GHSA-V222-HVCR-RGHC

Vulnerability from github – Published: 2026-06-26 21:32 – Updated: 2026-07-06 21:30
VLAI
Details

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

tty: hvc_iucv: fix off-by-one in number of supported devices

MAX_HVC_IUCV_LINES == HVC_ALLOC_TTY_ADAPTERS == 8. This is the number of entries in: static struct hvc_iucv_private *hvc_iucv_table[MAX_HVC_IUCV_LINES];

Sometimes hvc_iucv_table[] is limited by: (a) if (num > hvc_iucv_devices) // for error detection or (b) for (i = 0; i < hvc_iucv_devices; i++) // in 2 places (so these 2 don't agree; second one appears to be correct to me.)

hvc_iucv_devices can be 0..8. This is a counter. (c) if (hvc_iucv_devices > MAX_HVC_IUCV_LINES)

If hvc_iucv_devices == 8, (a) allows the code to access hvc_iucv_table[8]. Oops.

Severity
5.5 (Medium)
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
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{
  "affected": [],
  "aliases": [
    "CVE-2026-53306"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-193"
    ],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2026-06-26T20:17:23Z",
    "severity": "MODERATE"
  },
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\ntty: hvc_iucv: fix off-by-one in number of supported devices\n\nMAX_HVC_IUCV_LINES == HVC_ALLOC_TTY_ADAPTERS == 8.\nThis is the number of entries in:\n  static struct hvc_iucv_private *hvc_iucv_table[MAX_HVC_IUCV_LINES];\n\nSometimes hvc_iucv_table[] is limited by:\n(a)\tif (num \u003e hvc_iucv_devices) // for error detection\nor\n(b)\tfor (i = 0; i \u003c hvc_iucv_devices; i++) // in 2 places\n(so these 2 don\u0027t agree; second one appears to be correct to me.)\n\nhvc_iucv_devices can be 0..8. This is a counter.\n(c)\tif (hvc_iucv_devices \u003e MAX_HVC_IUCV_LINES)\n\nIf hvc_iucv_devices == 8, (a) allows the code to access hvc_iucv_table[8].\nOops.",
  "id": "GHSA-v222-hvcr-rghc",
  "modified": "2026-07-06T21:30:25Z",
  "published": "2026-06-26T21:32:17Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-53306"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/11207e42a332eb8bbcb9fe74df9edd2a807c5607"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/3104a3f40feb107f77d7116ad9bf6c210ab7babf"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/3d3b89e6ab93bdd0efd45828bda6b0e61cc46dff"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/484357dff256c816d9466bda35eb765685e4dc86"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/a76511bc654819425d3b15e77b523d7f9d81f064"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/f1dc8e72de9aabe5d96767a4e97219ac26b79fe5"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/f2a880e802ad12d1e38039d1334fb1475d0f5241"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/fed8b8f33a46db0ee2efdb000f4f630c86ed8ca4"
    }
  ],
  "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"
    }
  ]
}



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