Subject: CVE-2021-47359: cifs: Fix soft lockup during fsstress

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

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

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

cifs: Fix soft lockup during fsstress

Below traces are observed during fsstress and system got hung.
[  130.698396] watchdog: BUG: soft lockup - CPU#6 stuck for 26s!

The Linux kernel CVE team has assigned CVE-2021-47359 to this issue.

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

	Fixed in 5.14.9 with commit 9f6c7aff21f8
	Fixed in 5.15 with commit 71826b068884

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-2021-47359
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:
	fs/cifs/misc.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/9f6c7aff21f81ae8856da1f63847d1362d523409
	https://git.kernel.org/stable/c/71826b068884050d5fdd37fda857ba1539c513d3