Summary

Vulnerability in Kernel (CVE-2025-38443). Risk of unauthorized operations or information disclosure. Mitigation: upgrade to 5.15.189, 6.1.146, 6.6.99, 6.12.39, 6.15.7 or later.

Original description

The description as published by the source.

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

nbd: fix uaf in nbd_genl_connect() error path

There is a use-after-free issue in nbd:

block nbd6: Receive control failed (result -104)
block nbd6: shutting down sockets

BUG: KASAN: slab-use-after-free in recv_work+0x694/0xa80 drivers/block/nbd.c:1022
Write of size 4 at addr ffff8880295de478 by task kworker/u33:0/67

CPU: 2 UID: 0 PID: 67 Comm: kworker/u33:0 Not tainted 6.15.0-rc5-syzkaller-00123-g2c89c1b655c0 #0 PREEMPT(full)
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014
Workqueue: nbd6-recv recv_work
Call Trace:

__dump_stack lib/dump_stack.c:94 [inline]
dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:120
print_address_description mm/kasan/report.c:408 [inline]
print_report+0xc3/0x670 mm/kasan/report.c:521
kasan_report+0xe0/0x110 mm/kasan/report.c:634
check_region_inline mm/kasan/generic.c:183 [inline]
kasan_check_range+0xef/0x1a0 mm/kasan/generic.c:189
instrument_atomic_read_write include/linux/instrumented.h:96 [inline]
atomic_dec include/linux/atomic/atomic-instrumented.h:592 [inline]
recv_work+0x694/0xa80 drivers/block/nbd.c:1022
process_one_work+0x9cc/0x1b70 kernel/workqueue.c:3238
process_scheduled_works kernel/workqueue.c:3319 [inline]
worker_thread+0x6c8/0xf10 kernel/workqueue.c:3400
kthread+0x3c2/0x780 kernel/kthread.c:464
ret_from_fork+0x45/0x80 arch/x86/kernel/proc…

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-2025-38443 has been found in Kernel.
Risk of unauthorized operations or information disclosure.
What to do: upgrade Kernel to 5.15.189, 6.1.146, 6.6.99, 6.12.39, 6.15.7 or later.
If unsure, ask your IT team or search "Kernel CVE-2025-38443" on the vendor's site.

CVE-2025-38443 (Kernel)
Patched: 5.15.189, 6.1.146, 6.6.99, 6.12.39, 6.15.7 — 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 5.15.189, 6.1.146, 6.6.99, 6.12.39, 6.15.7.

🛡️ 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 5.15.189, 6.1.146, 6.6.99, 6.12.39, 6.15.7
```
ステージング環境で 5.15.189, 6.1.146, 6.6.99, 6.12.39, 6.15.7 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":"5.14.0"},{"fixed":"5.15.189"}]},{"type":"ECOSYSTEM","events":[{"introduced":"5.16.0"},{"fixed":"6.1.146"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.2.0"},{"fixed":"6.6.99"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.7.0"},{"fixed":"6.12.39"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.13.0"},{"fixed":"6.15.7"}]}]

Fix status by distribution

Fixed packages published by each distribution for this CVE

BellSoft Alpaquita BELL-CVE-2025-38443 linux-lts Fixed in: 6.1.147-r0
Debian DEBIAN-CVE-2025-38443 linux Fixed in: 6.1.147-1
Ubuntu UBUNTU-CVE-2025-38443 linux-hwe-edge