CVE-2025-39686 (GCVE-0-2025-39686)

Vulnerability from cvelistv5 – Published: 2025-09-05 17:20 – Updated: 2025-11-03 17:42
VLAI?
Title
comedi: Make insn_rw_emulate_bits() do insn->n samples
Summary
In the Linux kernel, the following vulnerability has been resolved: comedi: Make insn_rw_emulate_bits() do insn->n samples The `insn_rw_emulate_bits()` function is used as a default handler for `INSN_READ` instructions for subdevices that have a handler for `INSN_BITS` but not for `INSN_READ`. Similarly, it is used as a default handler for `INSN_WRITE` instructions for subdevices that have a handler for `INSN_BITS` but not for `INSN_WRITE`. It works by emulating the `INSN_READ` or `INSN_WRITE` instruction handling with a constructed `INSN_BITS` instruction. However, `INSN_READ` and `INSN_WRITE` instructions are supposed to be able read or write multiple samples, indicated by the `insn->n` value, but `insn_rw_emulate_bits()` currently only handles a single sample. For `INSN_READ`, the comedi core will copy `insn->n` samples back to user-space. (That triggered KASAN kernel-infoleak errors when `insn->n` was greater than 1, but that is being fixed more generally elsewhere in the comedi core.) Make `insn_rw_emulate_bits()` either handle `insn->n` samples, or return an error, to conform to the general expectation for `INSN_READ` and `INSN_WRITE` handlers.
Severity ?
No CVSS data available.
Assigner
References
Impacted products
Vendor Product Version
Linux Linux Affected: ed9eccbe8970f6eedc1b978c157caf1251a896d4 , < ab77e85bd3bc006ef40738f26f446a660813da44 (git)
Affected: ed9eccbe8970f6eedc1b978c157caf1251a896d4 , < ae8bc1f07bcb31b8636420e03d1f9c3df6219a2b (git)
Affected: ed9eccbe8970f6eedc1b978c157caf1251a896d4 , < 842f307a1d115b24f2bcb2415c4e344f11f55930 (git)
Affected: ed9eccbe8970f6eedc1b978c157caf1251a896d4 , < 92352ed2f9ac422181e381c2430c2d0dfb46faa0 (git)
Affected: ed9eccbe8970f6eedc1b978c157caf1251a896d4 , < dc0a2f142d655700db43de90cb6abf141b73d908 (git)
Affected: ed9eccbe8970f6eedc1b978c157caf1251a896d4 , < 7afba9221f70d4cbce0f417c558879cba0eb5e66 (git)
Create a notification for this product.
    Linux Linux Affected: 2.6.29
Unaffected: 0 , < 2.6.29 (semver)
Unaffected: 5.15.190 , ≤ 5.15.* (semver)
Unaffected: 6.1.149 , ≤ 6.1.* (semver)
Unaffected: 6.6.103 , ≤ 6.6.* (semver)
Unaffected: 6.12.44 , ≤ 6.12.* (semver)
Unaffected: 6.16.4 , ≤ 6.16.* (semver)
Unaffected: 6.17 , ≤ * (original_commit_for_fix)
Create a notification for this product.
Show details on NVD website
To clipboard 

