GHSA-35Q9-FP2V-JHCQ

Vulnerability from github – Published: 2026-04-10 12:31 – Updated: 2026-04-10 12:31
VLAI?
Details

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.

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{
  "affected": [],
  "aliases": [
    "CVE-2026-31412"
  ],
  "database_specific": {
    "cwe_ids": [],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2026-04-10T11:16:22Z",
    "severity": null
  },
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nusb: gadget: f_mass_storage: Fix potential integer overflow in check_command_size_in_blocks()\n\nThe `check_command_size_in_blocks()` function calculates the data size\nin bytes by left shifting `common-\u003edata_size_from_cmnd` by the block\nsize (`common-\u003ecurlun-\u003eblkbits`). However, it does not validate whether\nthis shift operation will cause an integer overflow.\n\nInitially, the block size is set up in `fsg_lun_open()` , and the\n`common-\u003edata_size_from_cmnd` is set up in `do_scsi_command()`. During\ninitialization, there is no integer overflow check for the interaction\nbetween two variables.\n\nSo if a malicious USB host sends a SCSI READ or WRITE command\nrequesting a large amount of data (`common-\u003edata_size_from_cmnd`), the\nleft shift operation can wrap around. This results in a truncated data\nsize, which can bypass boundary checks and potentially lead to memory\ncorruption or out-of-bounds accesses.\n\nFix this by using the check_shl_overflow() macro to safely perform the\nshift and catch any overflows.",
  "id": "GHSA-35q9-fp2v-jhcq",
  "modified": "2026-04-10T12:31:44Z",
  "published": "2026-04-10T12:31:44Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-31412"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/228b37936376143f4b60cc6828663f6eaceb81b5"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/3428dc5520c811e66622b2f5fa43341bf9a1f8b3"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/387ebb0453b99d71491419a5dc4ab4bee0cacbac"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/8479891d1f04a8ce55366fe4ca361ccdb96f02e1"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/91817ad5452defe69bc7bc0e355f0ed5d01125cc"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/ce0caaed5940162780c5c223b8ae54968a5f059b"
    }
  ],
  "schema_version": "1.4.0",
  "severity": []
}


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