{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2025-68208", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2025-12-16T13:41:40.255Z", "datePublished": "2025-12-16T13:48:35.298Z", "dateUpdated": "2026-08-05T12:10:13.855Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-05T12:10:13.855Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nbpf: account for current allocated stack depth in widen_imprecise_scalars()\n\nThe usage pattern for widen_imprecise_scalars() looks as follows:\n\n prev_st = find_prev_entry(env, ...);\n queued_st = push_stack(...);\n widen_imprecise_scalars(env, prev_st, queued_st);\n\nWhere prev_st is an ancestor of the queued_st in the explored states\ntree. This ancestor is not guaranteed to have same allocated stack\ndepth as queued_st. E.g. in the following case:\n\n def main():\n for i in 1..2:\n foo(i) // same callsite, differnt param\n\n def foo(i):\n if i == 1:\n use 128 bytes of stack\n iterator based loop\n\nHere, for a second 'foo' call prev_st->allocated_stack is 128,\nwhile queued_st->allocated_stack is much smaller.\nwiden_imprecise_scalars() needs to take this into account and avoid\naccessing bpf_verifier_state->frame[*]->stack out of bounds." } ], "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 - The attacker reaches the vulnerable verifier through a local BPF_PROG_LOAD syscall; no network or physical path invokes it.\nAC:L - A crafted BPF program deterministically creates the mismatched verifier stack depths, as confirmed by the upstream KASAN regression test. Any heap grooming needed for exploitation is attacker-controlled, with no race or victim-dependent condition.\nPR:L - The trigger requires permission to load privileged BPF bytecode; ordinary unprivileged BPF is insufficient. However, CAP_BPF can be delegated through a BPF token to a user namespace, making this reachable without host-administrator privileges in a reasonable container deployment.\nUI:N - Submitting the crafted BPF program directly triggers verification without any action by another user.\nS:U - The vulnerability compromises the kernel containing the BPF verifier and does not inherently cross a VM, IOMMU, or separate security authority boundary.\nC:H - The loop can read numerous bpf_stack_state entries beyond the shorter heap allocation, substantially exceeding a small bounded disclosure. Adjacent verifier-state corruption can also enable further kernel-memory disclosure primitives.\nI:H - If attacker-groomed out-of-bounds bytes resemble an imprecise spilled scalar, maybe_widen_reg() passes the invalid pointer to __mark_reg_unknown(), overwriting an entire bpf_reg_state outside the allocation. This kernel-heap corruption can support data or control-flow manipulation.\nA:H - The upstream reproducer triggers a KASAN out-of-bounds failure, and deeper mismatches can fault or corrupt adjacent kernel objects. Repeated BPF_PROG_LOAD requests can therefore crash or panic the kernel." } ] } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "kernel/bpf/verifier.c" ], "versions": [ { "version": "ab470fefce2837e66b771c60858118d50bb5bb10", "lessThan": "64b12dca2b0abcb5fc0542887d18b926ea5cf711", "status": "affected", "versionType": "git" }, { "version": "2793a8b015f7f1caadb9bce9c63dc659f7522676", "lessThan": "9944c7938cd5b3f37b0afec0481c7c015e4f1c58", "status": "affected", "versionType": "git" }, { "version": "2793a8b015f7f1caadb9bce9c63dc659f7522676", "lessThan": "57e04e2ff56e32f923154f0f7bc476fcb596ffe7", "status": "affected", "versionType": "git" }, { "version": "2793a8b015f7f1caadb9bce9c63dc659f7522676", "lessThan": "b0c8e6d3d866b6a7f73877f71968dbffd27b7785", "status": "affected", "versionType": "git" }, { "version": "6.6.15", "lessThan": "6.6.117", "status": "affected", "versionType": "semver" } ] }, { "product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "kernel/bpf/verifier.c" ], "versions": [ { "version": "6.7", "status": "affected" }, { "version": "0", "lessThan": "6.7", "status": "unaffected", "versionType": "semver" }, { "version": "6.6.117", "lessThanOrEqual": "6.6.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.12.59", "lessThanOrEqual": "6.12.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.17.9", "lessThanOrEqual": "6.17.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.18", "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": "6.6.15", "versionEndExcluding": "6.6.117" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.7", "versionEndExcluding": "6.12.59" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.7", "versionEndExcluding": "6.17.9" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.7", "versionEndExcluding": "6.18" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/64b12dca2b0abcb5fc0542887d18b926ea5cf711" }, { "url": "https://git.kernel.org/stable/c/9944c7938cd5b3f37b0afec0481c7c015e4f1c58" }, { "url": "https://git.kernel.org/stable/c/57e04e2ff56e32f923154f0f7bc476fcb596ffe7" }, { "url": "https://git.kernel.org/stable/c/b0c8e6d3d866b6a7f73877f71968dbffd27b7785" } ], "title": "bpf: account for current allocated stack depth in widen_imprecise_scalars()", "x_generator": { "engine": "bippy-1.2.0" } } } }