{"id":"CVE-2024-58098","state":"PUBLISHED","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.","publishedAt":"2025-05-05T14:53:32.417Z","updatedAt":"2026-10-15T21:51:50.990Z","severity":{"score":7.8,"label":"High","version":"3.1","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","source":"Linux"},"assigner":"Linux","products":["Linux Linux"],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"51c39bb1d5d105a02e29aa7960f0a395086e6342","status":"affected","lessThan":"79751e9227a5910c0e5a2c7186877d91821d957d","versionType":"git"},{"version":"51c39bb1d5d105a02e29aa7960f0a395086e6342","status":"affected","lessThan":"1d572c60488b52882b719ed273767ee3b280413d","versionType":"git"},{"version":"51c39bb1d5d105a02e29aa7960f0a395086e6342","status":"affected","lessThan":"51081a3f25c742da5a659d7fc6fd77ebfdd555be","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["include/linux/bpf_verifier.h","kernel/bpf/verifier.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"5.6","status":"affected"},{"version":"0","status":"unaffected","lessThan":"5.6","versionType":"semver"},{"version":"6.6.90","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.25","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.13","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["include/linux/bpf_verifier.h","kernel/bpf/verifier.c"]}],"references":["https://git.kernel.org/stable/c/79751e9227a5910c0e5a2c7186877d91821d957d","https://git.kernel.org/stable/c/1d572c60488b52882b719ed273767ee3b280413d","https://git.kernel.org/stable/c/51081a3f25c742da5a659d7fc6fd77ebfdd555be"],"weaknesses":[],"ingestedAt":"2026-10-29T20:08:12.933Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2024/58xxx/CVE-2024-58098.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2024-58098","state":"PUBLISHED","datePublished":"2025-05-05T14:53:32.417Z","dateUpdated":"2026-10-15T21:51:50.990Z","assignerShortName":"Linux","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateReserved":"2025-03-06T15:52:09.189Z"},"containers":{"cna":{"title":"bpf: track changes_pkt_data property for global functions","descriptions":[{"lang":"en","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."}],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"51c39bb1d5d105a02e29aa7960f0a395086e6342","status":"affected","lessThan":"79751e9227a5910c0e5a2c7186877d91821d957d","versionType":"git"},{"version":"51c39bb1d5d105a02e29aa7960f0a395086e6342","status":"affected","lessThan":"1d572c60488b52882b719ed273767ee3b280413d","versionType":"git"},{"version":"51c39bb1d5d105a02e29aa7960f0a395086e6342","status":"affected","lessThan":"51081a3f25c742da5a659d7fc6fd77ebfdd555be","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["include/linux/bpf_verifier.h","kernel/bpf/verifier.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"5.6","status":"affected"},{"version":"0","status":"unaffected","lessThan":"5.6","versionType":"semver"},{"version":"6.6.90","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.25","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.13","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["include/linux/bpf_verifier.h","kernel/bpf/verifier.c"]}],"references":[{"url":"https://git.kernel.org/stable/c/79751e9227a5910c0e5a2c7186877d91821d957d"},{"url":"https://git.kernel.org/stable/c/1d572c60488b52882b719ed273767ee3b280413d"},{"url":"https://git.kernel.org/stable/c/51081a3f25c742da5a659d7fc6fd77ebfdd555be"}],"metrics":[{"cvssV3_1":{"version":"3.1","vectorString":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","baseScore":7.8,"baseSeverity":"HIGH"},"scenarios":[{"lang":"en","value":"AV:L - Exploitation requires loading a crafted eBPF program via the local `bpf(BPF_PROG_LOAD)` syscall and attaching it (tc/XDP/sockmap), all of which are local operations. No remote peer can reach the verifier.\nAC:L - The verifier omission is deterministic — the attacker writes the global subprogram, the bounds check, and the stale-pointer dereference, then triggers it with a packet on an interface they control. No race and no uncontrolled precondition.\nPR:L - The affected program types need CAP_BPF/CAP_NET_ADMIN, but `bpf_token_capable()` evaluates these against `token->userns` through `bpf_ns_capable()`, so BPF-token delegation grants them to an unprivileged process in a user namespace; the same capabilities are commonly held by non-root container-networking daemons.\nUI:N - The attacker loads, attaches, and triggers the program entirely on their own; no victim action of any kind is needed.\nS:U - The corruption is of kernel heap memory within the same kernel security authority — a conventional local privilege-escalation path, with no VM, IOMMU, or sandbox boundary crossed.\nC:H - The stale `PTR_TO_PACKET` dereferences a `kfree()`d `skb->head` (or reads past a shrunk buffer), giving attacker-chosen-offset reads of freed/adjacent kernel heap memory that can be exfiltrated to userspace via a BPF map.\nI:H - The same dangling pointer is writable with attacker-controlled offset and data (`*p = 42` in the PoC), yielding a use-after-free/out-of-bounds kernel heap write primitive that can be groomed into control-flow hijack or privilege escalation.\nA:H - Writing through a freed or out-of-bounds skb data pointer corrupts the slab allocator's state and neighbouring objects, reliably producing an oops or panic even when full exploitation is not achieved."}]}],"providerMetadata":{"shortName":"Linux","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateUpdated":"2026-08-05T11:47:43.812Z"},"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.6","versionEndExcluding":"6.6.90"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.6","versionEndExcluding":"6.12.25"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.6","versionEndExcluding":"6.13"}]}]}],"x_generator":{"engine":"bippy-1.2.0"}},"adp":[{"title":"CISA ADP Vulnrichment","metrics":[{"other":{"type":"ssvc","content":{"id":"CVE-2024-58098","role":"CISA Coordinator","options":[{"Exploitation":"none"},{"Automatable":"no"},{"Technical Impact":"total"}],"version":"2.0.3","timestamp":"2026-10-15T21:42:18.671562Z"}}}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-10-15T21:51:50.990Z"}}]}}}