{
    "dataType": "CVE_RECORD",
    "dataVersion": "5.1",
    "cveMetadata": {
        "cveId": "CVE-2024-47702",
        "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "state": "PUBLISHED",
        "assignerShortName": "Linux",
        "dateReserved": "2024-09-30T16:00:12.945Z",
        "datePublished": "2024-10-21T11:53:37.958Z",
        "dateUpdated": "2024-10-21T13:14:13.443Z"
    },
    "containers": {
        "cna": {
            "providerMetadata": {
                "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
                "shortName": "Linux",
                "dateUpdated": "2024-10-21T11:53:37.958Z"
            },
            "descriptions": [
                {
                    "lang": "en",
                    "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nbpf: Fail verification for sign-extension of packet data/data_end/data_meta\n\nsyzbot reported a kernel crash due to\n  commit 1f1e864b6555 (\"bpf: Handle sign-extenstin ctx member accesses\").\nThe reason is due to sign-extension of 32-bit load for\npacket data/data_end/data_meta uapi field.\n\nThe original code looks like:\n        r2 = *(s32 *)(r1 + 76) /* load __sk_buff->data */\n        r3 = *(u32 *)(r1 + 80) /* load __sk_buff->data_end */\n        r0 = r2\n        r0 += 8\n        if r3 > r0 goto +1\n        ...\nNote that __sk_buff->data load has 32-bit sign extension.\n\nAfter verification and convert_ctx_accesses(), the final asm code looks like:\n        r2 = *(u64 *)(r1 +208)\n        r2 = (s32)r2\n        r3 = *(u64 *)(r1 +80)\n        r0 = r2\n        r0 += 8\n        if r3 > r0 goto pc+1\n        ...\nNote that 'r2 = (s32)r2' may make the kernel __sk_buff->data address invalid\nwhich may cause runtime failure.\n\nCurrently, in C code, typically we have\n        void *data = (void *)(long)skb->data;\n        void *data_end = (void *)(long)skb->data_end;\n        ...\nand it will generate\n        r2 = *(u64 *)(r1 +208)\n        r3 = *(u64 *)(r1 +80)\n        r0 = r2\n        r0 += 8\n        if r3 > r0 goto pc+1\n\nIf we allow sign-extension,\n        void *data = (void *)(long)(int)skb->data;\n        void *data_end = (void *)(long)skb->data_end;\n        ...\nthe generated code looks like\n        r2 = *(u64 *)(r1 +208)\n        r2 <<= 32\n        r2 s>>= 32\n        r3 = *(u64 *)(r1 +80)\n        r0 = r2\n        r0 += 8\n        if r3 > r0 goto pc+1\nand this will cause verification failure since \"r2 <<= 32\" is not allowed\nas \"r2\" is a packet pointer.\n\nTo fix this issue for case\n  r2 = *(s32 *)(r1 + 76) /* load __sk_buff->data */\nthis patch added additional checking in is_valid_access() callback\nfunction for packet data/data_end/data_meta access. If those accesses\nare with sign-extenstion, the verification will fail.\n\n  [1] https://lore.kernel.org/bpf/000000000000c90eee061d236d37@google.com/"
                }
            ],
            "affected": [
                {
                    "product": "Linux",
                    "vendor": "Linux",
                    "defaultStatus": "unaffected",
                    "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
                    "programFiles": [
                        "include/linux/bpf.h",
                        "kernel/bpf/verifier.c",
                        "net/core/filter.c"
                    ],
                    "versions": [
                        {
                            "version": "1f1e864b6555",
                            "lessThan": "f1620c93a1ec",
                            "status": "affected",
                            "versionType": "git"
                        },
                        {
                            "version": "1f1e864b6555",
                            "lessThan": "f09757fe97a2",
                            "status": "affected",
                            "versionType": "git"
                        },
                        {
                            "version": "1f1e864b6555",
                            "lessThan": "92de36080c93",
                            "status": "affected",
                            "versionType": "git"
                        }
                    ]
                },
                {
                    "product": "Linux",
                    "vendor": "Linux",
                    "defaultStatus": "affected",
                    "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
                    "programFiles": [
                        "include/linux/bpf.h",
                        "kernel/bpf/verifier.c",
                        "net/core/filter.c"
                    ],
                    "versions": [
                        {
                            "version": "6.6",
                            "status": "affected"
                        },
                        {
                            "version": "0",
                            "lessThan": "6.6",
                            "status": "unaffected",
                            "versionType": "custom"
                        },
                        {
                            "version": "6.10.13",
                            "lessThanOrEqual": "6.10.*",
                            "status": "unaffected",
                            "versionType": "custom"
                        },
                        {
                            "version": "6.11.2",
                            "lessThanOrEqual": "6.11.*",
                            "status": "unaffected",
                            "versionType": "custom"
                        },
                        {
                            "version": "6.12-rc1",
                            "lessThanOrEqual": "*",
                            "status": "unaffected",
                            "versionType": "original_commit_for_fix"
                        }
                    ]
                }
            ],
            "references": [
                {
                    "url": "https://git.kernel.org/stable/c/f1620c93a1ec950d87ef327a565d3907736d3340"
                },
                {
                    "url": "https://git.kernel.org/stable/c/f09757fe97a225ae505886eac572e4cbfba96537"
                },
                {
                    "url": "https://git.kernel.org/stable/c/92de36080c93296ef9005690705cba260b9bd68a"
                }
            ],
            "title": "bpf: Fail verification for sign-extension of packet data/data_end/data_meta",
            "x_generator": {
                "engine": "bippy-c9c4e1df01b2"
            }
        },
        "adp": [
            {
                "metrics": [
                    {
                        "other": {
                            "type": "ssvc",
                            "content": {
                                "id": "CVE-2024-47702",
                                "role": "CISA Coordinator",
                                "options": [
                                    {
                                        "Exploitation": "none"
                                    },
                                    {
                                        "Automatable": "no"
                                    },
                                    {
                                        "Technical Impact": "partial"
                                    }
                                ],
                                "version": "2.0.3",
                                "timestamp": "2024-10-21T13:04:24.861686Z"
                            }
                        }
                    }
                ],
                "title": "CISA ADP Vulnrichment",
                "providerMetadata": {
                    "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
                    "shortName": "CISA-ADP",
                    "dateUpdated": "2024-10-21T13:14:13.443Z"
                }
            }
        ]
    }
}