[CVE-2026-97428][MODERATE REGULAR] drm/amdgpu: harden FRU PIA parsing with bounded helpers [ Upstream

[CVE-2026-97428][MODERATE REGULAR] drm/amdgpu: harden FRU PIA parsing with bounded helpers [ Upstream

[AL-KERNEL]

CVE: CVE-2026-97428
Priority: MODERATE REGULAR
AL-KERNEL base severity: MODERATE
KPANIC flag: NO
Patch: drm/amdgpu: harden FRU PIA parsing with bounded helpers [ Upstream
Commit: 813311512505e95e4e3c898ff94b11886a15e494
Upstream patch: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=813311512505e95e4e3c898ff94b11886a15e494
Original CVE announcement: https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-97428
Analysis date: Thu, 24 Sep 2026 21:21:43 -0400
ActionableScore: 3
ActionableScore lower bound: 1
Actionable bucket: Borderline / manual review recommended
Manual review required: YES

Summary:
No one-sentence report phrase was found.

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

The original Linux kernel CVE announcement for CVE-2026-97428 is available here:
https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-97428

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 REGULAR
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-2026-97428	MODERATE	https://www.kernelcve.org/list/?q=CVE-2026-97428 CHECK WITH IMPACT FROM ORIG NN MODERATE	Maybe valid. Check manually. Hints by AL-KERNEL: The best (paranoid) CVSS is 'AV:P/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H';CWE-125;CWE-126;*CWE-20;Other CVSS 'AV:P/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:L';BEST CVSS score: '6.1';DESCR 'The AMDGPU FRU Product Info Area parser can read beyond the allocated EEPROM buffer because the original TLV handling checks that a field header exists but does not limit each copy to the number of bytes remaining in the buffer. Truncated or malformed FRU data can therefore cause a heap out of bounds read while manufacturer, product, serial, or FRU identifier fields are parsed. The issue may expose adjacent kernel heap data through device information fields or cause a kernel fault if the read reaches inaccessible memory. For the CVSS the PR:N value is used because exploitation through a malicious physical EEPROM does not require an authenticated user account or local process on the target. AV:P is used because reliable triggering normally requires physical replacement or modification of the GPU FRU EEPROM. The base impact is limited information disclosure and availability degradation. The paranoid impact allows high confidentiality loss and a kernel crash, but integrity remains unaffected because the available primitive is an out of bounds read rather than a write. Public Internet reachability is not expected, although platforms that expose FRU programming through a BMC or another management path require separate review.';YES REQUIRES MANUAL CHECK; ,and ActionableScore result is Borderline / manual review recommended (with actual score 2)  SKIP CVE-2026-97428 UNKNOWN SKIP No affected files built, so skip this CVE NO  - - unknown 	MAYBE	READ OOB HARDWARE  DECREASED_TO_MODERATEREG_BASED_ON_ACTIONABLESCORELESSTHAN4	-	-	checked

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

ActionableScore=3
ActionableScoreLower=1
PrimitiveClass=CLASS_C
RealUAF=NO
HostAdminRequired=NO
NamespaceScopedPrivilege=NO
ImportantCandidate=NO
ManualReview=RECOMMENDED
AutoDowngradeAllowed=YES

1. ActionableScore

* Raw conservative score: 1
* Conservative score: 1
* Raw paranoid score: 3
* Paranoid score: 3
* No floor or cap was applied.
* Final recommended bucket: **Borderline / manual review recommended**::

2. Signal breakdown

Conservative signals:

* +1 Firmware-mediated external influence. Malformed or truncated FRU EEPROM data directly controls the TLV lengths consumed by the parser.
* +0 Limited source OOB read. The destination copy remains bounded, and no write beyond the destination, UAF, or lifetime corruption is established.
* +0 Confidentiality. Bytes can be copied from beyond the EEPROM buffer into FRU fields, but the supplied context does not show a concrete user-visible read-back path.
* +0 Availability. The patch establishes an OOB read but does not document an actual Oops, panic, or host crash.
* +0 Physical-only penalty. Reliable exploitation likely involves EEPROM modification or device replacement, but exclusive physical reachability is not positively established because a platform management or firmware programming path may exist.

