CVE-2023-52619: pstore/ram: Fix crash when setting number of cpus to an odd number

CVE-2023-52619: pstore/ram: Fix crash when setting number of cpus to an odd number

[Lee Jones]

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

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

pstore/ram: Fix crash when setting number of cpus to an odd number

When the number of cpu cores is adjusted to 7 or other odd numbers,
the zone size will become an odd number.
The address of the zone will become:
    addr of zone0 = BASE
    addr of zone1 = BASE + zone_size
    addr of zone2 = BASE + zone_size*2
    ...
The address of zone1/3/5/7 will be mapped to non-alignment va.
Eventually crashes will occur when accessing these va.

So, use ALIGN_DOWN() to make sure the zone size is even
to avoid this bug.

The Linux kernel CVE team has assigned CVE-2023-52619 to this issue.


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

	Fixed in 4.19.307 with commit 8b69c30f4e8b
	Fixed in 5.4.269 with commit e9f6ac508901
	Fixed in 5.10.210 with commit a63e48cd835c
	Fixed in 5.15.149 with commit 2a37905d47bf
	Fixed in 6.1.77 with commit 75b0f71b26b3
	Fixed in 6.6.16 with commit 0593cfd321df
	Fixed in 6.7.4 with commit cd40e43f870c
	Fixed in 6.8 with commit d49270a04623

Please see https://www.kernel.org or 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-2023-52619
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/pstore/ram.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/8b69c30f4e8b69131d92096cb296dc1f217101e4
	https://git.kernel.org/stable/c/e9f6ac50890104fdf8194f2865680689239d30fb
	https://git.kernel.org/stable/c/a63e48cd835c34c38ef671d344cc029b1ea5bf10
	https://git.kernel.org/stable/c/2a37905d47bffec61e95d99f0c1cc5dc6377956c
	https://git.kernel.org/stable/c/75b0f71b26b3ad833c5c0670109c0af6e021e86a
	https://git.kernel.org/stable/c/0593cfd321df9001142a9d2c58d4144917dff7ee
	https://git.kernel.org/stable/c/cd40e43f870cf21726b22487a95ed223790b3542
	https://git.kernel.org/stable/c/d49270a04623ce3c0afddbf3e984cb245aa48e9c