119 lines
7.2 KiB
JSON
119 lines
7.2 KiB
JSON
{
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"dataType": "CVE_RECORD",
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"dataVersion": "5.2",
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"cveMetadata": {
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"cveId": "CVE-2026-98376",
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"assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
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"state": "PUBLISHED",
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"assignerShortName": "Linux",
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"dateReserved": "2026-09-25T10:25:14.345Z",
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"datePublished": "2026-10-09T07:34:17.043Z",
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"dateUpdated": "2026-10-24T14:08:36.004Z"
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},
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"containers": {
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"cna": {
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"providerMetadata": {
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"orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
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"shortName": "Linux",
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"dateUpdated": "2026-10-24T14:08:36.004Z"
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},
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"descriptions": [
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{
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"lang": "en",
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"value": "In the Linux kernel, the following vulnerability has been resolved:\n\nbpf: Use array_map_meta_equal for percpu array inner map replacement\n\npercpu_array_map_ops.map_meta_equal points to the generic\nbpf_map_meta_equal(), which does not compare max_entries. When a\npercpu array serves as an inner map, replacing it with one that has\nfewer max_entries bypasses the check. Since percpu_array_map_gen_lookup()\ninlines the original template's index_mask as a JIT immediate, a lookup\non the replacement map can access pptrs[] out of bounds.\n\nPoint percpu_array_map_ops.map_meta_equal to array_map_meta_equal(),\nwhich already enforces the max_entries equality check.\n\nAdd a selftest to verify that replacing a percpu array inner map with\na differently-sized one is rejected."
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}
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],
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"metrics": [
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{
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"cvssV3_1": {
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"version": "3.1",
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"vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
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"baseScore": 7.8,
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"baseSeverity": "HIGH"
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},
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"scenarios": [
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{
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"lang": "en",
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"value": "AV:L - The local bpf(BPF_MAP_UPDATE_ELEM) path reaches map_update_elem()->bpf_map_update_value()->bpf_fd_array_map_update_elem()->bpf_map_fd_get_ptr(), where the patched percpu_array_map_ops.map_meta_equal validates the replacement map; no network handler supplies its FD or dimensions.\nAC:L - The attacker chooses the template and replacement max_entries, lookup key, program, and trigger; an index below the template limit but beyond the replacement deterministically reads pptrs[] out of bounds. No race or other actor is required on a JIT-enabled x86-64 or arm64 target.\nPR:L - map_create() places PERCPU_ARRAY and ARRAY_OF_MAPS in its unprivileged branch, and bpf_prog_load() permits SOCKET_FILTER without CAP_BPF when unprivileged BPF is enabled; alternatively, a user-namespace BPF token satisfies the gates without init-namespace root.\nUI:N - The attacker creates and replaces the maps, loads the lookup program, attaches it through SO_ATTACH_BPF to their own socket, and sends the triggering data themselves; no victim action is needed.\nS:U - percpu_array_map_gen_lookup() converts the out-of-bounds pptrs[] slot into a pointer used against the same host kernel's memory; this is ordinary kernel privilege escalation, not a guest-to-host, IOMMU, or other security-authority crossing.\nC:H - percpu_array_map_gen_lookup() loads a 64-bit pptrs[index] out of bounds and returns its adjusted value as a verifier-trusted map-value pointer. Because bpf_map_area_alloc() kmallocs the flexible object, map spraying can place chosen bytes at that slot, enabling kernel reads copied into another map.\nI:H - The forged PTR_TO_MAP_VALUE is writable because default map flags grant BPF_MAP_CAN_WRITE; direct BPF stores through an attacker-groomed out-of-bounds pptrs[] value therefore provide an arbitrary kernel-write primitive suitable for control-flow hijacking.\nA:H - Without successful grooming, BPF_MOV64_PERCPU_REG adjusts the garbage pointer loaded beyond pptrs[] and the attacker's next value access dereferences it, causing a kernel oops or panic; the attacker can repeatedly run the same socket-filter program."
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}
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]
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}
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],
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"affected": [
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{
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"product": "Linux",
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"vendor": "Linux",
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"defaultStatus": "unaffected",
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"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
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"programFiles": [
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"kernel/bpf/arraymap.c",
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"tools/testing/selftests/bpf/prog_tests/percpu_array_inner_map.c"
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],
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"versions": [
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{
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"version": "db69718b8efac802c7cc20d5a6c7dfc913f99c43",
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"lessThan": "593980175389a05793f6060aa20e626330960395",
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"status": "affected",
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"versionType": "git"
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}
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]
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},
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{
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"product": "Linux",
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"vendor": "Linux",
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"defaultStatus": "affected",
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"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
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"programFiles": [
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"kernel/bpf/arraymap.c",
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"tools/testing/selftests/bpf/prog_tests/percpu_array_inner_map.c"
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],
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"versions": [
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{
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"version": "6.10",
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"status": "affected"
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},
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{
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"version": "0",
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"lessThan": "6.10",
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"status": "unaffected",
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"versionType": "semver"
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},
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{
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"version": "7.1",
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"lessThanOrEqual": "*",
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"status": "unaffected",
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"versionType": "original_commit_for_fix"
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}
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]
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}
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],
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"cpeApplicability": [
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{
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"nodes": [
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{
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"operator": "OR",
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"negate": false,
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"cpeMatch": [
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{
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"vulnerable": true,
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"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
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"versionStartIncluding": "6.10",
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"versionEndExcluding": "7.1"
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}
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]
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}
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]
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}
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],
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"references": [
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{
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"url": "https://git.kernel.org/stable/c/593980175389a05793f6060aa20e626330960395"
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}
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],
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"title": "bpf: Use array_map_meta_equal for percpu array inner map replacement",
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"x_generator": {
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"engine": "bippy-1.2.0"
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}
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}
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}
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} |