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vuln-cve/data/2026/93xxx/CVE-2026-93112.json
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{
"dataType": "CVE_RECORD",
"dataVersion": "5.2",
"cveMetadata": {
"cveId": "CVE-2026-93112",
"assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"state": "PUBLISHED",
"assignerShortName": "Linux",
"dateReserved": "2026-09-17T16:02:15.086Z",
"datePublished": "2026-09-17T16:11:21.122Z",
"dateUpdated": "2026-10-19T09:05:45.809Z"
},
"containers": {
"cna": {
"providerMetadata": {
"orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"shortName": "Linux",
"dateUpdated": "2026-10-19T09:05:45.809Z"
},
"descriptions": [
{
"lang": "en",
"value": "In the Linux kernel, the following vulnerability has been resolved:\n\nbpf: Require a BPF cpumask for bpf_cpumask_populate()\n\nbpf_cpumask_populate() writes to its destination with bitmap_copy(), but\nthe destination is typed as struct cpumask *. That allows the verifier to\naccept borrowed cpumask pointers returned by read-only kfuncs, such as\nscx_bpf_get_online_cpumask(), as a writable destination.\n\nMake the destination a struct bpf_cpumask * so populate follows the same\nownership rule as the other mutating cpumask kfuncs. Query kfuncs continue\nto accept const struct cpumask * inputs."
}
],
"metrics": [
{
"cvssV3_1": {
"version": "3.1",
"vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:H",
"baseScore": 7.1,
"baseSeverity": "HIGH"
},
"scenarios": [
{
"lang": "en",
"value": "AV:L - bpf_cpumask_populate() is a kfunc on BPF_PROG_TYPE_SYSCALL/TRACING/STRUCT_OPS programs loaded via bpf(BPF_PROG_LOAD); the src bitmap is program-local memory, and a SYSCALL program runs it through BPF_PROG_TEST_RUN (bpf_prog_test_run_syscall). Those bits do not arrive in a network protocol message.\nAC:L - A program can call scx_bpf_get_online_cpumask() then bpf_cpumask_populate() in one path; process_kf_arg_ptr_to_btf_id() does not require strict matching here, so the borrowed struct cpumask * is accepted and bitmap_copy() runs with no race or layout dependency.\nPR:L - bpf_prog_load() of BPF_PROG_TYPE_SYSCALL needs only bpf_token_capable(CAP_BPF) (SYSCALL is not in is_perfmon_prog_type); TRACING/STRUCT_OPS also need CAP_PERFMON. bpf_token_capable() checks token->userns, so a delegated BPF token grants this to userns root rather than init-namespace root.\nUI:N - The attacker loads their own program and either BPF_PROG_TEST_RUN it or fork() to fire their tp_btf/task_newtask hook; no other user must mount, open a file, or otherwise interact.\nS:U - bitmap_copy() overwrites host kernel objects (__cpu_online_mask from scx_bpf_get_online_cpumask(), or task_struct.cpus_mask via cpus_ptr) in the same kernel; this is not a KVM/Xen escape or IOMMU bypass.\nC:N - bpf_cpumask_populate() only bitmap_copy()s the caller-supplied src buffer into the destination mask; it does not read kernel memory back to the program or otherwise disclose confidential data.\nI:H - The destination was typed struct cpumask * rather than struct bpf_cpumask *, so bitmap_copy() writes attacker-controlled bits into borrowed kernel masks such as cpu_online_mask from scx_bpf_get_online_cpumask() or task->cpus_ptr, which bpf_cpumask_set_cpu() would reject.\nA:H - Overwriting writable __cpu_online_mask forges the set walked by for_each_online_cpu(), so the scheduler IPIs or indexes per-CPU state for offline CPUs or sees num_online_cpus()==0, causing a kernel oops or hang."
}
]
}
],
"affected": [
{
"product": "Linux",
"vendor": "Linux",
"defaultStatus": "unaffected",
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"programFiles": [
"kernel/bpf/cpumask.c",
"tools/sched_ext/include/scx/compat.bpf.h"
],
"versions": [
{
"version": "950ad93df2fce70445e655ed2e74f5c1a8653ab2",
"lessThan": "0cfc9348a045da64955af2dd6902e66dfc7d6469",
"status": "affected",
"versionType": "git"
},
{
"version": "950ad93df2fce70445e655ed2e74f5c1a8653ab2",
"lessThan": "b7e2a5c6519adc73be55c3de2cb545e095a0fbc5",
"status": "affected",
"versionType": "git"
},
{
"version": "950ad93df2fce70445e655ed2e74f5c1a8653ab2",
"lessThan": "8740156ad33be5071b588b594c55f279457f667c",
"status": "affected",
"versionType": "git"
}
]
},
{
"product": "Linux",
"vendor": "Linux",
"defaultStatus": "affected",
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"programFiles": [
"kernel/bpf/cpumask.c",
"tools/sched_ext/include/scx/compat.bpf.h"
],
"versions": [
{
"version": "6.15",
"status": "affected"
},
{
"version": "0",
"lessThan": "6.15",
"status": "unaffected",
"versionType": "semver"
},
{
"version": "6.18.52",
"lessThanOrEqual": "6.18.*",
"status": "unaffected",
"versionType": "semver"
},
{
"version": "7.2.6",
"lessThanOrEqual": "7.2.*",
"status": "unaffected",
"versionType": "semver"
},
{
"version": "7.3",
"lessThanOrEqual": "*",
"status": "unaffected",
"versionType": "original_commit_for_fix"
}
]
}
],
"cpeApplicability": [
{
"nodes": [
{
"operator": "OR",
"negate": false,
"cpeMatch": [
{
"vulnerable": true,
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionStartIncluding": "6.15",
"versionEndExcluding": "6.18.52"
},
{
"vulnerable": true,
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionStartIncluding": "6.15",
"versionEndExcluding": "7.2.6"
},
{
"vulnerable": true,
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionStartIncluding": "6.15",
"versionEndExcluding": "7.3"
}
]
}
]
}
],
"references": [
{
"url": "https://git.kernel.org/stable/c/0cfc9348a045da64955af2dd6902e66dfc7d6469"
},
{
"url": "https://git.kernel.org/stable/c/b7e2a5c6519adc73be55c3de2cb545e095a0fbc5"
},
{
"url": "https://git.kernel.org/stable/c/8740156ad33be5071b588b594c55f279457f667c"
}
],
"title": "bpf: Require a BPF cpumask for bpf_cpumask_populate()",
"x_generator": {
"engine": "bippy-1.2.0"
}
}
}
}