Subject: CVE-2024-35986: phy: ti: tusb1210: Resolve charger-det crash if charger psy is unregistered

From: Greg Kroah-Hartman <[email-masked]>

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

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

phy: ti: tusb1210: Resolve charger-det crash if charger psy is unregistered

The power_supply frame-work is not really designed for there to be
long living in kernel references to power_supply devices.

Specifically unregistering a power_supply while some other code has
a reference to it triggers a WARN in power_supply_unregister():

	WARN_ON(atomic_dec_return(&psy->use_cnt));

Folllowed by the power_supply still getting removed and the
backing data freed anyway, leaving the tusb1210 charger-detect code
with a dangling reference, resulting in a crash the next time
tusb1210_get_online() is called.

Fix this by only holding the reference in tusb1210_get_online()
freeing it at the end of the function. Note this still leaves
a theoretical race window, but it avoids the issue when manually
rmmod-ing the charger chip driver during development.

The Linux kernel CVE team has assigned CVE-2024-35986 to this issue.

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

	Issue introduced in 5.18 with commit 48969a5623ed and fixed in 6.1.90 with commit 25b3498485ac
	Issue introduced in 5.18 with commit 48969a5623ed and fixed in 6.6.30 with commit 73224a5d2180
	Issue introduced in 5.18 with commit 48969a5623ed and fixed in 6.8.9 with commit 9827caa5105f
	Issue introduced in 5.18 with commit 48969a5623ed and fixed in 6.9 with commit bf6e4ee5c436

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-2024-35986
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/phy/ti/phy-tusb1210.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/25b3498485ac281e5851700e33b97f12c9533fd8
	https://git.kernel.org/stable/c/73224a5d2180066c7fe05b4656647601ba08d588
	https://git.kernel.org/stable/c/9827caa5105fb16d1fae2e75c8d0e4662014b3ca
	https://git.kernel.org/stable/c/bf6e4ee5c43690e4c5a8a057bbcd4ff986bed052