Vulnerability in Kernel (CVE-2026-23390)

Summary

Vulnerability in Kernel (CVE-2026-23390). Risk of unauthorized operations or information disclosure. Mitigation: upgrade to 6.12.74, 6.18.13 or later.

Original description

The description as published by the source.

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

tracing/dma: Cap dma_map_sg tracepoint arrays to prevent buffer overflow

The dma_map_sg tracepoint can trigger a perf buffer overflow when
tracing large scatter-gather lists. With devices like virtio-gpu
creating large DRM buffers, nents can exceed 1000 entries, resulting
in:

phys_addrs: 1000 * 8 bytes = 8,000 bytes
dma_addrs: 1000 * 8 bytes = 8,000 bytes
lengths: 1000 * 4 bytes = 4,000 bytes
Total: ~20,000 bytes

This exceeds PERF_MAX_TRACE_SIZE (8192 bytes), causing:

WARNING: CPU: 0 PID: 5497 at kernel/trace/trace_event_perf.c:405
perf buffer not large enough, wanted 24620, have 8192

Cap all three dynamic arrays at 128 entries using min() in the array
size calculation. This ensures arrays are only as large as needed
(up to the cap), avoiding unnecessary memory allocation for small
operations while preventing overflow for large ones.

The tracepoint now records the full nents/ents counts and a truncated
flag so users can see when data has been capped.

Changes in v2:

Use min(nents, DMA_TRACE_MAX_ENTRIES) for dynamic array sizing
instead of fixed DMA_TRACE_MAX_ENTRIES allocation (feedback from
Steven Rostedt)
This allocates only what's needed up to the cap, avoiding waste
for small operations

Reviwed-by: Sean Anderson

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-2026-23390 has been found in Kernel.
Risk of unauthorized operations or information disclosure.
What to do: upgrade Kernel to 6.12.74, 6.18.13 or later.
If unsure, ask your IT team or search "Kernel CVE-2026-23390" on the vendor's site.

CVE-2026-23390 (Kernel)
Patched: 6.12.74, 6.18.13 — 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 6.12.74, 6.18.13.

🛡️ 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 6.12.74, 6.18.13
```
ステージング環境で 6.12.74, 6.18.13 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":"6.12.0"},{"fixed":"6.12.74"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.13.0"},{"fixed":"6.18.13"}]}]

Fix status by distribution

Fixed packages published by each distribution for this CVE

BellSoft Alpaquita BELL-CVE-2026-23390 linux-lts Fixed in: 6.12.74-r0
Debian DEBIAN-CVE-2026-23390 linux Fixed in: 6.12.74-1
Ubuntu UBUNTU-CVE-2026-23390 linux