CVE-2022-49362: NFSD: Fix potential use-after-free in nfsd_file_put()

CVE-2022-49362: NFSD: Fix potential use-after-free in nfsd_file_put()

[Greg Kroah-Hartman]

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

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

NFSD: Fix potential use-after-free in nfsd_file_put()

nfsd_file_put_noref() can free @nf, so don't dereference @nf
immediately upon return from nfsd_file_put_noref().

The Linux kernel CVE team has assigned CVE-2022-49362 to this issue.


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

	Issue introduced in 5.18 with commit 999397926ab3f78c7d1235cc4ca6e3c89d2769bf and fixed in 5.18.4 with commit 333dcc94ebf53f79f3dc0e7a7c16700bc7ff7e57
	Issue introduced in 5.18 with commit 999397926ab3f78c7d1235cc4ca6e3c89d2769bf and fixed in 5.19 with commit b6c71c66b0ad8f2b59d9bc08c7a5079b110bec01

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-2022-49362
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/nfsd/filecache.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/ada1757b259f353cade47037ee0a0249b4cddad3
	https://git.kernel.org/stable/c/261eabe19cb28e4a8587a4442d257b543d7c2d57
	https://git.kernel.org/stable/c/333dcc94ebf53f79f3dc0e7a7c16700bc7ff7e57
	https://git.kernel.org/stable/c/b6c71c66b0ad8f2b59d9bc08c7a5079b110bec01