CVE-2026-98150
📛 CVE Title
bpf: Fix BPF_F_CPU validation for sparse CPU IDs
Description
In the Linux kernel, the following vulnerability has been resolved: bpf: Fix BPF_F_CPU validation for sparse CPU IDs BPF_F_CPU stores the target CPU ID in the upper 32 bits of the map operation flags. bpf_map_check_op_flags() currently compares that ID with num_possible_cpus(), which is the number of possible CPUs rather than a bound on CPU IDs. On an arm64 QEMU guest with a CPU device-tree hole, the possible CPU mask was 0,2-3. A userspace program using raw bpf() syscalls creates a BPF_MAP_TYPE_PERCPU_ARRAY and performs update and lookup operations for each CPU by setting BPF_F_CPU and the CPU ID in the flags. With the old check, CPU 1 is incorrectly accepted while valid CPU 3 is rejected with -ERANGE. The CPU 1 update then reaches the per-CPU map access path and triggers: Unable to handle kernel paging request at virtual address ... pc : __pi_memcpy_generic+0x5c/0x22c lr : bpf_percpu_array_update+0x2dc/0x2e8 Call trace: __pi_memcpy_generic bpf_map_update_value map_update_elem __sys_bpf Check the CPU ID against nr_cpu_ids and cpu_possible() instead. This rejects CPU IDs outside the valid range and CPUs absent from the possible mask, while allowing valid sparse CPU IDs.
Overview
- State
- PUBLISHED
- Assigner (CNA)
- Linux
- CVSS severity
- HIGH
- CVSS score
- 7.0 / 10
- CVSS vector
CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H- Effective score
- 7.0 / 10 HIGH source: CNA overview
- CWE(s)
- —
- Reserved
- 2026-09-25
- Published
- 2026-09-25 10:36 UTC
- Last updated
- 2026-09-25 14:42 UTC
- Source
- https://raw.githubusercontent.com/CVEProject/cvelistV5/main/cves/2026/98xxx/CVE-2026-98150.json
- Linked Threat
- CVE-2026-98150 — bpf: Fix BPF_F_CPU validation for sparse CPU IDs
NVD triage scoring NVD CVE 2.0
Layer NVD adds on top of the CNA's CVE record — published / last-modified timestamps, exploitability / impact subscores, and the FIRST.org EPSS probability that this CVE will be exploited in the wild in the next 30 days.
- NVD published
- 2026-09-25 11:17:46 UTC
- NVD last modified
- 2026-09-25 15:18:06 UTC
- NVD CVSS v3.1
- 7.0 / 10 HIGH source: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
- NVD CVSS vector
CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H- Exploitability subscore
- 1.0 / 10
- Impact subscore
- 5.9 / 10
NVD / KEV / EPSS data refreshed 2026-09-26 04:21 UTC. Re-run the 🛰 Backfill from NVD button above to refresh.
Affected products (2)
| Vendor | Product | Versions | Platforms |
|---|---|---|---|
| Linux | Linux |
2b421662c7887a0649fe409155a1f101562d0fa9 (affected),
2b421662c7887a0649fe409155a1f101562d0fa9 (affected)
|
— |
| Linux | Linux |
7.0 (affected),
0 (unaffected),
7.2.7 (unaffected),
7.3-rc2 (unaffected)
|
— |
Vendor references (2)
References embedded in the original CVE record by the assigning CNA.
Web references (0)
DuckDuckGo results ranked by threat-intel / vendor advisory domains. Generated by the 🔎 Find references (web) button above — same flow as the Remediations search.
No web references attached yet.
NVD-tagged references (2)
Reference list NVD curates from the CNA record, vendor advisories, and third-party reports. The tag chips below are NVD's analyst-assigned categories.
- https://git.kernel.org/stable/c/bdc5941f6eeef90b76a07fd8ca38ac1933ba2195 416baaa9-dc9f-4396-8d5f-8c081fb06d67
- https://git.kernel.org/stable/c/ed54bf564ac52699cf4def3d0c2125d493e756f9 416baaa9-dc9f-4396-8d5f-8c081fb06d67
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Raw JSON
The full cvelistV5 record. Download as CVE-2026-98150.json.
