Vulnerability in Kernel (CVE-2025-21951)

Summary

Vulnerability in Kernel (CVE-2025-21951). Risk of unauthorized operations or information disclosure. Mitigation: upgrade to 5.15.179, 6.1.131, 6.6.83, 6.12.19, 6.13.7 or later.

Original description

The description as published by the source.

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

bus: mhi: host: pci_generic: Use pci_try_reset_function() to avoid deadlock

There are multiple places from where the recovery work gets scheduled
asynchronously. Also, there are multiple places where the caller waits
synchronously for the recovery to be completed. One such place is during
the PM shutdown() callback.

If the device is not alive during recovery_work, it will try to reset the
device using pci_reset_function(). This function internally will take the
device_lock() first before resetting the device. By this time, if the lock
has already been acquired, then recovery_work will get stalled while
waiting for the lock. And if the lock was already acquired by the caller
which waits for the recovery_work to be completed, it will lead to
deadlock.

This is what happened on the X1E80100 CRD device when the device died
before shutdown() callback. Driver core calls the driver's shutdown()
callback while holding the device_lock() leading to deadlock.

And this deadlock scenario can occur on other paths as well, like during
the PM suspend() callback, where the driver core would hold the
device_lock() before calling driver's suspend() callback. And if the
recovery_work was already started, it could lead to deadlock. This is also
observed on the X1E80100 CRD.

So to fix both issues, use pci_try_reset_function() in recovery_work. This
function first checks for the availability of the device_lock() before
trying…

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-2025-21951 has been found in Kernel.
Risk of unauthorized operations or information disclosure.
What to do: upgrade Kernel to 5.15.179, 6.1.131, 6.6.83, 6.12.19, 6.13.7 or later.
If unsure, ask your IT team or search "Kernel CVE-2025-21951" on the vendor's site.

CVE-2025-21951 (Kernel)
Attack vector: local / no user interaction
Patched: 5.15.179, 6.1.131, 6.6.83, 6.12.19, 6.13.7 — 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 5.15.179, 6.1.131, 6.6.83, 6.12.19, 6.13.7.

🛡️ 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 5.15.179, 6.1.131, 6.6.83, 6.12.19, 6.13.7
```
ステージング環境で 5.15.179, 6.1.131, 6.6.83, 6.12.19, 6.13.7 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":"5.12.0"},{"fixed":"5.15.179"}]},{"type":"ECOSYSTEM","events":[{"introduced":"5.16.0"},{"fixed":"6.1.131"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.2.0"},{"fixed":"6.6.83"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.7.0"},{"fixed":"6.12.19"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.13.0"},{"fixed":"6.13.7"}]}]

Fix status by distribution

Fixed packages published by each distribution for this CVE

BellSoft Alpaquita BELL-CVE-2025-21951 linux-lts Fixed in: 6.1.131-r0
Debian DEBIAN-CVE-2025-21951 linux Fixed in: 6.1.133-1
Ubuntu UBUNTU-CVE-2025-21951 linux-hwe-edge