2025-40084.json"
      }
    },
    "related_cves": [
      {
        "value": "CVE-2025-40084",
        "evidence": "/id"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
  },
  "source_id": "core-osv",
  "document_id": 512484,
  "published_at": "2025-10-29T13:37:03.185+00:00"
}