Subject: CVE-2024-41032: mm: vmalloc: check if a hash-index is in cpu_possible_mask

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

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

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

mm: vmalloc: check if a hash-index is in cpu_possible_mask

The problem is that there are systems where cpu_possible_mask has gaps
between set CPUs, for example SPARC.  In this scenario addr_to_vb_xa()
hash function can return an index which accesses to not-possible and not
setup CPU area using per_cpu() macro.  This results in an oops on SPARC.

A per-cpu vmap_block_queue is also used as hash table, incorrectly
assuming the cpu_possible_mask has no gaps.  Fix it by adjusting an index
to a next possible CPU.

The Linux kernel CVE team has assigned CVE-2024-41032 to this issue.

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

	Issue introduced in 6.4 with commit 062eacf57ad9 and fixed in 6.6.41 with commit 28acd531c9a3
	Issue introduced in 6.4 with commit 062eacf57ad9 and fixed in 6.9.10 with commit 47f9b6e49b42
	Issue introduced in 6.4 with commit 062eacf57ad9 and fixed in 6.10 with commit a34acf30b19b

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-2024-41032
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:
	mm/vmalloc.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/28acd531c9a365dac01b32e6bc54aed8c1429bcb
	https://git.kernel.org/stable/c/47f9b6e49b422392fb0e348a65eb925103ba1882
	https://git.kernel.org/stable/c/a34acf30b19bc4ee3ba2f1082756ea2604c19138