Vulnerability in Kernel (CVE-2025-40120)

Summary

Vulnerability in Kernel (CVE-2025-40120). Risk of unauthorized operations or information disclosure. Mitigation: upgrade to 5.15.195, 6.1.156, 6.6.112, 6.12.53, 6.17.3 or later.

Original description

The description as published by the source.

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

net: usb: asix: hold PM usage ref to avoid PM/MDIO + RTNL deadlock

Prevent USB runtime PM (autosuspend) for AX88772* in bind.

usbnet enables runtime PM (autosuspend) by default, so disabling it via
the usb_driver flag is ineffective. On AX88772B, autosuspend shows no
measurable power saving with current driver (no link partner, admin
up/down). The ~0.453 W -> ~0.248 W drop on v6.1 comes from phylib powering
the PHY off on admin-down, not from USB autosuspend.

The real hazard is that with runtime PM enabled, ndo_open() (under RTNL)
may synchronously trigger autoresume (usb_autopm_get_interface()) into
asix_resume() while the USB PM lock is held. Resume paths then invoke
phylink/phylib and MDIO, which also expect RTNL, leading to possible
deadlocks or PM lock vs MDIO wake issues.

To avoid this, keep the device runtime-PM active by taking a usage
reference in ax88772_bind() and dropping it in unbind(). A non-zero PM
usage count blocks runtime suspend regardless of userspace policy
(.../power/control - pm_runtime_allow/forbid), making this approach
robust against sysfs overrides.

Holding a runtime-PM usage ref does not affect system-wide suspend;
system sleep/resume callbacks continue to run as before.

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-2025-40120 has been found in Kernel.
Risk of unauthorized operations or information disclosure.
What to do: upgrade Kernel to 5.15.195, 6.1.156, 6.6.112, 6.12.53, 6.17.3 or later.
If unsure, ask your IT team or search "Kernel CVE-2025-40120" on the vendor's site.

CVE-2025-40120 (Kernel)
Patched: 5.15.195, 6.1.156, 6.6.112, 6.12.53, 6.17.3 — 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 5.15.195, 6.1.156, 6.6.112, 6.12.53, 6.17.3.

🛡️ 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 5.15.195, 6.1.156, 6.6.112, 6.12.53, 6.17.3
```
ステージング環境で 5.15.195, 6.1.156, 6.6.112, 6.12.53, 6.17.3 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":"5.14.0"},{"fixed":"5.15.195"}]},{"type":"ECOSYSTEM","events":[{"introduced":"5.16.0"},{"fixed":"6.1.156"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.2.0"},{"fixed":"6.6.112"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.7.0"},{"fixed":"6.12.53"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.13.0"},{"fixed":"6.17.3"}]}]

Fix status by distribution

Fixed packages published by each distribution for this CVE

BellSoft Alpaquita BELL-CVE-2025-40120 linux-lts Fixed in: 6.1.156-r0
Debian DEBIAN-CVE-2025-40120 linux Fixed in: 6.1.158-1
Ubuntu UBUNTU-CVE-2025-40120 linux-hwe-edge