[CVE-2026-98435][MODERATE 7.0] EDAC/altera: Use parent device for devres in altr_portb_setup() [ Upstream

[CVE-2026-98435][MODERATE 7.0] EDAC/altera: Use parent device for devres in altr_portb_setup() [ Upstream

[AL-KERNEL]

CVE: CVE-2026-98435
Priority: MODERATE 7.0
AL-KERNEL base severity: MODERATE
KPANIC flag: YES
Patch: EDAC/altera: Use parent device for devres in altr_portb_setup() [ Upstream
Commit: 8325ecf3f16d764a0e0ba42c95b63f08e38710a8
Upstream patch: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=8325ecf3f16d764a0e0ba42c95b63f08e38710a8
Original CVE announcement: https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-98435
Analysis date: Sat, 24 Oct 2026 09:42:25 -0400
ActionableScore: 1
ActionableScore lower bound: unknown
Actionable bucket: Ordinary Moderate
Manual review required: NO

Summary:
Incorrect devres ownership can leave an Altera EDAC IRQ registered with a freed per-port context, permitting a later hardware interrupt to cause a kernel UAF and crash.

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

The original Linux kernel CVE announcement for CVE-2026-98435 is available here:
https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-98435

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: NO

A detailed explanation of the methodology and priority rules is included
at the end of this message.

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

CVE-2026-98435	MODERATE	https://www.kernelcve.org/list/?q=CVE-2026-98435 CHECK WITH IMPACT FROM ORIG NN LOW | AEGIS IMPACT MODERATE_KPANIC AEGIS_AS=3 LEGACY=MODERATE_KPANIC RESULT=SAME V39_AEGIS_ONE_STEP_UP=MODERATE->MODERATE_KPANIC TEMP_DISTANCE_MERGE=LOW->MODERATE;AEGIS=MODERATE_KPANIC;GAP=2 (final reconciliation agrees; DECISION: both MODERATE_KPANIC)	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-416;*CWE-664;CWE-404;Other CVSS 'AV:L/AC:H/PR:H/UI:N/S:U/C:N/I:N/A:H';BEST CVSS score: '7';DESCR 'A device lifetime mismatch in altr_portb_setup attaches the devres group and managed IRQs to an embedded struct device inside copied per port state rather than to the actual parent device. If the per port allocation is freed while an IRQ remains registered, the interrupt handler can later receive a stale altdev pointer as its dev_id, creating a plausible use after free and kernel crash path. The issue is not directly network reachable and exploitation depends on an affected Altera platform, device teardown or setup failure, and delivery of the relevant ECC interrupt. For the CVSS the PR:L in the paranoid vector represents deployments where device management is delegated to a reduced capability service or local administrative context. Confidentiality and integrity impact remain worst case consequences of the UAF candidate rather than demonstrated attacker controlled primitives. Automated impact decision path. The original SimpleNet classifier selected LOW. The primary LLM estimated paranoid CVSS 7 and the production ActionableScore returned 1 with recommendation Ordinary Moderate. The production rules then evaluated CVSS thresholds and ActionableScore thresholds. Recorded rule transitions were final reconciliation stage LOW to MODERATE_KPANIC because the cross model evidence reconciliation rule was applied. The legacy KP specialist has no review artifact for this run. The legacy FD or DH downgrade specialist has no review artifact for this run. Exact triggered rule markers were TEMP_DISTANCE_MERGE and V39_AEGIS_ONE_STEP_UP and MANUAL_REVIEW_REQUIRED. The independent weaker Aegis shadow evaluated CVSS 2.5 and ActionableScore 3 with primitive class CLASS_B and manual review REQUIRED. Its independently reconciled impact was MODERATE_KPANIC. Cross model aggregation changed the production result under an enabled evidence gated merge rule. The final reported impact is MODERATE_KPANIC.';YES REQUIRES MANUAL CHECK; ,and ActionableScore result is Ordinary Moderate (with actual score 1)	MAYBE	SIMPLEFIX HARDWARE LINUS TEMP_DISTANCE_MERGE KPANIC V39_AEGIS_ONE_STEP_UP MANUAL_REVIEW_REQUIRED	-	-	checked

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

ActionableScore=1
PrimitiveClass=CLASS_B
RealUAF=YES
HostAdminRequired=UNKNOWN
NamespaceScopedPrivilege=NO
ImportantCandidate=NO
ManualReview=RECOMMENDED
AutoDowngradeAllowed=YES
RequiresHostUID0=UNKNOWN
AuthorizationDecisionBypass=NO
ProtectedResourceImpact=NONE
B4PendingReview=NO
B4PendingConfirmed=NO

1. ActionableScore

* Raw base score: 1
* Conservative score: 1
* Raw paranoid score: 1
* Paranoid score: 1
* No floor or cap applied; fixed asynchronous stale storage is excluded from the general UAF floor.
* Final recommended bucket: **Ordinary Moderate**::

2. Signal breakdown

* +2 Real lifetime violation: IRQs are registered with `altdev` as `dev_id`, but their devres ownership is attached to the copied embedded `altdev->ddev` rather than the long-lived parent. This can leave the handler registered after the per-port allocation ends.
* +1 Plausible kernel crash: a later ECC interrupt can invoke the handler with stale `altdev`.
* -2 Rare hardware dependency: the path requires an affected Altera/Arria10 EDAC platform and its ECC interrupt machinery.
* No controlled reclaim, attacker-shaped replacement, arbitrary write, disclosure, authorization bypass, or integrity effect is shown.
* No extra availability point: it would duplicate the same stale-pointer crash.
* NEW52/B5-R and NEW53/B3-PENDING do not apply; no retry-accumulated OOB or shared-backing write exists.

3. Reachability analysis

The supplied evidence does not establish an attacker-invocable userspace operation. Triggering requires affected hardware, device setup or teardown that frees the per-port allocation, and a subsequent ECC interrupt. Whether a non-host-admin actor can drive the complete sequence is unresolved; no namespace-scoped capability path is involved. No timing penalty is applied because a narrow attacker-contested race is not shown.

4. Primitive and severity reading

The primitive is a fixed asynchronous stale driver context: a managed IRQ can outlive the allocation used as its `dev_id`. This is a clearly implied CLASS_B UAF, but the patch does not show attacker-controlled reuse or consumption of a substituted structured object. The supported consequence is crash/DoS; C/I impact and LPE remain speculative. Therefore this is not an Important candidate and constrained-UAF auto-downgrade remains allowed.

5. One-sentence report phrase

Incorrect devres ownership can leave an Altera EDAC IRQ registered with a freed per-port context, permitting a later hardware interrupt to cause a kernel UAF and crash.

6. Manual review advice

MANUAL CHECK RECOMMENDED

Confirm the parent teardown path actually frees `dci` while the old managed IRQ remains registered.

7. Call-site confidence

Call-site confidence: medium

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

Patch: EDAC/altera: Use parent device for devres in altr_portb_setup() [ Upstream
Commit: 8325ecf3f16d764a0e0ba42c95b63f08e38710a8
Upstream URL: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=8325ecf3f16d764a0e0ba42c95b63f08e38710a8

Changed files:
  drivers/edac/altera_edac.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=8325ecf3f16d764a0e0ba42c95b63f08e38710a8

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

The original Linux kernel CVE announcement for CVE-2026-98435 can be found here:
https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-98435

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:H/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: unknown
  Paranoid ActionableScore: 1

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).