[CVE-2026-80883][MODERATE 7.0] drm/tegra: gr2d/gr3d: Initialize address register map before HOST1X client is registered [ Upstream

[CVE-2026-80883][MODERATE 7.0] drm/tegra: gr2d/gr3d: Initialize address register map before HOST1X client is registered [ Upstream

[AL-KERNEL]

CVE: CVE-2026-80883
Priority: MODERATE 7.0
AL-KERNEL base severity: MODERATE
KPANIC flag: YES
Patch: drm/tegra: gr2d/gr3d: Initialize address register map before HOST1X client is registered [ Upstream
Commit: 6e22d5ad61cfa38aa53fab86a530113aff6a3619
Upstream patch: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=6e22d5ad61cfa38aa53fab86a530113aff6a3619
Original CVE announcement: https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-80883
Analysis date: Fri, 04 Sep 2026 15:47:27 -0400
ActionableScore: 6
ActionableScore lower bound: 4
Actionable bucket: Actionable Moderate at minimum
Manual review required: YES

Summary:
A local race in the Tegra DRM gr2d/gr3d probe path can expose the HOST1X client before address register maps are initialized, allowing early userspace job submission while GPU address validation state is incomplete and potentially causing DoS or security-relevant DMA validation bypass.

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ABOUT THIS REPORT
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The original Linux kernel CVE announcement for CVE-2026-80883 is available here:
https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-80883

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.

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AL-KERNEL CLASSIFICATION RESULT
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CVE-2026-80883	MODERATE	https://www.kernelcve.org/list/?q=CVE-2026-80883 CHECK WITH IMPACT FROM ORIG NN MODERATE	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-665;CWE-362;CWE-284;Other CVSS 'AV:L/AC:H/PR:L/UI:N/S:U/C:L/I:L/A:H';BEST CVSS score: '7';DESCR 'A race in the Tegra DRM gr2d/gr3d probe path can expose the HOST1X client to userspace before the address register map is initialized. A local process may then submit a GPU job during this small window while address register validation state is incomplete. For the CVSS the PR:L is used because triggering requires local access to the Tegra DRM or host1x userspace interface, not administrator privileges in the paranoid interpretation. The issue is not network reachable and is limited to systems using the affected Tegra DRM engines. Impact is at least local denial of service, and in the worst case may include confidentiality or integrity impact if an early job can program GPU address registers before the normal address validation data is ready.';YES REQUIRES MANUAL CHECK; ,and ActionableScore result is Actionable Moderate at minimum (with actual score 5)	YES	OOB DANGER INIT SIMPLEFIX HARDWARE KPANIC  KPANIC INCREASED_TO_HIGH_BASED_ON_GUESSCVSS DECREASED_TO_MODERATE7_BASED_ON_FALSEPOSCHECKOFKP	NO	NO	checked

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ACTIONABLESCORE ANALYSIS
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ActionableScore=6
ActionableScoreLower=4

## 1. ActionableScore

* Conservative score: 4
* Paranoid score: 6
* Final recommended bucket: **Actionable Moderate at minimum**::

## 2. Signal breakdown

Conservative signals:

* Local unprivileged trigger: +1. A local process with access to the Tegra DRM or host1x userspace interface may submit a job after HOST1X client registration.
* Weak/indirect corruption candidate: +1. The bug exposes job submission while address register validation state is incomplete, but the patch does not demonstrate a direct arbitrary write, UAF, or controlled overwrite primitive.
* Privileged kernel/device-management or DMA-adjacent path: +1. The affected state is an address register map used by GPU/host1x job handling, which is security-relevant because GPU jobs may program address-bearing registers.
* Integrity impact plausible: +1. If address registers are not recognized or validated correctly during the window, incorrect GPU address programming or validation bypass is plausible.
* Availability impact realistic: +1. An early malformed or improperly validated job can plausibly cause GPU faults, job failure, or device instability.
* Hard or unreliable race / special timing required: -1. The window exists only between HOST1X client registration and the following address map initialization loop during probe.

Paranoid additional signals:

* Weak LPE concern: +1. The incomplete address register map is in a DMA-capable GPU submission path, so a manually reviewed worst case should consider whether early job submission can affect memory access policy.
* Confidentiality impact plausible: +1. If address register validation is bypassed in the race window, unauthorized GPU reads are a defensible concern, although not demonstrated by the patch.

Not applied:

* Remote reachable: +0. No network trigger is shown.
* Strong generic memory corruption: +0. No UAF, double free, OOB write, heap overwrite, or arbitrary write is shown.
* Strong LPE plausibility: +0. There is no demonstrated reclaim, callback control, arbitrary write, or concrete privilege escalation chain.
* Broad/default exposure: +0. This is limited to Tegra systems with gr2d/gr3d and accessible DRM/host1x device nodes.

## 3. Reachability analysis

The bug is locally reachable on affected Tegra systems if a user can access the DRM/host1x interface and race job submission against driver probe. In typical deployments, access may be limited by device node permissions such as video or render group membership, but it does not inherently require full root if userspace GPU submission is available. Containers do not automatically gain reachability unless the relevant device node is passed through. The path is not network reachable and is hardware-specific to Tegra gr2d/gr3d. Realistic exploitation depends on hitting a narrow initialization window, so the race condition materially reduces reliability.

## 4. Severity interpretation

This is stronger than an ordinary low-risk initialization bug because the uninitialized state is an address register map used before exposing a GPU client to userspace. The realistic demonstrated impact is local DoS or device instability from early job submission. The theoretical concern is incomplete validation of address-bearing GPU registers, which may affect confidentiality or integrity in a worst-case DMA-style interpretation. However, the patch does not show a concrete arbitrary memory access primitive or a proven privilege escalation path, so the conservative result remains borderline and the paranoid result is Actionable Moderate rather than Strong Important.

## 5. One-sentence report phrase

A local race in the Tegra DRM gr2d/gr3d probe path can expose the HOST1X client before address register maps are initialized, allowing early userspace job submission while GPU address validation state is incomplete and potentially causing DoS or security-relevant DMA validation bypass.

## 6. Manual review recommendation

MANUAL CHECK REQUIRED

This should not be auto-closed because the affected data is an address register map in a GPU job submission path, and the worst-case impact depends on whether an early job can program address-bearing registers before normal validation is ready.

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

Patch: drm/tegra: gr2d/gr3d: Initialize address register map before HOST1X client is registered [ Upstream
Commit: 6e22d5ad61cfa38aa53fab86a530113aff6a3619
Upstream URL: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=6e22d5ad61cfa38aa53fab86a530113aff6a3619

Changed files:
  drivers/gpu/drm/tegra/gr2d.c
  drivers/gpu/drm/tegra/gr3d.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=6e22d5ad61cfa38aa53fab86a530113aff6a3619

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

The original Linux kernel CVE announcement for CVE-2026-80883 can be found here:
https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-80883

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:L/I:L/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: 4
  Paranoid ActionableScore: 6

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).