CVE-2022-48668: smb3: fix temporary data corruption in collapse range

CVE-2022-48668: smb3: fix temporary data corruption in collapse range

[Greg Kroah-Hartman]

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

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

smb3: fix temporary data corruption in collapse range

collapse range doesn't discard the affected cached region
so can risk temporarily corrupting the file data. This
fixes xfstest generic/031

I also decided to merge a minor cleanup to this into the same patch
(avoiding rereading inode size repeatedly unnecessarily) to make it
clearer.

The Linux kernel CVE team has assigned CVE-2022-48668 to this issue.


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

	Issue introduced in 5.13 with commit 5476b5dd82c8 and fixed in 5.19.12 with commit 49523a473220
	Issue introduced in 5.13 with commit 5476b5dd82c8 and fixed in 6.0 with commit fa30a81f255a

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-2022-48668
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/smb2ops.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/49523a4732204bdacbf3941a016503ddb4ddb3b9
	https://git.kernel.org/stable/c/fa30a81f255a56cccd89552cd6ce7ea6e8d8acc4