Subject: CVE-2022-48927: iio: adc: tsc2046: fix memory corruption by preventing array overflow

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

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

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

iio: adc: tsc2046: fix memory corruption by preventing array overflow

On one side we have indio_dev->num_channels includes all physical channels +
timestamp channel. On other side we have an array allocated only for
physical channels. So, fix memory corruption by ARRAY_SIZE() instead of
num_channels variable.

Note the first case is a cleanup rather than a fix as the software
timestamp channel bit in active_scanmask is never set by the IIO core.

The Linux kernel CVE team has assigned CVE-2022-48927 to this issue.

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

	Issue introduced in 5.14 with commit 9374e8f5a38d and fixed in 5.15.26 with commit 0cb9b2f73c18
	Issue introduced in 5.14 with commit 9374e8f5a38d and fixed in 5.16.12 with commit 082d2c047b0d
	Issue introduced in 5.14 with commit 9374e8f5a38d and fixed in 5.17 with commit b7a78a8adaa8

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-2022-48927
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/ti-tsc2046.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/0cb9b2f73c182d242a640e512f4785c7c504512f
	https://git.kernel.org/stable/c/082d2c047b0d305bb0b6e9f9d671a09470e2db2d
	https://git.kernel.org/stable/c/b7a78a8adaa8849c02f174d707aead0f85dca0da