Vulnerability in Kernel (CVE-2025-38221)

Summary

Vulnerability in Kernel (CVE-2025-38221). Risk of unauthorized operations or information disclosure. Mitigation: upgrade to 6.15.4 or later.

Original description

The description as published by the source.

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

ext4: fix out of bounds punch offset

Punching a hole with a start offset that exceeds max_end is not
permitted and will result in a negative length in the
truncate_inode_partial_folio() function while truncating the page cache,
potentially leading to undesirable consequences.

A simple reproducer:

truncate -s 9895604649994 /mnt/foo
xfs_io -c "pwrite 8796093022208 4096" /mnt/foo
xfs_io -c "fpunch 8796093022213 25769803777" /mnt/foo

kernel BUG at include/linux/highmem.h:275!
Oops: invalid opcode: 0000 [#1] SMP PTI
CPU: 3 UID: 0 PID: 710 Comm: xfs_io Not tainted 6.15.0-rc3
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.3-2.fc40 04/01/2014
RIP: 0010:zero_user_segments.constprop.0+0xd7/0x110
RSP: 0018:ffffc90001cf3b38 EFLAGS: 00010287
RAX: 0000000000000005 RBX: ffffea0001485e40 RCX: 0000000000001000
RDX: 000000000040b000 RSI: 0000000000000005 RDI: 000000000040b000
RBP: 000000000040affb R08: ffff888000000000 R09: ffffea0000000000
R10: 0000000000000003 R11: 00000000fffc7fc5 R12: 0000000000000005
R13: 000000000040affb R14: ffffea0001485e40 R15: ffff888031cd3000
FS: 00007f4f63d0b780(0000) GS:ffff8880d337d000(0000)
knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000001ae0b038 CR3: 00000000536aa000 CR4: 00000000000006f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0f…

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-2025-38221 has been found in Kernel.
Risk of unauthorized operations or information disclosure.
What to do: upgrade Kernel to 6.15.4 or later.
If unsure, ask your IT team or search "Kernel CVE-2025-38221" on the vendor's site.

CVE-2025-38221 (Kernel)
Patched: 6.15.4 — 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 6.15.4.

🛡️ 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 6.15.4
```
ステージング環境で 6.15.4 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":"6.15.0"},{"fixed":"6.15.4"}]}]

Fix status by distribution

Fixed packages published by each distribution for this CVE

BellSoft Alpaquita BELL-CVE-2025-38221 linux-lts Fixed in: 6.18.35-r1