# CVE-2021-47425: i2c: acpi: fix resource leak in reconfiguration device addition

> A resource leak in the Linux kernel's I2C ACPI driver prevents adapter removal, potentially leading to denial of service.

- **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:** 21 May 2024
- **Updated:** 11 May 2026
- **Also known as:** DEBIAN-CVE-2021-47425, GHSA-x858-gx5h-mfp9, UBUNTU-CVE-2021-47425

## What is CVE-2021-47425?

CVE-2021-47425 is a medium-severity denial of service vulnerability in Linux kernel, published on 21 May 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:

i2c: acpi: fix resource leak in reconfiguration device addition

acpi_i2c_find_adapter_by_handle() calls bus_find_device() which takes a
reference on the adapter which is never released which will result in a
reference count leak and render the adapter unremovable.  Make sure to
put the adapter after creating the client in the same manner that we do
for OF.

[wsa: fixed title]

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

## Which versions are affected by CVE-2021-47425?

It affects 1 product.


Products: Linux kernel.

## How do I fix CVE-2021-47425?

Apply the vendor's patch.

## Is CVE-2021-47425 being exploited?

There is no known exploitation of CVE-2021-47425 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-2021-47425 and fix it if it is affected.

What it is: CVE-2021-47425 is a medium-severity denial of service vulnerability in Linux kernel, published on 21 May 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-2021-47425 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-2021-47425/ (Markdown: https://insights.sbomify.com/CVE-2021-47425/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2021-47425
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2021-47425
- OSV: https://osv.dev/vulnerability/CVE-2021-47425

---
From sbomify Insights: https://insights.sbomify.com/CVE-2021-47425/
Summaries are generated and may contain mistakes; the official description above is the record.