[CVE-2026-97427][MODERATE 7.0] drm/amd/pm: bound pp_dpm_set_pp_table() memcpy [ Upstream

[CVE-2026-97427][MODERATE 7.0] drm/amd/pm: bound pp_dpm_set_pp_table() memcpy [ Upstream

[AL-KERNEL]

CVE: CVE-2026-97427
Priority: MODERATE 7.0
AL-KERNEL base severity: MODERATE
KPANIC flag: YES
Patch: drm/amd/pm: bound pp_dpm_set_pp_table() memcpy [ Upstream
Commit: 43d2ab8408f9f468b232350c74160ae21e763020
Upstream patch: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=43d2ab8408f9f468b232350c74160ae21e763020
Original CVE announcement: https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-97427
Analysis date: Thu, 24 Sep 2026 19:18:11 -0400
ActionableScore: 5
ActionableScore lower bound: unknown
Actionable bucket: Actionable Moderate / Strong Important candidate requiring manual review
Manual review required: YES

Summary:
No one-sentence report phrase was found.

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

The original Linux kernel CVE announcement for CVE-2026-97427 is available here:
https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-97427

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-2026-97427	MODERATE	https://www.kernelcve.org/list/?q=CVE-2026-97427 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:H/I:H/A:H';CWE-122;*CWE-787;*CWE-20;Other CVSS 'AV:L/AC:L/PR:H/UI:N/S:U/C:L/I:L/A:H';BEST CVSS score: '7.8';DESCR 'A heap buffer overflow in the AMD PowerPlay path occurs because pp_dpm_set_pp_table() copies the sysfs store size into hardcode_pp_table, while that buffer is allocated only with soft_pp_table_size bytes. A local actor able to write an oversized powerplay table can overwrite adjacent kernel heap memory with attacker supplied data. This can cause a kernel crash and may permit confidentiality or integrity impact, including potential privilege escalation, depending on the overwritten object and heap layout. For the CVSS the PR:L value in the paranoid score reflects deployments where GPU management access is delegated to a service account, container, or local group instead of being restricted to unrestricted root. The issue is not network reachable and requires local access to the AMD GPU power management sysfs interface. Impact is at least local denial of service and the direct heap overwrite supports manual review for possible privilege escalation.';YES REQUIRES MANUAL CHECK; ,and ActionableScore result is Actionable Moderate / Strong Important candidate requiring manual review (with actual score 5)  SKIP CVE-2026-97427 UNKNOWN SKIP No affected files built, so skip this CVE NO  - - unknown 	MAYBE	HARDWARE KPANIC MEMORY  KPANIC INCREASED_TO_HIGH_BASED_ON_GUESSCVSS DECREASED_TO_MODERATE7_BASED_ON_FALSEPOSCHECKOFKP	-	-	checked

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

ActionableScore=5
PrimitiveClass=CLASS_A
RealUAF=NO
HostAdminRequired=UNKNOWN
NamespaceScopedPrivilege=NO
ImportantCandidate=YES
ManualReview=REQUIRED
AutoDowngradeAllowed=NO

1. ActionableScore

* Raw conservative score: 4
* Conservative score: 5
* Applied conservative manual-review safety floor: 4 -> 5 because a controlled kernel heap overwrite is established.
* Raw paranoid score: 5
* Paranoid score: 5
* No paranoid floor or cap applied.
* Final recommended bucket: **Actionable Moderate / Strong Important candidate requiring manual review**::

2. Signal breakdown

Conservative signals:

* +2 Strong corruption primitive. The sysfs count controls the length of a memcpy into a heap allocation sized only to soft_pp_table_size, establishing an attacker-influenced heap OOB write.
* +1 Weak exploitation leverage. The payload is supplied through the sysfs buffer and can overwrite adjacent heap bytes, but the target object and resulting operation are not established.
* +1 Reliable kernel crash or strong DoS. Corrupting adjacent kernel heap storage realistically supports an Oops or kernel crash.
* Raw conservative total: 2 + 1 + 1 = 4.
* Safety floor to 5. Controlled kernel corruption must not be automatically downgraded merely because the adjacent object and full exploitation chain are unknown.

