usb: gadget: f_mass_storage: Fix potential integer overflow in check_command_size_in_blocks()

{
  "id": "be632d93a81019769012e9ae3e3c3af05f7450dcc7099f88ce51dc3a541e2ed3",
  "url": "https://osv.dev/vulnerability/CVE-2026-31412",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "usb: gadget: f_mass_storage: Fix potential integer overflow in check_command_size_in_blocks()",
    "summary": "In the Linux kernel, the following vulnerability has been resolved: usb: gadget: f_mass_storage: Fix potential integer overflow in check_command_size_in_blocks() The `check_command_size_in_blocks()` function calculates the data size in bytes by left shifting `common->data_size_from_cmnd` by the block size (`common->curlun->blkbits`). However, it does not validate whether this shift operation will cause an integer overflow. Initially, the block size is set up in `fsg_lun_open()` , and the `common->data_size_from_cmnd` is set up in `do_scsi_command()`. During initialization, there is no integer overflow check for the interaction between two variables. So if a malicious USB host sends a SCSI READ or WRITE command requesting a large amount of data (`common->data_size_from_cmnd`), the left shift operation can wrap around. This results in a truncated data size, which can bypass boundary checks and potentially lead to memory corruption or out-of-bounds accesses. Fix this by using the check_shl_overflow() macro to safely perform the shift and catch any overflows.",
    "evidence": "osv:CVE-2026-31412",
    "products": [
      {
        "name": {
          "value": "Kernel",
          "evidence": "/affected/1/package/name"
        },
        "prerequisites": [],
        "fixed_versions": [
          {
            "value": "6.1.167",
            "evidence": "/affected/1/ranges"
          },
          {
            "value": "6.6.130",
            "evidence": "/affected/1/ranges"
          },
          {
            "value": "6.12.78",
            "evidence": "/affected/1/ranges"
          },
          {
            "value": "6.18.19",
            "evidence": "/affected/1/ranges"
          },
          {
            "value": "6.19.9",
            "evidence": "/affected/1/ranges"
          }
        ],
        "affected_versions": []
      }
    ],
    "severity": "unknown",
    "structured": {
      "id": "CVE-2026-31412",
      "aliases": [
        "CVE-2026-31412"
      ],
      "affected": [
        {
          "ranges": [
            {
              "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
              "type": "GIT",
              "events": [
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                  "introduced": "144974e7f9e32b53b02f6c8632be45d8f43d6ab5"
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                {
                  "fixed": "91817ad5452defe69bc7bc0e355f0ed5d01125cc"
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                {
                  "fixed": "ce0caaed5940162780c5c223b8ae54968a5f059b"
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                {
                  "fixed": "228b37936376143f4b60cc6828663f6eaceb81b5"
                },
                {
                  "fixed": "3428dc5520c811e66622b2f5fa43341bf9a1f8b3"
                },
                {
                  "fixed": "387ebb0453b99d71491419a5dc4ab4bee0cacbac"
                },
                {
                  "fixed": "8479891d1f04a8ce55366fe4ca361ccdb96f02e1"
                }
              ]
            }
          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-31412.json"
          }
        },
        {
          "ranges": [
            {
              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "3.3.0"
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                  "fixed": "6.1.167"
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              "type": "ECOSYSTEM",
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                  "introduced": "6.2.0"
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                  "fixed": "6.6.130"
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            {
              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "6.7.0"
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                {
                  "fixed": "6.12.78"
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            {
              "type": "ECOSYSTEM",
              "events": [
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                  "introduced": "6.13.0"
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                {
                  "fixed": "6.18.19"
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            {
              "type": "ECOSYSTEM",
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                  "introduced": "6.19.0"
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                {
                  "fixed": "6.19.9"
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              ]
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          ],
          "package": {
            "name": "Kernel",
            "ecosystem": "Linux"
          },
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-31412.json"
          }
        }
      ],
      "modified": "2026-10-28T02:30:43.206526483Z",
      "provider": "osv",
      "references": [
        "https://git.kernel.org/stable/c/228b37936376143f4b60cc6828663f6eaceb81b5",
        "https://git.kernel.org/stable/c/3428dc5520c811e66622b2f5fa43341bf9a1f8b3",
        "https://git.kernel.org/stable/c/387ebb0453b99d71491419a5dc4ab4bee0cacbac",
        "https://git.kernel.org/stable/c/8479891d1f04a8ce55366fe4ca361ccdb96f02e1",
        "https://git.kernel.org/stable/c/91817ad5452defe69bc7bc0e355f0ed5d01125cc",
        "https://git.kernel.org/stable/c/ce0caaed5940162780c5c223b8ae54968a5f059b",
        "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/31xxx/CVE-2026-31412.json",
        "https://nvd.nist.gov/vuln/detail/CVE-2026-31412",
        "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/2026/31xxx/CVE-2026-31412.json"
      }
    },
    "related_cves": [
      {
        "value": "CVE-2026-31412",
        "evidence": "/id"
      }
    ],
    "security_relevant": true,
    "severity_evidence": null
  },
  "source_id": "core-osv",
  "document_id": 510698,
  "published_at": "2026-04-10T10:35:05.796+00:00"
}