CVE-2026-89623

What the bug is

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.

Where it lives

The fix touches these files. If the subsystem is one you do not use, the practical exposure is lower, though the package is still the vulnerable one.

drivers/hid/hid-mcp2221.c

What this is

MCP2221A MICROCHIP USB-HID TO I2C BRIDGE DRIVERMAINTAINERS section matched on drivers/hid/hid-mcp2221.c · linux-i2c@vger.kernel.org · Maintained

Kernel module

hid_mcp2221

Check it on the machine

grep -wE 'CONFIG_HID|CONFIG_HID_MCP2221|CONFIG_HID_SUPPORT' /boot/config-$(uname -r)

Reads the booted kernel's own configuration, on the machine and nowhere else. =y is built in, =m is a module, and an is not set line means the code is not there.

lsmod | grep -w hid_mcp2221

Prints a line if that module is loaded right now, and nothing if it is not. One that is not loaded can still be loaded later by anything that needs it.

Show whether Debian builds this, per release

Debian builds this, but not on every flavour. At least one release below builds the code on some of its kernel flavours and not on others, so the answer depends on the architecture and flavour installed.

• bookworm, trixie, forky, sidMnot built on amd64/cloud-amd64, arm64/cloud-arm64

M

a module where it is built at all; some flavours do not build it

Build switches

CONFIG_HID, CONFIG_HID_MCP2221, CONFIG_HID_SUPPORT

Reads as

all on means the file is compiled; any one off means it is not.

From the configuration Debian publishes for every kernel flavour it builds. It covers only the architectures Debian ships a linux-config package for, and nothing about a kernel you built yourself. Debian's own status above stays authoritative about the source package.MAINTAINERS kbuild Makefiles Debian linux-config packages

Signals

Published

2026-09-11 (37 days ago)source

CVSS

no vector published, unrated

Attack vector

not published

EPSS

0.21%, higher than 10.3% of all CVEssource

CISA KEV

not listedthe KEV catalogue

Debian urgency

unimportantsource

Subsystem

drivers/hid

Upstream fixes

The versions the CNA records as introducing and fixing this, and the commit for each. source

Introduced	Fixed in	Commit
6.6.8	6.6.157	85d963499f1f
6.6.8	6.12.109	0ae90a19e6b5
6.6.8	6.18.50	c99ba6c234d4
6.6.8	7.2.4	2eda1513f573
6.6.8	7.3	dca151633c0f