CVE-2026-98423

Received Received - Intake

mac80211_hwsim Race Condition in Linux Kernel

Publication date: 2026-10-14

Last updated on: 2026-10-19

Assigner: kernel.org

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.

CVSS Scores

EPSS Scores

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Meta Information

Published

2026-10-14

Last Modified

2026-10-19

Generated

2026-10-19

AI Q&A

2026-10-15

EPSS Evaluated

2026-10-18

NVD

CVE-2026-98423

EUVD

EUVD-2026-101072

Affected Vendors & Products

Vendor	Product	Version / Range
Linux	Linux	7882513bacb176ab4aacceefdd035ca9479da4fb
Linux	Linux	7882513bacb176ab4aacceefdd035ca9479da4fb
Linux	Linux	7882513bacb176ab4aacceefdd035ca9479da4fb
Linux	Linux	7882513bacb176ab4aacceefdd035ca9479da4fb
Linux	Linux	7882513bacb176ab4aacceefdd035ca9479da4fb
Linux	Linux	7882513bacb176ab4aacceefdd035ca9479da4fb
Linux	Linux	3.1

Helpful Resources

Exploitability

CWE

KEV

CWE ID	Description
CWE-UNKNOWN

Attack-Flow Graph

Executive Summary

This vulnerability in the Linux kernel involves a race condition in the mac80211_hwsim module. When a radio is stopped, frames from wmediumd can still be processed by mac80211, causing a warning due to a check for the started state. The fix expands a mutex to synchronize frame delivery during radio stopping, preventing the warning.

Detection Guidance

This vulnerability is specific to the Linux kernel's mac80211_hwsim module and may not have direct detection commands. Monitoring kernel logs for WARN_ON warnings related to mac80211 or hwsim during radio operations could indicate exploitation. Check kernel logs with 'dmesg | grep mac80211' or 'journalctl -k | grep mac80211'.

Impact Analysis

This vulnerability could cause system instability or crashes in Linux systems using the mac80211_hwsim module, particularly in Wi-Fi simulation environments. It may lead to kernel warnings or errors during radio operations.

Compliance Impact

This vulnerability does not directly affect compliance with GDPR, HIPAA, or similar standards. It is a Linux kernel issue related to a race condition in the mac80211_hwsim driver, causing a warning but not a data breach or security failure.

Mitigation Strategies

Update the Linux kernel to the latest patched version to resolve the mac80211_hwsim vulnerability. Disable the hwsim module if not in use. Monitor system logs for WARN_ON(!local->started) messages indicating the issue.

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