Subject: CVE-2021-47322: NFSv4: Fix an Oops in pnfs_mark_request_commit() when doing O_DIRECT

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

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

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

NFSv4: Fix an Oops in pnfs_mark_request_commit() when doing O_DIRECT

Fix an Oopsable condition in pnfs_mark_request_commit() when we're
putting a set of writes on the commit list to reschedule them after a
failed pNFS attempt.

The Linux kernel CVE team has assigned CVE-2021-47322 to this issue.

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

	Issue introduced in 5.7 with commit 9c455a8c1e14 and fixed in 5.10.52 with commit 5c7ef8a37055
	Issue introduced in 5.7 with commit 9c455a8c1e14 and fixed in 5.12.19 with commit 7c96a2ee45be
	Issue introduced in 5.7 with commit 9c455a8c1e14 and fixed in 5.13.4 with commit 7aec9f862411
	Issue introduced in 5.7 with commit 9c455a8c1e14 and fixed in 5.14 with commit 3731d44bba8e

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-2021-47322
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/nfs/direct.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/5c7ef8a3705542136a1e19b070e951f0730b2153
	https://git.kernel.org/stable/c/7c96a2ee45be41d5a167e6332d202086752c36bb
	https://git.kernel.org/stable/c/7aec9f862411906f8c27071ba65a1e110ad7d2fd
	https://git.kernel.org/stable/c/3731d44bba8e0116b052b1b374476c5f6dd9a456