Paranoid signals:

* +2 Strong corruption primitive.
* +2 Strong exploitation leverage. A multi-byte, attacker-supplied linear overwrite beyond a kernel heap allocation is established. This replaces the conservative weak-leverage point rather than stacking with it.
* +1 Reliable kernel crash or strong DoS.
* Raw paranoid total: 2 + 2 + 1 = 5.

Not awarded:

* No UAF or post-lifetime stale-object use is established.
* No arbitrary-target write, controlled reclaim, callback overwrite, credential corruption, or demonstrated LPE is established.
* No confidentiality point is awarded because no read-back or disclosure path is shown.
* No separate integrity point is awarded because no specific protected adjacent object or security-sensitive field is identified.
* No extra Availability point is awarded because it would duplicate the same potential kernel crash.
* No local-unprivileged point is awarded because below-host-admin write access to the exact sysfs attribute is not established.
* No remote-reachability point is awarded.
* No hardware rarity penalty is applied. AMD GPU hardware is hardware-specific but not inherently rare.
* No race penalty applies because this is a direct bounds error, not a timing race.
* The memory-layout invariant is not scored separately because it is the same allocation-size versus copy-size defect already counted as the OOB write.

3. Reachability analysis

The attacker must write an oversized PowerPlay table through the AMD GPU power-management sysfs interface. The ordinary default permission model is likely restrictive, but the supplied context does not include the attribute declaration, mode, ownership, ACLs, or complete store call path. It therefore does not positively establish that host-admin-equivalent privilege is always required.

An ordinary logged-in user, DRM client, or compositor is not automatically able to write this power-management attribute. A delegated graphics or GPU-management service could potentially have access, but such delegation is not established in the supplied evidence. HostAdminRequired is therefore UNKNOWN rather than YES or NO.

The operation controls a host physical-device sysfs attribute and is not an attacker-created user-namespace or network-namespace operation. Namespace capabilities do not establish the complete trigger, so NamespaceScopedPrivilege is NO.

Prerequisites include a supported AMD GPU, the affected PowerPlay implementation, power management being enabled, and exposure of the relevant writable attribute. No network trigger, race, boot-time timing condition, or unusual physical access is required once write access exists.

4. Primitive and severity interpretation

The exact primitive is a controlled linear heap-buffer overflow. hardcode_pp_table is allocated with soft_pp_table_size bytes, while memcpy previously accepted the larger sysfs store count without enforcing that allocation boundary.

This is not fixed stale storage, an active-object UAF, a cleanup defect, or a repeated refcount mutation. RealUAF is NO.

PrimitiveClass is CLASS_A because attacker-supplied bytes can be written beyond a kernel heap allocation. The demonstrated primitive is stronger than a generic validation failure or invalid dereference.

Kernel heap corruption is established. A kernel crash is a realistic direct consequence. Corruption of a useful adjacent object, arbitrary kernel read or write, credential modification, and privilege escalation remain plausible but unproven consequences.

ImportantCandidate is YES because the overwrite has attacker-controlled contents and unresolved adjacent-object effects. AutoDowngradeAllowed is NO because automatically closing it as ordinary Moderate would discard a concrete controlled kernel-corruption primitive. Operational severity depends heavily on the actual sysfs access boundary, allocator placement, overflow length, and neighboring object types.

5. One-sentence report phrase

An oversized AMD PowerPlay sysfs write can copy attacker-supplied data beyond the hardcode_pp_table heap allocation, causing controlled kernel heap corruption and requiring manual review for crash and possible privilege-escalation impact.

6. Manual review recommendation

MANUAL CHECK REQUIRED

The exact sysfs permissions and reachable overflow layout must be verified, and allocator analysis is needed to determine whether adjacent active objects can provide a practical privilege-escalation primitive.

7. Call-site confidence

Call-site confidence: medium

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

Patch: drm/amd/pm: bound pp_dpm_set_pp_table() memcpy [ Upstream
Commit: 43d2ab8408f9f468b232350c74160ae21e763020
Upstream URL: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=43d2ab8408f9f468b232350c74160ae21e763020

Changed files:
  drivers/gpu/drm/amd/pm/powerplay/amd_powerplay.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=43d2ab8408f9f468b232350c74160ae21e763020

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

The original Linux kernel CVE announcement for CVE-2026-97427 can be found here:
https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-97427

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:H/UI:N/S:U/C:L/I:L/A:H
  The Best / paranoid CVSS vector: AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
  The Best / paranoid CVSS score: 7.8

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: 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).