ghsa-3mxh-p32w-7p56
Vulnerability from github
Published
2025-12-04 18:30
Modified
2025-12-04 18:30
Details

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.

Show details on source website

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{
  "affected": [],
  "aliases": [
    "CVE-2025-40255"
  ],
  "database_specific": {
    "cwe_ids": [],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2025-12-04T16:16:19Z",
    "severity": null
  },
  "details": "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.",
  "id": "GHSA-3mxh-p32w-7p56",
  "modified": "2025-12-04T18:30:53Z",
  "published": "2025-12-04T18:30:53Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2025-40255"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/8817f816ae41908e9625c0770c4af0dcdcc01238"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/f796a8dec9beafcc0f6f0d3478ed685a15c5e062"
    }
  ],
  "schema_version": "1.4.0",
  "severity": []
}


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