ghsa-xhj3-2vvm-6mr5
Vulnerability from github
Published
2024-04-03 18:30
Modified
2025-03-17 18:31
Severity ?
5.5 (Medium) - CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Details

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

l2tp: pass correct message length to ip6_append_data

l2tp_ip6_sendmsg needs to avoid accounting for the transport header twice when splicing more data into an already partially-occupied skbuff.

To manage this, we check whether the skbuff contains data using skb_queue_empty when deciding how much data to append using ip6_append_data.

However, the code which performed the calculation was incorrect:

 ulen = len + skb_queue_empty(&sk->sk_write_queue) ? transhdrlen : 0;

...due to C operator precedence, this ends up setting ulen to transhdrlen for messages with a non-zero length, which results in corrupted packets on the wire.

Add parentheses to correct the calculation in line with the original intent.

Show details on source website

To clipboard 

{
  "affected": [],
  "aliases": [
    "CVE-2024-26752"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-131"
    ],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2024-04-03T17:15:51Z",
    "severity": "MODERATE"
  },
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nl2tp: pass correct message length to ip6_append_data\n\nl2tp_ip6_sendmsg needs to avoid accounting for the transport header\ntwice when splicing more data into an already partially-occupied skbuff.\n\nTo manage this, we check whether the skbuff contains data using\nskb_queue_empty when deciding how much data to append using\nip6_append_data.\n\nHowever, the code which performed the calculation was incorrect:\n\n     ulen = len + skb_queue_empty(\u0026sk-\u003esk_write_queue) ? transhdrlen : 0;\n\n...due to C operator precedence, this ends up setting ulen to\ntranshdrlen for messages with a non-zero length, which results in\ncorrupted packets on the wire.\n\nAdd parentheses to correct the calculation in line with the original\nintent.",
  "id": "GHSA-xhj3-2vvm-6mr5",
  "modified": "2025-03-17T18:31:41Z",
  "published": "2024-04-03T18:30:42Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2024-26752"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/0da15a70395182ee8cb75716baf00dddc0bea38d"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/13cd1daeea848614e585b2c6ecc11ca9c8ab2500"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/359e54a93ab43d32ee1bff3c2f9f10cb9f6b6e79"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/4c3ce64bc9d36ca9164dd6c77ff144c121011aae"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/804bd8650a3a2bf3432375f8c97d5049d845ce56"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/83340c66b498e49353530e41542500fc8a4782d6"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/c1d3a84a67db910ce28a871273c992c3d7f9efb5"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/dcb4d14268595065c85dc5528056713928e17243"
    },
    {
      "type": "WEB",
      "url": "https://lists.debian.org/debian-lts-announce/2024/06/msg00017.html"
    },
    {
      "type": "WEB",
      "url": "https://lists.debian.org/debian-lts-announce/2024/06/msg00020.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"
    }
  ]
}


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.