CVE-2026-89462: power: supply: max17040: propagate register read errors

CVE-2026-89462: power: supply: max17040: propagate register read errors

[Greg Kroah-Hartman]

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

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

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

power: supply: max17040: propagate register read errors

max17040_get_vcell() and max17040_get_soc() ignore errors returned by
regmap_read().  When an I2C transfer fails, the uninitialized register
value is converted and reported to userspace as a valid voltage or state
of charge.  The polling worker can also replace the cached state of charge
with the bogus value and emit a spurious change event.

Propagate read errors through the power supply get_property callback and
keep the last valid cached state of charge when polling fails.

The Linux kernel CVE team has assigned CVE-2026-89462 to this issue.


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

	Issue introduced in 2.6.31 with commit c6f4a42de60b981dd210de01cd3e575835e3158e and fixed in 6.12.109 with commit 2943a0edd4865ed744702ada647921c3981207f6
	Issue introduced in 2.6.31 with commit c6f4a42de60b981dd210de01cd3e575835e3158e and fixed in 6.18.50 with commit 13fb0477da9b400071b9d518b24d6434c4965263
	Issue introduced in 2.6.31 with commit c6f4a42de60b981dd210de01cd3e575835e3158e and fixed in 7.2.4 with commit c7aa4c3708cc0d8487336f8281665eaea87130f6
	Issue introduced in 2.6.31 with commit c6f4a42de60b981dd210de01cd3e575835e3158e and fixed in 7.3-rc1 with commit 659cc3d8d5ef246263873fce72c8cadeeed073cc

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-2026-89462
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/max17040_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/2943a0edd4865ed744702ada647921c3981207f6
	https://git.kernel.org/stable/c/13fb0477da9b400071b9d518b24d6434c4965263
	https://git.kernel.org/stable/c/c7aa4c3708cc0d8487336f8281665eaea87130f6
	https://git.kernel.org/stable/c/659cc3d8d5ef246263873fce72c8cadeeed073cc