CVE-2025-21646 (GCVE-0-2025-21646)
Vulnerability from cvelistv5
Published
2025-01-19 10:18
Modified
2025-11-03 20:58
Severity ?
Summary
In the Linux kernel, the following vulnerability has been resolved: afs: Fix the maximum cell name length The kafs filesystem limits the maximum length of a cell to 256 bytes, but a problem occurs if someone actually does that: kafs tries to create a directory under /proc/net/afs/ with the name of the cell, but that fails with a warning: WARNING: CPU: 0 PID: 9 at fs/proc/generic.c:405 because procfs limits the maximum filename length to 255. However, the DNS limits the maximum lookup length and, by extension, the maximum cell name, to 255 less two (length count and trailing NUL). Fix this by limiting the maximum acceptable cellname length to 253. This also allows us to be sure we can create the "/afs/.<cell>/" mountpoint too. Further, split the YFS VL record cell name maximum to be the 256 allowed by the protocol and ignore the record retrieved by YFSVL.GetCellName if it exceeds 253.
References
Impacted products
Vendor Product Version
Linux Linux Version: c3e9f888263bb4df11cbd623ceced02081cb2f9f
Version: c3e9f888263bb4df11cbd623ceced02081cb2f9f
Version: c3e9f888263bb4df11cbd623ceced02081cb2f9f
Version: c3e9f888263bb4df11cbd623ceced02081cb2f9f
Version: c3e9f888263bb4df11cbd623ceced02081cb2f9f
Version: c3e9f888263bb4df11cbd623ceced02081cb2f9f
 Create a notification for this product.
Show details on NVD website

To clipboard 

{
  "containers": {
    "adp": [
      {
        "providerMetadata": {
          "dateUpdated": "2025-11-03T20:58:26.381Z",
          "orgId": "af854a3a-2127-422b-91ae-364da2661108",
          "shortName": "CVE"
        },
        "references": [
          {
            "url": "https://lists.debian.org/debian-lts-announce/2025/03/msg00001.html"
          },
          {
            "url": "https://lists.debian.org/debian-lts-announce/2025/03/msg00002.html"
          }
        ],
        "title": "CVE Program Container"
      }
    ],
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "fs/afs/afs.h",
            "fs/afs/afs_vl.h",
            "fs/afs/vl_alias.c",
            "fs/afs/vlclient.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "9340385468d056bb700b8f28df236b81fc86a079",
              "status": "affected",
              "version": "c3e9f888263bb4df11cbd623ceced02081cb2f9f",
              "versionType": "git"
            },
            {
              "lessThan": "7cb3e77e9b4e6ffa325a5559393d3283c9af3d01",
              "status": "affected",
              "version": "c3e9f888263bb4df11cbd623ceced02081cb2f9f",
              "versionType": "git"
            },
            {
              "lessThan": "aabe47cf5ac5e1db2ae0635f189d836f67024904",
              "status": "affected",
              "version": "c3e9f888263bb4df11cbd623ceced02081cb2f9f",
              "versionType": "git"
            },
            {
              "lessThan": "7673030efe0f8ca1056d3849d61784c6caa052af",
              "status": "affected",
              "version": "c3e9f888263bb4df11cbd623ceced02081cb2f9f",
              "versionType": "git"
            },
            {
              "lessThan": "7922b1f058fe24a93730511dd0ae2e1630920096",
              "status": "affected",
              "version": "c3e9f888263bb4df11cbd623ceced02081cb2f9f",
              "versionType": "git"
            },
            {
              "lessThan": "8fd56ad6e7c90ac2bddb0741c6b248c8c5d56ac8",
              "status": "affected",
              "version": "c3e9f888263bb4df11cbd623ceced02081cb2f9f",
              "versionType": "git"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "fs/afs/afs.h",
            "fs/afs/afs_vl.h",
            "fs/afs/vl_alias.c",
            "fs/afs/vlclient.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "5.8"
            },
            {
              "lessThan": "5.8",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "5.10.*",
              "status": "unaffected",
              "version": "5.10.234",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "5.15.*",
              "status": "unaffected",
              "version": "5.15.177",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.1.*",
              "status": "unaffected",
              "version": "6.1.125",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.6.*",
              "status": "unaffected",
              "version": "6.6.72",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.12.*",
              "status": "unaffected",
              "version": "6.12.10",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "6.13",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
      "cpeApplicability": [
        {
          "nodes": [
            {
              "cpeMatch": [
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "5.10.234",
                  "versionStartIncluding": "5.8",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "5.15.177",
                  "versionStartIncluding": "5.8",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.1.125",
                  "versionStartIncluding": "5.8",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.6.72",
                  "versionStartIncluding": "5.8",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.12.10",
                  "versionStartIncluding": "5.8",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.13",
                  "versionStartIncluding": "5.8",
                  "vulnerable": true
                }
              ],
              "negate": false,
              "operator": "OR"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nafs: Fix the maximum cell name length\n\nThe kafs filesystem limits the maximum length of a cell to 256 bytes, but a\nproblem occurs if someone actually does that: kafs tries to create a\ndirectory under /proc/net/afs/ with the name of the cell, but that fails\nwith a warning:\n\n        WARNING: CPU: 0 PID: 9 at fs/proc/generic.c:405\n\nbecause procfs limits the maximum filename length to 255.\n\nHowever, the DNS limits the maximum lookup length and, by extension, the\nmaximum cell name, to 255 less two (length count and trailing NUL).\n\nFix this by limiting the maximum acceptable cellname length to 253.  This\nalso allows us to be sure we can create the \"/afs/.\u003ccell\u003e/\" mountpoint too.\n\nFurther, split the YFS VL record cell name maximum to be the 256 allowed by\nthe protocol and ignore the record retrieved by YFSVL.GetCellName if it\nexceeds 253."
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2025-05-04T07:18:10.155Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
      },
      "references": [
        {
          "url": "https://git.kernel.org/stable/c/9340385468d056bb700b8f28df236b81fc86a079"
        },
        {
          "url": "https://git.kernel.org/stable/c/7cb3e77e9b4e6ffa325a5559393d3283c9af3d01"
        },
        {
          "url": "https://git.kernel.org/stable/c/aabe47cf5ac5e1db2ae0635f189d836f67024904"
        },
        {
          "url": "https://git.kernel.org/stable/c/7673030efe0f8ca1056d3849d61784c6caa052af"
        },
        {
          "url": "https://git.kernel.org/stable/c/7922b1f058fe24a93730511dd0ae2e1630920096"
        },
        {
          "url": "https://git.kernel.org/stable/c/8fd56ad6e7c90ac2bddb0741c6b248c8c5d56ac8"
        }
      ],
      "title": "afs: Fix the maximum cell name length",
      "x_generator": {
        "engine": "bippy-1.2.0"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
    "assignerShortName": "Linux",
    "cveId": "CVE-2025-21646",
    "datePublished": "2025-01-19T10:18:02.776Z",
    "dateReserved": "2024-12-29T08:45:45.728Z",
    "dateUpdated": "2025-11-03T20:58:26.381Z",
    "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 seen somewhere by the user.
  • Confirmed: The vulnerability is confirmed from an analyst perspective.
  • Published Proof of Concept: A public proof of concept is available for this vulnerability.
  • Exploited: This vulnerability was exploited and seen by the user reporting the sighting.
  • Patched: This vulnerability was successfully patched by the user reporting the sighting.
  • Not exploited: This vulnerability was not exploited or seen by the user reporting the sighting.
  • Not confirmed: The user expresses doubt about the veracity of the vulnerability.
  • Not patched: This vulnerability was not successfully patched by the user reporting the sighting.