# CVE-2021-47105: ice: xsk: return xsk buffers back to pool when cleaning the ring

> A memory leak in the Linux kernel ice driver allows attackers to exhaust buffer pools, causing 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:** 4 Mar 2024
- **Updated:** 11 May 2026
- **Also known as:** DEBIAN-CVE-2021-47105, GHSA-477j-vcp2-hh67, ROOT-OS-DEBIAN-11-CVE-2021-47105, UBUNTU-CVE-2021-47105

## What is CVE-2021-47105?

CVE-2021-47105 is a medium-severity denial of service vulnerability in Linux kernel, published on 4 Mar 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:

ice: xsk: return xsk buffers back to pool when cleaning the ring

Currently we only NULL the xdp_buff pointer in the internal SW ring but
we never give it back to the xsk buffer pool. This means that buffers
can be leaked out of the buff pool and never be used again.

Add missing xsk_buff_free() call to the routine that is supposed to
clean the entries that are left in the ring so that these buffers in the
umem can be used by other sockets.

Also, only go through the space that is actually left to be cleaned
instead of a whole ring.

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

## Which versions are affected by CVE-2021-47105?

It affects 1 product.


Products: Linux kernel.

## How do I fix CVE-2021-47105?

Apply the vendor's patch.

## Is CVE-2021-47105 being exploited?

There is no known exploitation of CVE-2021-47105 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-2021-47105 and fix it if it is affected.

What it is: CVE-2021-47105 is a medium-severity denial of service vulnerability in Linux kernel, published on 4 Mar 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-2021-47105 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-2021-47105/ (Markdown: https://insights.sbomify.com/CVE-2021-47105/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2021-47105
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2021-47105
- OSV: https://osv.dev/vulnerability/CVE-2021-47105

---
From sbomify Insights: https://insights.sbomify.com/CVE-2021-47105/
Summaries are generated and may contain mistakes; the official description above is the record.