Subject: CVE-2023-52494: bus: mhi: host: Add alignment check for event ring read pointer

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

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

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

bus: mhi: host: Add alignment check for event ring read pointer

Though we do check the event ring read pointer by "is_valid_ring_ptr"
to make sure it is in the buffer range, but there is another risk the
pointer may be not aligned.  Since we are expecting event ring elements
are 128 bits(struct mhi_ring_element) aligned, an unaligned read pointer
could lead to multiple issues like DoS or ring buffer memory corruption.

So add a alignment check for event ring read pointer.

The Linux kernel CVE team has assigned CVE-2023-52494 to this issue.

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

	Issue introduced in 5.13 with commit ec32332df764 and fixed in 5.15.149 with commit 94991728c84f
	Issue introduced in 5.13 with commit ec32332df764 and fixed in 6.1.76 with commit 2df39ac8f813
	Issue introduced in 5.13 with commit ec32332df764 and fixed in 6.6.15 with commit a9ebfc405fe1
	Issue introduced in 5.13 with commit ec32332df764 and fixed in 6.7.3 with commit ecf832011182
	Issue introduced in 5.13 with commit ec32332df764 and fixed in 6.8 with commit eff9704f5332
	Issue introduced in 5.10.36 with commit a1d2bd164c1c
	Issue introduced in 5.11.20 with commit fd5f40fc8874
	Issue introduced in 5.12.3 with commit 76879a980cd5

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-2023-52494
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/bus/mhi/host/main.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/94991728c84f8df54fd9eec9b85855ef9057ea08
	https://git.kernel.org/stable/c/2df39ac8f813860f79782807c3f7acff40b3c551
	https://git.kernel.org/stable/c/a9ebfc405fe1be145f414eafadcbf09506082010
	https://git.kernel.org/stable/c/ecf8320111822a1ae5d5fc512953eab46d543d0b
	https://git.kernel.org/stable/c/eff9704f5332a13b08fbdbe0f84059c9e7051d5f