FKIE_CVE-2025-38480

Vulnerability from fkie_nvd - Published: 2025-07-28 12:15 - Updated: 2026-01-07 16:24
Severity ?
5.5 (Medium) - CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Summary
In the Linux kernel, the following vulnerability has been resolved: comedi: Fix use of uninitialized data in insn_rw_emulate_bits() For Comedi `INSN_READ` and `INSN_WRITE` instructions on "digital" subdevices (subdevice types `COMEDI_SUBD_DI`, `COMEDI_SUBD_DO`, and `COMEDI_SUBD_DIO`), it is common for the subdevice driver not to have `insn_read` and `insn_write` handler functions, but to have an `insn_bits` handler function for handling Comedi `INSN_BITS` instructions. In that case, the subdevice's `insn_read` and/or `insn_write` function handler pointers are set to point to the `insn_rw_emulate_bits()` function by `__comedi_device_postconfig()`. For `INSN_WRITE`, `insn_rw_emulate_bits()` currently assumes that the supplied `data[0]` value is a valid copy from user memory. It will at least exist because `do_insnlist_ioctl()` and `do_insn_ioctl()` in "comedi_fops.c" ensure at lease `MIN_SAMPLES` (16) elements are allocated. However, if `insn->n` is 0 (which is allowable for `INSN_READ` and `INSN_WRITE` instructions, then `data[0]` may contain uninitialized data, and certainly contains invalid data, possibly from a different instruction in the array of instructions handled by `do_insnlist_ioctl()`. This will result in an incorrect value being written to the digital output channel (or to the digital input/output channel if configured as an output), and may be reflected in the internal saved state of the channel. Fix it by returning 0 early if `insn->n` is 0, before reaching the code that accesses `data[0]`. Previously, the function always returned 1 on success, but it is supposed to be the number of data samples actually read or written up to `insn->n`, which is 0 in this case.
References
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/10f9024a8c824a41827fff1fefefb314c98e2c88Patch
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/16256d7efcf7acc9f39abe21522c4c6b77f67c00Patch
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/2af1e7d389c2619219171d23f5b96dbcbb7f9656Patch
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/3050d197d6bc9ef128944a70210f42d2430b3000Patch
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/3ab55ffaaf75d0c7b68e332c1cdcc1b0e0044870Patch
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/4c2981bf30401adfcdbfece4ab6f411f7c5875a1Patch
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/c53570e62b5b28bdb56bb563190227f8307817a5Patch
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/e9cb26291d009243a4478a7ffb37b3a9175bfce9Patch
af854a3a-2127-422b-91ae-364da2661108https://lists.debian.org/debian-lts-announce/2025/10/msg00007.htmlThird Party Advisory
af854a3a-2127-422b-91ae-364da2661108https://lists.debian.org/debian-lts-announce/2025/10/msg00008.htmlThird Party Advisory
Impacted products
Vendor Product Version
linux linux_kernel *
linux linux_kernel *
linux linux_kernel *
linux linux_kernel *
linux linux_kernel *
linux linux_kernel *
linux linux_kernel *
linux linux_kernel 6.16
linux linux_kernel 6.16
linux linux_kernel 6.16
linux linux_kernel 6.16
linux linux_kernel 6.16
linux linux_kernel 6.16
debian debian_linux 11.0
To clipboard 

