[CVE-2026-98630][LOW] eth: fbnic: Fix payload page pool error cleanup [ Upstream

[CVE-2026-98630][LOW] eth: fbnic: Fix payload page pool error cleanup [ Upstream

[AL-KERNEL]

CVE: CVE-2026-98630
Priority: LOW
AL-KERNEL base severity: LOW
KPANIC flag: NO
Patch: eth: fbnic: Fix payload page pool error cleanup [ Upstream
Commit: f4277b19edbc6abc9e1db7d6f6148608e8cb3c34
Upstream patch: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=f4277b19edbc6abc9e1db7d6f6148608e8cb3c34
Original CVE announcement: https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-98630
Analysis date: Sat, 24 Oct 2026 04:23:45 -0400
ActionableScore: 2
ActionableScore lower bound: unknown
Actionable bucket: Ordinary Moderate
Manual review required: NO

Summary:
Payload page-pool allocation failure can pass an ERR_PTR to page-pool destruction, causing a possible kernel Oops while leaking the valid header page pool.

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

The original Linux kernel CVE announcement for CVE-2026-98630 is available here:
https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-98630

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.

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

CVE-2026-98630	LOW	https://www.kernelcve.org/list/?q=CVE-2026-98630 CHECK WITH IMPACT FROM ORIG NN IMPORTANT | AEGIS IMPACT MODERATE_KPANIC AEGIS_AS=1 LEGACY=LOW RESULT=DIFF TEMP_DISTANCE_MERGE_SKIP=AEGIS_NO_POSITIVE_SEVERITY_EVIDENCE (final Legacy and Aegis differ; FINAL: LOW, Aegis: 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:N/I:N/A:H';**CWE-476;*CWE-401;CWE-703;Other CVSS 'AV:L/AC:H/PR:H/UI:N/S:U/C:N/I:N/A:H';BEST CVSS score: '4.7';DESCR 'The fbnic payload page pool allocation can return an ERR_PTR after the header page pool has already been created. Error cleanup then passes the ERR_PTR to page_pool_destroy instead of destroying the valid header pool, which can cause an invalid pointer dereference and leave the header pool allocated. Triggering requires payload pool allocation to fail during fbnic queue page pool setup and is not directly reachable through network packets. For the CVSS the PR:L value in the paranoid vector reflects environments where network device administration is delegated to a less privileged service or container, while normal host configuration usually requires CAP_NET_ADMIN. AC:H reflects the required allocation failure. The demonstrated impact is availability loss through a possible kernel oops, with no supported confidentiality or integrity primitive. Automated impact decision path. The original SimpleNet classifier selected IMPORTANT. The primary LLM estimated paranoid CVSS 4.7 and the production ActionableScore returned 2 with recommendation Ordinary Moderate. The production rules then evaluated CVSS thresholds and ActionableScore thresholds. Recorded rule transitions were CVSS and initial triage stage IMPORTANT to MODERATE_KPANIC because the CVSS score, vector or bug class threshold rule was applied. ActionableScore thresholds stage MODERATE_KPANIC to LOW because the ActionableScore threshold rule was applied. final reconciliation stage LOW to LOW because KP specialist did not establish a qualifying panic and 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 LOWERED_FROM_HIGH_BASED_ON_GUESSCVSS and DECREASED_TO_MODERATEREG_BASED_ON_ACTIONABLESCORELESSTHAN4 and DECREASED_TO_LOW_FROM_MODERATE_BASED_ON_ACTIONABLESCORELESSTHAN3 and KPANIC_UNSUPPORTED_REMOVED and V64_AEGIS_UNSUPPORTED_PROMOTION_BLOCKED. The independent weaker Aegis shadow evaluated CVSS 2.6 and ActionableScore 1 with primitive class CLASS_C and manual review REQUIRED. Its independently reconciled impact was MODERATE_KPANIC. The models disagreed but the aggregation rules retained the production result. The final reported impact is LOW.';NO MANUAL CHECK; ,and ActionableScore result is Ordinary Moderate (with actual score 2)	MAYBE	REMOTE SIMPLEFIX NETWORK LINUS LOWERED_FROM_HIGH_BASED_ON_GUESSCVSS DECREASED_TO_MODERATEREG_BASED_ON_ACTIONABLESCORELESSTHAN4 DECREASED_TO_LOW_FROM_MODERATE_BASED_ON_ACTIONABLESCORELESSTHAN3 KPANIC_UNSUPPORTED_REMOVED V64_AEGIS_UNSUPPORTED_PROMOTION_BLOCKED	-	-	checked

