CVE-2026-89623: HID: mcp2221: stop device IO before hid_hw_stop

CVE-2026-89623: HID: mcp2221: stop device IO before hid_hw_stop

[Greg Kroah-Hartman]

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

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

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

HID: mcp2221: stop device IO before hid_hw_stop

Quiesce device IO at the start of the devm cleanup callback
mcp2221_hid_unregister() so that incoming HID reports cannot race with
hardware teardown during probe failure or device removal, addressing a
potential use-after-free.

Guard the call to hid_device_io_stop() with io_started. On normal
removal hid_device_remove() has already cleared io_started before the
devres group is released, so an unconditional call would otherwise hit
the !io_started path and emit a spurious "io already stopped" warning
on every removal. The guard preserves the probe-failure balancing,
where io_started is still set after hid_device_io_start(), while
staying silent on the normal removal path.

The Linux kernel CVE team has assigned CVE-2026-89623 to this issue.


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

	Issue introduced in 6.6.8 with commit d4b50ac06ea6e47bdd2b04e97d1090c673c80645 and fixed in 6.12.109 with commit 0ae90a19e6b5a8557d25d95facb7e01c9c07af38
	Issue introduced in 6.6.8 with commit d4b50ac06ea6e47bdd2b04e97d1090c673c80645 and fixed in 6.18.50 with commit c99ba6c234d4d537c317336376b78c088174034a
	Issue introduced in 6.6.8 with commit d4b50ac06ea6e47bdd2b04e97d1090c673c80645 and fixed in 7.2.4 with commit 2eda1513f573945c1e3a0090341f3d28740463b1
	Issue introduced in 6.6.8 with commit d4b50ac06ea6e47bdd2b04e97d1090c673c80645 and fixed in 7.3-rc1 with commit dca151633c0fde90935311c60e7cfc064aa56134

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-2026-89623
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:
	drivers/hid/hid-mcp2221.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/0ae90a19e6b5a8557d25d95facb7e01c9c07af38
	https://git.kernel.org/stable/c/c99ba6c234d4d537c317336376b78c088174034a
	https://git.kernel.org/stable/c/2eda1513f573945c1e3a0090341f3d28740463b1
	https://git.kernel.org/stable/c/dca151633c0fde90935311c60e7cfc064aa56134