{
  "containers": {
    "adp": [
      {
        "providerMetadata": {
          "dateUpdated": "2025-11-03T17:42:18.407Z",
          "orgId": "af854a3a-2127-422b-91ae-364da2661108",
          "shortName": "CVE"
        },
        "references": [
          {
            "url": "https://lists.debian.org/debian-lts-announce/2025/10/msg00008.html"
          }
        ],
        "title": "CVE Program Container"
      }
    ],
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "drivers/comedi/drivers.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "ab77e85bd3bc006ef40738f26f446a660813da44",
              "status": "affected",
              "version": "ed9eccbe8970f6eedc1b978c157caf1251a896d4",
              "versionType": "git"
            },
            {
              "lessThan": "ae8bc1f07bcb31b8636420e03d1f9c3df6219a2b",
              "status": "affected",
              "version": "ed9eccbe8970f6eedc1b978c157caf1251a896d4",
              "versionType": "git"
            },
            {
              "lessThan": "842f307a1d115b24f2bcb2415c4e344f11f55930",
              "status": "affected",
              "version": "ed9eccbe8970f6eedc1b978c157caf1251a896d4",
              "versionType": "git"
            },
            {
              "lessThan": "92352ed2f9ac422181e381c2430c2d0dfb46faa0",
              "status": "affected",
              "version": "ed9eccbe8970f6eedc1b978c157caf1251a896d4",
              "versionType": "git"
            },
            {
              "lessThan": "dc0a2f142d655700db43de90cb6abf141b73d908",
              "status": "affected",
              "version": "ed9eccbe8970f6eedc1b978c157caf1251a896d4",
              "versionType": "git"
            },
            {
              "lessThan": "7afba9221f70d4cbce0f417c558879cba0eb5e66",
              "status": "affected",
              "version": "ed9eccbe8970f6eedc1b978c157caf1251a896d4",
              "versionType": "git"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "drivers/comedi/drivers.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "2.6.29"
            },
            {
              "lessThan": "2.6.29",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "5.15.*",
              "status": "unaffected",
              "version": "5.15.190",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.1.*",
              "status": "unaffected",
              "version": "6.1.149",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.6.*",
              "status": "unaffected",
              "version": "6.6.103",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.12.*",
              "status": "unaffected",
              "version": "6.12.44",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.16.*",
              "status": "unaffected",
              "version": "6.16.4",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "6.17",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
      "cpeApplicability": [
        {
          "nodes": [
            {
              "cpeMatch": [
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "5.15.190",
                  "versionStartIncluding": "2.6.29",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.1.149",
                  "versionStartIncluding": "2.6.29",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.6.103",
                  "versionStartIncluding": "2.6.29",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.12.44",
                  "versionStartIncluding": "2.6.29",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.16.4",
                  "versionStartIncluding": "2.6.29",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.17",
                  "versionStartIncluding": "2.6.29",
                  "vulnerable": true
                }
              ],
              "negate": false,
              "operator": "OR"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\ncomedi: Make insn_rw_emulate_bits() do insn-\u003en samples\n\nThe `insn_rw_emulate_bits()` function is used as a default handler for\n`INSN_READ` instructions for subdevices that have a handler for\n`INSN_BITS` but not for `INSN_READ`.  Similarly, it is used as a default\nhandler for `INSN_WRITE` instructions for subdevices that have a handler\nfor `INSN_BITS` but not for `INSN_WRITE`. It works by emulating the\n`INSN_READ` or `INSN_WRITE` instruction handling with a constructed\n`INSN_BITS` instruction.  However, `INSN_READ` and `INSN_WRITE`\ninstructions are supposed to be able read or write multiple samples,\nindicated by the `insn-\u003en` value, but `insn_rw_emulate_bits()` currently\nonly handles a single sample.  For `INSN_READ`, the comedi core will\ncopy `insn-\u003en` samples back to user-space.  (That triggered KASAN\nkernel-infoleak errors when `insn-\u003en` was greater than 1, but that is\nbeing fixed more generally elsewhere in the comedi core.)\n\nMake `insn_rw_emulate_bits()` either handle `insn-\u003en` samples, or return\nan error, to conform to the general expectation for `INSN_READ` and\n`INSN_WRITE` handlers."
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2025-09-29T05:57:24.508Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
      },
      "references": [
        {
          "url": "https://git.kernel.org/stable/c/ab77e85bd3bc006ef40738f26f446a660813da44"
        },
        {
          "url": "https://git.kernel.org/stable/c/ae8bc1f07bcb31b8636420e03d1f9c3df6219a2b"
        },
        {
          "url": "https://git.kernel.org/stable/c/842f307a1d115b24f2bcb2415c4e344f11f55930"
        },
        {
          "url": "https://git.kernel.org/stable/c/92352ed2f9ac422181e381c2430c2d0dfb46faa0"
        },
        {
          "url": "https://git.kernel.org/stable/c/dc0a2f142d655700db43de90cb6abf141b73d908"
        },
        {
          "url": "https://git.kernel.org/stable/c/7afba9221f70d4cbce0f417c558879cba0eb5e66"
        }
      ],
      "title": "comedi: Make insn_rw_emulate_bits() do insn-\u003en samples",
      "x_generator": {
        "engine": "bippy-1.2.0"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
    "assignerShortName": "Linux",
    "cveId": "CVE-2025-39686",
    "datePublished": "2025-09-05T17:20:53.071Z",
    "dateReserved": "2025-04-16T07:20:57.113Z",
    "dateUpdated": "2025-11-03T17:42:18.407Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}


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.