CVE-2026-53141: drm/v3d: Fix global performance monitor reference counting

CVE-2026-53141: drm/v3d: Fix global performance monitor reference counting

[Greg Kroah-Hartman]

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

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

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

drm/v3d: Fix global performance monitor reference counting

In the SET_GLOBAL ioctl, v3d_perfmon_find() bumps the reference count on
the perfmon it returns, but v3d_perfmon_set_global_ioctl() and
v3d_perfmon_delete() fail to release that reference on several paths:

  1. v3d_perfmon_set_global_ioctl() leaks the reference on its error
     paths.

  2. CLEAR_GLOBAL leaks both the find reference and the reference
     previously stashed in v3d->global_perfmon by the SET_GLOBAL ioctl
     that configured it.

  3. Destroying a perfmon that is the current global perfmon leaks the
     reference stashed by the SET_GLOBAL ioctl.

Release each of these references explicitly.

The Linux kernel CVE team has assigned CVE-2026-53141 to this issue.


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

	Issue introduced in 6.14 with commit c6eabbab359c156669e10d5dec3e71e80ff09bd2 and fixed in 6.18.36 with commit 3e1947573140a57119294f0bff39ee18d93f23e1
	Issue introduced in 6.14 with commit c6eabbab359c156669e10d5dec3e71e80ff09bd2 and fixed in 7.0.13 with commit ed2eaf3b7b1820b690e4b896d344e00027526a25
	Issue introduced in 6.14 with commit c6eabbab359c156669e10d5dec3e71e80ff09bd2 and fixed in 7.1 with commit 6bf7e2affc6e62da7add393d7f352d4040f5bc27

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-2026-53141
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/v3d/v3d_perfmon.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/3e1947573140a57119294f0bff39ee18d93f23e1
	https://git.kernel.org/stable/c/ed2eaf3b7b1820b690e4b896d344e00027526a25
	https://git.kernel.org/stable/c/6bf7e2affc6e62da7add393d7f352d4040f5bc27