CVE-2025-40255 (GCVE-0-2025-40255)

Vulnerability from cvelistv5 – Published: 2025-12-04 16:08 – Updated: 2026-05-11 21:45
VLAI
Title
net: core: prevent NULL deref in generic_hwtstamp_ioctl_lower()
Summary
In the Linux kernel, the following vulnerability has been resolved: net: core: prevent NULL deref in generic_hwtstamp_ioctl_lower() The ethtool tsconfig Netlink path can trigger a null pointer dereference. A call chain such as: tsconfig_prepare_data() -> dev_get_hwtstamp_phylib() -> vlan_hwtstamp_get() -> generic_hwtstamp_get_lower() -> generic_hwtstamp_ioctl_lower() results in generic_hwtstamp_ioctl_lower() being called with kernel_cfg->ifr as NULL. The generic_hwtstamp_ioctl_lower() function does not expect a NULL ifr and dereferences it, leading to a system crash. Fix this by adding a NULL check for kernel_cfg->ifr in generic_hwtstamp_ioctl_lower(). If ifr is NULL, return -EINVAL.
Severity
No CVSS data available.
Assigner
Linux CNA under the mitre root
CNA scorecard D 53/100 over 6971 records in the last 180 days details
References
Impacted products
Vendor Product Version CPE status
Linux Linux Affected: 6e9e2eed4f39d52edf5fd006409d211facf49f6b , < 8817f816ae41908e9625c0770c4af0dcdcc01238 (git)
Affected: 6e9e2eed4f39d52edf5fd006409d211facf49f6b , < f796a8dec9beafcc0f6f0d3478ed685a15c5e062 (git)
guessed Create a notification for this product.
Linux Linux Affected: 6.14
Unaffected: 0 , < 6.14 (semver)
Unaffected: 6.17.10 , ≤ 6.17.* (semver)
Unaffected: 6.18 , ≤ * (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": [
            "net/core/dev_ioctl.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "8817f816ae41908e9625c0770c4af0dcdcc01238",
              "status": "affected",
              "version": "6e9e2eed4f39d52edf5fd006409d211facf49f6b",
              "versionType": "git"
            },
            {
              "lessThan": "f796a8dec9beafcc0f6f0d3478ed685a15c5e062",
              "status": "affected",
              "version": "6e9e2eed4f39d52edf5fd006409d211facf49f6b",
              "versionType": "git"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "net/core/dev_ioctl.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "6.14"
            },
            {
              "lessThan": "6.14",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.17.*",
              "status": "unaffected",
              "version": "6.17.10",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "6.18",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
      "cpeApplicability": [
        {
          "nodes": [
            {
              "cpeMatch": [
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.17.10",
                  "versionStartIncluding": "6.14",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.18",
                  "versionStartIncluding": "6.14",
                  "vulnerable": true
                }
              ],
              "negate": false,
              "operator": "OR"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nnet: core: prevent NULL deref in generic_hwtstamp_ioctl_lower()\n\nThe ethtool tsconfig Netlink path can trigger a null pointer\ndereference. A call chain such as:\n\n  tsconfig_prepare_data() -\u003e\n  dev_get_hwtstamp_phylib() -\u003e\n  vlan_hwtstamp_get() -\u003e\n  generic_hwtstamp_get_lower() -\u003e\n  generic_hwtstamp_ioctl_lower()\n\nresults in generic_hwtstamp_ioctl_lower() being called with\nkernel_cfg-\u003eifr as NULL.\n\nThe generic_hwtstamp_ioctl_lower() function does not expect\na NULL ifr and dereferences it, leading to a system crash.\n\nFix this by adding a NULL check for kernel_cfg-\u003eifr in\ngeneric_hwtstamp_ioctl_lower(). If ifr is NULL, return -EINVAL."
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-05-11T21:45:47.848Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
      },
      "references": [
        {
          "url": "https://git.kernel.org/stable/c/8817f816ae41908e9625c0770c4af0dcdcc01238"
        },
        {
