# CVE-2024-56665: bpf,perf: Fix invalid prog_array access in perf_event_detach_bpf_prog

> A null pointer dereference in the Linux kernel's perf subsystem allows local attackers to cause a system crash by triggering a specific race condition during event detachment.

- **Severity:** Medium 5.5 (`CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/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:** 27 Dec 2024
- **Updated:** 23 May 2026
- **Also known as:** AZL-54770, AZL-55306, BELL-CVE-2024-56665, DEBIAN-CVE-2024-56665, GHSA-2x5w-q4pc-79qx, ROOT-OS-UBUNTU-2204-CVE-2024-56665, UBUNTU-CVE-2024-56665

## What is CVE-2024-56665?

CVE-2024-56665 is a medium-severity vulnerability in Linux kernel, published on 27 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:

bpf,perf: Fix invalid prog_array access in perf_event_detach_bpf_prog

Syzbot reported [1] crash that happens for following tracing scenario:

  - create tracepoint perf event with attr.inherit=1, attach it to the
    process and set bpf program to it
  - attached process forks -> chid creates inherited event

    the new child event shares the parent's bpf program and tp_event
    (hence prog_array) which is global for tracepoint

  - exit both process and its child -> release both events
  - first perf_event_detach_bpf_prog call will release tp_event->prog_array
    and second perf_event_detach_bpf_prog will crash, because
    tp_event->prog_array is NULL

The fix makes sure the perf_event_detach_bpf_prog checks prog_array
is valid before it tries to remove the bpf program from it.

[1] https://lore.kernel.org/bpf/Z1MR6dCIKajNS6nU@krava/T/#m91dbf0688221ec7a7fc95e896a7ef9ff93b0b8ad

## Which versions are affected by CVE-2024-56665?

It affects 1 product.


Products: Linux kernel.

## How do I fix CVE-2024-56665?

Apply the vendor's patch.

## Is CVE-2024-56665 being exploited?

There is no known exploitation of CVE-2024-56665 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-2024-56665 and fix it if it is affected.

What it is: CVE-2024-56665 is a medium-severity vulnerability in Linux kernel, published on 27 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-2024-56665 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-2024-56665/ (Markdown: https://insights.sbomify.com/CVE-2024-56665/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2024-56665
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2024-56665
- OSV: https://osv.dev/vulnerability/CVE-2024-56665

---
From sbomify Insights: https://insights.sbomify.com/CVE-2024-56665/
Summaries are generated and may contain mistakes; the official description above is the record.