Subject: CVE-2024-38635: soundwire: cadence: fix invalid PDI offset

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

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

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

soundwire: cadence: fix invalid PDI offset

For some reason, we add an offset to the PDI, presumably to skip the
PDI0 and PDI1 which are reserved for BPT.

This code is however completely wrong and leads to an out-of-bounds
access. We were just lucky so far since we used only a couple of PDIs
and remained within the PDI array bounds.

A Fixes: tag is not provided since there are no known platforms where
the out-of-bounds would be accessed, and the initial code had problems
as well.

A follow-up patch completely removes this useless offset.

The Linux kernel CVE team has assigned CVE-2024-38635 to this issue.

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

	Fixed in 5.4.278 with commit 002364b2d594
	Fixed in 5.10.219 with commit fd4bcb991eba
	Fixed in 5.15.161 with commit 902f6d656441
	Fixed in 6.1.93 with commit 2ebcaa0e5db9
	Fixed in 6.6.33 with commit 7eeef1e935d2
	Fixed in 6.9.4 with commit 4e99103f757c
	Fixed in 6.10 with commit 8ee1b439b154

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-2024-38635
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/soundwire/cadence_master.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/002364b2d594a9afc0385c09e00994c510b1d089
	https://git.kernel.org/stable/c/fd4bcb991ebaf0d1813d81d9983cfa99f9ef5328
	https://git.kernel.org/stable/c/902f6d656441a511ac25c6cffce74496db10a078
	https://git.kernel.org/stable/c/2ebcaa0e5db9b6044bb487ae1cf41bc601761567
	https://git.kernel.org/stable/c/7eeef1e935d23db5265233d92395bd5c648a4021
	https://git.kernel.org/stable/c/4e99103f757cdf636c6ee860994a19a346a11785
	https://git.kernel.org/stable/c/8ee1b439b1540ae543149b15a2a61b9dff937d91