{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2024-58098", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2025-03-06T15:52:09.189Z", "datePublished": "2025-05-05T14:53:32.417Z", "dateUpdated": "2026-08-05T11:47:43.812Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-05T11:47:43.812Z" }, "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." } ], "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." } ] } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "include/linux/bpf_verifier.h", "kernel/bpf/verifier.c" ], "versions": [ { "version": "51c39bb1d5d105a02e29aa7960f0a395086e6342", "lessThan": "79751e9227a5910c0e5a2c7186877d91821d957d", "status": "affected", "versionType": "git" }, { "version": "51c39bb1d5d105a02e29aa7960f0a395086e6342", "lessThan": "1d572c60488b52882b719ed273767ee3b280413d", "status": "affected", "versionType": "git" }, { "version": "51c39bb1d5d105a02e29aa7960f0a395086e6342", "lessThan": "51081a3f25c742da5a659d7fc6fd77ebfdd555be", "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_verifier.h", "kernel/bpf/verifier.c" ], "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" } ] } ], "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" } ] } ] } ], "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" } ], "title": "bpf: track changes_pkt_data property for global functions", "x_generator": { "engine": "bippy-1.2.0" } } } }