Vulnerability in Kernel (CVE-2025-39771)

Summary

Vulnerability in Kernel (CVE-2025-39771). Risk of unauthorized operations or information disclosure. Mitigation: upgrade to 6.16.4 or later.

Original description

The description as published by the source.

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

regulator: pca9450: Use devm_register_sys_off_handler

With module test, there is error dump:
------------[ cut here ]------------
notifier callback pca9450_i2c_restart_handler already registered
WARNING: kernel/notifier.c:23 at notifier_chain_register+0x5c/0x88,
CPU#0: kworker/u16:3/50
Call trace:
notifier_chain_register+0x5c/0x88 (P)
atomic_notifier_chain_register+0x30/0x58
register_restart_handler+0x1c/0x28
pca9450_i2c_probe+0x418/0x538
i2c_device_probe+0x220/0x3d0
really_probe+0x114/0x410
__driver_probe_device+0xa0/0x150
driver_probe_device+0x40/0x114
__device_attach_driver+0xd4/0x12c

So use devm_register_sys_off_handler to let kernel handle the resource
free to avoid kernel dump.

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-2025-39771 has been found in Kernel.
Risk of unauthorized operations or information disclosure.
What to do: upgrade Kernel to 6.16.4 or later.
If unsure, ask your IT team or search "Kernel CVE-2025-39771" on the vendor's site.

CVE-2025-39771 (Kernel)
Patched: 6.16.4 — 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 6.16.4.

🛡️ 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 6.16.4
```
ステージング環境で 6.16.4 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":"6.16.0"},{"fixed":"6.16.4"}]}]

Fix status by distribution

Fixed packages published by each distribution for this CVE

BellSoft Alpaquita BELL-CVE-2025-39771 linux-lts Fixed in: 6.18.35-r1
Debian DEBIAN-CVE-2025-39771 linux Fixed in: 6.16.5-1
Ubuntu UBUNTU-CVE-2025-39771 linux