Subject: CVE-2023-52802: iio: adc: stm32-adc: harden against NULL pointer deref in stm32_adc_probe()

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

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

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

iio: adc: stm32-adc: harden against NULL pointer deref in stm32_adc_probe()

of_match_device() may fail and returns a NULL pointer.

In practice there is no known reasonable way to trigger this, but
in case one is added in future, harden the code by adding the check

The Linux kernel CVE team has assigned CVE-2023-52802 to this issue.

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

	Fixed in 6.1.64 with commit b80aaff5f781
	Fixed in 6.5.13 with commit b028f89c56e9
	Fixed in 6.6.3 with commit 5b82e4240533
	Fixed in 6.7 with commit 3a23b384e7e3

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-2023-52802
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/iio/adc/stm32-adc-core.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/b80aaff5f7817d50798ac61ed75973f004dd5202
	https://git.kernel.org/stable/c/b028f89c56e964a22d3ddb8eab1a0e7e980841b9
	https://git.kernel.org/stable/c/5b82e4240533bcd4691e50b64ec86d0d7fbd21b9
	https://git.kernel.org/stable/c/3a23b384e7e3d64d5587ad10729a34d4f761517e