{
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"cna": {
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"defaultStatus": "unaffected",
"product": "Linux",
"programFiles": [
"include/linux/bpf.h"
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"status": "affected",
"version": "2b421662c7887a0649fe409155a1f101562d0fa9",
"versionType": "git"
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"status": "affected",
"version": "2b421662c7887a0649fe409155a1f101562d0fa9",
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"versions": [
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"version": "7.0"
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{
"lessThan": "7.0",
"status": "unaffected",
"version": "0",
"versionType": "semver"
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{
"lessThanOrEqual": "7.2.*",
"status": "unaffected",
"version": "7.2.7",
"versionType": "semver"
},
{
"lessThanOrEqual": "*",
"status": "unaffected",
"version": "7.3-rc2",
"versionType": "original_commit_for_fix"
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"cpeApplicability": [
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"nodes": [
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"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
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{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
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],
"descriptions": [
{
"lang": "en",
"value": "In the Linux kernel, the following vulnerability has been resolved:\n\nbpf: Fix BPF_F_CPU validation for sparse CPU IDs\n\nBPF_F_CPU stores the target CPU ID in the upper 32 bits of the map\noperation flags. bpf_map_check_op_flags() currently compares that ID\nwith num_possible_cpus(), which is the number of possible CPUs rather\nthan a bound on CPU IDs.\n\nOn an arm64 QEMU guest with a CPU device-tree hole, the possible CPU\nmask was 0,2-3. A userspace program using raw bpf() syscalls creates\na BPF_MAP_TYPE_PERCPU_ARRAY and performs update and lookup operations\nfor each CPU by setting BPF_F_CPU and the CPU ID in the flags.\n\nWith the old check, CPU 1 is incorrectly accepted while valid CPU 3 is\nrejected with -ERANGE. The CPU 1 update then reaches the per-CPU map\naccess path and triggers:\n\n Unable to handle kernel paging request at virtual address ...\n pc : __pi_memcpy_generic+0x5c/0x22c\n lr : bpf_percpu_array_update+0x2dc/0x2e8\n Call trace:\n __pi_memcpy_generic\n bpf_map_update_value\n map_update_elem\n __sys_bpf\n\nCheck the CPU ID against nr_cpu_ids and cpu_possible() instead. This\nrejects CPU IDs outside the valid range and CPUs absent from the\npossible mask, while allowing valid sparse CPU IDs."
}
],
"metrics": [
{
"cvssV3_1": {
"baseScore": 7,
"baseSeverity": "HIGH",
"vectorString": "CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H",
"version": "3.1"
},
"scenarios": [
{
"lang": "en",
"value": "AV:L - The out-of-range CPU ID arrives in attr->flags of the local bpf(2) BPF_MAP_UPDATE_ELEM/LOOKUP_ELEM syscall (map_update_elem/map_lookup_elem -> bpf_map_check_op_flags); no network or adjacent protocol carries it.\nAC:H - The check only lets through a CPU ID in a hole of the possible-CPU mask (e.g. 0,2-3 on arm64 device-tree systems). That topology comes from firmware/hardware and the attacker can't create it. It also needs a permissive BPF setup, and where the stray per_cpu_ptr() lands (unmapped init memory vs mapped .data) depends on percpu allocator placement.\nPR:L - BPF_MAP_TYPE_PERCPU_ARRAY/PERCPU_HASH are in map_create()'s unprivileged list when unprivileged_bpf_disabled=0 or with a delegated BPF token, and map_update_elem/map_lookup_elem check only FMODE_CAN_WRITE/READ on the map fd, not a capability.\nUI:N - The attacker creates or opens the per-CPU map and issues the update/lookup with BPF_F_CPU and a hole CPU ID entirely on their own; no other user acts.\nS:U - The bad access corrupts or reads kernel memory within the same kernel security authority; no VM, IOMMU or sandbox boundary is crossed.\nC:H - bpf_percpu_array_copy() copies value_size bytes from per_cpu_ptr(pptr, cpu) for a missing CPU whose __per_cpu_offset is 0, i.e. from a stray kernel address, back to userspace via BPF_MAP_LOOKUP_ELEM, and the attacker can repeat it.\nI:H - bpf_percpu_array_update() does copy_map_value() of attacker-supplied value bytes to per_cpu_ptr(pptr, cpu) for the missing CPU. That is an out-of-bounds write of controlled data to an address outside any valid per-CPU unit, which can land in kernel .data past __init_end.\nA:H - As the fix commit shows, the update faults in __pi_memcpy_generic from bpf_percpu_array_update on unmapped memory (the freed/vunmapped __init region on arm64), causing a kernel oops."
}
]
}
],
"providerMetadata": {
"dateUpdated": "2026-09-25T14:42:12.855Z",
"orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"shortName": "Linux"
},
"references": [
{
"url": "https://git.kernel.org/stable/c/bdc5941f6eeef90b76a07fd8ca38ac1933ba2195"
},
{
"url": "https://git.kernel.org/stable/c/ed54bf564ac52699cf4def3d0c2125d493e756f9"
}
],
"title": "bpf: Fix BPF_F_CPU validation for sparse CPU IDs",
"x_generator": {
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"cveMetadata": {
"assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"assignerShortName": "Linux",
"cveId": "CVE-2026-98150",
"datePublished": "2026-09-25T10:36:22.774Z",
"dateReserved": "2026-09-25T10:25:14.320Z",
"dateUpdated": "2026-09-25T14:42:12.855Z",
"state": "PUBLISHED"
},
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