CVE-2026-68408

What the bug is

When a netlink socket that owns a PMSR session is closed, cfg80211_release_pmsr() clears the request's nl_portid and queues pmsr_free_wk to call cfg80211_pmsr_process_abort() asynchronously. If the interface tears down concurrently, cfg80211_pmsr_wdev_down() is called under wiphy_lock and calls cancel_work_sync(&pmsr_free_wk) to wait for any running work. The work function acquires wiphy_lock via guard(wiphy) before calling process_abort. This is a deadlock: wdev_down holds wiphy_lock and blocks inside cancel_work_sync(); pmsr_free_wk blocks trying to acquire that same wiphy_lock. Neither thread can proceed. The same deadlock is reachable from cfg80211_leave_locked(), which calls cfg80211_pmsr_wdev_down() for all interface types under wiphy_lock. Fix this by converting pmsr_free_wk from a plain work_struct to a wiphy_work. The wiphy_work dispatcher holds wiphy_lock when running work items, so the explicit guard(wiphy) in the work function is no longer needed. wiphy_work_cancel() can be called safely while holding wiphy_lock - since wiphy_lock prevents the work from running concurrently, wiphy_work_cancel() never blocks, eliminating the deadlock. Remove the cancel_work_sync() for pmsr_free_wk from the NETDEV_GOING_DOWN handler. cfg80211_leave(), called unconditionally just before it, already cancels any pending work under wiphy_lock via wiphy_work_cancel() inside cfg80211_pmsr_wdev_down().

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.

include/net/cfg80211.h
net/wireless/core.c
net/wireless/core.h
net/wireless/pmsr.c

What this is

802.11 (including CFG80211/NL80211)MAINTAINERS section matched on include/net/cfg80211.h · 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 cfg80211

Prints 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

no vector published, unrated

Attack vector

not published

EPSS

0.17%, higher than 5.7% of all CVEssource

CISA KEV

not listedthe KEV catalogue

Debian urgency

not yet assignedsource

Subsystem

include/net

Upstream fixes

The versions the CNA records as introducing and fixing this, and the commit for each. source

Introduced	Fixed in	Commit
6.12.78	6.12.101	21512b5f7a74
6.18.20	6.18.42	133684982dd0
7.0	7.1.6	0a77d9fb4d5c
7.0	7.2	2b0eab425e1f
6.1.167	0	0
6.6.130	0	0
6.19.10	0	0

Debian advisories