CVE-2026-45882: power: supply: pm8916_bms_vm: Fix use-after-free in power_supply_changed()

CVE-2026-45882: power: supply: pm8916_bms_vm: 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: pm8916_bms_vm: 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-2026-45882 to this issue.


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

	Issue introduced in 6.7 with commit 098bce1838e0549228c8d426e5de72ec5594b5c4 and fixed in 6.12.75 with commit b69bb88e20c6f8e998dff3e13a316207f49d3fa2
	Issue introduced in 6.7 with commit 098bce1838e0549228c8d426e5de72ec5594b5c4 and fixed in 6.18.14 with commit a8b7117ae3a791c6a328674d05a06cd45d8241bd
	Issue introduced in 6.7 with commit 098bce1838e0549228c8d426e5de72ec5594b5c4 and fixed in 6.19.4 with commit 17db6b3abd823c9fba3f3413c4f0f432d99d49dc
	Issue introduced in 6.7 with commit 098bce1838e0549228c8d426e5de72ec5594b5c4 and fixed in 7.0 with commit 62914959b35e9a1e29cc0f64cb8cfc5075a5366f

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-2026-45882
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/pm8916_bms_vm.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/b69bb88e20c6f8e998dff3e13a316207f49d3fa2
	https://git.kernel.org/stable/c/a8b7117ae3a791c6a328674d05a06cd45d8241bd
	https://git.kernel.org/stable/c/17db6b3abd823c9fba3f3413c4f0f432d99d49dc
	https://git.kernel.org/stable/c/62914959b35e9a1e29cc0f64cb8cfc5075a5366f