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CVE-2026-68414
wifi: cfg80211: cancel sched scan results work on unregister
Published 2026-08-10 (2 months ago) by the Linux kernel CNA. Subsystem net/wireless. Debian urgency: not yet assigned.
What to do, per Debian release
Debian's own status for CVE-2026-68414 in every release this site tracks, and what each one means in practice. Every status below is the one the Debian Security Team publishes for this CVE. source
| Release | Status | Version | What this means |
|---|---|---|---|
| Debian 12bookworm | fixedDLA-4777-1 · 2026-09-08 · text | 6.1.187-1 | Update the kernel and reboot. DLA-4777-1 shipped the fix on 2026-09-08, in 6.1.187-1. A running kernel keeps the old code until the machine restarts. |
| Debian 13trixie | fixed | 6.12.101-1 | Update the kernel and reboot. Fixed in 6.12.101-1. A running kernel keeps the old code until the machine restarts. |
| Debian 14forky | fixed | 7.1.6-1 | Update the kernel and reboot. Fixed in 7.1.6-1. A running kernel keeps the old code until the machine restarts. |
| Debian unstablesid | fixed | 7.1.6-1 | Update the kernel and reboot. Fixed in 7.1.6-1. A running kernel keeps the old code until the machine restarts. |
| Debian 12bookworm · linux-6.12 | fixedDLA-4745-1 · 2026-08-18 · text | 6.12.101-1~deb12u1 | Update the kernel and reboot. DLA-4745-1 shipped the fix on 2026-08-18, in 6.12.101-1~deb12u1. A running kernel keeps the old code until the machine restarts. |
The vulnerability
What the bug is
cfg80211_sched_scan_results() can queue rdev->sched_scan_res_wk from a driver result notification while a scheduled scan request is present. The work callback recovers the containing cfg80211_registered_device and then locks the wiphy and walks the scheduled-scan request list. wiphy_unregister() already makes the wiphy unreachable and drains rdev work items before cfg80211_dev_free() can release the object, but it does not drain sched_scan_res_wk. A queued or running result work item can therefore cross the unregister/free boundary and access freed rdev state. The buggy scenario involves two paths, with each column showing the order within that path: scheduled-scan result path: unregister/free path: 1. cfg80211_sched_scan_results() 1. interface teardown stops and queues rdev->sched_scan_res_wk. removes the scheduled scan request. 2. cfg80211_wq starts the work 2. wiphy_unregister() drains other item and recovers rdev. rdev work items. 3. The worker locks rdev->wiphy 3. cfg80211_dev_free() destroys and and walks rdev state. frees rdev. Cancel sched_scan_res_wk in wiphy_unregister() alongside the other rdev work items. cancel_work_sync() removes a pending result notification and waits for an already running callback, so cfg80211_dev_free() cannot free rdev while this work item is still active. Validation reproduced this kernel report: BUG: KASAN: use-after-free in cfg80211_sched_scan_results_wk+0x4a6/0x530 Workqueue: cfg80211 cfg80211_sched_scan_results_wk [cfg80211] Read of size 8 Call trace: dump_stack_lvl+0x66/0xa0 print_report+0xce/0x630 cfg80211_sched_scan_results_wk+0x4a6/0x530 srso_alias_return_thunk+0x5/0xfbef5 __virt_addr_valid+0x224/0x430 kasan_report+0xac/0xe0 lockdep_hardirqs_on_prepare+0xea/0x1a0 process_one_work+0x8d0/0x18f0 (kernel/workqueue.c:3212) lock_is_held_type+0x8f/0x100 worker_thread+0x5ad/0xfd0 __kthread_parkme+0xc6/0x200 kthread+0x31e/0x410 trace_hardirqs_on+0x1a/0x170 ret_from_fork+0x576/0x810 __switch_to+0x57e/0xe20 __switch_to_asm+0x33/0x70 ret_from_fork_asm+0x1a/0x30
Where it lives
The fix touches these files. If the subsystem is one you do not use, the practical exposure is lower, though the package is still the vulnerable one.
net/wireless/core.c
- What this is
- 802.11 (including CFG80211/NL80211)MAINTAINERS section matched on net/wireless/ · linux-wireless@vger.kernel.org · Maintained
- Kernel module
- cfg80211
Check it on the machine
grep -wE 'CONFIG_CFG80211|CONFIG_WIRELESS' /boot/config-$(uname -r)Reads the booted kernel's own configuration, on the machine and nowhere else. =y is built in, =m is a module, and an is not set line means the code is not there.
lsmod | grep -w cfg80211Prints a line if that module is loaded right now, and nothing if it is not. One that is not loaded can still be loaded later by anything that needs it.
