CVE-2026-68404: wifi: cfg80211: use wiphy work for socket owner autodisconnect

From: Greg Kroah-Hartman <[email protected]>

Description
===========

In the Linux kernel, the following vulnerability has been resolved:

wifi: cfg80211: use wiphy work for socket owner autodisconnect

nl80211_netlink_notify() walks the cfg80211 wireless device list when a
NETLINK_GENERIC socket is released. If the socket owns a connection, the
notifier queues the embedded wdev->disconnect_wk work item.

That work is a plain work_struct today. NETDEV_GOING_DOWN cancels it, but a
NETLINK_URELEASE notifier that already observed conn_owner_nlportid can
queue it after that cancel returns. _cfg80211_unregister_wdev() then
removes the wdev from the list and waits for RCU readers, but
synchronize_net() does not drain work queued by such a reader.

Make the autodisconnect work a wiphy_work instead. The callback already
needs the wiphy mutex, and wiphy_work runs under that mutex. This lets
teardown cancel pending autodisconnect work while holding the mutex,
without a cancel_work_sync() vs. worker locking concern.

Also cancel the wiphy work after list_del_rcu() and synchronize_net(). Any
NETLINK_URELEASE notifier that had already reached the wdev list has then
either queued the work and it is removed, or can no longer find the wdev.

The Linux kernel CVE team has assigned CVE-2026-68404 to this issue.


Affected and fixed versions
===========================

	Issue introduced in 4.11 with commit bd2522b168847106c1885f0319a2833bdf88bf9a and fixed in 7.1.6 with commit 6d6123fef5a4af175cc6b6b12a03dd0f3c240b79
	Issue introduced in 4.11 with commit bd2522b168847106c1885f0319a2833bdf88bf9a and fixed in 7.2-rc4 with commit 0c2ed186bbe14304415476d6707b747dddcd8583

Please see https://www.kernel.org for a full list of currently supported
kernel versions by the kernel community.

Unaffected versions might change over time as fixes are backported to
older supported kernel versions.  The official CVE entry at
	https://cve.org/CVERecord/?id=CVE-2026-68404
will be updated if fixes are backported, please check that for the most
up to date information about this issue.


Affected files
==============

The file(s) affected by this issue are:
	include/net/cfg80211.h
	net/wireless/core.c
	net/wireless/core.h
	net/wireless/nl80211.c
	net/wireless/sme.c


Mitigation
==========

The Linux kernel CVE team recommends that you update to the latest
stable kernel version for this, and many other bugfixes.  Individual
changes are never tested alone, but rather are part of a larger kernel
release.  Cherry-picking individual commits is not recommended or
supported by the Linux kernel community at all.  If however, updating to
the latest release is impossible, the individual changes to resolve this
issue can be found at these commits:
	https://git.kernel.org/stable/c/6d6123fef5a4af175cc6b6b12a03dd0f3c240b79
	https://git.kernel.org/stable/c/0c2ed186bbe14304415476d6707b747dddcd8583