Subject: CVE-2021-47148: octeontx2-pf: fix a buffer overflow in otx2_set_rxfh_context()

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

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

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

octeontx2-pf: fix a buffer overflow in otx2_set_rxfh_context()

This function is called from ethtool_set_rxfh() and "*rss_context"
comes from the user.  Add some bounds checking to prevent memory
corruption.

The Linux kernel CVE team has assigned CVE-2021-47148 to this issue.

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

	Issue introduced in 5.12 with commit 81a4362016e7 and fixed in 5.12.9 with commit 389146bc6d2b
	Issue introduced in 5.12 with commit 81a4362016e7 and fixed in 5.13 with commit e5cc361e2164

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-2021-47148
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/ethernet/marvell/octeontx2/nic/otx2_ethtool.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/389146bc6d2bbb20714d06624b74856320ce40f7
	https://git.kernel.org/stable/c/e5cc361e21648b75f935f9571d4003aaee480214