Vulnerability in Kernel (CVE-2025-21953)

Summary

Vulnerability in Kernel (CVE-2025-21953). Risk of unauthorized operations or information disclosure. Mitigation: upgrade to 6.13.8 or later.

Original description

The description as published by the source.

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

net: mana: cleanup mana struct after debugfs_remove()

When on a MANA VM hibernation is triggered, as part of hibernate_snapshot(),
mana_gd_suspend() and mana_gd_resume() are called. If during this
mana_gd_resume(), a failure occurs with HWC creation, mana_port_debugfs
pointer does not get reinitialized and ends up pointing to older,
cleaned-up dentry.
Further in the hibernation path, as part of power_down(), mana_gd_shutdown()
is triggered. This call, unaware of the failures in resume, tries to cleanup
the already cleaned up mana_port_debugfs value and hits the following bug:

[ 191.359296] mana 7870:00:00.0: Shutdown was called
[ 191.359918] BUG: kernel NULL pointer dereference, address: 0000000000000098
[ 191.360584] #PF: supervisor write access in kernel mode
[ 191.361125] #PF: error_code(0x0002) - not-present page
[ 191.361727] PGD 1080ea067 P4D 0
[ 191.362172] Oops: Oops: 0002 [#1] SMP NOPTI
[ 191.362606] CPU: 11 UID: 0 PID: 1674 Comm: bash Not tainted 6.14.0-rc5+ #2
[ 191.363292] Hardware name: Microsoft Corporation Virtual Machine/Virtual Machine, BIOS Hyper-V UEFI Release v4.1 11/21/2024
[ 191.364124] RIP: 0010:down_write+0x19/0x50
[ 191.364537] Code: 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 0f 1f 44 00 00 55 48 89 e5 53 48 89 fb e8 de cd ff ff 31 c0 ba 01 00 00 00 48 0f b1 13 75 16 65 48 8b 05 88 24 4c 6a 48 89 43 08 48 8b 5d
[ 191.365867] RSP: 0000:ff45fbe0c1c037b8 EFLAGS: 0…

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-2025-21953 has been found in Kernel.
Risk of unauthorized operations or information disclosure.
What to do: upgrade Kernel to 6.13.8 or later.
If unsure, ask your IT team or search "Kernel CVE-2025-21953" on the vendor's site.

CVE-2025-21953 (Kernel)
Attack vector: local / no user interaction
Patched: 6.13.8 — 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 6.13.8.

🛡️ 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 6.13.8
```
ステージング環境で 6.13.8 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":"6.13.0"},{"fixed":"6.13.8"}]}]

Fix status by distribution

Fixed packages published by each distribution for this CVE

BellSoft Alpaquita BELL-CVE-2025-21953 linux-lts Fixed in: 6.18.35-r1