CVE-2026-68405 is a vulnerability in Linux Kernel
Published on August 10, 2026
wifi: mac80211: free AP_VLAN bc_buf SKBs outside IRQ lock
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
Products Associated with CVE-2026-68405
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Affected Versions
Linux:- Version 397a7a24ef8c2967a3e8090013f9c54714110c48 and below be9dfcb0654c1f6c0fce7ba2a909683bb6f1e0ef is affected.
- Version 397a7a24ef8c2967a3e8090013f9c54714110c48 and below 962f755a47d7ec3bbf6c709697d7f4c5f798441d is affected.
- Version 397a7a24ef8c2967a3e8090013f9c54714110c48 and below a424985c3ef2a87ce6057a853e18d0c441a86be8 is affected.
- Version 397a7a24ef8c2967a3e8090013f9c54714110c48 and below 4b8abf43bf34791c99d99dc3be13f897adefc461 is affected.
- Version 397a7a24ef8c2967a3e8090013f9c54714110c48 and below f3858d5b1432098c1936e03d6e03dd0e33facf60 is affected.
- Version 3.9 is affected.
- Before 3.9 is unaffected.
- Version 6.6.148, <= 6.6.* is unaffected.
- Version 6.12.101, <= 6.12.* is unaffected.
- Version 6.18.42, <= 6.18.* is unaffected.
- Version 7.1.6, <= 7.1.* is unaffected.
- Version 7.2-rc4, <= * is unaffected.