CVE-2026-68405

Technical 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

Remediation

Check the references section for vendor advisories, patches, and mitigation guidance. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.

References