Subject: CVE-2021-47501: i40e: Fix NULL pointer dereference in i40e_dbg_dump_desc

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

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

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

i40e: Fix NULL pointer dereference in i40e_dbg_dump_desc

When trying to dump VFs VSI RX/TX descriptors
using debugfs there was a crash
due to NULL pointer dereference in i40e_dbg_dump_desc.
Added a check to i40e_dbg_dump_desc that checks if
VSI type is correct for dumping RX/TX descriptors.

The Linux kernel CVE team has assigned CVE-2021-47501 to this issue.

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

	Issue introduced in 3.12 with commit 02e9c290814c and fixed in 5.10.85 with commit e5b7fb2198ab
	Issue introduced in 3.12 with commit 02e9c290814c and fixed in 5.15.8 with commit 16431e442db2
	Issue introduced in 3.12 with commit 02e9c290814c and fixed in 5.16 with commit 23ec111bf354

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-2021-47501
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/intel/i40e/i40e_debugfs.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/e5b7fb2198abc50058f1a29c395b004f76ab1c83
	https://git.kernel.org/stable/c/16431e442db248ecd8aa9457cf0a656f1885f56e
	https://git.kernel.org/stable/c/23ec111bf3549aae37140330c31a16abfc172421