CVE-2026-89474: power: supply: bq256xx: drain usb_work before freeing the charger

CVE-2026-89474: power: supply: bq256xx: drain usb_work before freeing the charger

[Greg Kroah-Hartman]

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

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

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

power: supply: bq256xx: drain usb_work before freeing the charger

The USB-PHY notifier queues usb_work, whose handler calls
power_supply_changed(bq->charger). The reset devm action only unregisters
the notifier and was registered before the power supplies, so devm frees
bq->charger on unwind before the action runs; a usb_work still queued can
then dereference it.

Register the reset action after the power supplies, so it unregisters
the notifiers and drains usb_work before the supplies are released.
Initialize usb_work and obtain the PHY references before registering
the notifiers, so the worker cannot run before the supplies exist.

Found by static analysis.

The Linux kernel CVE team has assigned CVE-2026-89474 to this issue.


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

	Issue introduced in 5.12 with commit 32e4978bb920d047fe5de3ea42d176f267c01f63 and fixed in 6.12.109 with commit 9a467bd1e6811011026ad4c8de701b940d88a00c
	Issue introduced in 5.12 with commit 32e4978bb920d047fe5de3ea42d176f267c01f63 and fixed in 6.18.50 with commit 9e1aba34df9a87d53460888e05718717c0f69343
	Issue introduced in 5.12 with commit 32e4978bb920d047fe5de3ea42d176f267c01f63 and fixed in 7.2.4 with commit c8addb842ae8dcf69c15fc976e33e3bd538a41d7
	Issue introduced in 5.12 with commit 32e4978bb920d047fe5de3ea42d176f267c01f63 and fixed in 7.3-rc1 with commit 2dd6cd823777bea6d9a880a12a92a73ec76aee0b

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-2026-89474
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/power/supply/bq256xx_charger.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/9a467bd1e6811011026ad4c8de701b940d88a00c
	https://git.kernel.org/stable/c/9e1aba34df9a87d53460888e05718717c0f69343
	https://git.kernel.org/stable/c/c8addb842ae8dcf69c15fc976e33e3bd538a41d7
	https://git.kernel.org/stable/c/2dd6cd823777bea6d9a880a12a92a73ec76aee0b