CVE-2026-45867: power: supply: act8945a: Fix use-after-free in power_supply_changed()

CVE-2026-45867: power: supply: act8945a: Fix use-after-free in power_supply_changed()

[Greg Kroah-Hartman]

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

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

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

power: supply: act8945a: Fix use-after-free in power_supply_changed()

Using the `devm_` variant for requesting IRQ _before_ the `devm_`
variant for allocating/registering the `power_supply` handle, means that
the `power_supply` handle will be deallocated/unregistered _before_ the
interrupt handler (since `devm_` naturally deallocates in reverse
allocation order). This means that during removal, there is a race
condition where an interrupt can fire just _after_ the `power_supply`
handle has been freed, *but* just _before_ the corresponding
unregistration of the IRQ handler has run.

This will lead to the IRQ handler calling `power_supply_changed()` with
a freed `power_supply` handle. Which usually crashes the system or
otherwise silently corrupts the memory...

Note that there is a similar situation which can also happen during
`probe()`; the possibility of an interrupt firing _before_ registering
the `power_supply` handle. This would then lead to the nasty situation
of using the `power_supply` handle *uninitialized* in
`power_supply_changed()`.

Fix this racy use-after-free by making sure the IRQ is requested _after_
the registration of the `power_supply` handle.

The Linux kernel CVE team has assigned CVE-2026-45867 to this issue.


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

	Issue introduced in 4.9 with commit a09209acd6a808794bdd7866af3678d1fd1d90e7 and fixed in 5.10.252 with commit f2a0777b1e5a3cee1712c4d3e9095c0df8fc8cb3
	Issue introduced in 4.9 with commit a09209acd6a808794bdd7866af3678d1fd1d90e7 and fixed in 5.15.202 with commit 0768e8525a46df103647ca5059b32320d7fd17e4
	Issue introduced in 4.9 with commit a09209acd6a808794bdd7866af3678d1fd1d90e7 and fixed in 6.1.165 with commit d023ef9f748b2090f7a9dbdd5c622b6ad99088ea
	Issue introduced in 4.9 with commit a09209acd6a808794bdd7866af3678d1fd1d90e7 and fixed in 6.6.128 with commit 697bb5dc0cb4791e244f3970b067bc1ef33be9d9
	Issue introduced in 4.9 with commit a09209acd6a808794bdd7866af3678d1fd1d90e7 and fixed in 6.12.75 with commit 76a42ba547a9b2e2337894f67a4d9247445007d5
	Issue introduced in 4.9 with commit a09209acd6a808794bdd7866af3678d1fd1d90e7 and fixed in 6.18.14 with commit f27eb76def5c07e4d7cc468b40741f19dafc83ce
	Issue introduced in 4.9 with commit a09209acd6a808794bdd7866af3678d1fd1d90e7 and fixed in 6.19.4 with commit 83c1bd466c514cb24ca6ef347c5aac76a13c4e1e
	Issue introduced in 4.9 with commit a09209acd6a808794bdd7866af3678d1fd1d90e7 and fixed in 7.0 with commit 3291c51d4684d048dd2eb91b5b65fcfdaf72141f

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-2026-45867
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/act8945a_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/f2a0777b1e5a3cee1712c4d3e9095c0df8fc8cb3
	https://git.kernel.org/stable/c/0768e8525a46df103647ca5059b32320d7fd17e4
	https://git.kernel.org/stable/c/d023ef9f748b2090f7a9dbdd5c622b6ad99088ea
	https://git.kernel.org/stable/c/697bb5dc0cb4791e244f3970b067bc1ef33be9d9
	https://git.kernel.org/stable/c/76a42ba547a9b2e2337894f67a4d9247445007d5
	https://git.kernel.org/stable/c/f27eb76def5c07e4d7cc468b40741f19dafc83ce
	https://git.kernel.org/stable/c/83c1bd466c514cb24ca6ef347c5aac76a13c4e1e
	https://git.kernel.org/stable/c/3291c51d4684d048dd2eb91b5b65fcfdaf72141f