[CVE-2026-80915][LOW] drm/xe: Fix DPT allocation paths. [ Upstream

[CVE-2026-80915][LOW] drm/xe: Fix DPT allocation paths. [ Upstream

[AL-KERNEL]

CVE: CVE-2026-80915
Priority: LOW
AL-KERNEL base severity: LOW
KPANIC flag: NO
Patch: drm/xe: Fix DPT allocation paths. [ Upstream
Commit: 491c499295fb0b90308b230b0a1075dcdf7f4d12
Upstream patch: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=491c499295fb0b90308b230b0a1075dcdf7f4d12
Original CVE announcement: https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-80915
Analysis date: Wed, 09 Sep 2026 12:55:17 -0400
ActionableScore: 2
ActionableScore lower bound: unknown
Actionable bucket: Ordinary Moderate
Manual review required: NO

Summary:
The drm/xe display path could allocate DPT objects from unsafe memory regions, causing black screens, pipe faults, or system hangs under load on affected Intel Xe systems, with impact limited to local denial of service.

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

The original Linux kernel CVE announcement for CVE-2026-80915 is available here:
https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-80915

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.

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

CVE-2026-80915	LOW	https://www.kernelcve.org/list/?q=CVE-2026-80915 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-400;CWE-770;CWE-665;Other CVSS 'AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H';BEST CVSS score: '5.5';DESCR 'The drm xe display path could allocate DPT objects from stolen memory or fall back to system memory in cases where those allocation choices are unsafe for the hardware path. This can lead to black screens, pipe fault errors, and random system hangs under load on affected Intel Xe systems. For the CVSS the PR:L value is used because a local user with access to the graphical stack may be able to create display or GPU workload that reaches the vulnerable allocation path, while administrative control of the driver is not necessarily required for practical triggering. The issue is not network reachable and depends on local hardware, display configuration, and GPU load. Impact is denial of service only through display failure or system hang. There is no clear UAF, OOB write, arbitrary write, or information leak primitive in the patch context.';NO MANUAL CHECK; ,and ActionableScore result is Ordinary Moderate (with actual score 2)	YES	HARDWARE TEST MEMORY  DECREASED_TO_MODERATE_REGULAR_FROM_MODERATE7_BASED_ON_GUESSCVSS_AND_CIANNH DECREASED_TO_LOW_FROM_MODERATE_BASED_ON_ACTIONABLESCORELESSTHAN3	YES	NO	checked

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

ActionableScore=2
PrimitiveClass=CLASS_C
RealUAF=NO
HostAdminRequired=UNKNOWN
NamespaceScopedPrivilege=NO
ImportantCandidate=NO
ManualReview=NO
AutoDowngradeAllowed=YES

## 1. ActionableScore

* Raw conservative score: 2
* Conservative score: 2
* Raw paranoid score: 2
* Paranoid score: 2
* No floor or cap changed the score.
* Final recommended bucket: **Ordinary Moderate**::

## 2. Signal breakdown

Positive signals:

* +1 Reliable DoS / availability failure: commit reports black screen, pipe fault errors, and random system hangs under load.
* +1 Broadly exercised path on affected systems: display / fbdev DPT allocation is a normal runtime path on affected Intel Xe display systems, not an obscure debug-only path.

Negative or non-awarded signals:

* +0 RealUAF not awarded: no use-after-free, stale pointer, double release, or lifetime violation is shown.
* +0 Memory corruption not awarded: no OOB write, arbitrary write, controlled overwrite, type confusion, or refcount corruption is established.
* +0 Confidentiality / integrity not awarded: the evidence supports display failure or hang only.
* +0 Remote reachability not awarded: this is not packet-triggered or remotely reachable.
* +0 Local unprivileged trigger not awarded: a local graphics workload may contribute, but the complete vulnerable DRM/KMS/fbdev control path is not proven reachable by an ordinary unprivileged user.
* +0 Strong LPE / weak LPE not awarded: no exploit primitive beyond DoS is established.
* +0 Extra availability point not awarded: black screen and hang are part of the same availability failure class, so they are not double-counted.
* +0 Hardware rarity penalty not applied: affected Intel Xe GPU/display hardware is hardware-dependent but not proven rare or physical-only.
* +0 Race penalty not applied: this is not a timing race.

## 3. Reachability analysis

The likely trigger is local display or GPU/display-stack activity that reaches `__xe_pin_fb_vma_dpt()` and causes DPT allocation for framebuffer/display use. The most plausible actors are a compositor, DRM master, display server, fbdev user, or another local graphics/display management component.

For DRM/KMS/display scoring, below-host-admin reachability is plausible but not fully established from the supplied patch alone. A normal logged-in user may indirectly cause display workload through the compositor, but the complete vulnerable display-control operation is not proven to be directly available to an ordinary user. Therefore `HostAdminRequired=UNKNOWN`, not `NO`.

The issue is not namespace-scoped. No network trigger exists. Prior setup requires affected Intel Xe hardware, the xe driver, and a display/fbdev path using DPT allocation. This is hardware-dependent but not enough to apply a rare-hardware penalty. No race or special timing requirement is established.

## 4. Primitive and severity interpretation

The exact primitive is an unsafe memory-region selection for DPT allocation in the drm/xe display path. The old code could allocate DPT objects from stolen memory or fall back to system memory, both of which are described as unsafe or non-working for this path.

This is not an active structured UAF and not fixed stale storage. It is best classified as invalid-state / device-display availability behavior. The demonstrated consequence is black screen, pipe faults, and possible random system hangs under load.

No concrete corruption primitive is established. The note about theoretically filling stolen memory with DPTs suggests resource pressure risk, but not a concrete persistent leak or isolation bypass. The patch context supports DoS only.

Primitive class is `CLASS_C`. `ImportantCandidate=NO` because there is no memory corruption, ownership violation, authorization bypass, or unresolved lifetime/refcount primitive. `AutoDowngradeAllowed=YES` because the issue is ordinary availability impact with no meaningful unresolved exploitation leverage.

Operational severity is Low-like to ordinary Moderate, depending on how critical local display availability is for the product.

## 5. One-sentence report phrase

The drm/xe display path could allocate DPT objects from unsafe memory regions, causing black screens, pipe faults, or system hangs under load on affected Intel Xe systems, with impact limited to local denial of service.

## 6. Manual review recommendation

NO MANUAL CHECK NEEDED

Reason: the patch supports DoS/display hang only and does not establish UAF, memory corruption, security-boundary bypass, information disclosure, or privilege escalation.

## 7. Call-site confidence

Call-site confidence: medium

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

Patch: drm/xe: Fix DPT allocation paths. [ Upstream
Commit: 491c499295fb0b90308b230b0a1075dcdf7f4d12
Upstream URL: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=491c499295fb0b90308b230b0a1075dcdf7f4d12

Changed files:
  drivers/gpu/drm/xe/display/xe_fb_pin.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=491c499295fb0b90308b230b0a1075dcdf7f4d12

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

The original Linux kernel CVE announcement for CVE-2026-80915 can be found here:
https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-80915

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: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: unknown
  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).