# CVE-2021-47172: iio: adc: ad7124: Fix potential overflow due to non sequential channel numbers

> A potential integer overflow in the AD7124 ADC driver allows attackers to cause memory corruption or denial of service via non-sequential channel numbers.

- **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:** 25 Mar 2024
- **Updated:** 23 May 2026
- **Also known as:** DEBIAN-CVE-2021-47172, GHSA-mpx6-5vmm-97rr, UBUNTU-CVE-2021-47172

## What is CVE-2021-47172?

CVE-2021-47172 is a medium-severity vulnerability in Linux kernel, published on 25 Mar 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:

iio: adc: ad7124: Fix potential overflow due to non sequential channel numbers

Channel numbering must start at 0 and then not have any holes, or
it is possible to overflow the available storage.  Note this bug was
introduced as part of a fix to ensure we didn't rely on the ordering
of child nodes.  So we need to support arbitrary ordering but they all
need to be there somewhere.

Note I hit this when using qemu to test the rest of this series.
Arguably this isn't the best fix, but it is probably the most minimal
option for backporting etc.

Alexandru's sign-off is here because he carried this patch in a larger
set that Jonathan then applied.

Weakness: CWE-120 (Buffer Copy without Checking Size of Input)

## Which versions are affected by CVE-2021-47172?

It affects 1 product.


Products: Linux kernel.

## How do I fix CVE-2021-47172?

Apply the vendor's patch.

## Is CVE-2021-47172 being exploited?

There is no known exploitation of CVE-2021-47172 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-2021-47172 and fix it if it is affected.

What it is: CVE-2021-47172 is a medium-severity vulnerability in Linux kernel, published on 25 Mar 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-2021-47172 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-2021-47172/ (Markdown: https://insights.sbomify.com/CVE-2021-47172/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2021-47172
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2021-47172
- OSV: https://osv.dev/vulnerability/CVE-2021-47172

---
From sbomify Insights: https://insights.sbomify.com/CVE-2021-47172/
Summaries are generated and may contain mistakes; the official description above is the record.