{
  "schema_version": "1.6.1",
  "id": "RPI-CVE-2024-35981",
  "modified": "2026-10-07T17:22:01Z",
  "upstream": [
    "CVE-2024-35981"
  ],
  "published": "2024-05-20T09:42:41Z",
  "summary": "virtio_net: Do not send RSS key if it is not supported",
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nvirtio_net: Do not send RSS key if it is not supported\n\nThere is a bug when setting the RSS options in virtio_net that can break\nthe whole machine, getting the kernel into an infinite loop.\n\nRunning the following command in any QEMU virtual machine with virtionet\nwill reproduce this problem:\n\n    # ethtool -X eth0  hfunc toeplitz\n\nThis is how the problem happens:\n\n1) ethtool_set_rxfh() calls virtnet_set_rxfh()\n\n2) virtnet_set_rxfh() calls virtnet_commit_rss_command()\n\n3) virtnet_commit_rss_command() populates 4 entries for the rss\nscatter-gather\n\n4) Since the command above does not have a key, then the last\nscatter-gatter entry will be zeroed, since rss_key_size == 0.\nsg_buf_size = vi->rss_key_size;\n\n5) This buffer is passed to qemu, but qemu is not happy with a buffer\nwith zero length, and do the following in virtqueue_map_desc() (QEMU\nfunction):\n\n  if (!sz) {\n      virtio_error(vdev, \"virtio: zero sized buffers are not allowed\");\n\n6) virtio_error() (also QEMU function) set the device as broken\n\n    vdev->broken = true;\n\n7) Qemu bails out, and do not repond this crazy kernel.\n\n8) The kernel is waiting for the response to come back (function\nvirtnet_send_command())\n\n9) The kernel is waiting doing the following :\n\n      while (!virtqueue_get_buf(vi->cvq, &tmp) &&\n\t     !virtqueue_is_broken(vi->cvq))\n\t      cpu_relax();\n\n10) None of the following functions above is true, thus, the kernel\nloops here forever. Keeping in mind that virtqueue_is_broken() does\nnot look at the qemu `vdev->broken`, so, it never realizes that the\nvitio is broken at QEMU side.\n\nFix it by not sending RSS commands if the feature is not available in\nthe device.",
  "affected": [
    {
      "package": {
        "ecosystem": "Raspberry Pi OS:12",
        "name": "linux"
      },
      "versions": [
        "1:6.1.47-1+rpt4"
      ],
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "linux-image-6.1.0-rpi3-rpi-2712",
            "binary_version": "1:6.1.47-1+rpt4"
          },
          {
            "binary_name": "linux-image-6.1.0-rpi3-rpi-v6",
            "binary_version": "1:6.1.47-1+rpt4"
          },
          {
            "binary_name": "linux-image-6.1.0-rpi3-rpi-v7",
            "binary_version": "1:6.1.47-1+rpt4"
          },
          {
            "binary_name": "linux-image-6.1.0-rpi3-rpi-v7l",
            "binary_version": "1:6.1.47-1+rpt4"
          },
          {
            "binary_name": "linux-image-6.1.0-rpi3-rpi-v8",
            "binary_version": "1:6.1.47-1+rpt4"
          }
        ]
      },
      "database_specific": {
        "per_version": {
          "1:6.1.47-1+rpt4": {
            "linux_commit": "655fc658a15ae7a6f37103754adb39ba52a9a14e",
            "upstream_version": "6.1.47",
            "assessment": "commit ancestry (strak rule)",
            "upstream_fixed": "6.1.90",
            "compiled_filter": false
          }
        }
      }
    }
  ],
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://www.cve.org/CVERecord?id=CVE-2024-35981"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/539a2b995a4ed93125cb0efae0f793b00ab2158b"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/43a71c1b4b3a6d4db857b1435d271540279fc7de"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/28e9a64638cd16bc1ecac9ff74ffeacb9fb652de"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/059a49aa2e25c58f90b50151f109dd3c4cdb3a47"
    }
  ],
  "database_specific": {
    "source": "https://git.kernel.org/pub/scm/linux/security/vulns.git",
    "upstream_modified": "2026-05-12T04:54:46Z"
  }
}