Subject: CVE-2024-44931: gpio: prevent potential speculation leaks in gpio_device_get_desc()

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

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

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

gpio: prevent potential speculation leaks in gpio_device_get_desc()

Userspace may trigger a speculative read of an address outside the gpio
descriptor array.
Users can do that by calling gpio_ioctl() with an offset out of range.
Offset is copied from user and then used as an array index to get
the gpio descriptor without sanitization in gpio_device_get_desc().

This change ensures that the offset is sanitized by using
array_index_nospec() to mitigate any possibility of speculative
information leaks.

This bug was discovered and resolved using Coverity Static Analysis
Security Testing (SAST) by Synopsys, Inc.

The Linux kernel CVE team has assigned CVE-2024-44931 to this issue.

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

	Fixed in 5.10.227 with commit 9d682e89c44b
	Fixed in 5.15.168 with commit c65ab97efcd4
	Fixed in 6.1.112 with commit 672c19165fc9
	Fixed in 6.6.46 with commit 1b955f786a4b
	Fixed in 6.10.5 with commit d776c0486b03
	Fixed in 6.11 with commit d795848ecce2

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-2024-44931
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/gpio/gpiolib.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/9d682e89c44bd5819b01f3fbb45a8e3681a4b6d0
	https://git.kernel.org/stable/c/c65ab97efcd438cb4e9f299400f2ea55251f3a67
	https://git.kernel.org/stable/c/672c19165fc96dfad531a5458e0b3cdab414aae4
	https://git.kernel.org/stable/c/1b955f786a4bcde8c0ccb2b7d519def2acb6f3cc
	https://git.kernel.org/stable/c/d776c0486b03a5c4afca65b8ff44573592bf93bb
	https://git.kernel.org/stable/c/d795848ecce24a75dfd46481aee066ae6fe39775