# CVE-2024-56706: s390/cpum_sf: Fix and protect memory allocation of SDBs with mutex

> A race condition in the s390 CPU measurement facility allows concurrent allocations, potentially causing memory corruption or information disclosure.

- **Severity:** High 7.8 (`CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 28 Dec 2024
- **Updated:** 5 Aug 2026
- **Also known as:** BELL-CVE-2024-56706, GHSA-m2p9-vjrp-wj7v, UBUNTU-CVE-2024-56706

## What is CVE-2024-56706?

CVE-2024-56706 is a high-severity vulnerability in Linux kernel, published on 28 Dec 2024. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

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

s390/cpum_sf: Fix and protect memory allocation of SDBs with mutex

Reservation of the PMU hardware is done at first event creation
and is protected by a pair of mutex_lock() and mutex_unlock().
After reservation of the PMU hardware the memory
required for the PMUs the event is to be installed on is
allocated by allocate_buffers() and alloc_sampling_buffer().
This done outside of the mutex protection.
Without mutex protection two or more concurrent invocations of
perf_event_init() may run in parallel.
This can lead to allocation of Sample Data Blocks (SDBs)
multiple times for the same PMU.
Prevent this and protect memory allocation of SDBs by
mutex.

Weakness: CWE-362 (Concurrent Execution using Shared Resource with Improper Synchronization), CWE-125 (Out-of-bounds Read)

## Which versions are affected by CVE-2024-56706?

It affects 1 product.


Products: Linux kernel.

## How do I fix CVE-2024-56706?

Apply the vendor's patch.

## Is CVE-2024-56706 being exploited?

There is no known exploitation of CVE-2024-56706 in the wild and no public exploit code.

## Other vulnerabilities in Linux kernel

- [CVE-2026-53266](https://insights.sbomify.com/CVE-2026-53266/): Linux Kernel Out-of-Bounds Write (high 8.8, exploited in the wild)
- [CVE-2013-6282](https://insights.sbomify.com/CVE-2013-6282/): Linux Kernel Improper Input Validation (high 8.8, exploited in the wild)
- [CVE-2022-0185](https://insights.sbomify.com/CVE-2022-0185/): Linux Kernel Heap-Based Buffer Overflow (high 8.4, exploited in the wild)
- [CVE-2013-2094](https://insights.sbomify.com/CVE-2013-2094/): Linux Kernel Privilege Escalation (high 8.4, exploited in the wild)
- [CVE-2026-53362](https://insights.sbomify.com/CVE-2026-53362/): Linux Kernel Unspecified (high 7.8, exploited in the wild)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2024-56706 and fix it if it is affected.

What it is: CVE-2024-56706 is a high-severity vulnerability in Linux kernel, published on 28 Dec 2024. It can only be exploited from the same machine or local network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2024-56706 in the wild and no public exploit code.

Affected product: Linux kernel. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2024-56706/ (Markdown: https://insights.sbomify.com/CVE-2024-56706/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2024-56706
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2024-56706
- OSV: https://osv.dev/vulnerability/CVE-2024-56706

---
From sbomify Insights: https://insights.sbomify.com/CVE-2024-56706/
Summaries are generated and may contain mistakes; the official description above is the record.