# CVE-2024-27066: virtio: packed: fix unmap leak for indirect desc table

> A memory leak in the Linux kernel virtio driver can cause resource exhaustion and denial of service when specific DMA configurations are used.

- **Severity:** High 7.5 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/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:** 1 May 2024
- **Updated:** 5 Aug 2026
- **Also known as:** BELL-CVE-2024-27066, DEBIAN-CVE-2024-27066, GHSA-857r-xmrg-gj95, UBUNTU-CVE-2024-27066

## What is CVE-2024-27066?

CVE-2024-27066 is a high-severity memory corruption vulnerability in Linux kernel, published on 1 May 2024. 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: packed: fix unmap leak for indirect desc table

When use_dma_api and premapped are true, then the do_unmap is false.

Because the do_unmap is false, vring_unmap_extra_packed is not called by
detach_buf_packed.

  if (unlikely(vq->do_unmap)) {
                curr = id;
                for (i = 0; i < state->num; i++) {
                        vring_unmap_extra_packed(vq,
                                                 &vq->packed.desc_extra[curr]);
                        curr = vq->packed.desc_extra[curr].next;
                }
  }

So the indirect desc table is not unmapped. This causes the unmap leak.

So here, we check vq->use_dma_api instead. Synchronously, dma info is
updated based on use_dma_api judgment

This bug does not occur, because no driver use the premapped with
indirect.

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

## Which versions are affected by CVE-2024-27066?

It affects 1 product.


Products: Linux kernel.

## How do I fix CVE-2024-27066?

Apply the vendor's patch.

## Is CVE-2024-27066 being exploited?

There is no known exploitation of CVE-2024-27066 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-2024-27066 and fix it if it is affected.

What it is: CVE-2024-27066 is a high-severity memory corruption vulnerability in Linux kernel, published on 1 May 2024. 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-2024-27066 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-2024-27066/ (Markdown: https://insights.sbomify.com/CVE-2024-27066/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2024-27066
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2024-27066
- OSV: https://osv.dev/vulnerability/CVE-2024-27066

---
From sbomify Insights: https://insights.sbomify.com/CVE-2024-27066/
Summaries are generated and may contain mistakes; the official description above is the record.