Subject: CVE-2021-47306: net: fddi: fix UAF in fza_probe

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

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

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

net: fddi: fix UAF in fza_probe

fp is netdev private data and it cannot be
used after free_netdev() call. Using fp after free_netdev()
can cause UAF bug. Fix it by moving free_netdev() after error message.

TURBOchannel adapter")

The Linux kernel CVE team has assigned CVE-2021-47306 to this issue.

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

	Issue introduced in 4.20 with commit 61414f5ec983 and fixed in 5.4.135 with commit 04b06716838b
	Issue introduced in 4.20 with commit 61414f5ec983 and fixed in 5.10.53 with commit f33605908a9b
	Issue introduced in 4.20 with commit 61414f5ec983 and fixed in 5.13.5 with commit bdfbb51f7a43
	Issue introduced in 4.20 with commit 61414f5ec983 and fixed in 5.14 with commit deb7178eb940

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-2021-47306
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/net/fddi/defza.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/04b06716838bfc26742dbed3ae1d3697fe5317ee
	https://git.kernel.org/stable/c/f33605908a9b6063525e9f68e62d739948c5fccf
	https://git.kernel.org/stable/c/bdfbb51f7a437ae8ea91317a5c133ec13adf3c47
	https://git.kernel.org/stable/c/deb7178eb940e2c5caca1b1db084a69b2e59b4c9