CVE-2026-43104: drm/vc4: Fix a memory leak in hang state error path

CVE-2026-43104: drm/vc4: Fix a memory leak in hang state error path

[Greg Kroah-Hartman]

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

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

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

drm/vc4: Fix a memory leak in hang state error path

When vc4_save_hang_state() encounters an early return condition, it
returns without freeing the previously allocated `kernel_state`,
leaking memory.

Add the missing kfree() calls by consolidating the early return paths
into a single place.

The Linux kernel CVE team has assigned CVE-2026-43104 to this issue.


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

	Issue introduced in 4.5 with commit 214613656b5179f0daab6e0a080814b5100d45f0 and fixed in 6.6.136 with commit dd5c49787a32da96a2b154427eb17cbf12a83c28
	Issue introduced in 4.5 with commit 214613656b5179f0daab6e0a080814b5100d45f0 and fixed in 6.12.83 with commit d8fdd6adc07b78ad3e9ee0004876d90cb59ca941
	Issue introduced in 4.5 with commit 214613656b5179f0daab6e0a080814b5100d45f0 and fixed in 6.18.24 with commit e352e9adc9f6df54d63150ff832f71c04e30744b
	Issue introduced in 4.5 with commit 214613656b5179f0daab6e0a080814b5100d45f0 and fixed in 6.19.14 with commit 3eb7dd55021d0f4308fbea0bea21d2118984d8e7
	Issue introduced in 4.5 with commit 214613656b5179f0daab6e0a080814b5100d45f0 and fixed in 7.0 with commit 9525d169e5fd481538cf8c663cc5839e54f2e481

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-2026-43104
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/vc4/vc4_gem.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/dd5c49787a32da96a2b154427eb17cbf12a83c28
	https://git.kernel.org/stable/c/d8fdd6adc07b78ad3e9ee0004876d90cb59ca941
	https://git.kernel.org/stable/c/e352e9adc9f6df54d63150ff832f71c04e30744b
	https://git.kernel.org/stable/c/3eb7dd55021d0f4308fbea0bea21d2118984d8e7
	https://git.kernel.org/stable/c/9525d169e5fd481538cf8c663cc5839e54f2e481