Subject: CVE-2024-26747: usb: roles: fix NULL pointer issue when put module's reference

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

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

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

usb: roles: fix NULL pointer issue when put module's reference

In current design, usb role class driver will get usb_role_switch parent's
module reference after the user get usb_role_switch device and put the
reference after the user put the usb_role_switch device. However, the
parent device of usb_role_switch may be removed before the user put the
usb_role_switch. If so, then, NULL pointer issue will be met when the user
put the parent module's reference.

This will save the module pointer in structure of usb_role_switch. Then,
we don't need to find module by iterating long relations.

The Linux kernel CVE team has assigned CVE-2024-26747 to this issue.

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

	Issue introduced in 4.19 with commit 5c54fcac9a9d and fixed in 5.10.211 with commit e279bf8e5189
	Issue introduced in 4.19 with commit 5c54fcac9a9d and fixed in 5.15.150 with commit ef982fc41055
	Issue introduced in 4.19 with commit 5c54fcac9a9d and fixed in 6.1.80 with commit 0158216805ca
	Issue introduced in 4.19 with commit 5c54fcac9a9d and fixed in 6.6.19 with commit 4b45829440b1
	Issue introduced in 4.19 with commit 5c54fcac9a9d and fixed in 6.7.7 with commit 01f82de440f2
	Issue introduced in 4.19 with commit 5c54fcac9a9d and fixed in 6.8 with commit 1c9be13846c0
	Issue introduced in 4.18.12 with commit 7b169e33a3bc

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-2024-26747
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/usb/roles/class.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/e279bf8e51893e1fe160b3d8126ef2dd00f661e1
	https://git.kernel.org/stable/c/ef982fc41055fcebb361a92288d3225783d12913
	https://git.kernel.org/stable/c/0158216805ca7e498d07de38840d2732166ae5fa
	https://git.kernel.org/stable/c/4b45829440b1b208948b39cc71f77a37a2536734
	https://git.kernel.org/stable/c/01f82de440f2ab07c259b7573371e1c42e5565db
	https://git.kernel.org/stable/c/1c9be13846c0b2abc2480602f8ef421360e1ad9e