          "url": "https://git.kernel.org/stable/c/f796a8dec9beafcc0f6f0d3478ed685a15c5e062"
        }
      ],
      "title": "net: core: prevent NULL deref in generic_hwtstamp_ioctl_lower()",
      "x_generator": {
        "engine": "bippy-1.2.0"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
    "assignerShortName": "Linux",
    "cveId": "CVE-2025-40255",
    "datePublished": "2025-12-04T16:08:17.023Z",
    "dateReserved": "2025-04-16T07:20:57.181Z",
    "dateUpdated": "2026-05-11T21:45:47.848Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2",
  "vulnerability-lookup:meta": {
    "epss": {
      "cve": "CVE-2025-40255",
      "date": "2026-11-02",
      "epss": "0.00186",
      "percentile": "0.08242"
    },
    "nvd": {
      "cve": {
        "affected": [
          {
            "affectedData": [
              {
                "defaultStatus": "unaffected",
                "product": "Linux",
                "programFiles": [
                  "net/core/dev_ioctl.c"
                ],
                "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
                "vendor": "Linux",
                "versions": [
                  {
                    "lessThan": "8817f816ae41908e9625c0770c4af0dcdcc01238",
                    "status": "affected",
                    "version": "6e9e2eed4f39d52edf5fd006409d211facf49f6b",
                    "versionType": "git"
                  },
                  {
                    "lessThan": "f796a8dec9beafcc0f6f0d3478ed685a15c5e062",
                    "status": "affected",
                    "version": "6e9e2eed4f39d52edf5fd006409d211facf49f6b",
                    "versionType": "git"
                  }
                ]
              },
              {
                "defaultStatus": "affected",
                "product": "Linux",
                "programFiles": [
                  "net/core/dev_ioctl.c"
                ],
                "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
                "vendor": "Linux",
                "versions": [
                  {
                    "status": "affected",
                    "version": "6.14"
                  },
                  {
                    "lessThan": "6.14",
                    "status": "unaffected",
                    "version": "0",
                    "versionType": "semver"
                  },
                  {
                    "lessThanOrEqual": "6.17.*",
                    "status": "unaffected",
                    "version": "6.17.10",
                    "versionType": "semver"
                  },
                  {
                    "lessThanOrEqual": "*",
                    "status": "unaffected",
                    "version": "6.18",
                    "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\nnet: core: prevent NULL deref in generic_hwtstamp_ioctl_lower()\n\nThe ethtool tsconfig Netlink path can trigger a null pointer\ndereference. A call chain such as:\n\n  tsconfig_prepare_data() -\u003e\n  dev_get_hwtstamp_phylib() -\u003e\n  vlan_hwtstamp_get() -\u003e\n  generic_hwtstamp_get_lower() -\u003e\n  generic_hwtstamp_ioctl_lower()\n\nresults in generic_hwtstamp_ioctl_lower() being called with\nkernel_cfg-\u003eifr as NULL.\n\nThe generic_hwtstamp_ioctl_lower() function does not expect\na NULL ifr and dereferences it, leading to a system crash.\n\nFix this by adding a NULL check for kernel_cfg-\u003eifr in\ngeneric_hwtstamp_ioctl_lower(). If ifr is NULL, return -EINVAL."
          },
          {
            "lang": "es",
            "value": "En el kernel de Linux, la siguiente vulnerabilidad ha sido resuelta:\n\nnet: core: prevenir desreferencia NULL en generic_hwtstamp_ioctl_lower()\n\nLa ruta Netlink ethtool tsconfig puede desencadenar una desreferencia de puntero nulo. Una cadena de llamadas como:\n\n  tsconfig_prepare_data()  -\u003e \n  dev_get_hwtstamp_phylib()  -\u003e \n  vlan_hwtstamp_get()  -\u003e \n  generic_hwtstamp_get_lower()  -\u003e \n  generic_hwtstamp_ioctl_lower()\n\nresulta en generic_hwtstamp_ioctl_lower() siendo llamada con kernel_cfg -\u003e ifr como NULL.\n\nLa funci\u00f3n generic_hwtstamp_ioctl_lower() no espera un ifr NULL y lo desreferencia, llevando a una ca\u00edda del sistema.\n\nSolucione esto a\u00f1adiendo una comprobaci\u00f3n de NULL para kernel_cfg -\u003e ifr en generic_hwtstamp_ioctl_lower(). Si ifr es NULL, devuelva -EINVAL."
