Subject: CVE-2024-26933: USB: core: Fix deadlock in port "disable" sysfs attribute

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

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

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

USB: core: Fix deadlock in port "disable" sysfs attribute

The show and store callback routines for the "disable" sysfs attribute
file in port.c acquire the device lock for the port's parent hub
device.  This can cause problems if another process has locked the hub
to remove it or change its configuration:

	Removing the hub or changing its configuration requires the
	hub interface to be removed, which requires the port device
	to be removed, and device_del() waits until all outstanding
	sysfs attribute callbacks for the ports have returned.  The
	lock can't be released until then.

	But the disable_show() or disable_store() routine can't return
	until after it has acquired the lock.

The resulting deadlock can be avoided by calling
sysfs_break_active_protection().  This will cause the sysfs core not
to wait for the attribute's callback routine to return, allowing the
removal to proceed.  The disadvantage is that after making this call,
there is no guarantee that the hub structure won't be deallocated at
any moment.  To prevent this, we have to acquire a reference to it
first by calling hub_get().

The Linux kernel CVE team has assigned CVE-2024-26933 to this issue.

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

	Issue introduced in 6.0 with commit f061f43d7418 and fixed in 6.1.84 with commit 9dac54f08198
	Issue introduced in 6.0 with commit f061f43d7418 and fixed in 6.6.24 with commit f51849833705
	Issue introduced in 6.0 with commit f061f43d7418 and fixed in 6.7.12 with commit 4facc9421117
	Issue introduced in 6.0 with commit f061f43d7418 and fixed in 6.8.3 with commit 73d1589b91f2
	Issue introduced in 6.0 with commit f061f43d7418 and fixed in 6.9 with commit f4d1960764d8

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-2024-26933
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/core/port.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/9dac54f08198147f5ec0ec52fcf1bc8ac899ac05
	https://git.kernel.org/stable/c/f51849833705dea5b4f9b0c8de714dd87bd6c95c
	https://git.kernel.org/stable/c/4facc9421117ba9d8148c73771b213887fec77f7
	https://git.kernel.org/stable/c/73d1589b91f2099e5f6534a8497b7c6b527e064e
	https://git.kernel.org/stable/c/f4d1960764d8a70318b02f15203a1be2b2554ca1