CVE-2026-64097: drm/amd/display: Validate GPIO pin LUT table size before iterating

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

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

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

drm/amd/display: Validate GPIO pin LUT table size before iterating

[Why&How]
The GPIO pin table parsers in get_gpio_i2c_info() and
bios_parser_get_gpio_pin_info() derive an element count from the VBIOS
table_header.structuresize field, then iterate over gpio_pin[] entries.
However, GET_IMAGE() only validates that the table header itself fits
within the BIOS image. If the VBIOS reports a structuresize larger than
the actual mapped data, the loop reads past the end of the BIOS image,
causing an out-of-bounds read.

Fix this by calling bios_get_image() to validate that the full claimed
structuresize is accessible within the BIOS image before entering the
loop in both functions.

(cherry picked from commit ba5e95b43b773ae1bf1f66ee6b31eb774e65afe3)

The Linux kernel CVE team has assigned CVE-2026-64097 to this issue.


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

	Fixed in 6.1.175 with commit 9900f6954be779011e7c2cd42addd87baf028bc5
	Fixed in 6.6.142 with commit fb30a3890d62fd50a95aef684faf64a307592e42
	Fixed in 6.12.92 with commit 67461e0c15335894cc5d3b84cda823bf8cbdc886
	Fixed in 6.18.34 with commit 7ca695b3122297b06a3ed605bbe1cd32c85d9f5a
	Fixed in 7.0.11 with commit f2a4827e980ba07de4391fa84d9c39a12726bdd7
	Fixed in 7.1 with commit 86d2b20644b11d21fe52c596e6e922b4590a3e3f

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-2026-64097
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/gpu/drm/amd/display/dc/bios/bios_parser2.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/9900f6954be779011e7c2cd42addd87baf028bc5
	https://git.kernel.org/stable/c/fb30a3890d62fd50a95aef684faf64a307592e42
	https://git.kernel.org/stable/c/67461e0c15335894cc5d3b84cda823bf8cbdc886
	https://git.kernel.org/stable/c/7ca695b3122297b06a3ed605bbe1cd32c85d9f5a
	https://git.kernel.org/stable/c/f2a4827e980ba07de4391fa84d9c39a12726bdd7
	https://git.kernel.org/stable/c/86d2b20644b11d21fe52c596e6e922b4590a3e3f