# CVE-2024-43856: dma: fix call order in dmam_free_coherent

> A race condition in the Linux kernel DMA subsystem can cause a kernel warning and potential denial of service due to incorrect resource cleanup order.

- **Severity:** High 7.8 (`CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/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:** 17 Aug 2024
- **Updated:** 15 Oct 2026
- **Also known as:** AZL-47937, AZL-48027, BELL-CVE-2024-43856, DEBIAN-CVE-2024-43856, GHSA-g877-jjjq-5fjc, UBUNTU-CVE-2024-43856

## What is CVE-2024-43856?

CVE-2024-43856 is a high-severity vulnerability in Linux kernel, published on 17 Aug 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:

dma: fix call order in dmam_free_coherent

dmam_free_coherent() frees a DMA allocation, which makes the
freed vaddr available for reuse, then calls devres_destroy()
to remove and free the data structure used to track the DMA
allocation. Between the two calls, it is possible for a
concurrent task to make an allocation with the same vaddr
and add it to the devres list.

If this happens, there will be two entries in the devres list
with the same vaddr and devres_destroy() can free the wrong
entry, triggering the WARN_ON() in dmam_match.

Fix by destroying the devres entry before freeing the DMA
allocation.

  kokonut //net/encryption
    http://sponge2/b9145fe6-0f72-4325-ac2f-a84d81075b03

Weakness: CWE-770 (Allocation of Resources Without Limits or Throttling)

## Which versions are affected by CVE-2024-43856?

It affects 1 product.


Products: Linux kernel.

## How do I fix CVE-2024-43856?

Apply the vendor's patch.

## Is CVE-2024-43856 being exploited?

There is no known exploitation of CVE-2024-43856 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-2024-43856 and fix it if it is affected.

What it is: CVE-2024-43856 is a high-severity vulnerability in Linux kernel, published on 17 Aug 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-2024-43856 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-2024-43856/ (Markdown: https://insights.sbomify.com/CVE-2024-43856/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2024-43856
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2024-43856
- OSV: https://osv.dev/vulnerability/CVE-2024-43856

---
From sbomify Insights: https://insights.sbomify.com/CVE-2024-43856/
Summaries are generated and may contain mistakes; the official description above is the record.