CVE-2023-52823: kernel: kexec: copy user-array safely

[Greg Kroah-Hartman <gregkh@linuxfoundation.org>]

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

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

kernel: kexec: copy user-array safely

Currently, there is no overflow-check with memdup_user().

Use the new function memdup_array_user() instead of memdup_user() for
duplicating the user-space array safely.

The Linux kernel CVE team has assigned CVE-2023-52823 to this issue.


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

	Fixed in 5.15.140 with commit d4f2c09d4672
	Fixed in 6.1.64 with commit 8332523b13db
	Fixed in 6.5.13 with commit b0ed017a2b97
	Fixed in 6.6.3 with commit 4fc857cc5cb9
	Fixed in 6.7 with commit 569c8d82f95e

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-2023-52823
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:
	kernel/kexec.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/d4f2c09d4672f0e997ba4b1b589cc376be7ec938
	https://git.kernel.org/stable/c/8332523b13dbfcce60f631dfb34ac90df021b4bd
	https://git.kernel.org/stable/c/b0ed017a2b9735753eb95798d9f60176480424ca
	https://git.kernel.org/stable/c/4fc857cc5cb9b7ce6940898857d773564973a584
	https://git.kernel.org/stable/c/569c8d82f95eb5993c84fb61a649a9c4ddd208b3