Vulnerability in Kernel (CVE-2025-21722)

Summary

Vulnerability in Kernel (CVE-2025-21722). Successful exploitation can lead to full system takeover. Mitigation: upgrade to 5.4.291, 5.10.235, 5.15.179, 6.1.129, 6.12.13, 6.13.2 or later.

Original description

The description as published by the source.

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

nilfs2: do not force clear folio if buffer is referenced

Patch series "nilfs2: protect busy buffer heads from being force-cleared".

This series fixes the buffer head state inconsistency issues reported by
syzbot that occurs when the filesystem is corrupted and falls back to
read-only, and the associated buffer head use-after-free issue.

This patch (of 2):

Syzbot has reported that after nilfs2 detects filesystem corruption and
falls back to read-only, inconsistencies in the buffer state may occur.

One of the inconsistencies is that when nilfs2 calls mark_buffer_dirty()
to set a data or metadata buffer as dirty, but it detects that the buffer
is not in the uptodate state:

WARNING: CPU: 0 PID: 6049 at fs/buffer.c:1177 mark_buffer_dirty+0x2e5/0x520
fs/buffer.c:1177
...
Call Trace:

nilfs_palloc_commit_alloc_entry+0x4b/0x160 fs/nilfs2/alloc.c:598
nilfs_ifile_create_inode+0x1dd/0x3a0 fs/nilfs2/ifile.c:73
nilfs_new_inode+0x254/0x830 fs/nilfs2/inode.c:344
nilfs_mkdir+0x10d/0x340 fs/nilfs2/namei.c:218
vfs_mkdir+0x2f9/0x4f0 fs/namei.c:4257
do_mkdirat+0x264/0x3a0 fs/namei.c:4280
__do_sys_mkdirat fs/namei.c:4295 [inline]
__se_sys_mkdirat fs/namei.c:4293 [inline]
__x64_sys_mkdirat+0x87/0xa0 fs/namei.c:4293
do_syscall_x64 arch/x86/entry/common.c:52 [inline]
do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
entry_SYSCALL_64_after_hwframe+0x77/0x7f

The other is when nilfs_btree_propag…

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-2025-21722 has been found in Kernel.
Successful exploitation can lead to full system takeover.
What to do: upgrade Kernel to 5.4.291, 5.10.235, 5.15.179, 6.1.129, 6.12.13, 6.13.2 or later.
If unsure, ask your IT team or search "Kernel CVE-2025-21722" on the vendor's site.

CVE-2025-21722 (Kernel)
Attack vector: local / no user interaction
Patched: 5.4.291, 5.10.235, 5.15.179, 6.1.129, 6.12.13, 6.13.2 — 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: ?. Successful exploitation can lead to full system takeover.

🔧 How to fix

Update to 5.4.291, 5.10.235, 5.15.179, 6.1.129, 6.12.13, 6.13.2.

🛡️ 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 5.4.291, 5.10.235, 5.15.179, 6.1.129, 6.12.13, 6.13.2
```
ステージング環境で 5.4.291, 5.10.235, 5.15.179, 6.1.129, 6.12.13, 6.13.2 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":"3.10.0"},{"fixed":"5.4.291"}]},{"type":"ECOSYSTEM","events":[{"introduced":"5.5.0"},{"fixed":"5.10.235"}]},{"type":"ECOSYSTEM","events":[{"introduced":"5.11.0"},{"fixed":"5.15.179"}]},{"type":"ECOSYSTEM","events":[{"introduced":"5.16.0"},{"fixed":"6.1.129"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.2.0"},{"fixed":"6.12.13"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.13.0"},{"fixed":"6.13.2"}]}]

Fix status by distribution

Fixed packages published by each distribution for this CVE

BellSoft Alpaquita BELL-CVE-2025-21722 linux-lts Fixed in: 6.1.130-r0
Debian DEBIAN-CVE-2025-21722 linux Fixed in: 5.10.237-1
Ubuntu UBUNTU-CVE-2025-21722 linux