Subject: CVE-2021-47070: uio_hv_generic: Fix another memory leak in error handling paths

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

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

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

uio_hv_generic: Fix another memory leak in error handling paths

Memory allocated by 'vmbus_alloc_ring()' at the beginning of the probe
function is never freed in the error handling path.

Add the missing 'vmbus_free_ring()' call.

Note that it is already freed in the .remove function.

The Linux kernel CVE team has assigned CVE-2021-47070 to this issue.

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

	Issue introduced in 4.20 with commit cdfa835c6e5e and fixed in 5.12.7 with commit 5f59240cf25b
	Issue introduced in 4.20 with commit cdfa835c6e5e and fixed in 5.13 with commit 0b0226be3a52

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-2021-47070
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/uio/uio_hv_generic.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/5f59240cf25b2f7a0fdffc2701482a70310fec07
	https://git.kernel.org/stable/c/0b0226be3a52dadd965644bc52a807961c2c26df