Subject: CVE-2024-40936: cxl/region: Fix memregion leaks in devm_cxl_add_region()

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

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

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

cxl/region: Fix memregion leaks in devm_cxl_add_region()

Move the mode verification to __create_region() before allocating the
memregion to avoid the memregion leaks.

The Linux kernel CVE team has assigned CVE-2024-40936 to this issue.

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

	Issue introduced in 6.3 with commit 6e099264185d and fixed in 6.6.35 with commit d8316838aa06
	Issue introduced in 6.3 with commit 6e099264185d and fixed in 6.9.6 with commit bbb5d8746381
	Issue introduced in 6.3 with commit 6e099264185d and fixed in 6.10 with commit 49ba7b515c4c

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-2024-40936
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/cxl/core/region.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/d8316838aa0686da63a8be4194b7a17b0103ae4a
	https://git.kernel.org/stable/c/bbb5d8746381c82f7e0fb6171094d375b492f266
	https://git.kernel.org/stable/c/49ba7b515c4c0719b866d16f068e62d16a8a3dd1