# CVE-2024-57843: virtio-net: fix overflow inside virtnet_rq_alloc

> An integer overflow in the Linux kernel virtio-net driver can cause system crashes or denial of service when specific network allocation settings are enabled.

- **Severity:** Critical 9.8 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 11 Jan 2025
- **Updated:** 5 Aug 2026
- **Also known as:** AZL-67779, BELL-CVE-2024-57843, DEBIAN-CVE-2024-57843, GHSA-rvwg-gc58-2352, ROOT-OS-DEBIAN-11-CVE-2024-57843, ROOT-OS-DEBIAN-12-CVE-2024-57843, ROOT-OS-UBUNTU-2204-CVE-2024-57843, UBUNTU-CVE-2024-57843

## What is CVE-2024-57843?

CVE-2024-57843 is a critical vulnerability in Linux kernel, published on 11 Jan 2025. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

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

virtio-net: fix overflow inside virtnet_rq_alloc

When the frag just got a page, then may lead to regression on VM.
Specially if the sysctl net.core.high_order_alloc_disable value is 1,
then the frag always get a page when do refill.

Which could see reliable crashes or scp failure (scp a file 100M in size
to VM).

The issue is that the virtnet_rq_dma takes up 16 bytes at the beginning
of a new frag. When the frag size is larger than PAGE_SIZE,
everything is fine. However, if the frag is only one page and the
total size of the buffer and virtnet_rq_dma is larger than one page, an
overflow may occur.

The commit f9dac92ba908 ("virtio_ring: enable premapped mode whatever
use_dma_api") introduced this problem. And we reverted some commits to
fix this in last linux version. Now we try to enable it and fix this
bug directly.

Here, when the frag size is not enough, we reduce the buffer len to fix
this problem.

Weakness: CWE-191 (Integer Underflow (Wrap or Wraparound))

## Which versions are affected by CVE-2024-57843?

It affects 1 product.


Products: Linux kernel.

## How do I fix CVE-2024-57843?

Apply the vendor's patch.

## Is CVE-2024-57843 being exploited?

There is no known exploitation of CVE-2024-57843 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-2024-57843 and fix it if it is affected.

What it is: CVE-2024-57843 is a critical vulnerability in Linux kernel, published on 11 Jan 2025. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2024-57843 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-2024-57843/ (Markdown: https://insights.sbomify.com/CVE-2024-57843/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2024-57843
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2024-57843
- OSV: https://osv.dev/vulnerability/CVE-2024-57843

---
From sbomify Insights: https://insights.sbomify.com/CVE-2024-57843/
Summaries are generated and may contain mistakes; the official description above is the record.