[CVE-2026-53378][LOW] drm/colorop: Fix blob property reference tracking in state lifecycle

[CVE-2026-53378][LOW] drm/colorop: Fix blob property reference tracking in state lifecycle

[AL-KERNEL]

CVE: CVE-2026-53378
Priority: LOW
AL-KERNEL base severity: LOW
KPANIC flag: NO
Patch: drm/colorop: Fix blob property reference tracking in state lifecycle
Commit: 271059f1d9020e9ac967524e319fbbaa22d0475b
Upstream patch: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=271059f1d9020e9ac967524e319fbbaa22d0475b
Original CVE announcement: https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-53378
Analysis date: Sun, 19 Jul 2026 06:55:21 -0400
ActionableScore: 2
ActionableScore lower bound: 1
Actionable bucket: Ordinary Moderate / Low-like
Manual review required: NO

Summary:
A local DRM/KMS user may trigger leaked drm/colorop blob property references during state destroy, reset, or cleanup paths, causing gradual kernel memory growth and possible resource-exhaustion DoS.

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ABOUT THIS REPORT
======================================================================

The original Linux kernel CVE announcement for CVE-2026-53378 is available here:
https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-53378

The original announcement does not normally provide a security severity
estimate, CVSS assessment, or enough information to determine whether the
reported kernel bug represents a practically relevant security issue.

This report was generated by AL-KERNEL, an AI-assisted Linux kernel
vulnerability analysis system developed by Alexander Larkin. It combines
an autonomous classifier with LLM-assisted technical analysis and a
separate ActionableScore mechanism.

The purpose of this report is to prioritize Linux kernel CVEs before
manual review, identify cases that require prompt investigation, and
support automatic closure of issues that are unlikely to have meaningful
security impact.

Published priority for this report: LOW
Manual review required: NO

A detailed explanation of the methodology and priority rules is included
at the end of this message.

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AL-KERNEL CLASSIFICATION RESULT
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CVE-2026-53378	LOW	CHECK WITH IMPACT FROM ORIG NN LOW	Maybe valid. Check manually. Hints by AL-KERNEL: The best (paranoid) CVSS is 'AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H';*CWE-401;*CWE-772;**CWE-400;Other CVSS 'AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L';BEST CVSS score: '5.5';DESCR 'drm colorop state lifecycle can leak references to DRM blob properties because state destruction, reset, and cleanup paths may free or replace the state without dropping the state data blob reference. A local process that can exercise DRM color management or atomic KMS state operations could cause repeated leaked blob references and gradual kernel memory growth. For the CVSS the PR:L is used because reliable triggering normally requires local access to the DRM control interface such as a compositor, DRM master, or a user with delegated graphics device access. The issue is not network reachable and does not provide an obvious memory corruption primitive. Impact is denial of service via resource exhaustion, with no supported confidentiality or integrity impact.';NO MANUAL CHECK; ,and ActionableScore result is Ordinary Moderate / Low-like (with actual score 2)  SKIP CVE-2026-53378 UNKNOWN SKIP The Fixes patch not applied yet, so unlikely that actual: cfc27680ee208cdf7a61cda817b4158c4142595f YES  NO NO unknown 	MAYBE	LEAK HARDWARE  INCREASED_FROM_LOW_BASED_ON_HIGHCVSSSCORE DECREASED_TO_MODERATEREG_BASED_ON_ACTIONABLESCORELESSTHAN5 DECREASED_TO_LOW_FROM_MODERATE_BASED_ON_ACTIONABLESCORELESSTHAN3	-	-	checked

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ACTIONABLESCORE ANALYSIS
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ActionableScore=2
ActionableScoreLower=1

## 1. ActionableScore

* Conservative score: 1
* Paranoid score: 2
* Final recommended bucket: **Ordinary Moderate / Low-like**

## 2. Signal breakdown

Conservative signals:

* Local non-root trigger: +1. A local process with access to DRM/KMS color management or atomic modesetting paths may exercise the affected lifecycle operations.
* Rare or limited feature exposure: -1. drm/colorop is a newer DRM color pipeline object and depends on driver and userspace support.
* Availability impact, limited: +1. Repeated operations can leak blob references and kernel memory, but the patch does not show immediate crash or fast system-wide failure.

