CVE-2026-45869: power: supply: wm97xx: Fix NULL pointer dereference in power_supply_changed()

[Greg Kroah-Hartman <gregkh@linuxfoundation.org>]

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

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

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

power: supply: wm97xx: Fix NULL pointer dereference in power_supply_changed()

In `probe()`, `request_irq()` is called before allocating/registering a
`power_supply` handle. If an interrupt is fired between the call to
`request_irq()` and `power_supply_register()`, the `power_supply` handle
will be used uninitialized in `power_supply_changed()` in
`wm97xx_bat_update()` (triggered from the interrupt handler). This will
lead to a `NULL` pointer dereference since

Fix this racy `NULL` pointer dereference by making sure the IRQ is
requested _after_ the registration of the `power_supply` handle. Since
the IRQ is the last thing requests in the `probe()` now, remove the
error path for freeing it. Instead add one for unregistering the
`power_supply` handle when IRQ request fails.

The Linux kernel CVE team has assigned CVE-2026-45869 to this issue.


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

	Issue introduced in 2.6.32 with commit 7c87942aef52d2120e95ff1dec739998b9f95a78 and fixed in 5.10.252 with commit 3d7b5391bb95505b3581c1fb77150c467ab92864
	Issue introduced in 2.6.32 with commit 7c87942aef52d2120e95ff1dec739998b9f95a78 and fixed in 5.15.202 with commit 438f9a303ea8b55162b2d5376490c2ab3ec165a0
	Issue introduced in 2.6.32 with commit 7c87942aef52d2120e95ff1dec739998b9f95a78 and fixed in 6.1.165 with commit 9b7d77cb046b4487e8e511e04e62b6f416ce845c
	Issue introduced in 2.6.32 with commit 7c87942aef52d2120e95ff1dec739998b9f95a78 and fixed in 6.6.128 with commit 86183153c299e8bb1839e717286d6c6f39508a59
	Issue introduced in 2.6.32 with commit 7c87942aef52d2120e95ff1dec739998b9f95a78 and fixed in 6.12.75 with commit 93bdf715d33cf5ee01c58e8546c2469c71ce082a
	Issue introduced in 2.6.32 with commit 7c87942aef52d2120e95ff1dec739998b9f95a78 and fixed in 6.18.14 with commit c0def811ad8d642dca9b6d31a198cc39f5f90837
	Issue introduced in 2.6.32 with commit 7c87942aef52d2120e95ff1dec739998b9f95a78 and fixed in 6.19.4 with commit dfaf235d5a6b60cbf115a14a656946303ad007b7
	Issue introduced in 2.6.32 with commit 7c87942aef52d2120e95ff1dec739998b9f95a78 and fixed in 7.0 with commit 39fe0eac6d755ef215026518985fcf8de9360e9e

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-2026-45869
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/wm97xx_battery.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/3d7b5391bb95505b3581c1fb77150c467ab92864
	https://git.kernel.org/stable/c/438f9a303ea8b55162b2d5376490c2ab3ec165a0
	https://git.kernel.org/stable/c/9b7d77cb046b4487e8e511e04e62b6f416ce845c
	https://git.kernel.org/stable/c/86183153c299e8bb1839e717286d6c6f39508a59
	https://git.kernel.org/stable/c/93bdf715d33cf5ee01c58e8546c2469c71ce082a
	https://git.kernel.org/stable/c/c0def811ad8d642dca9b6d31a198cc39f5f90837
	https://git.kernel.org/stable/c/dfaf235d5a6b60cbf115a14a656946303ad007b7
	https://git.kernel.org/stable/c/39fe0eac6d755ef215026518985fcf8de9360e9e