Vulnerability in Kernel (CVE-2025-38147)

Summary

Vulnerability in Kernel (CVE-2025-38147). Risk of unauthorized operations or information disclosure. Mitigation: upgrade to 5.4.295, 5.10.239, 5.15.186, 6.1.142, 6.6.94, 6.12.34, 6.15.3 or later.

Original description

The description as published by the source.

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

calipso: Don't call calipso functions for AF_INET sk.

syzkaller reported a null-ptr-deref in txopt_get(). [0]

The offset 0x70 was of struct ipv6_txoptions in struct ipv6_pinfo,
so struct ipv6_pinfo was NULL there.

However, this never happens for IPv6 sockets as inet_sk(sk)->pinet6
is always set in inet6_create(), meaning the socket was not IPv6 one.

The root cause is missing validation in netlbl_conn_setattr().

netlbl_conn_setattr() switches branches based on struct
sockaddr.sa_family, which is passed from userspace. However,
netlbl_conn_setattr() does not check if the address family matches
the socket.

The syzkaller must have called connect() for an IPv6 address on
an IPv4 socket.

We have a proper validation in tcp_v[46]_connect(), but
security_socket_connect() is called in the earlier stage.

Let's copy the validation to netlbl_conn_setattr().

[0]:
Oops: general protection fault, probably for non-canonical address 0xdffffc000000000e: 0000 [#1] PREEMPT SMP KASAN NOPTI
KASAN: null-ptr-deref in range [0x0000000000000070-0x0000000000000077]
CPU: 2 UID: 0 PID: 12928 Comm: syz.9.1677 Not tainted 6.12.0 #1
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.15.0-1 04/01/2014
RIP: 0010:txopt_get include/net/ipv6.h:390 [inline]
RIP: 0010:
Code: 02 00 00 49 8b ac 24 f8 02 00 00 e8 84 69 2a fd e8 ff 00 16 fd 48 8d 7d 70 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 <80> 3c 02 00 0f 85 53 02 00…

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-2025-38147 has been found in Kernel.
Risk of unauthorized operations or information disclosure.
What to do: upgrade Kernel to 5.4.295, 5.10.239, 5.15.186, 6.1.142, 6.6.94, 6.12.34, 6.15.3 or later.
If unsure, ask your IT team or search "Kernel CVE-2025-38147" on the vendor's site.

CVE-2025-38147 (Kernel)
Patched: 5.4.295, 5.10.239, 5.15.186, 6.1.142, 6.6.94, 6.12.34, 6.15.3 — 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 5.4.295, 5.10.239, 5.15.186, 6.1.142, 6.6.94, 6.12.34, 6.15.3.

🛡️ 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 5.4.295, 5.10.239, 5.15.186, 6.1.142, 6.6.94, 6.12.34, 6.15.3
```
ステージング環境で 5.4.295, 5.10.239, 5.15.186, 6.1.142, 6.6.94, 6.12.34, 6.15.3 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":"4.8.0"},{"fixed":"5.4.295"}]},{"type":"ECOSYSTEM","events":[{"introduced":"5.5.0"},{"fixed":"5.10.239"}]},{"type":"ECOSYSTEM","events":[{"introduced":"5.11.0"},{"fixed":"5.15.186"}]},{"type":"ECOSYSTEM","events":[{"introduced":"5.16.0"},{"fixed":"6.1.142"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.2.0"},{"fixed":"6.6.94"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.7.0"},{"fixed":"6.12.34"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.13.0"},{"fixed":"6.15.3"}]}]

Fix status by distribution

Fixed packages published by each distribution for this CVE

BellSoft Alpaquita BELL-CVE-2025-38147 linux-lts Fixed in: 6.1.143-r1
Debian DEBIAN-CVE-2025-38147 linux Fixed in: 5.10.244-1
Ubuntu UBUNTU-CVE-2025-38147 linux-azure