# CVE-2023-54020: dmaengine: sf-pdma: pdma_desc memory leak fix

> A memory leak in the Linux kernel sf-pdma driver allows attackers to cause memory starvation and denial of service.

- **Severity:** Not scored
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Not stated
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 24 Dec 2025
- **Updated:** 23 May 2026
- **Also known as:** BELL-CVE-2023-54020, DEBIAN-CVE-2023-54020, GHSA-4cm4-vw36-jc7r, ROOT-OS-DEBIAN-11-CVE-2023-54020, UBUNTU-CVE-2023-54020

## What is CVE-2023-54020?

CVE-2023-54020 is a denial of service vulnerability in Linux, published on 24 Dec 2025. 

### Official description

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

dmaengine: sf-pdma: pdma_desc memory leak fix

Commit b2cc5c465c2c ("dmaengine: sf-pdma: Add multithread support for a
DMA channel") changed sf_pdma_prep_dma_memcpy() to unconditionally
allocate a new sf_pdma_desc each time it is called.

The driver previously recycled descs, by checking the in_use flag, only
allocating additional descs if the existing one was in use. This logic
was removed in commit b2cc5c465c2c ("dmaengine: sf-pdma: Add multithread
support for a DMA channel"), but sf_pdma_free_desc() was not changed to
handle the new behaviour.

As a result, each time sf_pdma_prep_dma_memcpy() is called, the previous
descriptor is leaked, over time leading to memory starvation:

  unreferenced object 0xffffffe008447300 (size 192):
  comm "irq/39-mchp_dsc", pid 343, jiffies 4294906910 (age 981.200s)
  hex dump (first 32 bytes):
    00 00 00 ff 00 00 00 00 b8 c1 00 00 00 00 00 00  ................
    00 00 70 08 10 00 00 00 00 00 00 c0 00 00 00 00  ..p.............
  backtrace:
    [<00000000064a04f4>] kmemleak_alloc+0x1e/0x28
    [<00000000018927a7>] kmem_cache_alloc+0x11e/0x178
    [<000000002aea8d16>] sf_pdma_prep_dma_memcpy+0x40/0x112

Add the missing kfree() to sf_pdma_free_desc(), and remove the redundant
in_use flag.

## Which versions are affected by CVE-2023-54020?


## How do I fix CVE-2023-54020?

Apply the vendor's patch.

## Is CVE-2023-54020 being exploited?

There is no known exploitation of CVE-2023-54020 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2023-54020 and fix it if it is affected.

What it is: CVE-2023-54020 is a denial of service vulnerability in Linux, published on 24 Dec 2025. 
Exploitation: There is no known exploitation of CVE-2023-54020 in the wild and no public exploit code.

Affected product: 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-2023-54020/ (Markdown: https://insights.sbomify.com/CVE-2023-54020/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2023-54020
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2023-54020
- OSV: https://osv.dev/vulnerability/CVE-2023-54020

---
From sbomify Insights: https://insights.sbomify.com/CVE-2023-54020/
Summaries are generated and may contain mistakes; the official description above is the record.