{"api_version":"1","generated_at":"2026-09-26T20:43:59+00:00","cve":"CVE-2026-98150","urls":{"html":"https://cve.report/CVE-2026-98150","api":"https://cve.report/api/cve/CVE-2026-98150.json","docs":"https://cve.report/api","cve_org":"https://www.cve.org/CVERecord?id=CVE-2026-98150","nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-98150"},"summary":{"title":"bpf: Fix BPF_F_CPU validation for sparse CPU IDs","description":"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.","state":"PUBLISHED","assigner":"Linux","published_at":"2026-09-25 11:17:46","updated_at":"2026-09-25 15:18:06"},"problem_types":[],"metrics":[{"version":"3.1","source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","type":"Secondary","score":"7","severity":"HIGH","vector":"CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H","data":{"version":"3.1","vectorString":"CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H","baseScore":7,"baseSeverity":"HIGH","attackVector":"LOCAL","attackComplexity":"HIGH","privilegesRequired":"LOW","userInteraction":"NONE","scope":"UNCHANGED","confidentialityImpact":"HIGH","integrityImpact":"HIGH","availabilityImpact":"HIGH"}},{"version":"3.1","source":"CNA","type":"DECLARED","score":"7","severity":"HIGH","vector":"CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H","data":{"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"}}],"references":[{"url":"https://git.kernel.org/stable/c/bdc5941f6eeef90b76a07fd8ca38ac1933ba2195","name":"https://git.kernel.org/stable/c/bdc5941f6eeef90b76a07fd8ca38ac1933ba2195","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/ed54bf564ac52699cf4def3d0c2125d493e756f9","name":"https://git.kernel.org/stable/c/ed54bf564ac52699cf4def3d0c2125d493e756f9","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-98150","name":"CVE Program record","refsource":"CVE.ORG","tags":["canonical"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-98150","name":"NVD vulnerability detail","refsource":"NVD","tags":["canonical","analysis"]}],"affected":[{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 2b421662c7887a0649fe409155a1f101562d0fa9 bdc5941f6eeef90b76a07fd8ca38ac1933ba2195 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 2b421662c7887a0649fe409155a1f101562d0fa9 ed54bf564ac52699cf4def3d0c2125d493e756f9 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 7.0","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 7.0 semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 7.2.7 7.2.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 7.3-rc2 * original_commit_for_fix","platforms":[]}],"timeline":[],"solutions":[],"workarounds":[],"exploits":[],"credits":[],"nvd_cpes":[],"vendor_comments":[],"enrichments":{"kev":null,"epss":null,"legacy_qids":[]},"source_records":{"cve_program":{"containers":{"cna":{"affected":[{"defaultStatus":"unaffected","product":"Linux","programFiles":["include/linux/bpf.h"],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","vendor":"Linux","versions":[{"lessThan":"bdc5941f6eeef90b76a07fd8ca38ac1933ba2195","status":"affected","version":"2b421662c7887a0649fe409155a1f101562d0fa9","versionType":"git"},{"lessThan":"ed54bf564ac52699cf4def3d0c2125d493e756f9","status":"affected","version":"2b421662c7887a0649fe409155a1f101562d0fa9","versionType":"git"}]},{"defaultStatus":"affected","product":"Linux","programFiles":["include/linux/bpf.h"],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","vendor":"Linux","versions":[{"status":"affected","version":"7.0"},{"lessThan":"7.0","status":"unaffected","version":"0","versionType":"semver"},{"lessThanOrEqual":"7.2.*","status":"unaffected","version":"7.2.7","versionType":"semver"},{"lessThanOrEqual":"*","status":"unaffected","version":"7.3-rc2","versionType":"original_commit_for_fix"}]}],"cpeApplicability":[{"nodes":[{"cpeMatch":[{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"7.2.7","versionStartIncluding":"7.0","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"7.3-rc2","versionStartIncluding":"7.0","vulnerable":true}],"negate":false,"operator":"OR"}]}],"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":{"engine":"bippy-1.2.0"}}},"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"},"dataType":"CVE_RECORD","dataVersion":"5.2"},"nvd":{"publishedDate":"2026-09-25 11:17:46","lastModifiedDate":"2026-09-25 15:18:06","problem_types":[],"metrics":{"cvssMetricV31":[{"source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","type":"Secondary","cvssData":{"version":"3.1","vectorString":"CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H","baseScore":7,"baseSeverity":"HIGH","attackVector":"LOCAL","attackComplexity":"HIGH","privilegesRequired":"LOW","userInteraction":"NONE","scope":"UNCHANGED","confidentialityImpact":"HIGH","integrityImpact":"HIGH","availabilityImpact":"HIGH"},"exploitabilityScore":1,"impactScore":5.9}]},"configurations":[]},"legacy_mitre":{"record":{"CveYear":"2026","CveId":"98150","Ordinal":"1","Title":"bpf: Fix BPF_F_CPU validation for sparse CPU IDs","CVE":"CVE-2026-98150","Year":"2026"},"notes":[{"CveYear":"2026","CveId":"98150","Ordinal":"1","NoteData":"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.","Type":"Description","Title":"bpf: Fix BPF_F_CPU validation for sparse CPU IDs"}]}}}