CVE-2026-74354 (GCVE-0-2026-74354)
Vulnerability from cvelistv5
Published
2026-08-15 05:58
Modified
2026-08-17 05:46
Severity ?
VLAI Severity ?
EPSS score ?
Summary
In the Linux kernel, the following vulnerability has been resolved:
bpf: Take mmap_lock in zap_pages()
zap_vma_range() requires the owning mm's mmap_lock to be held.
Taking mmap_read_lock under arena->lock would AB-BA against
arena_vm_close() and arena_map_mmap(), both of which run with
mmap_write_lock held and then acquire arena->lock. Instead drop
arena->lock, mmget_not_zero() the vma's mm, take mmap_read_lock, and
re-resolve the vma via find_vma() since it may have been unmapped or
replaced while waiting.
Track processed vmls with a per-call generation in vml->zap_gen and
serialize zap_pages() callers with a new arena->zap_mutex so
concurrent callers on different uaddr ranges do not mark each other's
vmls processed before the zap is done.
References
Impacted products
{
"containers": {
"cna": {
"affected": [
{
"defaultStatus": "unaffected",
"product": "Linux",
"programFiles": [
"kernel/bpf/arena.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"versions": [
{
"lessThan": "36b1d997866f6083d33934983aa2ce0a184ed642",
"status": "affected",
"version": "317460317a02a1af512697e6e964298dedd8a163",
"versionType": "git"
},
{
"lessThan": "80b89d0226a05e8b67969de99c31b51fcd54f76a",
"status": "affected",
"version": "317460317a02a1af512697e6e964298dedd8a163",
"versionType": "git"
}
]
},
{
"defaultStatus": "affected",
"product": "Linux",
"programFiles": [
"kernel/bpf/arena.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"versions": [
{
"status": "affected",
"version": "6.9"
},
{
"lessThan": "6.9",
"status": "unaffected",
"version": "0",
"versionType": "semver"
},
{
"lessThanOrEqual": "7.1.*",
"status": "unaffected",
"version": "7.1.5",
"versionType": "semver"
},
{
"lessThanOrEqual": "*",
"status": "unaffected",
"version": "7.2",
"versionType": "original_commit_for_fix"
}
]
}
],
"cpeApplicability": [
{
"nodes": [
{
"cpeMatch": [
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionEndExcluding": "7.1.5",
"versionStartIncluding": "6.9",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionEndExcluding": "7.2",
"versionStartIncluding": "6.9",
"vulnerable": true
}
],
"negate": false,
"operator": "OR"
}
]
}
],
"descriptions": [
{
"lang": "en",
"value": "In the Linux kernel, the following vulnerability has been resolved:\n\nbpf: Take mmap_lock in zap_pages()\n\nzap_vma_range() requires the owning mm\u0027s mmap_lock to be held.\n\nTaking mmap_read_lock under arena-\u003elock would AB-BA against\narena_vm_close() and arena_map_mmap(), both of which run with\nmmap_write_lock held and then acquire arena-\u003elock. Instead drop\narena-\u003elock, mmget_not_zero() the vma\u0027s mm, take mmap_read_lock, and\nre-resolve the vma via find_vma() since it may have been unmapped or\nreplaced while waiting.\n\nTrack processed vmls with a per-call generation in vml-\u003ezap_gen and\nserialize zap_pages() callers with a new arena-\u003ezap_mutex so\nconcurrent callers on different uaddr ranges do not mark each other\u0027s\nvmls processed before the zap is done."
}
],
"metrics": [
{
"cvssV3_1": {
"baseScore": 7.8,
"baseSeverity": "HIGH",
"vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
"version": "3.1"
},
"scenarios": [
{
"lang": "en",
"value": "AV:L - The flaw is reached only via local bpf(2) syscalls: creating a BPF_MAP_TYPE_ARENA, loading a JIT BPF program using bpf_arena_free_pages(), mmap()ing the arena, and executing that program, which calls zap_pages() and zap_vma_range() without mmap_lock.\nAC:L - Exploitation requires racing page unmap with concurrent VMA teardown; the attacker controls both sides by running bpf_arena_free_pages() from BPF while another thread or process concurrently munmap()s or remaps the same arena mapping.\nPR:L - Arena map creation requires CAP_BPF and verifier-enforced CAP_BPF plus CAP_PERFMON (bpf_allow_ptr_leaks), not init-namespace root; these capabilities are obtainable by an unprivileged user via user namespaces or perf-group membership on typical systems.\nUI:N - No victim interaction is required beyond the attacker loading their own BPF program and mmaping their own arena; triggering the race is fully automated once those attacker-controlled setup steps are done.\nS:U - Impact is confined to kernel memory management and process address spaces on the host; it does not cross a VM, container, or IOMMU security boundary into a separate authority such as a hypervisor host escape.\nC:H - Calling zap_vma_range() without mmap_lock races with munmap and page faults, enabling stale VMA use, page-table corruption, and use-after-free conditions that can be leveraged for arbitrary kernel or cross-process memory disclosure.\nI:H - Unsynchronized PTE zapping and rmap updates can corrupt page tables and VMA metadata, providing memory corruption primitives that can be developed into arbitrary kernel writes and control-flow hijacking.\nA:H - The mmap_lock violation can cause kernel oopses, panics, or hung memory management from inconsistent page tables and invalid VMA access during concurrent unmap operations."
}
]
}
],
"providerMetadata": {
"dateUpdated": "2026-08-17T05:46:14.991Z",
"orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"shortName": "Linux"
},
"references": [
{
"url": "https://git.kernel.org/stable/c/36b1d997866f6083d33934983aa2ce0a184ed642"
},
{
"url": "https://git.kernel.org/stable/c/80b89d0226a05e8b67969de99c31b51fcd54f76a"
}
],
"title": "bpf: Take mmap_lock in zap_pages()",
"x_generator": {
"engine": "bippy-1.2.0"
}
}
},
"cveMetadata": {
"assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"assignerShortName": "Linux",
"cveId": "CVE-2026-74354",
"datePublished": "2026-08-15T05:58:40.067Z",
"dateReserved": "2026-08-15T05:44:03.887Z",
"dateUpdated": "2026-08-17T05:46:14.991Z",
"state": "PUBLISHED"
},
"dataType": "CVE_RECORD",
"dataVersion": "5.2"
}
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Sightings
| Author | Source | Type | Date |
|---|
Nomenclature
- Seen: The vulnerability was mentioned, discussed, or seen somewhere by the user.
- Confirmed: The vulnerability is confirmed from an analyst perspective.
- Published Proof of Concept: A public proof of concept is available for this vulnerability.
- Exploited: This vulnerability was exploited and seen by the user reporting the sighting.
- Patched: This vulnerability was successfully patched by the user reporting the sighting.
- Not exploited: This vulnerability was not exploited or seen by the user reporting the sighting.
- Not confirmed: The user expresses doubt about the veracity of the vulnerability.
- Not patched: This vulnerability was not successfully patched by the user reporting the sighting.
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