[CVE-2026-53054][MODERATE 7.0] drm/msm: Fix VM_BIND UNMAP locking [ Upstream

[CVE-2026-53054][MODERATE 7.0] drm/msm: Fix VM_BIND UNMAP locking [ Upstream

[AL-KERNEL]

CVE: CVE-2026-53054
Priority: MODERATE 7.0
AL-KERNEL base severity: MODERATE
KPANIC flag: YES
Patch: drm/msm: Fix VM_BIND UNMAP locking [ Upstream
Commit: 206f812ef140727b75697111391ae320fd8aa652
Upstream patch: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=206f812ef140727b75697111391ae320fd8aa652
Original CVE announcement: https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-53054
Analysis date: Fri, 26 Jun 2026 14:56:27 -0400
ActionableScore: 7
ActionableScore lower bound: 3
Actionable bucket: Strong Important candidate / Actionable Moderate at minimum
Manual review required: YES

Summary:
A local user with access to the msm DRM VM_BIND ioctl may trigger an UNMAP locking bug that leaves non_NO_SHARE buffer objects unprotected, causing GPUVM state corruption and potential kernel memory corruption.

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

The original Linux kernel CVE announcement for CVE-2026-53054 is available here:
https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-53054

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: MODERATE 7.0
Manual review required: YES

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

======================================================================
AL-KERNEL CLASSIFICATION RESULT
======================================================================

CVE-2026-53054	MODERATE	CHECK	Maybe valid. Check manually. Hints by AL-KERNEL: The best (paranoid) CVSS is 'AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H';CWE-667;CWE-362;CWE-662;Other CVSS 'AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H';BEST CVSS score: '7';DESCR 'A locking bug in the msm DRM VM_BIND UNMAP path can leave some buffer objects involved in an unmap operation without the required reservation lock. This can happen because the unmap locking helper was called with an object offset value instead of the full unmap range, so non_NO_SHARE BOs may be modified while not fully protected by the expected lock context. For the CVSS the PR:L is used because a local user or process needs access to the msm DRM VM_BIND ioctl, typically through a render node or a GPU enabled sandbox. The issue is not network reachable and requires local interaction with the DRM GPU interface. Impact is at least local denial of service through a kernel crash or GPUVM state corruption. For the paranoid score, the highest still defensible interpretation is used because missing locks around GPU VM object lifetime and mapping updates may plausibly lead to memory corruption and possible privilege escalation.';YES REQUIRES MANUAL CHECK; ,and ActionableScore result is Strong Important candidate / Actionable Moderate at minimum (with actual score 5)  SKIP CVE-2026-53054  SKIP No affected files built, so skip this CVE NO  - - unknown 	MAYBE	LOCK SIMPLEFIX HARDWARE LINUS  KPANIC INCREASED_TO_MODERATE_FROM_LOW_BASED_ON_GUESSCVSS	-	-	checked

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ACTIONABLESCORE ANALYSIS
======================================================================

ActionableScore=7
ActionableScoreLower=3

## 1. ActionableScore

* Conservative score: 3
* Paranoid score: 7
* Final recommended bucket: **Strong Important candidate / Actionable Moderate at minimum**::

## 2. Signal breakdown

Conservative signals:

* Local unprivileged trigger: +1. A local process with access to the msm DRM render node or GPU VM_BIND ioctl can likely reach this path.
* Memory corruption, weak or indirect corruption candidate: +1. The bug is a missing reservation lock on BOs involved in VM_BIND UNMAP, but the patch does not show a direct write primitive.
* Local unprivileged high-control kernel data-plane API: +1. VM_BIND gives userspace fine grained control over GPU virtual memory mappings and BO ranges.
* Availability impact realistic: +1. Incorrect locking in GPUVM unmap can plausibly cause driver instability, GPUVM state corruption, warnings, hangs, or kernel crash.
* Hard or unreliable race / special timing required: -1. Turning missing locking into a security impact likely requires a concurrent operation or timing window.

Paranoid additional signals:

* Weak LPE concern: +1. Missing BO reservation locking around GPUVM mapping teardown may affect object lifetime and mapping consistency, which is a plausible local privilege escalation concern even without a demonstrated primitive.
* Real lifetime corruption: +1. Reservation locks protect object lifetime and concurrent access. Skipping them for some BOs can create stale or inconsistent GPUVM object state.
* Confidentiality impact plausible: +1. If the race corrupts GPUVM mappings or object ownership, cross-object or cross-process exposure is technically plausible.
* Integrity impact plausible: +1. Incorrectly synchronized GPUVM unmap can plausibly corrupt mappings or allow unintended access to GPU memory objects.

Not applied:

* Remote reachable: 0. This is not network-triggerable.
* Requires admin/root/CAP_SYS_ADMIN: 0. DRM render node access is commonly available to local GPU users and containers with GPU passthrough.
* Strong memory corruption primitive: 0. No direct UAF reclaim, arbitrary write, OOB write, or controlled overwrite is shown by the patch.

## 3. Reachability analysis

The bug is reachable from the local DRM msm VM_BIND UNMAP path. A normal local user may reach it if they have access to the msm render node, which is common for GPU-enabled desktop, mobile, or sandboxed graphics workloads. Containers can also be relevant if the DRM device node is passed through.

The affected path is not default reachable on systems without Qualcomm msm DRM hardware or without the VM_BIND ioctl support. It also specifically affects non_NO_SHARE BOs because _NO_SHARE objects share the VM reservation object that is already locked. There is no realistic network trigger.

## 4. Severity interpretation

This is not an ordinary pure DoS cleanup. The one-line fix corrects the range passed to the GPUVM unmap locking helper, and the commit explicitly says that objects involved in UNMAP operations were not always locked.

Realistically, the patch proves a synchronization bug that can lead to GPUVM state corruption or crash. The patch does not prove a concrete exploit primitive such as arbitrary write, UAF reclaim, or controlled object confusion.

Paranoid interpretation is higher because DRM VM_BIND and GPUVM memory management are high-control local kernel interfaces, and missing reservation locks around BO mapping teardown can plausibly become memory corruption or privilege escalation. This should not be auto-closed without manual review.

## 5. One-sentence report phrase

A local user with access to the msm DRM VM_BIND ioctl may trigger an UNMAP locking bug that leaves non_NO_SHARE buffer objects unprotected, causing GPUVM state corruption and potential kernel memory corruption.

## 6. Manual review recommendation

MANUAL CHECK REQUIRED

Reason: this is a local GPUVM locking race in a high-control DRM memory-management interface, with plausible memory corruption and LPE implications even though the patch does not demonstrate a concrete exploit primitive.

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

Patch: drm/msm: Fix VM_BIND UNMAP locking [ Upstream
Commit: 206f812ef140727b75697111391ae320fd8aa652
Upstream URL: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=206f812ef140727b75697111391ae320fd8aa652

Changed files:
  drivers/gpu/drm/msm/msm_gem_vma.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=206f812ef140727b75697111391ae320fd8aa652

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

The original Linux kernel CVE announcement for CVE-2026-53054 can be found here:
https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-53054

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:H/PR:L/UI:N/S:U/C:N/I:N/A:H
  The Best / paranoid CVSS vector: AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H
  The Best / paranoid CVSS score: 7

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: 3
  Paranoid ActionableScore: 7

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: MODERATE
KPANIC detected for this report: YES
Published priority for this report (same as in Subject): MODERATE 7.0

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).