Vulnerability in Kernel (CVE-2025-38170)

Summary

Vulnerability in Kernel (CVE-2025-38170). Risk of unauthorized operations or information disclosure. Mitigation: upgrade to 6.1.142, 6.6.94, 6.12.34, 6.15.3 or later.

Original description

The description as published by the source.

In the Linux kernel, the following vulnerability has been resolved:

arm64/fpsimd: Discard stale CPU state when handling SME traps

The logic for handling SME traps manipulates saved FPSIMD/SVE/SME state
incorrectly, and a race with preemption can result in a task having
TIF_SME set and TIF_FOREIGN_FPSTATE clear even though the live CPU state
is stale (e.g. with SME traps enabled). This can result in warnings from
do_sme_acc() where SME traps are not expected while TIF_SME is set:

| /* With TIF_SME userspace shouldn't generate any traps */
| if (test_and_set_thread_flag(TIF_SME))
| WARN_ON(1);

This is very similar to the SVE issue we fixed in commit:

751ecf6afd6568ad ("arm64/sve: Discard stale CPU state when handling SVE traps")

The race can occur when the SME trap handler is preempted before and
after manipulating the saved FPSIMD/SVE/SME state, starting and ending on
the same CPU, e.g.

| void do_sme_acc(unsigned long esr, struct pt_regs regs)
| {
| // Trap on CPU 0 with TIF_SME clear, SME traps enabled
| // task->fpsimd_cpu is 0.
| // per_cpu_ptr(&fpsimd_last_state, 0) is task.
|
| ...
|
| // Preempted; migrated from CPU 0 to CPU 1.
| // TIF_FOREIGN_FPSTATE is set.
|
| get_cpu_fpsimd_context();
|
| / With TIF_SME userspace shouldn't generate any traps */
| if (test_and_set_thread_flag(TIF_SME))
| WARN_ON(1);
|
| if (!test_thread_flag(TIF_FORE…

Source: OSV.dev (Open Source Vulnerabilities) NVD OSV

Auto-generated summary

Assembled by SecPulse from the source data (CVSS, CWE, affected versions) using templates — no AI involved. Check the original description and references below for exact details.

A vulnerability tracked as CVE-2025-38170 has been found in Kernel.
Risk of unauthorized operations or information disclosure.
What to do: upgrade Kernel to 6.1.142, 6.6.94, 6.12.34, 6.15.3 or later.
If unsure, ask your IT team or search "Kernel CVE-2025-38170" on the vendor's site.

CVE-2025-38170 (Kernel)
Patched: 6.1.142, 6.6.94, 6.12.34, 6.15.3 — apply immediately
Plan: 1) Audit SBOM/dependencies, 2) Stage→prod upgrade, 3) Add WAF/proxy monitoring on affected endpoints, 4) Hunt IOCs in logs.
Refs: see the GHSA / vendor advisory / patched release linked on this page.

❓ What is the problem

A vulnerability (unclassified) exists in Kernel.

📍 Affected scope

Check the vendor advisory for the affected versions of Kernel.

🔥 Severity

Severity: ?. Risk of unauthorized operations or information disclosure.

🔧 How to fix

Update to 6.1.142, 6.6.94, 6.12.34, 6.15.3.

🛡️ Workaround

Until the patch is applied: disable the affected feature, apply WAF rules, or restrict access via network ACLs.

🔍 Detection

Search webserver/proxy logs for unusual request patterns matching this CVE's known IOCs. Run grep -r 'Kernel' . against your dependency files (package-lock.json, requirements.txt, go.sum) to find affected services.

Response actions

Concrete steps and command examples for SOC/SRE teams to execute in order

1
Identify exposure identify
```
grep -r 'Kernel' . | grep -v node_modules
```
リポジトリと本番環境の依存ファイル (package-lock.json / requirements.txt / go.sum / Gemfile.lock 等) で Kernel を grep し、稼働しているサービス・バージョンを把握する。
2
Apply patch patch
```
Upgrade Kernel to 6.1.142, 6.6.94, 6.12.34, 6.15.3
```
ステージング環境で 6.1.142, 6.6.94, 6.12.34, 6.15.3 に上げて回帰テスト → 本番反映。回帰テストはアプリの主要ハッピーパスを含めること。
3
Post-deployment verification verify
```
Confirm patched version is live in production
```
パッチ適用後、ステージングで PoC または同等の悪用パターンを再現して脆弱性が閉じたことを確認。本番ではアクセスログ・WAF でアラート再発が無いか継続監視。

Affected packages

Linux Kernel

[{"type":"ECOSYSTEM","events":[{"introduced":"5.19.0"},{"fixed":"6.1.142"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.2.0"},{"fixed":"6.6.94"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.7.0"},{"fixed":"6.12.34"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.13.0"},{"fixed":"6.15.3"}]}]

Fix status by distribution

Fixed packages published by each distribution for this CVE

BellSoft Alpaquita BELL-CVE-2025-38170 linux-lts Fixed in: 6.1.143-r1
Debian DEBIAN-CVE-2025-38170 linux Fixed in: 6.1.147-1
Ubuntu UBUNTU-CVE-2025-38170 linux-hwe-edge