{
    "data_version": "4.0",
    "data_type": "CVE",
    "data_format": "MITRE",
    "CVE_data_meta": {
        "ID": "CVE-2024-35981",
        "ASSIGNER": "cve@kernel.org",
        "STATE": "PUBLIC"
    },
    "description": {
        "description_data": [
            {
                "lang": "eng",
                "value": "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."
            }
        ]
    },
    "problemtype": {
        "problemtype_data": [
            {
                "description": [
                    {
                        "lang": "eng",
                        "value": "n/a"
                    }
                ]
            }
        ]
    },
    "affects": {
        "vendor": {
            "vendor_data": [
                {
                    "vendor_name": "Linux",
                    "product": {
                        "product_data": [
                            {
                                "product_name": "Linux",
                                "version": {
                                    "version_data": [
                                        {
                                            "version_affected": "<",
                                            "version_name": "c7114b1249fa",
                                            "version_value": "539a2b995a4e"
                                        },
                                        {
                                            "version_value": "not down converted",
                                            "x_cve_json_5_version_data": {
                                                "versions": [
                                                    {
                                                        "version": "5.18",
                                                        "status": "affected"
                                                    },
                                                    {
                                                        "version": "0",
                                                        "lessThan": "5.18",
                                                        "status": "unaffected",
                                                        "versionType": "custom"
                                                    },
                                                    {
                                                        "version": "6.1.90",
                                                        "lessThanOrEqual": "6.1.*",
                                                        "status": "unaffected",
                                                        "versionType": "custom"
                                                    },
                                                    {
                                                        "version": "6.6.29",
                                                        "lessThanOrEqual": "6.6.*",
                                                        "status": "unaffected",
                                                        "versionType": "custom"
                                                    },
                                                    {
                                                        "version": "6.8.7",
                                                        "lessThanOrEqual": "6.8.*",
                                                        "status": "unaffected",
                                                        "versionType": "custom"
                                                    },
                                                    {
                                                        "version": "6.9",
                                                        "lessThanOrEqual": "*",
                                                        "status": "unaffected",
                                                        "versionType": "original_commit_for_fix"
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                                                ],
                                                "defaultStatus": "affected"
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    "references": {
        "reference_data": [
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                "url": "https://git.kernel.org/stable/c/539a2b995a4ed93125cb0efae0f793b00ab2158b",
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                "name": "https://git.kernel.org/stable/c/43a71c1b4b3a6d4db857b1435d271540279fc7de"
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                "url": "https://git.kernel.org/stable/c/28e9a64638cd16bc1ecac9ff74ffeacb9fb652de",
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                "name": "https://git.kernel.org/stable/c/28e9a64638cd16bc1ecac9ff74ffeacb9fb652de"
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