Show whether Debian builds this, per release
Debian builds this, but not on every flavour. At least one release below builds the code on some of its kernel flavours and not on others, so the answer depends on the architecture and flavour installed.
- bookwormMnot built on amd64/cloud-amd64, arm64/cloud-arm64
- trixie, forky, sidMnot built on amd64/cloud-amd64, arm64/cloud-arm64, s390x/s390x
- bookworm · linux-6.12Mnot built on amd64/cloud-amd64, arm64/cloud-arm64
- M
- a module where it is built at all; some flavours do not build it
- Build switches
- CONFIG_CFG80211, CONFIG_WIRELESS
- Reads as
- all on means the file is compiled; any one off means it is not.
From the configuration Debian publishes for every kernel flavour it builds. It covers only the architectures Debian ships a linux-config package for, and nothing about a kernel you built yourself. Debian's own status above stays authoritative about the source package.MAINTAINERS kbuild Makefiles Debian linux-config packages
Signals
- Published
- 2026-08-10 (2 months ago)source
- CVSS
- 7.5 high
CVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:Hsource recompute it - Attack vector
- adjacent network (AV:A)source
- EPSS
- 0.23%, higher than 12.8% of all CVEssource
- CISA KEV
- not listedthe KEV catalogue
- Debian urgency
- not yet assignedsource
- Subsystem
- net/wireless
Upstream fixes
The versions the CNA records as introducing and fixing this, and the commit for each. source
| Introduced | Fixed in | Commit |
|---|---|---|
| 3.0 | 5.15.216 | c0fa1f3a4b02 |
| 3.0 | 6.1.183 | b51b42b97446 |
| 3.0 | 6.6.148 | 3368457b4871 |
| 3.0 | 6.12.101 | 308ffdf57556 |
| 3.0 | 6.18.42 | 9293574ac208 |
| 3.0 | 7.1.6 | b119c70b2477 |
| 3.0 | 7.2 | edf0730be336 |
Debian advisories
| Advisory | Date | Shipped to | Debian |
|---|---|---|---|
| DLA-4777-1 | 2026-09-08 | bookworm 6.1.187-1 | tracker |
| DLA-4745-1 | 2026-08-18 | bookworm 6.12.101-1~deb12u1 | tracker |
Why the CNA scored it this way
Quoted from the kernel CNA's own scoring file, word for word. A highlighted metric carries the most severe value CVSS v3.1 defines for it, which is what pushes the score up. source
- AV:AAttack vector, adjacent network
- The work item is queued from driver PNO/background-scan match notifications that are produced by received 802.11 frames, so an attacker within WiFi range can drive cfg80211_sched_scan_results() by beaconing SSIDs matching the device's scheduled-scan match set. This is 802.11 frame injection, i.e. adjacent network reach.
- AC:HAttack complexity, high
- The UAF requires the result-notification work to be queued or running exactly while wiphy_unregister()/cfg80211_dev_free() tears the rdev down; the attacker can drive and time the result notifications but cannot force the device-removal/module-unload half of the race, which is a condition outside their control.
- PR:NPrivileges required, none
- No credentials or association are needed — an unauthenticated attacker in range simply transmits beacons/probe responses matching the scheduled scan already running on the victim (started by the system's normal wpa_supplicant/NetworkManager PNO), and the driver notifies cfg80211 unconditionally.
- UI:NUser interaction, none
- Scheduled scan runs continuously in the background on typical laptop, phone and embedded WiFi deployments, and the unregister side is a system/device event; no victim action such as opening a file or mounting anything is required.
- S:UScope, unchanged
- The freed object and all corrupted state are cfg80211 kernel structures, so the impact stays within the kernel's own security authority with no crossing of a VM, IOMMU or sandbox boundary.
- C:HConfidentiality impact, high
- The worker reads freed rdev memory and then feeds freed scheduled-scan request contents into nl80211_send_sched_scan(), leaking reclaimed slab data to userspace netlink listeners; a controlled reallocation of the freed rdev gives an arbitrary-read style disclosure primitive.
- I:HIntegrity impact, high
- After the free the worker performs writes into the freed object — mutex_lock on rdev->wiphy.mtx, spin_lock on rdev->bss_lock, clearing req->report_results, and list/refcount manipulation in __cfg80211_bss_expire() — which corrupts whatever object reclaims the slab and is leverageable for control-flow hijack via heap spraying.
- A:HAvailability impact, high
- The confirmed KASAN use-after-free in cfg80211_sched_scan_results_wk() corrupts and dereferences freed memory from a workqueue context, reliably producing an oops/panic and taking down the system.