CVE-2026-68470: wifi: mac80211: validate extension-frame layout before RX

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

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

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

wifi: mac80211: validate extension-frame layout before RX

Extension frames only have the extension header at the regular 802.11
header offset. The generic RX path can still reach helpers and interface
dispatch code that read regular header address fields before unsupported
extension subtypes are dropped.

mac80211 currently only handles S1G beacon extension frames. Drop other
extension subtypes before they can reach regular-header RX processing.
For S1G beacons, linearize the SKB with the management-frame path and
require the fixed S1G beacon header, including optional fixed fields
indicated by frame control, before generic RX dispatch.

Route S1G beacons through the station/default-link RX path without
regular-header station lookup. Avoid regular-header address reads in the
mac80211 RX paths that process S1G extension beacons, including
accept-frame, duplicate-detection, address-copy, and MLO
address-translation paths.

Also make ieee80211_get_bssid() length-safe before returning the S1G
source-address pointer.

The Linux kernel CVE team has assigned CVE-2026-68470 to this issue.


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

	Issue introduced in 5.10 with commit 09a740ce352e1a1d16b9984115514ba9a4f4704b and fixed in 7.1.5 with commit 625fc704b19cb48d7d269ad54ffffb4d3bf9c7ed
	Issue introduced in 5.10 with commit 09a740ce352e1a1d16b9984115514ba9a4f4704b and fixed in 7.2-rc4 with commit 57d503ce32eccfa7650065ca4c560f7e29a2e676

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-2026-68470
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:
	net/mac80211/rx.c
	net/mac80211/util.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/625fc704b19cb48d7d269ad54ffffb4d3bf9c7ed
	https://git.kernel.org/stable/c/57d503ce32eccfa7650065ca4c560f7e29a2e676