{"id":"CVE-2024-58098","revision":"889401eb512e43c4ba7d7df4609dfe2d","records":[{"revision":"889401eb512e43c4ba7d7df4609dfe2d","observedAt":"2026-10-23T15:48:27.903+00:00","statement":{"source":"cve-program","id":"CVE-2024-58098","aliases":[],"title":"bpf: track changes_pkt_data property for global functions","description":"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.","state":0,"publishedAt":"2025-05-05T14:53:32.417+00:00","modifiedAt":"2026-10-15T21:51:50.99+00:00","affected":[{"ecosystem":"Vendor product","name":"Linux","ranges":[],"versions":[],"rawVersionEvidence":"{\n                    \"product\": \"Linux\",\n                    \"vendor\": \"Linux\",\n                    \"defaultStatus\": \"unaffected\",\n                    \"repo\": \"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\",\n                    \"programFiles\": [\n                        \"include/linux/bpf_verifier.h\",\n                        \"kernel/bpf/verifier.c\"\n                    ],\n                    \"versions\": [\n                        {\n                            \"version\": \"51c39bb1d5d105a02e29aa7960f0a395086e6342\",\n                            \"lessThan\": \"79751e9227a5910c0e5a2c7186877d91821d957d\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"51c39bb1d5d105a02e29aa7960f0a395086e6342\",\n                            \"lessThan\": \"1d572c60488b52882b719ed273767ee3b280413d\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"51c39bb1d5d105a02e29aa7960f0a395086e6342\",\n                            \"lessThan\": \"51081a3f25c742da5a659d7fc6fd77ebfdd555be\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        }\n                    ]\n                }"},{"ecosystem":"Vendor product","name":"Linux","ranges":[],"versions":[],"rawVersionEvidence":"{\n                    \"product\": \"Linux\",\n                    \"vendor\": \"Linux\",\n                    \"defaultStatus\": \"affected\",\n                    \"repo\": \"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\",\n                    \"programFiles\": [\n                        \"include/linux/bpf_verifier.h\",\n                        \"kernel/bpf/verifier.c\"\n                    ],\n                    \"versions\": [\n                        {\n                            \"version\": \"5.6\",\n                            \"status\": \"affected\"\n                        },\n                        {\n                            \"version\": \"0\",\n                            \"lessThan\": \"5.6\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"6.6.90\",\n                            \"lessThanOrEqual\": \"6.6.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"6.12.25\",\n                            \"lessThanOrEqual\": \"6.12.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"6.13\",\n                            \"lessThanOrEqual\": \"*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"original_commit_for_fix\"\n                        }\n                    ]\n                }"}],"metrics":[{"system":"CVSS 3.1","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","score":7.8,"severity":"HIGH"}],"references":["https://git.kernel.org/stable/c/79751e9227a5910c0e5a2c7186877d91821d957d","https://git.kernel.org/stable/c/1d572c60488b52882b719ed273767ee3b280413d","https://git.kernel.org/stable/c/51081a3f25c742da5a659d7fc6fd77ebfdd555be"],"sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2024-58098","license":"CVE Program Terms of Use","key":"cve-program:CVE-2024-58098","identifiers":["CVE-2024-58098"]},"retained":false,"historicalAffected":[]}],"coverage":[]}