Additional paranoid signals:

* +1 Confidentiality plausible. Adjacent heap bytes may be copied into manufacturer, product, serial, or FRU identifier fields. If these fields are exposed through sysfs, debugfs, logs, or management interfaces, this becomes a limited kernel information disclosure.
* +1 Reliable kernel fault plausible. A source OOB read crossing into inaccessible memory can fault in kernel context, although no observed crash is supplied.
* No Integrity point. The copies are bounded by destination size, and no OOB write or other state-modification primitive is shown.
* No remote-reachability point. Network delivery to this parser is not established.
* No strong corruption or exploitation-leverage point. Controlled reclaim, arbitrary write, type confusion, callback influence, and privilege escalation are not demonstrated.

3. Reachability analysis

The vulnerable input comes from the AMD GPU FRU EEPROM and is parsed when the driver obtains product information. An ordinary local user is not shown to be able to rewrite or substitute this EEPROM. A malicious physical device or modified EEPROM can trigger the path without an authenticated host account, so host-admin privilege is not inherently required for that attacker model.

The operation is not namespace-scoped, and user or network namespaces do not provide control over the EEPROM parser. No prior host configuration beyond use of a supported AMD GPU and execution of the FRU-reading path is established.

Direct network reachability is absent. A BMC, service processor, firmware update facility, or vendor-specific EEPROM programming interface could alter the practical attack vector, but none is shown in the supplied context. There is no race or timing requirement.

4. Primitive and severity interpretation

The exact primitive is a bounded-size heap source OOB read. The old code checked that a TLV header existed but selected the copy length from the untrusted TLV length and destination size without also limiting it to the bytes remaining in `pia`. A malformed final field could therefore make `memcpy` read beyond the allocated EEPROM buffer.

This is not a UAF and does not involve stale storage or repeated lifetime mutation. The destination buffers remain bounded, so no kernel overwrite is established. The demonstrated primitive is therefore CLASS_C rather than CLASS_A or CLASS_B.

The practical impact is most likely malformed device information or a limited internal OOB read. Information disclosure requires confirmation that the affected FRU fields are exposed to an attacker. A kernel fault is technically plausible but not demonstrated. ImportantCandidate is NO because there is no write, lifetime corruption, authorization bypass, or established substantial disclosure. AutoDowngradeAllowed is YES because the unresolved questions concern the observable effect of a limited read rather than a strong corruption primitive.

5. One-sentence report phrase

Malformed AMDGPU FRU TLV data can cause a bounded heap source out-of-bounds read, with possible limited information disclosure or kernel fault if copied FRU fields are externally exposed or the read crosses inaccessible memory.

6. Manual review recommendation

MANUAL CHECK RECOMMENDED

Confirm whether the populated FRU fields are readable through sysfs, debugfs, logs, ioctl output, or platform management interfaces, and whether any non-physical mechanism can modify the EEPROM contents.

7. Call-site confidence

Call-site confidence: medium

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

Patch: drm/amdgpu: harden FRU PIA parsing with bounded helpers [ Upstream
Commit: 813311512505e95e4e3c898ff94b11886a15e494
Upstream URL: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=813311512505e95e4e3c898ff94b11886a15e494

Changed files:
  drivers/gpu/drm/amd/amdgpu/amdgpu_fru_eeprom.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=813311512505e95e4e3c898ff94b11886a15e494

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

The original Linux kernel CVE announcement for CVE-2026-97428 can be found here:
https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-97428

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:P/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:L
  The Best / paranoid CVSS vector: AV:P/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H
  The Best / paranoid CVSS score: 6.1

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: 1
  Paranoid ActionableScore: 3

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: NO
Published priority for this report (same as in Subject): MODERATE REGULAR

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).