Vulnerability-Lookup

GHSA-3CF6-344V-4FMG

Vulnerability from github – Published: 2024-07-12 15:31 – Updated: 2025-11-04 00:30

Details

In the Linux kernel, the following vulnerability has been resolved:

tty: add the option to have a tty reject a new ldisc

... and use it to limit the virtual terminals to just N_TTY. They are kind of special, and in particular, the "con_write()" routine violates the "writes cannot sleep" rule that some ldiscs rely on.

This avoids the

BUG: sleeping function called from invalid context at kernel/printk/printk.c:2659

when N_GSM has been attached to a virtual console, and gsmld_write() calls con_write() while holding a spinlock, and con_write() then tries to get the console lock.

Severity

5.5 (Medium)


                  
                    CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

Show details on source website

JSON

To clipboard

{
  "affected": [],
  "aliases": [
    "CVE-2024-40966"
  ],
  "database_specific": {
    "cwe_ids": [],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2024-07-12T13:15:18Z",
    "severity": "MODERATE"
  },
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\ntty: add the option to have a tty reject a new ldisc\n\n... and use it to limit the virtual terminals to just N_TTY.  They are\nkind of special, and in particular, the \"con_write()\" routine violates\nthe \"writes cannot sleep\" rule that some ldiscs rely on.\n\nThis avoids the\n\n   BUG: sleeping function called from invalid context at kernel/printk/printk.c:2659\n\nwhen N_GSM has been attached to a virtual console, and gsmld_write()\ncalls con_write() while holding a spinlock, and con_write() then tries\nto get the console lock.",
  "id": "GHSA-3cf6-344v-4fmg",
  "modified": "2025-11-04T00:30:56Z",
  "published": "2024-07-12T15:31:28Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2024-40966"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/287b569a5b914903ba7c438a3c0dbc3410ebb409"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/3c6332f3bb1578b5b10ac2561247b1d6272ae937"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/5920ac19964f9e20181f63b410d9200ddbf8dc86"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/6bd23e0c2bb6c65d4f5754d1456bc9a4427fc59b"
    },
    {
      "type": "WEB",
      "url": "https://lists.debian.org/debian-lts-announce/2025/01/msg00001.html"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H",
      "type": "CVSS_V3"
    }
  ]
}

CVE-2024-40966 (GCVE-0-2024-40966)

Vulnerability from cvelistv5 – Published: 2024-07-12 12:32 – Updated: 2026-05-11 20:23

Title

tty: add the option to have a tty reject a new ldisc

Summary

In the Linux kernel, the following vulnerability has been resolved: tty: add the option to have a tty reject a new ldisc ... and use it to limit the virtual terminals to just N_TTY. They are kind of special, and in particular, the "con_write()" routine violates the "writes cannot sleep" rule that some ldiscs rely on. This avoids the BUG: sleeping function called from invalid context at kernel/printk/printk.c:2659 when N_GSM has been attached to a virtual console, and gsmld_write() calls con_write() while holding a spinlock, and con_write() then tries to get the console lock.

Severity

No CVSS data available.

SSVC

Exploitation: none Automatable: no Technical Impact: partial

CISA Coordinator · CISA-ADP (v2.0.3)

Decision recorded 2024-09-10 17:03 UTC

Assigner

Linux mitre root

References

5 references

URL	Tags
https://git.kernel.org/stable/c/3c6332f3bb1578b5b…
https://git.kernel.org/stable/c/287b569a5b914903b…
https://git.kernel.org/stable/c/5920ac19964f9e201…
https://git.kernel.org/stable/c/6bd23e0c2bb6c65d4…
https://lists.debian.org/debian-lts-announce/2025…

Impacted products

2 products

Vendor	Product	Version
Linux	Linux	Affected: e1eaea46bb4020b38a141b84f88565d4603f8dd0 , < 3c6332f3bb1578b5b10ac2561247b1d6272ae937 (git) Affected: e1eaea46bb4020b38a141b84f88565d4603f8dd0 , < 287b569a5b914903ba7c438a3c0dbc3410ebb409 (git) Affected: e1eaea46bb4020b38a141b84f88565d4603f8dd0 , < 5920ac19964f9e20181f63b410d9200ddbf8dc86 (git) Affected: e1eaea46bb4020b38a141b84f88565d4603f8dd0 , < 6bd23e0c2bb6c65d4f5754d1456bc9a4427fc59b (git)
Linux	Linux	Affected: 2.6.35 Unaffected: 0 , < 2.6.35 (semver) Unaffected: 6.1.96 , ≤ 6.1.* (semver) Unaffected: 6.6.36 , ≤ 6.6.* (semver) Unaffected: 6.9.7 , ≤ 6.9.* (semver) Unaffected: 6.10 , ≤ * (original_commit_for_fix)

