[CVE-2026-68273][MODERATE 7.0] drm/amdgpu: Fix context pstate override handling [ Upstream

[CVE-2026-68273][MODERATE 7.0] drm/amdgpu: Fix context pstate override handling [ Upstream

[AL-KERNEL]

CVE: CVE-2026-68273
Priority: MODERATE 7.0
AL-KERNEL base severity: MODERATE
KPANIC flag: YES
Patch: drm/amdgpu: Fix context pstate override handling [ Upstream
Commit: 23a8726e1d7597fe7c9a59d5dc42ba8b7d345b8a
Upstream patch: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=23a8726e1d7597fe7c9a59d5dc42ba8b7d345b8a
Original CVE announcement: https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-68273
Analysis date: Mon, 10 Aug 2026 19:47:52 -0400
ActionableScore: 5
ActionableScore lower bound: 4
Actionable bucket: Actionable Moderate at minimum
Manual review required: YES

Summary:
A race in amdgpu context stable pstate handling can allow local users with GPU context access to hit a stale or cleared context pointer during initialization or teardown, causing NULL pointer dereference or potential use-after-free and requiring manual review for LPE risk.

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

The original Linux kernel CVE announcement for CVE-2026-68273 is available here:
https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-68273

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-2026-68273	MODERATE	CHECK WITH IMPACT FROM ORIG NN LOW	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-362;*CWE-416;**CWE-476;Other CVSS 'AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H';BEST CVSS score: '7';DESCR 'amdgpu context stable pstate handling has a race because amdgpu_ctx_init() reads adev pm stable_pstate_ctx without holding stable_pstate_ctx_lock while sysfs and context teardown paths can update or clear the same stored context pointer. A local user with access to the amdgpu DRM interface may be able to race context creation, context exit, and pstate override handling so that initialization observes a stale or cleared context pointer. This can cause a NULL pointer dereference or use-after-free in kernel context handling. For the CVSS the PR:L is used because reliable triggering requires local code execution with access to GPU context operations, not full administrative privileges in common render node deployments. The issue is not network reachable. Impact is at least local denial of service via kernel crash and in the paranoid interpretation may include confidentiality and integrity impact because the bug class includes use-after-free on a kernel pointer.';YES REQUIRES MANUAL CHECK; ,and ActionableScore result is Actionable Moderate at minimum (with actual score 5)  SKIP CVE-2026-68273 UNKNOWN SKIP No affected files built, so skip this CVE NO  - - unknown 	MAYBE	LOCK NULLPTR UAF HARDWARE KPANIC 	-	-	checked

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

ActionableScore=5
ActionableScoreLower=4

## 1. ActionableScore

* Conservative score: 4
* Paranoid score: 5
* Final recommended bucket: **Actionable Moderate at minimum**

## 2. Signal breakdown

* Local unprivileged trigger: +1
  A local user with access to the amdgpu DRM interface or render node can plausibly create and destroy GPU contexts.

* Memory corruption, weak or indirect corruption candidate: +1
  The commit explicitly mentions potential use-after-free, but the patch does not show attacker-controlled reclaim, controlled replacement, type confusion, callback control, or arbitrary write.

* Real lifetime corruption: +1
  The bug is caused by missing locking around `adev->pm.stable_pstate_ctx`, allowing a stale or cleared context pointer to be observed during context initialization or teardown.

* Reliable kernel crash / strong DoS: +1
  The same race can also cause NULL pointer dereference, making kernel crash or GPU driver fatal error a realistic impact.

* Broad or common subsystem exposure: +1
  amdgpu is common on AMD GPU systems and DRM render node access is commonly available to local desktop or compute users.

* Hard or unreliable race / special timing required: -1
  Exploitation depends on racing context initialization, context finalization, and pstate override handling.

Conservative total: 4

Paranoid adjustment:

* Weak LPE concern: +1
  In the paranoid interpretation, the explicit UAF on a kernel context pointer is enough to require manual review, even though no reclaim or write primitive is demonstrated.

Paranoid total: 5

## 3. Reachability analysis

The bug is local, not network reachable. A realistic trigger requires local code execution with access to the amdgpu DRM context interface, and possibly interaction with pstate override state that may also be touched through sysfs or driver context paths. Full host root is not necessarily required in common deployments because DRM render nodes are often accessible to ordinary local users for GPU workloads.

Containers and delegated GPU access matter. If a container or sandbox is granted access to the amdgpu render node, the trigger may be reachable from a reduced privilege environment. The issue is not default reachable on systems without AMD GPU hardware or without exposed amdgpu device nodes.

Call-site confidence: high. The patch shows the relevant initialization, pstate set, and finalization paths.

## 4. Severity interpretation

This behaves more like an actionable Moderate than an ordinary Moderate. The realistic impact is local denial of service through NULL pointer dereference or stale pointer use. The Important-class concern comes from the explicit use-after-free class, but the patch does not demonstrate attacker-controlled reclaim, object replacement, arbitrary write, callback dispatch, or a practical LPE chain.

Therefore the conservative score should stay below Important. The paranoid score should not be auto-closed because kernel UAF in a local DRM path deserves manual review.

## 5. One-sentence report phrase

A race in amdgpu context stable pstate handling can allow local users with GPU context access to hit a stale or cleared context pointer during initialization or teardown, causing NULL pointer dereference or potential use-after-free and requiring manual review for LPE risk.

## 6. Manual review recommendation

MANUAL CHECK REQUIRED

Reason: the patch explicitly identifies potential use-after-free in a local kernel driver path reachable through GPU context operations, even though the demonstrated impact is mainly DoS and no concrete privilege escalation primitive is shown.

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

Patch: drm/amdgpu: Fix context pstate override handling [ Upstream
Commit: 23a8726e1d7597fe7c9a59d5dc42ba8b7d345b8a
Upstream URL: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=23a8726e1d7597fe7c9a59d5dc42ba8b7d345b8a

Changed files:
  drivers/gpu/drm/amd/amdgpu/amdgpu_ctx.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=23a8726e1d7597fe7c9a59d5dc42ba8b7d345b8a

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

The original Linux kernel CVE announcement for CVE-2026-68273 can be found here:
https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-68273

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: 4
  Paranoid ActionableScore: 5

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).