Paranoid delta:

* Sustained resource exhaustion concern: +1. If a local graphics client can repeatedly trigger reset, cleanup, or state replacement paths, leaked references could accumulate enough to cause memory pressure or DoS.

Not applied:

* No remote/network trigger.
* No generic memory corruption. The patch fixes missing drm_property_blob_put(), not UAF, OOB, double free, or type confusion.
* No confidentiality or integrity impact.
* No privilege escalation signal.
* No strong DoS signal, because the leak appears gradual rather than an immediate reliable crash.

Call-site confidence: high. The patch includes the relevant destroy, reset, and cleanup lifecycle paths.

## 3. Reachability analysis

The likely trigger is local access to DRM/KMS control paths, typically through a compositor, DRM master, graphics stack component, or a user with access to the relevant DRM device node. It is not network reachable. Namespaces or containers may matter only if DRM device access is delegated into the container. The affected feature is not a central default kernel path and depends on drm/colorop support in the running kernel and driver stack.

## 4. Severity interpretation

This behaves like a resource leak / DoS-only issue, not an Important-class kernel vulnerability. The realistic impact is gradual kernel memory growth from leaked DRM blob references. The theoretical worst case is local resource exhaustion, but there is no evidence of memory corruption, attacker-controlled overwrite, stale callback, credential impact, or LPE.

## 5. One-sentence report phrase

A local DRM/KMS user may trigger leaked drm/colorop blob property references during state destroy, reset, or cleanup paths, causing gradual kernel memory growth and possible resource-exhaustion DoS.

## 6. Manual review recommendation

NO MANUAL CHECK NEEDED

This is a reference leak/resource exhaustion bug with low practical severity and no evidence of memory corruption, privilege escalation, or security-boundary bypass.

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UPSTREAM PATCH SUMMARY
======================================================================

Patch: drm/colorop: Fix blob property reference tracking in state lifecycle
Commit: 271059f1d9020e9ac967524e319fbbaa22d0475b
Upstream URL: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=271059f1d9020e9ac967524e319fbbaa22d0475b

Commit description:

The colorop state blob property handling had memory leaks during state
duplication, destruction, and reset operations. The implementation
failed to follow the established pattern from drm_crtc's handling of
DEGAMMA/GAMMA blob properties.

Issues fixed:
- drm_colorop_atomic_destroy_state() was freeing state memory without
  releasing the blob reference, causing a leak
- drm_colorop_reset() was directly freeing old state with kfree()
  instead of properly destroying it, leaking blob references
- drm_colorop_cleanup() had duplicate blob cleanup code

Changes:
- Add __drm_atomic_helper_colorop_destroy_state() helper to properly
  release blob references before freeing state memory
- Update drm_colorop_atomic_destroy_state() to call the helper
- Fix drm_colorop_reset() to use drm_colorop_atomic_destroy_state()
  for proper cleanup of old state
- Simplify drm_colorop_cleanup() to use the common destruction path

This matches the well-tested pattern used by drm_crtc since 2016 and
ensures proper reference counting throughout the state lifecycle.

Co-developed by Claude Sonnet 4.5.

Fixes: cfc2768 ("drm/colorop: Introduce new drm_colorop mode object")
Cc: Simon Ser <contact@emersion.fr>
Cc: Alex Hung <alex.hung@amd.com>
Cc: Harry Wentland <harry.wentland@amd.com>
Cc: Daniel Stone <daniels@collabora.com>
Cc: Melissa Wen <mwen@igalia.com>
Cc: Sebastian Wick <sebastian.wick@redhat.com>
Cc: Uma Shankar <uma.shankar@intel.com>
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Cc: Jani Nikula <jani.nikula@intel.com>
Cc: Louis Chauvet <louis.chauvet@bootlin.com>
Cc: Chaitanya Kumar Borah <chaitanya.kumar.borah@intel.com>
Cc: <stable@vger.kernel.org> #v6.19+
Signed-off-by: Harry Wentland <harry.wentland@amd.com>
Reviewed-by: Alex Hung <alex.hung@amd.com>
Link: https://patch.msgid.link/20260312204145.829714-1-harry.wentland@amd.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Changed files:
  drivers/gpu/drm/drm_colorop.c

Diff excerpt:

Not included in this email. See the upstream URL for the full patch.

