GHSA-JC43-3M97-6P35

Vulnerability from github – Published: 2026-05-27 15:33 – Updated: 2026-05-27 15:33
VLAI
Details

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

xen-netback: reject zero-queue configuration from guest

A malicious or buggy Xen guest can write "0" to the xenbus key "multi-queue-num-queues". The connect() function in the backend only validates the upper bound (requested_num_queues > xenvif_max_queues) but not zero, allowing requested_num_queues=0 to reach vzalloc(array_size(0, sizeof(struct xenvif_queue))), which triggers WARN_ON_ONCE(!size) in __vmalloc_node_range().

On systems with panic_on_warn=1, this allows a guest-to-host denial of service.

The Xen network interface specification requires the queue count to be "greater than zero".

Add a zero check to match the validation already present in xen-blkback, which has included this guard since its multi-queue support was added.

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{
  "affected": [],
  "aliases": [
    "CVE-2026-45890"
  ],
  "database_specific": {
    "cwe_ids": [],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2026-05-27T14:17:03Z",
    "severity": null
  },
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nxen-netback: reject zero-queue configuration from guest\n\nA malicious or buggy Xen guest can write \"0\" to the xenbus key\n\"multi-queue-num-queues\". The connect() function in the backend only\nvalidates the upper bound (requested_num_queues \u003e xenvif_max_queues)\nbut not zero, allowing requested_num_queues=0 to reach\nvzalloc(array_size(0, sizeof(struct xenvif_queue))), which triggers\nWARN_ON_ONCE(!size) in __vmalloc_node_range().\n\nOn systems with panic_on_warn=1, this allows a guest-to-host denial\nof service.\n\nThe Xen network interface specification requires\nthe queue count to be \"greater than zero\".\n\nAdd a zero check to match the validation already present\nin xen-blkback, which has included this\nguard since its multi-queue support was added.",
  "id": "GHSA-jc43-3m97-6p35",
  "modified": "2026-05-27T15:33:15Z",
  "published": "2026-05-27T15:33:15Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-45890"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/2993e0f904c45f8af12917344bb1cac7ccd05a60"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/654780dee9eae419e1648ea58462c4efe54518fa"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/6d1dc8014334c7fb25719999bca84d811e60a559"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/787bfa423228c4b02ba3368128f625d579085353"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/88b0fced1bbbfdb356a007592604008ffc93a6a1"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/ce66d6786de45b7ed9cbbdc0988054bf09e58f54"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/d99f69ddc70fd9f4b8148add62209a1a8eb5c615"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/ec4859ac5c933e3315543a61adc1ca4358006a41"
    }
  ],
  "schema_version": "1.4.0",
  "severity": []
}


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