FKIE_CVE-2026-45890

Vulnerability from fkie_nvd - Published: 2026-05-27 14:17 - Updated: 2026-05-27 14:48
Severity
Summary
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.
References
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/2993e0f904c45f8af12917344bb1cac7ccd05a60
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/654780dee9eae419e1648ea58462c4efe54518fa
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/6d1dc8014334c7fb25719999bca84d811e60a559
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/787bfa423228c4b02ba3368128f625d579085353
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/88b0fced1bbbfdb356a007592604008ffc93a6a1
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/ce66d6786de45b7ed9cbbdc0988054bf09e58f54
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/d99f69ddc70fd9f4b8148add62209a1a8eb5c615
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/ec4859ac5c933e3315543a61adc1ca4358006a41
Impacted products
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{
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "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": "CVE-2026-45890",
  "lastModified": "2026-05-27T14:48:31.480",
  "metrics": {},
  "published": "2026-05-27T14:17:03.040",
  "references": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/2993e0f904c45f8af12917344bb1cac7ccd05a60"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/654780dee9eae419e1648ea58462c4efe54518fa"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/6d1dc8014334c7fb25719999bca84d811e60a559"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/787bfa423228c4b02ba3368128f625d579085353"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/88b0fced1bbbfdb356a007592604008ffc93a6a1"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/ce66d6786de45b7ed9cbbdc0988054bf09e58f54"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/d99f69ddc70fd9f4b8148add62209a1a8eb5c615"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/ec4859ac5c933e3315543a61adc1ca4358006a41"
    }
  ],
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "vulnStatus": "Awaiting Analysis"
}


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