CVE-2023-52607: powerpc/mm: Fix null-pointer dereference in pgtable_cache_add

CVE-2023-52607: powerpc/mm: Fix null-pointer dereference in pgtable_cache_add

[Greg Kroah-Hartman]

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

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

powerpc/mm: Fix null-pointer dereference in pgtable_cache_add

kasprintf() returns a pointer to dynamically allocated memory
which can be NULL upon failure. Ensure the allocation was successful
by checking the pointer validity.

The Linux kernel CVE team has assigned CVE-2023-52607 to this issue.


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

	Fixed in 4.19.307 with commit 21e45a7b08d7
	Fixed in 5.4.269 with commit f6781add1c31
	Fixed in 5.10.210 with commit aa28eecb43ca
	Fixed in 5.15.149 with commit ac3ed969a403
	Fixed in 6.1.77 with commit d482d61025e3
	Fixed in 6.6.16 with commit 145febd85c3b
	Fixed in 6.7.4 with commit ffd29dc45bc0
	Fixed in 6.8-rc1 with commit f46c8a75263f

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-2023-52607
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:
	arch/powerpc/mm/init-common.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/21e45a7b08d7cd98d6a53c5fc5111879f2d96611
	https://git.kernel.org/stable/c/f6781add1c311c17eff43e14c786004bbacf901e
	https://git.kernel.org/stable/c/aa28eecb43cac6e20ef14dfc50b8892c1fbcda5b
	https://git.kernel.org/stable/c/ac3ed969a40357b0542d20f096a6d43acdfa6cc7
	https://git.kernel.org/stable/c/d482d61025e303a2bef3733a011b6b740215cfa1
	https://git.kernel.org/stable/c/145febd85c3bcc5c74d87ef9a598fc7d9122d532
	https://git.kernel.org/stable/c/ffd29dc45bc0355393859049f6becddc3ed08f74
	https://git.kernel.org/stable/c/f46c8a75263f97bda13c739ba1c90aced0d3b071