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

ActionableScore=2
PrimitiveClass=CLASS_C
RealUAF=NO
HostAdminRequired=UNKNOWN
NamespaceScopedPrivilege=UNKNOWN
ImportantCandidate=NO
ManualReview=NO
AutoDowngradeAllowed=YES
RequiresHostUID0=UNKNOWN
AuthorizationDecisionBypass=NO
ProtectedResourceImpact=NONE
B4PendingReview=NO
B4PendingConfirmed=NO

1. ActionableScore

* Raw base score: 2.
* Conservative score: 2; no floor or cap applied.
* Raw paranoid score: 2.
* Paranoid score: 2; no stronger technically supported primitive.
* Final recommended bucket: **Ordinary Moderate**::

2. Signal breakdown

* +1 Reliable kernel crash/DoS: `page_pool_destroy(pp)` receives a confirmed `ERR_PTR` after payload-pool allocation failure, plausibly causing an invalid-pointer dereference/Oops.
* +1 Concrete resource leak: the valid header pool at `qt->sub0.page_pool` is not destroyed on this failure path.
* No UAF, OOB write, repeated release, active-state corruption, or authorization bypass is shown.
* No additional availability point: it would duplicate the same possible Oops.
* No C/I, arbitrary write, controlled target, or attacker-controlled payload is supported.
* No privilege or hardware penalty applied because the complete caller and deployment requirements are not supplied.
* NEW52 B5-R and NEW53 B3-PENDING do not apply: there is no retry-accumulated OOB write or shared-backing write.

3. Reachability analysis

The defect occurs during fbnic queue page-pool setup and requires payload-pool allocation failure after successful header-pool allocation. Ordinary network packets do not directly reach this allocation/cleanup sequence. The evidence does not establish whether a normal user, delegated network manager, namespace capability holder, or only host administrator can initiate the complete setup and failure sequence. Namespace-scoped reachability and prior privileged configuration therefore remain unknown. fbnic hardware is required, but rarity is not established. The allocation-failure prerequisite limits practical trigger reliability without proving a hard race.

4. Primitive and severity reading

The exact primitive is a fixed invalid error-pointer dereference plus failure to release an already allocated page pool. It is not stale storage, a lifetime UAF, or corrupted structured state later consumed in an active operation. The supported consequence is a possible kernel Oops and resource leak; exploitation beyond availability is unsupported. This is CLASS_C, not an Important candidate, and ordinary downgrade is safe.

5. One-sentence report phrase

Payload page-pool allocation failure can pass an ERR_PTR to page-pool destruction, causing a possible kernel Oops while leaking the valid header page pool.

6. Manual review advice

NO MANUAL CHECK NEEDED

The patch shows a narrow failure-path invalid dereference and leak without a material corruption or boundary primitive.

7. Call-site confidence

Call-site confidence: medium

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

Patch: eth: fbnic: Fix payload page pool error cleanup [ Upstream
Commit: f4277b19edbc6abc9e1db7d6f6148608e8cb3c34
Upstream URL: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=f4277b19edbc6abc9e1db7d6f6148608e8cb3c34

Changed files:
  drivers/net/ethernet/meta/fbnic/fbnic_txrx.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=f4277b19edbc6abc9e1db7d6f6148608e8cb3c34

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

The original Linux kernel CVE announcement for CVE-2026-98630 can be found here:
https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-98630

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:N/I:N/A:H
  The Best / paranoid CVSS score: 4.7

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: 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).