Vulnerability in Kernel (CVE-2024-56740)

Summary

Vulnerability in Kernel (CVE-2024-56740). Successful exploitation can lead to full system takeover. Mitigation: upgrade to 6.12.2 or later.

Original description

The description as published by the source.

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

nfs/localio: must clear res.replen in nfs_local_read_done

Otherwise memory corruption can occur due to NFSv3 LOCALIO reads
leaving garbage in res.replen:

nfs3_read_done() copies that into server->read_hdrsize; from there
nfs3_proc_read_setup() copies it to args.replen in new requests.
nfs3_xdr_enc_read3args() passes that to rpc_prepare_reply_pages()
which includes it in hdrsize for xdr_init_pages, so that rq_rcv_buf
contains a ridiculous len.
This is copied to rq_private_buf and xs_read_stream_request()
eventually passes the kvec to sock_recvmsg() which receives incoming
data into entirely the wrong place.

This is easily reproduced with NFSv3 LOCALIO that is servicing reads
when it is made to pivot back to using normal RPC. This switch back
to using normal NFSv3 with RPC can occur for a few reasons but this
issue was exposed with a test that stops and then restarts the NFSv3
server while LOCALIO is performing heavy read IO.

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-2024-56740 has been found in Kernel.
Successful exploitation can lead to full system takeover.
What to do: upgrade Kernel to 6.12.2 or later.
If unsure, ask your IT team or search "Kernel CVE-2024-56740" on the vendor's site.

CVE-2024-56740 (Kernel)
Attack vector: local / no user interaction
Patched: 6.12.2 — 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: ?. Successful exploitation can lead to full system takeover.

🔧 How to fix

Update to 6.12.2.

🛡️ 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 6.12.2
```
ステージング環境で 6.12.2 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":"6.12.2"}]}]

Fix status by distribution

Fixed packages published by each distribution for this CVE

BellSoft Alpaquita BELL-CVE-2024-56740 linux-lts Fixed in: 6.12.41-r0