{
  "configurations": [
    {
      "nodes": [
        {
          "cpeMatch": [
            {
              "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
              "matchCriteriaId": "B9F2FDF6-4EB5-4DFF-BC93-F12605A32B6E",
              "versionEndExcluding": "5.4.297",
              "versionStartIncluding": "2.6.29",
              "vulnerable": true
            },
            {
              "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
              "matchCriteriaId": "D0D21C35-EB8A-488A-BBF9-403E4817E5DD",
              "versionEndExcluding": "5.10.241",
              "versionStartIncluding": "5.5",
              "vulnerable": true
            },
            {
              "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
              "matchCriteriaId": "AD9E597F-3DDE-4D7E-976C-463D0611F13F",
              "versionEndExcluding": "5.15.190",
              "versionStartIncluding": "5.11",
              "vulnerable": true
            },
            {
              "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
              "matchCriteriaId": "A4FD62FC-0DAE-4ACE-8C9C-66156518C3E1",
              "versionEndExcluding": "6.1.147",
              "versionStartIncluding": "5.16",
              "vulnerable": true
            },
            {
              "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
              "matchCriteriaId": "094B81E0-B756-4727-85CA-F3F8D1C9D116",
              "versionEndExcluding": "6.6.100",
              "versionStartIncluding": "6.2",
              "vulnerable": true
            },
            {
              "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
              "matchCriteriaId": "0099D5A4-B157-4D36-8858-982C7D579030",
              "versionEndExcluding": "6.12.40",
              "versionStartIncluding": "6.7",
              "vulnerable": true
            },
            {
              "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
              "matchCriteriaId": "C7AFE5B0-F3B1-4D30-B8BF-EDA0385C4746",
              "versionEndExcluding": "6.15.8",
              "versionStartIncluding": "6.13",
              "vulnerable": true
            },
            {
              "criteria": "cpe:2.3:o:linux:linux_kernel:6.16:rc1:*:*:*:*:*:*",
              "matchCriteriaId": "6D4894DB-CCFE-4602-B1BF-3960B2E19A01",
              "vulnerable": true
            },
            {
              "criteria": "cpe:2.3:o:linux:linux_kernel:6.16:rc2:*:*:*:*:*:*",
              "matchCriteriaId": "09709862-E348-4378-8632-5A7813EDDC86",
              "vulnerable": true
            },
            {
              "criteria": "cpe:2.3:o:linux:linux_kernel:6.16:rc3:*:*:*:*:*:*",
              "matchCriteriaId": "415BF58A-8197-43F5-B3D7-D1D63057A26E",
              "vulnerable": true
            },
            {
              "criteria": "cpe:2.3:o:linux:linux_kernel:6.16:rc4:*:*:*:*:*:*",
              "matchCriteriaId": "A0517869-312D-4429-80C2-561086E1421C",
              "vulnerable": true
            },
            {
              "criteria": "cpe:2.3:o:linux:linux_kernel:6.16:rc5:*:*:*:*:*:*",
              "matchCriteriaId": "85421F4E-C863-4ABF-B4B4-E887CC2F7F92",
              "vulnerable": true
            },
            {
              "criteria": "cpe:2.3:o:linux:linux_kernel:6.16:rc6:*:*:*:*:*:*",
              "matchCriteriaId": "3827F0D4-5FEE-4181-B267-5A45E7CA11FC",
              "vulnerable": true
            }
          ],
          "negate": false,
          "operator": "OR"
        }
      ]
    },
    {
      "nodes": [
        {
          "cpeMatch": [
            {
              "criteria": "cpe:2.3:o:debian:debian_linux:11.0:*:*:*:*:*:*:*",
              "matchCriteriaId": "FA6FEEC2-9F11-4643-8827-749718254FED",
              "vulnerable": true
            }
          ],
          "negate": false,
          "operator": "OR"
        }
      ]
    }
  ],
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\ncomedi: Fix use of uninitialized data in insn_rw_emulate_bits()\n\nFor Comedi `INSN_READ` and `INSN_WRITE` instructions on \"digital\"\nsubdevices (subdevice types `COMEDI_SUBD_DI`, `COMEDI_SUBD_DO`, and\n`COMEDI_SUBD_DIO`), it is common for the subdevice driver not to have\n`insn_read` and `insn_write` handler functions, but to have an\n`insn_bits` handler function for handling Comedi `INSN_BITS`\ninstructions.  In that case, the subdevice\u0027s `insn_read` and/or\n`insn_write` function handler pointers are set to point to the\n`insn_rw_emulate_bits()` function by `__comedi_device_postconfig()`.\n\nFor `INSN_WRITE`, `insn_rw_emulate_bits()` currently assumes that the\nsupplied `data[0]` value is a valid copy from user memory.  It will at\nleast exist because `do_insnlist_ioctl()` and `do_insn_ioctl()` in\n\"comedi_fops.c\" ensure at lease `MIN_SAMPLES` (16) elements are\nallocated.  However, if `insn-\u003en` is 0 (which is allowable for\n`INSN_READ` and `INSN_WRITE` instructions, then `data[0]` may contain\nuninitialized data, and certainly contains invalid data, possibly from a\ndifferent instruction in the array of instructions handled by\n`do_insnlist_ioctl()`.  This will result in an incorrect value being\nwritten to the digital output channel (or to the digital input/output\nchannel if configured as an output), and may be reflected in the\ninternal saved state of the channel.\n\nFix it by returning 0 early if `insn-\u003en` is 0, before reaching the code\nthat accesses `data[0]`.  Previously, the function always returned 1 on\nsuccess, but it is supposed to be the number of data samples actually\nread or written up to `insn-\u003en`, which is 0 in this case."
