CVE-2026-98823: wifi: cfg80211: preserve hidden-group beacon IE ownership

CVE-2026-98823: wifi: cfg80211: preserve hidden-group beacon IE ownership

[Greg Kroah-Hartman]

From: Greg Kroah-Hartman <gregkh@kernel.org>

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

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

wifi: cfg80211: preserve hidden-group beacon IE ownership

A hidden-group probe-response entry borrows its beacon IEs from the
group's beacon entry. cfg80211_update_assoc_bss_entry() can pass such
an entry to cfg80211_update_known_bss() when merging scan entries
after a channel switch.

Copying the borrowed beacon_ies into the associated entry gives the
same allocation two owners. Releasing the group's beacon entry can
then leave the associated entry pointing to freed IEs, which are
freed again when that entry is released.

Skip beacon IE replacement when the source entry belongs to a hidden
group. Preserve probe-response processing, the subsequent metadata
updates, and the existing rejection path for conflicting hidden
beacon updates.

The Linux kernel CVE team has assigned CVE-2026-98823 to this issue.


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

	Issue introduced in 5.4 with commit 0afd425b1b64251f19b5d8d8b49bf56fefbc643f and fixed in 6.12.113 with commit 49b66110a08e4f926f6393e938f226de2750a08b
	Issue introduced in 5.4 with commit 0afd425b1b64251f19b5d8d8b49bf56fefbc643f and fixed in 6.18.56 with commit dd7973a4130b0862be38d7e08cc0e874b3d99967
	Issue introduced in 5.4 with commit 0afd425b1b64251f19b5d8d8b49bf56fefbc643f and fixed in 7.2.10 with commit 5f27581c176f84b52ec0ab9be7b500c10667ef60
	Issue introduced in 5.4 with commit 0afd425b1b64251f19b5d8d8b49bf56fefbc643f and fixed in 7.3-rc6 with commit cc45f313d85533d647ce619326302aad6f797c14

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-2026-98823
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/wireless/scan.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/49b66110a08e4f926f6393e938f226de2750a08b
	https://git.kernel.org/stable/c/dd7973a4130b0862be38d7e08cc0e874b3d99967
	https://git.kernel.org/stable/c/5f27581c176f84b52ec0ab9be7b500c10667ef60
	https://git.kernel.org/stable/c/cc45f313d85533d647ce619326302aad6f797c14