Vulnerability in Kernel (CVE-2025-21688)

Summary

Vulnerability in Kernel (CVE-2025-21688). Risk of unauthorized operations or information disclosure. Mitigation: upgrade to 5.15.178, 6.1.128, 6.6.75, 6.12.12, 6.13.1 or later.

Original description

The description as published by the source.

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

drm/v3d: Assign job pointer to NULL before signaling the fence

In commit e4b5ccd392b9 ("drm/v3d: Ensure job pointer is set to NULL
after job completion"), we introduced a change to assign the job pointer
to NULL after completing a job, indicating job completion.

However, this approach created a race condition between the DRM
scheduler workqueue and the IRQ execution thread. As soon as the fence is
signaled in the IRQ execution thread, a new job starts to be executed.
This results in a race condition where the IRQ execution thread sets the
job pointer to NULL simultaneously as the run_job() function assigns
a new job to the pointer.

This race condition can lead to a NULL pointer dereference if the IRQ
execution thread sets the job pointer to NULL after run_job() assigns
it to the new job. When the new job completes and the GPU emits an
interrupt, v3d_irq() is triggered, potentially causing a crash.

[ 466.310099] Unable to handle kernel NULL pointer dereference at virtual address 00000000000000c0
[ 466.318928] Mem abort info:
[ 466.321723] ESR = 0x0000000096000005
[ 466.325479] EC = 0x25: DABT (current EL), IL = 32 bits
[ 466.330807] SET = 0, FnV = 0
[ 466.333864] EA = 0, S1PTW = 0
[ 466.337010] FSC = 0x05: level 1 translation fault
[ 466.341900] Data abort info:
[ 466.344783] ISV = 0, ISS = 0x00000005, ISS2 = 0x00000000
[ 466.350285] CM = 0, WnR = 0, TnD = 0, TagAccess = 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-2025-21688 has been found in Kernel.
Risk of unauthorized operations or information disclosure.
What to do: upgrade Kernel to 5.15.178, 6.1.128, 6.6.75, 6.12.12, 6.13.1 or later.
If unsure, ask your IT team or search "Kernel CVE-2025-21688" on the vendor's site.

CVE-2025-21688 (Kernel)
Attack vector: local / no user interaction
Patched: 5.15.178, 6.1.128, 6.6.75, 6.12.12, 6.13.1 — 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 5.15.178, 6.1.128, 6.6.75, 6.12.12, 6.13.1.

🛡️ 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 5.15.178, 6.1.128, 6.6.75, 6.12.12, 6.13.1
```
ステージング環境で 5.15.178, 6.1.128, 6.6.75, 6.12.12, 6.13.1 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":"0"},{"fixed":"5.15.178"}]},{"type":"ECOSYSTEM","events":[{"introduced":"5.16.0"},{"fixed":"6.1.128"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.2.0"},{"fixed":"6.6.75"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.7.0"},{"fixed":"6.12.12"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.13.0"},{"fixed":"6.13.1"}]}]

Fix status by distribution

Fixed packages published by each distribution for this CVE

BellSoft Alpaquita BELL-CVE-2025-21688 linux-lts Fixed in: 6.1.130-r0
Debian DEBIAN-CVE-2025-21688 linux Fixed in: 5.10.234-1