# CVE-2021-29264: Denial of service in n/a

> Attackers can crash the system via a negative fragment size calculation in the Freescale Gianfar Ethernet driver when jumbo packets and NAPI are enabled.

- **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:** 26 Mar 2021
- **Updated:** 3 Aug 2024
- **Also known as:** AZL-6546, DEBIAN-CVE-2021-29264, GHSA-chjc-vrcx-99p5, UBUNTU-CVE-2021-29264

## What is CVE-2021-29264?

CVE-2021-29264 is a medium-severity denial of service vulnerability in Debian Debian Linux, published on 26 Mar 2021. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

An issue was discovered in the Linux kernel through 5.11.10. drivers/net/ethernet/freescale/gianfar.c in the Freescale Gianfar Ethernet driver allows attackers to cause a system crash because a negative fragment size is calculated in situations involving an rx queue overrun when jumbo packets are used and NAPI is enabled, aka CID-d8861bab48b6.

## Which versions are affected by CVE-2021-29264?

It affects 2 products.


Products: Debian Debian Linux, Linux kernel.

## How do I fix CVE-2021-29264?

Apply the vendor's patch.

## Is CVE-2021-29264 being exploited?

There is no known exploitation of CVE-2021-29264 in the wild and no public exploit code.

## Other vulnerabilities in Debian Debian Linux

- [CVE-2015-3306](https://insights.sbomify.com/CVE-2015-3306/): ProFTPD Improper Access Control (critical 10.0, exploited in the wild)
- [CVE-2025-49113](https://insights.sbomify.com/CVE-2025-49113/): RoundCube Webmail Deserialization of Untrusted Data (critical 9.9, exploited in the wild)
- [CVE-2026-24061](https://insights.sbomify.com/CVE-2026-24061/): GNU InetUtils Argument Injection (critical 9.8, exploited in the wild)
- [CVE-2025-39682](https://insights.sbomify.com/CVE-2025-39682/): Linux Kernel Improper Check for Unusual or Exceptional Conditions (critical 9.8, exploited in the wild)
- [CVE-2024-9680](https://insights.sbomify.com/CVE-2024-9680/): Mozilla Firefox Use-After-Free (critical 9.8, exploited in the wild)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2021-29264 and fix it if it is affected.

What it is: CVE-2021-29264 is a medium-severity denial of service vulnerability in Debian Debian Linux, published on 26 Mar 2021. 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-2021-29264 in the wild and no public exploit code.

Affected product: Debian Debian Linux. 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-2021-29264/ (Markdown: https://insights.sbomify.com/CVE-2021-29264/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2021-29264
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2021-29264
- OSV: https://osv.dev/vulnerability/CVE-2021-29264

---
From sbomify Insights: https://insights.sbomify.com/CVE-2021-29264/
Summaries are generated and may contain mistakes; the official description above is the record.