GHSA-CMJF-X265-CCVJ

Vulnerability from github – Published: 2026-08-27 06:31 – Updated: 2026-08-27 06:31
VLAI
Details

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

s390/qeth: validate user buffer length in SNMP and ARP query ioctls

qeth_snmp_command() and qeth_l3_arp_query() allocate a buffer sized by a user-supplied length (udata_len) without checking a lower bound, then set udata_offset to a fixed non-zero value and pass both to a reply callback. The callback bounds-checks the copy with

    if ((udata_len - udata_offset) < len)

Both fields are u32, so a udata_len smaller than udata_offset makes the subtraction wrap and the check pass, and the following memcpy() writes past the allocation. A udata_len of 0 also yields ZERO_SIZE_PTR from kzalloc(), which the existing NULL check does not catch.

Reject buffers smaller than udata_offset before allocating, so the callback subtraction can no longer underflow.

Severity
8.4 (High)
CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
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{
  "affected": [],
  "aliases": [
    "CVE-2026-80584"
  ],
  "database_specific": {
    "cwe_ids": [],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2026-08-26T15:17:14Z",
    "severity": "HIGH"
  },
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\ns390/qeth: validate user buffer length in SNMP and ARP query ioctls\n\nqeth_snmp_command() and qeth_l3_arp_query() allocate a buffer sized by\na user-supplied length (udata_len) without checking a lower bound, then\nset udata_offset to a fixed non-zero value and pass both to a reply\ncallback. The callback bounds-checks the copy with\n\n        if ((udata_len - udata_offset) \u003c len)\n\nBoth fields are u32, so a udata_len smaller than udata_offset makes the\nsubtraction wrap and the check pass, and the following memcpy() writes\npast the allocation. A udata_len of 0 also yields ZERO_SIZE_PTR from\nkzalloc(), which the existing NULL check does not catch.\n\nReject buffers smaller than udata_offset before allocating, so the\ncallback subtraction can no longer underflow.",
  "id": "GHSA-cmjf-x265-ccvj",
  "modified": "2026-08-27T06:31:33Z",
  "published": "2026-08-27T06:31:33Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-80584"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/3083818e67bcd656965797fbac9a3d6c1d44f78a"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/46443eaddebd84c51940857b11787229be169dec"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/75fb3151513d7d9f77a8f9545418279b119c06b8"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/91935843f9396a9e45253e2c0d4337ca1371754b"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/9d00eeb2d27f4cc817c5e408760226d43f811ec6"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/a3083647747942ea32faf14560d6397ff3068046"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/cc423f4105fe145b33e1d7cad34245a798358f73"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/d141f087b1af656f055d7c5793a3e87817ba0bbe"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
      "type": "CVSS_V3"
    }
  ]
}



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