[CVE-2026-98304][LOW] net: bcmgenet: restore the hardware filters on open [ Upstream

[CVE-2026-98304][LOW] net: bcmgenet: restore the hardware filters on open [ Upstream

[AL-KERNEL]

CVE: CVE-2026-98304
Priority: LOW
AL-KERNEL base severity: LOW
KPANIC flag: NO
Patch: net: bcmgenet: restore the hardware filters on open [ Upstream
Commit: 56db7ec462d6a2b886e299ad835109c089606969
Upstream patch: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=56db7ec462d6a2b886e299ad835109c089606969
Original CVE announcement: https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-98304
Analysis date: Sat, 10 Oct 2026 23:58:48 -0400
ActionableScore: 1
ActionableScore lower bound: unknown
Actionable bucket: Ordinary Moderate
Manual review required: NO

Summary:
No one-sentence report phrase was found.

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

The original Linux kernel CVE announcement for CVE-2026-98304 is available here:
https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-98304

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.

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

CVE-2026-98304	LOW	https://www.kernelcve.org/list/?q=CVE-2026-98304 CHECK WITH IMPACT FROM ORIG NN MODERATE | AEGIS IMPACT LOW AEGIS_AS=0 LEGACY=LOW RESULT=SAME (legacy and Aegis reconciliation agree; DECISION: both 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:N/I:L/A:L';CWE-665;CWE-684;CWE-693;Other CVSS 'AV:L/AC:L/PR:H/UI:N/S:U/C:N/I:L/A:L';BEST CVSS score: '4.4';DESCR 'The Broadcom GENET driver discarded configured RXNFC rules whenever the network interface was reopened because bcmgenet_hfb_init reinitialized the rule list during bcmgenet_open. An interface down and up cycle could therefore silently remove hardware receive filters and leave packet classification or queue steering behavior less restrictive than the administrator expected. For the CVSS the PR:L in the paranoid score reflects environments where interface lifecycle control is delegated to a reduced capability service account, container root, or a user with network administration capabilities. The realistic base case requires administrative control and is represented by PR:H. The issue is not directly network reachable because received packets do not invoke the affected initialization path. Impact is limited to network policy integrity and possible availability degradation. There is no demonstrated UAF, out of bounds access, information leak, arbitrary write, or privilege escalation primitive.';NO MANUAL CHECK; ,and ActionableScore result is Ordinary Moderate (with actual score 1)	MAYBE	REMOTE DANGER INIT SIMPLEFIX NETWORK HARDWARE LINUS DECREASED_TO_MODERATE_REGULAR_FROM_MODERATE7_BASED_ON_GUESSCVSS DECREASED_TO_LOW_FROM_MODERATE_BASED_ON_ACTIONABLESCORELESSTHAN3 KPANIC_UNSUPPORTED_REMOVED	-	-	checked

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

ActionableScore=1
PrimitiveClass=NONE
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 conservative score: 1
* Conservative score: 1
* Raw paranoid score: 1
* Paranoid score: 1
* No floor or cap applied.
* Final recommended bucket: **Ordinary Moderate**::

2. Signal breakdown

* +1 Limited integrity impact: reopening the interface silently removes configured RXNFC state and changes packet classification or queue-steering behavior.
* No UAF, OOB access, shared-backing write, resource leak, authorization bypass, or memory-corruption primitive is established.
* B5-R does not apply because there is no retry-accumulated heap OOB write.
* B3-PENDING does not apply because no shared or file-backed storage is modified.
* B4-PENDING does not apply because no authorization guard changes from DENY to ALLOW.
* Remote reachability is not awarded. Network traffic does not invoke the faulty initialization path.
* Availability is not separately awarded because no kernel crash, device failure, or reliable service outage is demonstrated.
* No privilege penalty is applied because host-admin-equivalent privilege is not positively established, although interface administration requires CAP_NET_ADMIN in the governing namespace.
* No hardware penalty is applied merely because the issue affects Broadcom GENET hardware.

3. Reachability analysis

The demonstrated trigger is an interface down and up cycle after RXNFC rules have been configured. Both rule configuration and interface lifecycle management require network-administration authority over the affected device. The evidence does not establish whether this must be host CAP_NET_ADMIN or may be delegated with the physical interface, so HostAdminRequired and NamespaceScopedPrivilege remain UNKNOWN.

This is not packet-triggerable. Prior configuration of RXNFC rules is required, and the affected Broadcom GENET device must be present. There is no race or timing requirement.

4. Primitive and severity interpretation

The exact defect is incorrect state reinitialization. `bcmgenet_hfb_init()` resets the software list and rule states during every open instead of initializing them once and restoring the hardware filters.

There is no stale post-lifetime access, repeated release, heap overwrite, or authorization decision bypass. PrimitiveClass is NONE. The demonstrated consequence is silent loss of receive-filter configuration, with limited policy-integrity impact. Security-boundary bypass, confidentiality impact, privilege escalation, and host-wide denial of service are not established.

ImportantCandidate is NO because no Important-preserving primitive exists. AutoDowngradeAllowed is YES because the issue is a constrained configuration-state bug without unresolved corruption or authorization leverage.

5. One-sentence report phrase

The Broadcom GENET driver silently loses configured RXNFC filters when an interface is reopened, changing receive classification behavior without establishing memory corruption, remote exploitation, or privilege escalation.

6. Manual review recommendation

NO MANUAL CHECK NEEDED

The patch establishes a low-impact state-restoration defect with no corruption, authorization bypass, or direct remote trigger.

7. Call-site confidence

Call-site confidence: high

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

Patch: net: bcmgenet: restore the hardware filters on open [ Upstream
Commit: 56db7ec462d6a2b886e299ad835109c089606969
Upstream URL: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=56db7ec462d6a2b886e299ad835109c089606969

Changed files:
  drivers/net/ethernet/broadcom/genet/bcmgenet.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=56db7ec462d6a2b886e299ad835109c089606969

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

The original Linux kernel CVE announcement for CVE-2026-98304 can be found here:
https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-98304

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:N/I:L/A:L
  The Best / paranoid CVSS vector: AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:L
  The Best / paranoid CVSS score: 4.4

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: 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).