          }
        ],
        "id": "CVE-2025-40255",
        "lastModified": "2026-10-19T19:10:00.130",
        "metrics": {},
        "published": "2025-12-04T16:16:19.227",
        "references": [
          {
            "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
            "url": "https://git.kernel.org/stable/c/8817f816ae41908e9625c0770c4af0dcdcc01238"
          },
          {
            "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
            "url": "https://git.kernel.org/stable/c/f796a8dec9beafcc0f6f0d3478ed685a15c5e062"
          }
        ],
        "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "vulnStatus": "Deferred"
      }
    },
    "redhat_vex": {
      "aggregate_severity": "Moderate",
      "current_release_date": "2026-06-30T10:20:59+00:00",
      "cve": "CVE-2025-40255",
      "id": "CVE-2025-40255",
      "initial_release_date": "2025-12-04T00:00:00+00:00",
      "product_status:known_affected": "184",
      "product_status:known_not_affected": "90",
      "source": "Red Hat CSAF VEX",
      "status": "final",
      "title": "kernel: net: core: prevent NULL deref in generic_hwtstamp_ioctl_lower()",
      "url": "https://security.access.redhat.com/data/csaf/v2/vex/2025/cve-2025-40255.json",
      "version": "3"
    },
    "suse_vex": {
      "aggregate_severity": "moderate",
      "current_release_date": "2026-11-01T01:16:05Z",
      "cve": "CVE-2025-40255",
      "id": "CVE-2025-40255",
      "initial_release_date": "2025-12-05T00:25:24Z",
      "product_status:known_affected": "545",
      "product_status:known_not_affected": "388",
      "product_status:recommended": "203",
      "source": "SUSE CSAF VEX",
      "status": "interim",
      "title": "SUSE CVE CVE-2025-40255",
      "url": "https://ftp.suse.com/pub/projects/security/csaf-vex/2025/cve-2025-40255.json",
      "version": "32"
    }
  }
}



Log in or create an account to share your comment.




Tags
Taxonomy of the tags.




Drag nodes to arrange them. Double-click a related vulnerability to open it, or a source to visit its link. The Physics button on the left tunes the layout and the simulation; the legend at the bottom left hides or shows nodes by kind and by sighting type.

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.
Vulnerability timeline

Sightings and recorded dates, grouped by day · UTC

JSON
How durations are calculated

Following the VTEM framework (Black Hat USA 2015), time to patch starts when the vendor or a coordinator was informed, total time to patch at discovery, and disclosure to patch at public disclosure; vendor response time runs from the report to its acknowledgement. Time to exploit and time unpatched start at the earliest discovery or report, falling back to public disclosure. Unpatched time ends at the first recorded patch, or the calculation time when no patch is recorded. Exploitation to patch shows the interval between those two events; a published proof of concept is a public exploit, not exploitation.

Each result shows its source dates. A negative interval means the end event came first; when date-only inputs leave the order open, the result says so. Date-only inputs are approximate. The earliest evidence wins: KEV report dates and sightings are labelled as such. Records describing another vulnerability are listed but never calculated from, and a PoC alone does not establish exploitation. Missing patch evidence does not prove that no patch exists. Filters below change the event list only.

Loading timeline…




    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.