Vulnerability in Kernel (CVE-2025-38370)

Summary

Vulnerability in Kernel (CVE-2025-38370). Risk of unauthorized operations or information disclosure. Mitigation: upgrade to 6.15.6 or later.

Original description

The description as published by the source.

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

btrfs: fix failure to rebuild free space tree using multiple transactions

If we are rebuilding a free space tree, while modifying the free space
tree we may need to allocate a new metadata block group.
If we end up using multiple transactions for the rebuild, when we call
btrfs_end_transaction() we enter btrfs_create_pending_block_groups()
which calls add_block_group_free_space() to add items to the free space
tree for the block group.

Then later during the free space tree rebuild, at
btrfs_rebuild_free_space_tree(), we may find such new block groups
and call populate_free_space_tree() for them, which fails with -EEXIST
because there are already items in the free space tree. Then we abort the
transaction with -EEXIST at btrfs_rebuild_free_space_tree().
Notice that we say "may find" the new block groups because a new block
group may be inserted in the block groups rbtree, which is being iterated
by the rebuild process, before or after the current node where the rebuild
process is currently at.

Syzbot recently reported such case which produces a trace like the
following:

------------[ cut here ]------------
BTRFS: Transaction aborted (error -17)
WARNING: CPU: 1 PID: 7626 at fs/btrfs/free-space-tree.c:1341 btrfs_rebuild_free_space_tree+0x470/0x54c fs/btrfs/free-space-tree.c:1341
Modules linked in:
CPU: 1 UID: 0 PID: 7626 Comm: syz.2.25 Not tainted 6.15.0-rc7-syzkaller-00085-gd7fa1af5b33e-dirty #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-2025-38370 has been found in Kernel.
Risk of unauthorized operations or information disclosure.
What to do: upgrade Kernel to 6.15.6 or later.
If unsure, ask your IT team or search "Kernel CVE-2025-38370" on the vendor's site.

CVE-2025-38370 (Kernel)
Patched: 6.15.6 — 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 6.15.6.

🛡️ 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 6.15.6
```
ステージング環境で 6.15.6 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":"6.14.0"},{"fixed":"6.15.6"}]}]

Fix status by distribution

Fixed packages published by each distribution for this CVE

BellSoft Alpaquita BELL-CVE-2025-38370 linux-lts Fixed in: 6.18.35-r1
Ubuntu UBUNTU-CVE-2025-38370 linux-hwe-edge