    },
    {
      "lang": "es",
      "value": "En el kernel de Linux, se ha resuelto la siguiente vulnerabilidad: comedi: Se corrige el uso de datos no inicializados en insn_rw_emulate_bits(). Para las instrucciones `INSN_READ` e `INSN_WRITE` de Comedi en subdispositivos \"digitales\" (tipos de subdispositivo `COMEDI_SUBD_DI`, `COMEDI_SUBD_DO` y `COMEDI_SUBD_DIO`), es com\u00fan que el controlador del subdispositivo no tenga las funciones de controlador `insn_read` e `insn_write`, sino una funci\u00f3n de controlador `insn_bits` para manejar las instrucciones `INSN_BITS` de Comedi. En ese caso, los punteros del controlador de funci\u00f3n `insn_read` y/o `insn_write` del subdispositivo se configuran para apuntar a la funci\u00f3n `insn_rw_emulate_bits()` mediante `__comedi_device_postconfig()`. Para `INSN_WRITE`, `insn_rw_emulate_bits()` actualmente asume que el valor `data[0]` proporcionado es una copia v\u00e1lida de la memoria del usuario. Al menos existir\u00e1 porque `do_insnlist_ioctl()` y `do_insn_ioctl()` en \"comedi_fops.c\" garantizan la asignaci\u00f3n de al menos `MIN_SAMPLES` (16) elementos. Sin embargo, si `insn-\u0026gt;n` es 0 (lo cual es permitido para las instrucciones `INSN_READ` e `INSN_WRITE`, entonces `data[0]` puede contener datos no inicializados, y ciertamente contiene datos no v\u00e1lidos, posiblemente de una instrucci\u00f3n diferente en la matriz de instrucciones manejadas por `do_insnlist_ioctl()`. Esto dar\u00e1 como resultado que se escriba un valor incorrecto en el canal de salida digital (o en el canal de entrada/salida digital si se configura como una salida), y puede reflejarse en el estado guardado interno del canal. Arr\u00e9glelo devolviendo 0 temprano si `insn-\u0026gt;n` es 0, antes de llegar al c\u00f3digo que accede a `data[0]`. Anteriormente, la funci\u00f3n siempre devolv\u00eda 1 en caso de \u00e9xito, pero se supone que es el n\u00famero de muestras de datos realmente le\u00eddas o escritas hasta `insn-\u0026gt;n`, que es 0 en este caso."
    }
  ],
  "id": "CVE-2025-38480",
  "lastModified": "2026-01-07T16:24:39.333",
  "metrics": {
    "cvssMetricV31": [
      {
        "cvssData": {
          "attackComplexity": "LOW",
          "attackVector": "LOCAL",
          "availabilityImpact": "HIGH",
          "baseScore": 5.5,
          "baseSeverity": "MEDIUM",
          "confidentialityImpact": "NONE",
          "integrityImpact": "NONE",
          "privilegesRequired": "LOW",
          "scope": "UNCHANGED",
          "userInteraction": "NONE",
          "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H",
          "version": "3.1"
        },
        "exploitabilityScore": 1.8,
        "impactScore": 3.6,
        "source": "nvd@nist.gov",
        "type": "Primary"
      }
    ]
  },
  "published": "2025-07-28T12:15:29.853",
  "references": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "tags": [
        "Patch"
      ],
      "url": "https://git.kernel.org/stable/c/10f9024a8c824a41827fff1fefefb314c98e2c88"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "tags": [
        "Patch"
      ],
      "url": "https://git.kernel.org/stable/c/16256d7efcf7acc9f39abe21522c4c6b77f67c00"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "tags": [
        "Patch"
      ],
      "url": "https://git.kernel.org/stable/c/2af1e7d389c2619219171d23f5b96dbcbb7f9656"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "tags": [
        "Patch"
      ],
      "url": "https://git.kernel.org/stable/c/3050d197d6bc9ef128944a70210f42d2430b3000"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "tags": [
        "Patch"
      ],
      "url": "https://git.kernel.org/stable/c/3ab55ffaaf75d0c7b68e332c1cdcc1b0e0044870"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "tags": [
        "Patch"
      ],
      "url": "https://git.kernel.org/stable/c/4c2981bf30401adfcdbfece4ab6f411f7c5875a1"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "tags": [
        "Patch"
      ],
      "url": "https://git.kernel.org/stable/c/c53570e62b5b28bdb56bb563190227f8307817a5"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "tags": [
        "Patch"
      ],
      "url": "https://git.kernel.org/stable/c/e9cb26291d009243a4478a7ffb37b3a9175bfce9"
    },
    {
      "source": "af854a3a-2127-422b-91ae-364da2661108",
      "tags": [
        "Third Party Advisory"
      ],
      "url": "https://lists.debian.org/debian-lts-announce/2025/10/msg00007.html"
    },
    {
      "source": "af854a3a-2127-422b-91ae-364da2661108",
      "tags": [
        "Third Party Advisory"
      ],
      "url": "https://lists.debian.org/debian-lts-announce/2025/10/msg00008.html"
    }
  ],
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "vulnStatus": "Analyzed",
  "weaknesses": [
    {
      "description": [
        {
          "lang": "en",
          "value": "CWE-908"
        }
      ],
      "source": "nvd@nist.gov",
      "type": "Primary"
    }
  ]
}


Log in or create an account to share your comment.




Tags
Taxonomy of the tags.




Sightings

Author Source Type Date

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.



Detection rules are retrieved from Rulezet.