{
    "data_version": "4.0",
    "data_type": "CVE",
    "data_format": "MITRE",
    "CVE_data_meta": {
        "ID": "CVE-2024-35944",
        "ASSIGNER": "cve@kernel.org",
        "STATE": "PUBLIC"
    },
    "description": {
        "description_data": [
            {
                "lang": "eng",
                "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nVMCI: Fix memcpy() run-time warning in dg_dispatch_as_host()\n\nSyzkaller hit 'WARNING in dg_dispatch_as_host' bug.\n\nmemcpy: detected field-spanning write (size 56) of single field \"&dg_info->msg\"\nat drivers/misc/vmw_vmci/vmci_datagram.c:237 (size 24)\n\nWARNING: CPU: 0 PID: 1555 at drivers/misc/vmw_vmci/vmci_datagram.c:237\ndg_dispatch_as_host+0x88e/0xa60 drivers/misc/vmw_vmci/vmci_datagram.c:237\n\nSome code commentry, based on my understanding:\n\n544 #define VMCI_DG_SIZE(_dg) (VMCI_DG_HEADERSIZE + (size_t)(_dg)->payload_size)\n/// This is 24 + payload_size\n\nmemcpy(&dg_info->msg, dg, dg_size);\n\tDestination = dg_info->msg ---> this is a 24 byte\n\t\t\t\t\tstructure(struct vmci_datagram)\n\tSource = dg --> this is a 24 byte structure (struct vmci_datagram)\n\tSize = dg_size = 24 + payload_size\n\n{payload_size = 56-24 =32} -- Syzkaller managed to set payload_size to 32.\n\n 35 struct delayed_datagram_info {\n 36         struct datagram_entry *entry;\n 37         struct work_struct work;\n 38         bool in_dg_host_queue;\n 39         /* msg and msg_payload must be together. */\n 40         struct vmci_datagram msg;\n 41         u8 msg_payload[];\n 42 };\n\nSo those extra bytes of payload are copied into msg_payload[], a run time\nwarning is seen while fuzzing with Syzkaller.\n\nOne possible way to fix the warning is to split the memcpy() into\ntwo parts -- one -- direct assignment of msg and second taking care of payload.\n\nGustavo quoted:\n\"Under FORTIFY_SOURCE we should not copy data across multiple members\nin a structure.\""
            }
        ]
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    "problemtype": {
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            {
                "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": "1da177e4c3f4",
                                            "version_value": "e87bb99d2df6"
                                        },
                                        {
                                            "version_value": "not down converted",
                                            "x_cve_json_5_version_data": {
                                                "versions": [
                                                    {
                                                        "version": "4.19.312",
                                                        "lessThanOrEqual": "4.19.*",
                                                        "status": "unaffected",
                                                        "versionType": "semver"
                                                    },
                                                    {
                                                        "version": "5.4.274",
                                                        "lessThanOrEqual": "5.4.*",
                                                        "status": "unaffected",
                                                        "versionType": "semver"
                                                    },
                                                    {
                                                        "version": "5.10.215",
                                                        "lessThanOrEqual": "5.10.*",
                                                        "status": "unaffected",
                                                        "versionType": "semver"
                                                    },
                                                    {
                                                        "version": "5.15.155",
                                                        "lessThanOrEqual": "5.15.*",
                                                        "status": "unaffected",
                                                        "versionType": "semver"
                                                    },
                                                    {
                                                        "version": "6.1.86",
                                                        "lessThanOrEqual": "6.1.*",
                                                        "status": "unaffected",
                                                        "versionType": "semver"
                                                    },
                                                    {
                                                        "version": "6.6.27",
                                                        "lessThanOrEqual": "6.6.*",
                                                        "status": "unaffected",
                                                        "versionType": "semver"
                                                    },
                                                    {
                                                        "version": "6.8.6",
                                                        "lessThanOrEqual": "6.8.*",
                                                        "status": "unaffected",
                                                        "versionType": "semver"
                                                    },
                                                    {
                                                        "version": "6.9",
                                                        "lessThanOrEqual": "*",
                                                        "status": "unaffected",
                                                        "versionType": "original_commit_for_fix"
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    "references": {
        "reference_data": [
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                "url": "https://git.kernel.org/stable/c/e87bb99d2df6512d8ee37a5d63d2ca9a39a8c051",
                "refsource": "MISC",
                "name": "https://git.kernel.org/stable/c/e87bb99d2df6512d8ee37a5d63d2ca9a39a8c051"
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                "url": "https://git.kernel.org/stable/c/f15eca95138b3d4ec17b63c3c1937b0aa0d3624b",
                "refsource": "MISC",
                "name": "https://git.kernel.org/stable/c/f15eca95138b3d4ec17b63c3c1937b0aa0d3624b"
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                "name": "https://git.kernel.org/stable/c/ad78c5047dc4076d0b3c4fad4f42ffe9c86e8100"
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                "name": "https://git.kernel.org/stable/c/feacd430b42bbfa9ab3ed9e4f38b86c43e348c75"
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                "refsource": "MISC",
                "name": "https://git.kernel.org/stable/c/dae70a57565686f16089737adb8ac64471570f73"
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                "refsource": "MISC",
                "name": "https://git.kernel.org/stable/c/491a1eb07c2bd8841d63cb5263455e185be5866f"
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                "url": "https://git.kernel.org/stable/c/19b070fefd0d024af3daa7329cbc0d00de5302ec",
                "refsource": "MISC",
                "name": "https://git.kernel.org/stable/c/19b070fefd0d024af3daa7329cbc0d00de5302ec"
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