CVE-2026-89825: drm/panthor: fix firmware control interface bounds checks

CVE-2026-89825: drm/panthor: fix firmware control interface bounds checks

[Greg Kroah-Hartman]

From: Greg Kroah-Hartman <gregkh@kernel.org>

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

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

drm/panthor: fix firmware control interface bounds checks

panthor_init_cs_iface() and panthor_init_csg_iface() validate firmware
control interface offsets with 32-bit arithmetic and the size of the host
wrapper structures. The offsets are derived from firmware-provided strides,
so the arithmetic can wrap before the bounds check, and the host wrapper
size is not the size of the firmware control interface being mapped.

Use 64-bit arithmetic for the computed offsets and validate against the
actual firmware control interface structure sizes with subtraction-based
bounds checks. Also validate that the shared section is large enough for
the global control interface before using it.

The Linux kernel CVE team has assigned CVE-2026-89825 to this issue.


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

	Issue introduced in 6.10 with commit 2718d91816eeed03c09c8abe872e45f59078768c and fixed in 6.12.110 with commit 33ae55809aee9b4dca1d00cdee35b527f2bf8626
	Issue introduced in 6.10 with commit 2718d91816eeed03c09c8abe872e45f59078768c and fixed in 6.18.51 with commit 80c9528661c774f899281c9a72011208ff39929e
	Issue introduced in 6.10 with commit 2718d91816eeed03c09c8abe872e45f59078768c and fixed in 7.2.5 with commit 3e5c7cddc0073eef6f9bb373189b11a969f1f6f6
	Issue introduced in 6.10 with commit 2718d91816eeed03c09c8abe872e45f59078768c and fixed in 7.3-rc1 with commit 6a47f9fd2d970674ed9dedc52fc7ab76fd015785

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-2026-89825
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/panthor/panthor_fw.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/33ae55809aee9b4dca1d00cdee35b527f2bf8626
	https://git.kernel.org/stable/c/80c9528661c774f899281c9a72011208ff39929e
	https://git.kernel.org/stable/c/3e5c7cddc0073eef6f9bb373189b11a969f1f6f6
	https://git.kernel.org/stable/c/6a47f9fd2d970674ed9dedc52fc7ab76fd015785