Full patch:
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=271059f1d9020e9ac967524e319fbbaa22d0475b

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DETAILED REPORT METHODOLOGY
======================================================================

The original Linux kernel CVE announcement for CVE-2026-53378 can be found here:
https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-53378

The original CVE announcement normally does not include a security-level
estimate. In particular, it may not contain a CVSS assessment, an impact
level, or enough information to determine whether the reported bug is a
practically relevant security issue. One purpose of this parallel CVE list
is to provide that missing technical and prioritization information.

The original goal of the AL-KERNEL project was to prioritize Linux kernel
CVE analysis automatically before manual review. The system can also help
identify non-security issues that may be suitable for automatic closure.

This report was generated by AL-KERNEL, an AI-assisted Linux kernel
vulnerability analysis system developed by Alexander Larkin.

The first analysis stage combines an autonomous classifier with additional
LLM-based analysis. The autonomous classifier runs locally on a CPU and is
based on a backpropagation neural network. Together, these mechanisms
produce a technical vulnerability description, identify likely weakness
types, estimate CVSS severity, and provide input for ActionableScore.

Two CVSS estimates are retained because incomplete kernel vulnerability
information often permits more than one defensible interpretation:

  Conservative CVSS vector: AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L
  The Best / paranoid CVSS vector: AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
  The Best / paranoid CVSS score: 5.5

The conservative vector represents a lower-impact interpretation.
The Best/paranoid vector intentionally represents a plausible upper-bound
interpretation and should not automatically be treated as demonstrated
real-world impact.

CVSS may also need to be adjusted for a particular Linux deployment,
because actual reachability, privileges, enabled kernel configuration,
hardware, namespaces, exposed device nodes, and other environmental
conditions can differ significantly between systems.

A separate ActionableScore mechanism evaluates practical remediation
urgency. Its analysis may include reachability, attack prerequisites,
subsystem exposure, memory-corruption characteristics, denial-of-service
reliability, and possible confidentiality, integrity, or
privilege-escalation impact.

  Conservative ActionableScore: 1
  Paranoid ActionableScore: 2

The final base severity is taken directly from the second tab-separated
field of the AL-KERNEL classification result. ActionableScore does not
replace or independently override that final AL-KERNEL decision, and
if ActionableScore adjusted impact level of ALKERNEL, then you would see
self-readable flags above like INCREASED_TO_HIGH_BASED_ON_ACTIONABLESCOREHIGHEREQTHAN7.

For an AL-KERNEL result of MODERATE, this report uses the following
additional presentation split:

  ActionableScore below 5   -> MODERATE REGULAR
  ActionableScore 5 or more -> MODERATE 7.0

The distinction between MODERATE REGULAR and MODERATE 7.0 makes it
possible to identify Moderate issues that should receive manual analysis
and fixes before lower-priority MODERATE REGULAR issues. In many cases,
MODERATE REGULAR fixes may wait for a later rebase or routine update.

There is one override in which MODERATE REGULAR becomes MODERATE 7.0
even when the ActionableScore is below 5. When the AL-KERNEL result
contains the KPANIC flag, a MODERATE result is always presented as
MODERATE 7.0. The KPANIC flag selected with few regexps without
usage of AI at all, so it helps to detect cases when Kernel Crash happens
and similar (to filter False-Negative results from the LLM usage).

KPANIC indicates that a reliable kernel crash, kernel panic, or similarly
serious kernel availability impact was identified by the classification
workflow.

AL-KERNEL base severity for this report: LOW
KPANIC detected for this report: NO
Published priority for this report (same as in Subject): LOW

These results are intended to support engineering triage. They are
machine-generated estimates, and cases marked for manual review should
be validated by a human security engineer before final disposition.
For more info read docs linked from here: https://kernelcve.org/
(and you can submit you own patch there to generate such a report
for non-existant CVE-id yet).

Note that in many cases this AI tool selects higher severity, than
real is (means you can expect Importants instead of Moderate 7.0 or
Moderates 7.0 instead of regular Moderates). If you see such cases,
please use reply email interface to add additional manual analyses
info to this particular CVE.
And please, please, let me know when you see Lows instead of Importants
or Important instead of Low (because particular for such cases I
need to tune this AI tool to make it better for this one and next similar).
My contact email for such notifications is alexanjelausa@gmail.com (and both
send reply to CVE record itself too and see "reply" button below for howto reply).