CVE-2026-68405
Received Received - Intake

Memory Leak in Linux Kernel WiFi Subsystem

Vulnerability report for CVE-2026-68405, including description, CVSS score, EPSS score, affected products, exploitability, helpful resources, and attack-flow context.

Publication date: 2026-08-10

Last updated on: 2026-08-10

Assigner: kernel.org

Description

In the Linux kernel, the following vulnerability has been resolved: wifi: mac80211: free AP_VLAN bc_buf SKBs outside IRQ lock ieee80211_do_stop() removes AP_VLAN packets from the parent AP ps->bc_buf while holding ps->bc_buf.lock with IRQs disabled. It then calls ieee80211_free_txskb() before dropping the lock. ieee80211_free_txskb() is not just a passive SKB release. For SKBs with TX status state it can report a dropped frame through cfg80211/nl80211, and that path can reach netlink tap transmit. This is the same reason the pending queue cleanup in ieee80211_do_stop() already unlinks SKBs under the queue lock and frees them after IRQ state is restored. The buggy scenario involves two paths, with each column showing the order within that path: AP_VLAN management TX: AP_VLAN stop: 1. attach ACK-status state 1. clear the running state 2. queue a multicast SKB on 2. take ps->bc_buf.lock with IRQs parent ps->bc_buf disabled 3. unlink the AP_VLAN SKB 4. call ieee80211_free_txskb() Unlink matching AP_VLAN SKBs from ps->bc_buf under the existing lock, but move them to a local free queue. Drop the lock and restore IRQ state before calling ieee80211_free_txskb(). WARNING: kernel/softirq.c:430 at __local_bh_enable_ip

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Meta Information

Published
2026-08-10
Last Modified
2026-08-10
Generated
2026-08-10
AI Q&A
2026-08-10
EPSS Evaluated
N/A
NVD
EUVD

Affected Vendors & Products

Showing 1 associated CPE
Vendor Product Version / Range
linux linux_kernel *

Helpful Resources

Exploitability

CWE
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CWE ID Description
CWE-UNKNOWN

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Executive Summary

This is a Linux kernel vulnerability where AP_VLAN packets are freed outside an IRQ lock. The ieee80211_do_stop() function removes packets while holding a lock with IRQs disabled, then calls ieee80211_free_txskb() which can trigger netlink tap transmit. This creates a race condition between AP_VLAN management and AP_VLAN stop operations.

Detection Guidance

This vulnerability is specific to the Linux kernel's mac80211 subsystem and requires kernel-level detection. Monitor kernel logs for warnings like 'kernel/softirq.c:430 at __local_bh_enable_ip' or errors related to AP_VLAN management. Check for crashes or hangs in wireless network interfaces during AP_VLAN operations.

Impact Analysis

This could lead to kernel crashes, memory corruption, or privilege escalation if exploited. Systems using affected Linux kernel versions with WiFi functionality may experience instability or security breaches.

Mitigation Strategies

Apply the latest kernel patches from your Linux distribution to resolve this issue. If immediate patching is not possible, disable AP_VLAN functionality or restrict multicast traffic on affected wireless interfaces as a temporary workaround.

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