# CVE-2026-68405: wifi: mac80211: free AP_VLAN bc_buf SKBs outside IRQ lock

Status: published. Published: 2026-08-10. Updated: 2026-11-06.

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

## Remediation

No remediation reported in collected sources

## Affected products and versions

- Linux / Linux: ≥ 397a7a24ef8c2967a3e8090013f9c54714110c48; < 0d2619e708e2ef02ba1c91642ea261d3f19d8f9a (affected, git); ≥ 397a7a24ef8c2967a3e8090013f9c54714110c48; < 659a81b62a61440b85e02c09903be861ae7679e5 (affected, git); ≥ 397a7a24ef8c2967a3e8090013f9c54714110c48; < aa01ef0ebbc3289154229ef58e65baf289eb9789 (affected, git); ≥ 397a7a24ef8c2967a3e8090013f9c54714110c48; < be9dfcb0654c1f6c0fce7ba2a909683bb6f1e0ef (affected, git); ≥ 397a7a24ef8c2967a3e8090013f9c54714110c48; < 962f755a47d7ec3bbf6c709697d7f4c5f798441d (affected, git); ≥ 397a7a24ef8c2967a3e8090013f9c54714110c48; < a424985c3ef2a87ce6057a853e18d0c441a86be8 (affected, git); ≥ 397a7a24ef8c2967a3e8090013f9c54714110c48; < 4b8abf43bf34791c99d99dc3be13f897adefc461 (affected, git); ≥ 397a7a24ef8c2967a3e8090013f9c54714110c48; < f3858d5b1432098c1936e03d6e03dd0e33facf60 (affected, git). Source: CNA: Linux
- Linux / Linux: 3.9 (affected); ≥ 0; < 3.9 (unaffected, semver); ≥ 5.10.265; ≤ 5.10.* (unaffected, semver); ≥ 5.15.216; ≤ 5.15.* (unaffected, semver); ≥ 6.1.183; ≤ 6.1.* (unaffected, semver); ≥ 6.6.148; ≤ 6.6.* (unaffected, semver); ≥ 6.12.101; ≤ 6.12.* (unaffected, semver); ≥ 6.18.42; ≤ 6.18.* (unaffected, semver); ≥ 7.1.6; ≤ 7.1.* (unaffected, semver); ≥ 7.2; ≤ * (unaffected, original_commit_for_fix). Source: CNA: Linux

## Severity and prioritization

- CISA KEV: No listing in collected sources

- EPSS: 0.22% as of 2026-11-06; percentile 12.61%

- SSVC: exploitation none; automatable no; technical impact partial; source ADP: CISA-ADP

- Weaknesses: Not reported

## Exploit evidence

No exploit evidence in collected sources. This is not proof of no exploitation.

## References

- https://git.kernel.org/stable/c/0d2619e708e2ef02ba1c91642ea261d3f19d8f9a (CNA: Linux)

- https://git.kernel.org/stable/c/659a81b62a61440b85e02c09903be861ae7679e5 (CNA: Linux)

- https://git.kernel.org/stable/c/aa01ef0ebbc3289154229ef58e65baf289eb9789 (CNA: Linux)

- https://git.kernel.org/stable/c/be9dfcb0654c1f6c0fce7ba2a909683bb6f1e0ef (CNA: Linux)

- https://git.kernel.org/stable/c/962f755a47d7ec3bbf6c709697d7f4c5f798441d (CNA: Linux)

- https://git.kernel.org/stable/c/a424985c3ef2a87ce6057a853e18d0c441a86be8 (CNA: Linux)

- https://git.kernel.org/stable/c/4b8abf43bf34791c99d99dc3be13f897adefc461 (CNA: Linux)

- https://git.kernel.org/stable/c/f3858d5b1432098c1936e03d6e03dd0e33facf60 (CNA: Linux)

- https://git.kernel.org/stable/c/0d2619e708e2ef02ba1c91642ea261d3f19d8f9a (416baaa9-dc9f-4396-8d5f-8c081fb06d67)

- https://git.kernel.org/stable/c/4b8abf43bf34791c99d99dc3be13f897adefc461 (416baaa9-dc9f-4396-8d5f-8c081fb06d67)

- https://git.kernel.org/stable/c/659a81b62a61440b85e02c09903be861ae7679e5 (416baaa9-dc9f-4396-8d5f-8c081fb06d67)

- https://git.kernel.org/stable/c/962f755a47d7ec3bbf6c709697d7f4c5f798441d (416baaa9-dc9f-4396-8d5f-8c081fb06d67)

- https://git.kernel.org/stable/c/a424985c3ef2a87ce6057a853e18d0c441a86be8 (416baaa9-dc9f-4396-8d5f-8c081fb06d67)

- https://git.kernel.org/stable/c/aa01ef0ebbc3289154229ef58e65baf289eb9789 (416baaa9-dc9f-4396-8d5f-8c081fb06d67)

- https://git.kernel.org/stable/c/be9dfcb0654c1f6c0fce7ba2a909683bb6f1e0ef (416baaa9-dc9f-4396-8d5f-8c081fb06d67)

- https://git.kernel.org/stable/c/f3858d5b1432098c1936e03d6e03dd0e33facf60 (416baaa9-dc9f-4396-8d5f-8c081fb06d67)

## Provenance

- CNA: Linux: https://www.cve.org/CVERecord?id=CVE-2026-68405; retrieved 2026-11-06; source updated 2026-11-06

- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-68405; retrieved 2026-11-06; source updated 2026-11-06

- FIRST EPSS: https://api.first.org/data/v1/epss?cve=CVE-2026-68405; retrieved 2026-11-06; source updated Not reported

Revision: a50bb016d739388767b0b39efbff10da0e620a17bb91264f37c0f6ae32438a26

Canonical: https://y2.dev/cve/CVE-2026-68405

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