cve/published/2022/CVE-2022-49234.mbox

From bippy-5f407fcff5a0 Mon Sep 17 00:00:00 2001
From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To: <linux-cve-announce@vger.kernel.org>
Reply-to: <cve@kernel.org>, <linux-kernel@vger.kernel.org>
Subject: CVE-2022-49234: net: dsa: Avoid cross-chip syncing of VLAN filtering

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

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

net: dsa: Avoid cross-chip syncing of VLAN filtering

Changes to VLAN filtering are not applicable to cross-chip
notifications.

On a system like this:

.-----.   .-----.   .-----.
| sw1 +---+ sw2 +---+ sw3 |
'-1-2-'   '-1-2-'   '-1-2-'

Before this change, upon sw1p1 leaving a bridge, a call to
dsa_port_vlan_filtering would also be made to sw2p1 and sw3p1.

In this scenario:

.---------.   .-----.   .-----.
|   sw1   +---+ sw2 +---+ sw3 |
'-1-2-3-4-'   '-1-2-'   '-1-2-'

When sw1p4 would leave a bridge, dsa_port_vlan_filtering would be
called for sw2 and sw3 with a non-existing port - leading to array
out-of-bounds accesses and crashes on mv88e6xxx.

The Linux kernel CVE team has assigned CVE-2022-49234 to this issue.


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

	Issue introduced in 5.2 with commit d371b7c92d190448f3ccbf082c90bf929285f648 and fixed in 5.17.2 with commit e1f2a4dd8d433eec393d09273a78a3d3551339cf
	Issue introduced in 5.2 with commit d371b7c92d190448f3ccbf082c90bf929285f648 and fixed in 5.18 with commit 108dc8741c203e9d6ce4e973367f1bac20c7192b

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-2022-49234
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/dsa/switch.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/e1f2a4dd8d433eec393d09273a78a3d3551339cf
	https://git.kernel.org/stable/c/108dc8741c203e9d6ce4e973367f1bac20c7192b