# CVE-2021-47516: nfp: Fix memory leak in nfp_cpp_area_cache_add()

> A memory leak in the Linux kernel's nfp driver can lead to resource exhaustion and denial of service.

- **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:** 24 May 2024
- **Updated:** 11 May 2026
- **Also known as:** DEBIAN-CVE-2021-47516, UBUNTU-CVE-2021-47516

## What is CVE-2021-47516?

CVE-2021-47516 is a medium-severity denial of service vulnerability in Linux kernel, published on 24 May 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:

nfp: Fix memory leak in nfp_cpp_area_cache_add()

In line 800 (#1), nfp_cpp_area_alloc() allocates and initializes a
CPP area structure. But in line 807 (#2), when the cache is allocated
failed, this CPP area structure is not freed, which will result in
memory leak.

We can fix it by freeing the CPP area when the cache is allocated
failed (#2).

792 int nfp_cpp_area_cache_add(struct nfp_cpp *cpp, size_t size)
793 {
794 	struct nfp_cpp_area_cache *cache;
795 	struct nfp_cpp_area *area;

800	area = nfp_cpp_area_alloc(cpp, NFP_CPP_ID(7, NFP_CPP_ACTION_RW, 0),
801 				  0, size);
	// #1: allocates and initializes

802 	if (!area)
803 		return -ENOMEM;

805 	cache = kzalloc(sizeof(*cache), GFP_KERNEL);
806 	if (!cache)
807 		return -ENOMEM; // #2: missing free

817	return 0;
818 }

Weakness: CWE-401 (Missing Release of Memory after Effective Lifetime)

## Which versions are affected by CVE-2021-47516?

It affects 1 product.


Products: Linux kernel.

## How do I fix CVE-2021-47516?

Apply the vendor's patch.

## Is CVE-2021-47516 being exploited?

There is no known exploitation of CVE-2021-47516 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-2021-47516 and fix it if it is affected.

What it is: CVE-2021-47516 is a medium-severity denial of service vulnerability in Linux kernel, published on 24 May 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-2021-47516 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-2021-47516/ (Markdown: https://insights.sbomify.com/CVE-2021-47516/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2021-47516
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2021-47516
- OSV: https://osv.dev/vulnerability/CVE-2021-47516

---
From sbomify Insights: https://insights.sbomify.com/CVE-2021-47516/
Summaries are generated and may contain mistakes; the official description above is the record.