Subject: CVE-2024-35883: spi: mchp-pci1xxx: Fix a possible null pointer dereference in pci1xxx_spi_probe

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

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

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

spi: mchp-pci1xxx: Fix a possible null pointer dereference in pci1xxx_spi_probe

In function pci1xxxx_spi_probe, there is a potential null pointer that
may be caused by a failed memory allocation by the function devm_kzalloc.
Hence, a null pointer check needs to be added to prevent null pointer
dereferencing later in the code.

To fix this issue, spi_bus->spi_int[iter] should be checked. The memory
allocated by devm_kzalloc will be automatically released, so just directly
return -ENOMEM without worrying about memory leaks.

The Linux kernel CVE team has assigned CVE-2024-35883 to this issue.

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

	Issue introduced in 6.2 with commit 1cc0cbea7167 and fixed in 6.6.26 with commit 4b31a226097c
	Issue introduced in 6.2 with commit 1cc0cbea7167 and fixed in 6.8.5 with commit 95e5d9eb2670
	Issue introduced in 6.2 with commit 1cc0cbea7167 and fixed in 6.9 with commit 1f886a7bfb3f

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-2024-35883
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/spi/spi-pci1xxxx.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/4b31a226097cf8cc3c9de5e855d97757fdb2bf06
	https://git.kernel.org/stable/c/95e5d9eb26705a9a76d2ef8bcba9ee2e195d653d
	https://git.kernel.org/stable/c/1f886a7bfb3faf4c1021e73f045538008ce7634e