Vulnerability in Kernel (CVE-2024-56755)

Summary

Vulnerability in Kernel (CVE-2024-56755). Risk of unauthorized operations or information disclosure. Mitigation: upgrade to 6.1.120, 6.6.64, 6.11.11, 6.12.2 or later.

Original description

The description as published by the source.

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

netfs/fscache: Add a memory barrier for FSCACHE_VOLUME_CREATING

In fscache_create_volume(), there is a missing memory barrier between the
bit-clearing operation and the wake-up operation. This may cause a
situation where, after a wake-up, the bit-clearing operation hasn't been
detected yet, leading to an indefinite wait. The triggering process is as
follows:

[cookie1] [cookie2] [volume_work]
fscache_perform_lookup
fscache_create_volume
fscache_perform_lookup
fscache_create_volume
fscache_create_volume_work
cachefiles_acquire_volume
clear_and_wake_up_bit
test_and_set_bit
test_and_set_bit
goto maybe_wait
goto no_wait

In the above process, cookie1 and cookie2 has the same volume. When cookie1
enters the -no_wait- process, it will clear the bit and wake up the waiting
process. If a barrier is missing, it may cause cookie2 to remain in the
-wait- process indefinitely.

In commit 3288666c7256 ("fscache: Use clear_and_wake_up_bit() in
fscache_create_volume_work()"), barriers were added to similar operations
in fscache_create_volume_work(), but fscache_create_volume() was missed.

By combining the clear and wake operations into clear_and…

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-2024-56755 has been found in Kernel.
Risk of unauthorized operations or information disclosure.
What to do: upgrade Kernel to 6.1.120, 6.6.64, 6.11.11, 6.12.2 or later.
If unsure, ask your IT team or search "Kernel CVE-2024-56755" on the vendor's site.

CVE-2024-56755 (Kernel)
Attack vector: local / no user interaction
Patched: 6.1.120, 6.6.64, 6.11.11, 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: ?. Risk of unauthorized operations or information disclosure.

🔧 How to fix

Update to 6.1.120, 6.6.64, 6.11.11, 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 6.1.120, 6.6.64, 6.11.11, 6.12.2
```
ステージング環境で 6.1.120, 6.6.64, 6.11.11, 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":"5.17.0"},{"fixed":"6.1.120"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.2.0"},{"fixed":"6.6.64"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.7.0"},{"fixed":"6.11.11"}]},{"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-2024-56755 linux-lts Fixed in: 6.1.120-r0
Debian DEBIAN-CVE-2024-56755 linux Fixed in: 6.1.123-1
Ubuntu UBUNTU-CVE-2024-56755 linux-hwe-edge