CVE-2021-47525: serial: liteuart: fix use-after-free and memleak on unbind

CVE-2021-47525: serial: liteuart: fix use-after-free and memleak on unbind

[Greg Kroah-Hartman]

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

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

serial: liteuart: fix use-after-free and memleak on unbind

Deregister the port when unbinding the driver to prevent it from being
used after releasing the driver data and leaking memory allocated by
serial core.

The Linux kernel CVE team has assigned CVE-2021-47525 to this issue.


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

	Issue introduced in 5.11 with commit 1da81e5562fa and fixed in 5.15.7 with commit 602824cf9aa9
	Issue introduced in 5.11 with commit 1da81e5562fa and fixed in 5.16 with commit 05f929b395de

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-2021-47525
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/tty/serial/liteuart.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/602824cf9aa9db8830ffe5cfb2cd54365cada4fe
	https://git.kernel.org/stable/c/05f929b395dec8957b636ff14e66b277ed022ed9