Show details on NVD website

JSON

To clipboard

{
  "containers": {
    "adp": [
      {
        "providerMetadata": {
          "dateUpdated": "2025-11-03T21:58:30.295Z",
          "orgId": "af854a3a-2127-422b-91ae-364da2661108",
          "shortName": "CVE"
        },
        "references": [
          {
            "tags": [
              "x_transferred"
            ],
            "url": "https://git.kernel.org/stable/c/3c6332f3bb1578b5b10ac2561247b1d6272ae937"
          },
          {
            "tags": [
              "x_transferred"
            ],
            "url": "https://git.kernel.org/stable/c/287b569a5b914903ba7c438a3c0dbc3410ebb409"
          },
          {
            "tags": [
              "x_transferred"
            ],
            "url": "https://git.kernel.org/stable/c/5920ac19964f9e20181f63b410d9200ddbf8dc86"
          },
          {
            "tags": [
              "x_transferred"
            ],
            "url": "https://git.kernel.org/stable/c/6bd23e0c2bb6c65d4f5754d1456bc9a4427fc59b"
          },
          {
            "url": "https://lists.debian.org/debian-lts-announce/2025/01/msg00001.html"
          }
        ],
        "title": "CVE Program Container"
      },
      {
        "metrics": [
          {
            "other": {
              "content": {
                "id": "CVE-2024-40966",
                "options": [
                  {
                    "Exploitation": "none"
                  },
                  {
                    "Automatable": "no"
                  },
                  {
                    "Technical Impact": "partial"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2024-09-10T17:03:10.358016Z",
                "version": "2.0.3"
              },
              "type": "ssvc"
            }
          }
        ],
        "providerMetadata": {
          "dateUpdated": "2024-09-11T17:34:23.131Z",
          "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
          "shortName": "CISA-ADP"
        },
        "title": "CISA ADP Vulnrichment"
      }
    ],
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "drivers/tty/tty_ldisc.c",
            "drivers/tty/vt/vt.c",
            "include/linux/tty_driver.h"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "3c6332f3bb1578b5b10ac2561247b1d6272ae937",
              "status": "affected",
              "version": "e1eaea46bb4020b38a141b84f88565d4603f8dd0",
              "versionType": "git"
            },
            {
              "lessThan": "287b569a5b914903ba7c438a3c0dbc3410ebb409",
              "status": "affected",
              "version": "e1eaea46bb4020b38a141b84f88565d4603f8dd0",
              "versionType": "git"
            },
            {
              "lessThan": "5920ac19964f9e20181f63b410d9200ddbf8dc86",
              "status": "affected",
              "version": "e1eaea46bb4020b38a141b84f88565d4603f8dd0",
              "versionType": "git"
            },
            {
              "lessThan": "6bd23e0c2bb6c65d4f5754d1456bc9a4427fc59b",
              "status": "affected",
              "version": "e1eaea46bb4020b38a141b84f88565d4603f8dd0",
              "versionType": "git"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "drivers/tty/tty_ldisc.c",
            "drivers/tty/vt/vt.c",
            "include/linux/tty_driver.h"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "2.6.35"
            },
            {
              "lessThan": "2.6.35",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.1.*",
              "status": "unaffected",
              "version": "6.1.96",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.6.*",
              "status": "unaffected",
              "version": "6.6.36",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.9.*",
              "status": "unaffected",
              "version": "6.9.7",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "6.10",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
      "cpeApplicability": [
        {
          "nodes": [
            {
              "cpeMatch": [
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.1.96",
                  "versionStartIncluding": "2.6.35",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.6.36",
                  "versionStartIncluding": "2.6.35",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.9.7",
                  "versionStartIncluding": "2.6.35",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.10",
                  "versionStartIncluding": "2.6.35",
                  "vulnerable": true
                }
              ],
              "negate": false,
              "operator": "OR"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\ntty: add the option to have a tty reject a new ldisc\n\n... and use it to limit the virtual terminals to just N_TTY.  They are\nkind of special, and in particular, the \"con_write()\" routine violates\nthe \"writes cannot sleep\" rule that some ldiscs rely on.\n\nThis avoids the\n\n   BUG: sleeping function called from invalid context at kernel/printk/printk.c:2659\n\nwhen N_GSM has been attached to a virtual console, and gsmld_write()\ncalls con_write() while holding a spinlock, and con_write() then tries\nto get the console lock."
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-05-11T20:23:17.510Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
      },
      "references": [
        {
          "url": "https://git.kernel.org/stable/c/3c6332f3bb1578b5b10ac2561247b1d6272ae937"
        },
        {
          "url": "https://git.kernel.org/stable/c/287b569a5b914903ba7c438a3c0dbc3410ebb409"
        },
        {
          "url": "https://git.kernel.org/stable/c/5920ac19964f9e20181f63b410d9200ddbf8dc86"
        },
        {
          "url": "https://git.kernel.org/stable/c/6bd23e0c2bb6c65d4f5754d1456bc9a4427fc59b"
        }
      ],
      "title": "tty: add the option to have a tty reject a new ldisc",
      "x_generator": {
        "engine": "bippy-1.2.0"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
    "assignerShortName": "Linux",
    "cveId": "CVE-2024-40966",
    "datePublished": "2024-07-12T12:32:06.122Z",
    "dateReserved": "2024-07-12T12:17:45.602Z",
    "dateUpdated": "2026-05-11T20:23:17.510Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}

Sightings

Author	Source	Type	Date	Other

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.

The MITRE ATT&CK techniques below are AI-generated suggestions, inferred from the description of the vulnerability by the CIRCL/vulnerability-attack-technique-classification-roberta-base model, served locally by ML-Gateway. They have not been verified by an analyst and are provided for guidance only.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
Browse all ATT&CK techniques and the vulnerabilities related to each.

Related by attack behaviour

Vulnerabilities whose description is nearest to this one in the vector space of the CIRCL/vulnerability-attack-technique-biencoder model. This is a similarity search over the bi-encoder space (plain cosine), not a classification, and it has no measured accuracy.