{
    "data_version": "4.0",
    "data_type": "CVE",
    "data_format": "MITRE",
    "CVE_data_meta": {
        "ID": "CVE-2024-58098",
        "ASSIGNER": "cve@kernel.org",
        "STATE": "PUBLIC"
    },
    "description": {
        "description_data": [
            {
                "lang": "eng",
                "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nbpf: track changes_pkt_data property for global functions\n\nWhen processing calls to certain helpers, verifier invalidates all\npacket pointers in a current state. For example, consider the\nfollowing program:\n\n    __attribute__((__noinline__))\n    long skb_pull_data(struct __sk_buff *sk, __u32 len)\n    {\n        return bpf_skb_pull_data(sk, len);\n    }\n\n    SEC(\"tc\")\n    int test_invalidate_checks(struct __sk_buff *sk)\n    {\n        int *p = (void *)(long)sk->data;\n        if ((void *)(p + 1) > (void *)(long)sk->data_end) return TCX_DROP;\n        skb_pull_data(sk, 0);\n        *p = 42;\n        return TCX_PASS;\n    }\n\nAfter a call to bpf_skb_pull_data() the pointer 'p' can't be used\nsafely. See function filter.c:bpf_helper_changes_pkt_data() for a list\nof such helpers.\n\nAt the moment verifier invalidates packet pointers when processing\nhelper function calls, and does not traverse global sub-programs when\nprocessing calls to global sub-programs. This means that calls to\nhelpers done from global sub-programs do not invalidate pointers in\nthe caller state. E.g. the program above is unsafe, but is not\nrejected by verifier.\n\nThis commit fixes the omission by computing field\nbpf_subprog_info->changes_pkt_data for each sub-program before main\nverification pass.\nchanges_pkt_data should be set if:\n- subprogram calls helper for which bpf_helper_changes_pkt_data\n  returns true;\n- subprogram calls a global function,\n  for which bpf_subprog_info->changes_pkt_data should be set.\n\nThe verifier.c:check_cfg() pass is modified to compute this\ninformation. The commit relies on depth first instruction traversal\ndone by check_cfg() and absence of recursive function calls:\n- check_cfg() would eventually visit every call to subprogram S in a\n  state when S is fully explored;\n- when S is fully explored:\n  - every direct helper call within S is explored\n    (and thus changes_pkt_data is set if needed);\n  - every call to subprogram S1 called by S was visited with S1 fully\n    explored (and thus S inherits changes_pkt_data from S1).\n\nThe downside of such approach is that dead code elimination is not\ntaken into account: if a helper call inside global function is dead\nbecause of current configuration, verifier would conservatively assume\nthat the call occurs for the purpose of the changes_pkt_data\ncomputation."
            }
        ]
    },
    "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": "51c39bb1d5d105a02e29aa7960f0a395086e6342",
                                            "version_value": "79751e9227a5910c0e5a2c7186877d91821d957d"
                                        },
                                        {
                                            "version_value": "not down converted",
                                            "x_cve_json_5_version_data": {
                                                "versions": [
                                                    {
                                                        "version": "5.6",
                                                        "status": "affected"
                                                    },
                                                    {
                                                        "version": "0",
                                                        "lessThan": "5.6",
                                                        "status": "unaffected",
                                                        "versionType": "semver"
                                                    },
                                                    {
                                                        "version": "6.6.90",
                                                        "lessThanOrEqual": "6.6.*",
                                                        "status": "unaffected",
                                                        "versionType": "semver"
                                                    },
                                                    {
                                                        "version": "6.12.25",
                                                        "lessThanOrEqual": "6.12.*",
                                                        "status": "unaffected",
                                                        "versionType": "semver"
                                                    },
                                                    {
                                                        "version": "6.13",
                                                        "lessThanOrEqual": "*",
                                                        "status": "unaffected",
                                                        "versionType": "original_commit_for_fix"
                                                    }
                                                ],
                                                "defaultStatus": "affected"
                                            }
                                        }
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    "references": {
        "reference_data": [
            {
                "url": "https://git.kernel.org/stable/c/79751e9227a5910c0e5a2c7186877d91821d957d",
                "refsource": "MISC",
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                "url": "https://git.kernel.org/stable/c/1d572c60488b52882b719ed273767ee3b280413d",
                "refsource": "MISC",
                "name": "https://git.kernel.org/stable/c/1d572c60488b52882b719ed273767ee3b280413d"
            },
            {
                "url": "https://git.kernel.org/stable/c/51081a3f25c742da5a659d7fc6fd77ebfdd555be",
                "refsource": "MISC",
                "name": "https://git.kernel.org/stable/c/51081a3f25c742da5a659d7fc6fd77ebfdd555be"
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