172 lines
11 KiB
JSON
172 lines
11 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-2026-74371",
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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": "2026-08-15T05:44:03.889Z",
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"datePublished": "2026-08-15T05:58:51.610Z",
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"dateUpdated": "2026-09-14T11:58:45.047Z"
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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": "2026-09-14T11:58:45.047Z"
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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: fix BPF_PROG_QUERY OOB write and cgroup backward compat\n\nBPF_PROG_QUERY writes back the 'query.revision' field unconditionally to\nuserspace. If userspace passes a smaller 'bpf_attr' structure (e.g. 40\nbytes, which was the layout before the addition of 'query.revision'),\nthe kernel performs an out-of-bounds write.\n\nFix this by propagating the user-provided attribute size 'uattr_size'\ndown to the cgroup query handlers, and conditionally skipping writing\nthe revision field to userspace when the provided buffer size is\ninsufficient.\n\nquery.revision in bpf_mprog_query is structurally identical to the\ncgroup case: a late tail field, written unconditionally.\n\nBut the backward-compat hazard is not the same.\n\nThe min-historical-size test is per command, and bpf_mprog_query only\nserves attach types that were born with revision in the struct:\n\n- tcx_prog_query -> BPF_TCX_INGRESS/EGRESS\n- netkit_prog_query -> BPF_NETKIT_PRIMARY/PEER\n\ntcx, netkit, the revision field, and bpf_mprog_query itself all landed in\nthe same v6.6 merge window (053c8e1f235d added the mprog query API +\nrevision; tcx in e420bed02507, netkit in 35dfaad7188c). There has never\nbeen a tcx/netkit BPF_PROG_QUERY userspace that doesn't know about\nrevision. So for these commands the minimum legitimate struct already\ncovers offset 56-64 — no old binary can be broken here.\n\nContrast with cgroup: BPF_PROG_QUERY on cgroup attach types shipped in\n2017; revision write-back was bolted on years later (120933984460). That\npath has a real population of pre-revision callers."
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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 flaw is reached only through the bpf(2) syscall BPF_PROG_QUERY command on cgroup attach types via __sys_bpf()→bpf_prog_query()→cgroup_bpf_prog_query(); per kernel CNA guidance BPF/tc/netlink paths are Local, not Network.\nAC:L - The attacker fully controls the bpf_attr buffer, its declared size (e.g. 40 bytes pre-revision), placement in memory, cgroup2 target_fd, and attach_type; passing a short size reliably triggers the 8-byte revision copy_to_user at offset 56 with no race or external precondition.\nPR:L - bpf_prog_query() enforces bpf_net_capable(), requiring CAP_NET_ADMIN or CAP_SYS_ADMIN; both are delegable and obtainable inside an unprivileged user namespace (unshare -Urn) on typical distributions, so this is Low rather than init-namespace administrator.\nUI:N - Exploitation requires only the attacker's own bpf(BPF_PROG_QUERY) syscall (or an auto-invoked legacy-sized query after kernel upgrade); no separate victim mount, file open, or interactive action is needed.\nS:U - copy_to_user() writes past the caller-supplied userspace buffer boundary, corrupting adjacent mappings in the calling process; it does not corrupt kernel heap/slab memory or cross VM, IOMMU, or container-to-host security boundaries.\nC:H - The kernel performs an out-of-bounds 8-byte write past the declared bpf_attr size; per CNA guidance any such memory corruption can be leveraged for information disclosure via adjacent userspace secrets, not merely a bounded metadata leak.\nI:H - The unconditional copy_to_user of query.revision at offset 56 when size is below offsetofend(revision) is an out-of-bounds write of up to 8 bytes (revision value partly influenced by prior cgroup BPF attach/detach), enabling userspace heap/stack corruption and potential code execution.\nA:H - The OOB write can crash or hang privileged BPF/cgroup management daemons (containerd, Cilium, kubelet) still issuing legacy-sized BPF_PROG_QUERY after a 6.17+ upgrade, and malicious CAP_NET_ADMIN callers can repeatedly corrupt adjacent mappings to induce process termination."
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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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"include/linux/bpf-cgroup.h",
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"kernel/bpf/cgroup.c",
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"kernel/bpf/syscall.c"
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],
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"versions": [
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{
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"version": "195814a38a6a712bcb44d3dfa5109e926e92bec4",
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"lessThan": "b78eb6efbf052d44a3a14726aa7c7d5aa2e544d7",
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"status": "affected",
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"versionType": "git"
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},
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{
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"version": "1209339844601ec1766f4ff430673fbcfe42bb51",
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"lessThan": "a7131340d0f95df9a541257dccab5d85e6bcdd2b",
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"status": "affected",
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"versionType": "git"
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},
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{
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"version": "1209339844601ec1766f4ff430673fbcfe42bb51",
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"lessThan": "d3d630e8a7f3421bc2d204b87bdff35b4432a8e3",
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"status": "affected",
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"versionType": "git"
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},
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{
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"version": "1209339844601ec1766f4ff430673fbcfe42bb51",
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"lessThan": "21c4b99b27f3f85b89256e81b3e997dec0a460d0",
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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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"include/linux/bpf-cgroup.h",
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"kernel/bpf/cgroup.c",
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"kernel/bpf/syscall.c"
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],
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"versions": [
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{
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"version": "6.17",
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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": "6.17",
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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": "6.18.40",
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"lessThanOrEqual": "6.18.*",
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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": "7.1.5",
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"lessThanOrEqual": "7.1.*",
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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": "7.2",
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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": "6.17",
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"versionEndExcluding": "6.18.40"
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},
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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": "6.17",
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"versionEndExcluding": "7.1.5"
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},
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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": "6.17",
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"versionEndExcluding": "7.2"
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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/b78eb6efbf052d44a3a14726aa7c7d5aa2e544d7"
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},
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{
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"url": "https://git.kernel.org/stable/c/a7131340d0f95df9a541257dccab5d85e6bcdd2b"
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},
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{
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"url": "https://git.kernel.org/stable/c/d3d630e8a7f3421bc2d204b87bdff35b4432a8e3"
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},
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{
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"url": "https://git.kernel.org/stable/c/21c4b99b27f3f85b89256e81b3e997dec0a460d0"
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}
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],
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"title": "bpf: fix BPF_PROG_QUERY OOB write and cgroup backward compat",
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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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} |