[CVE-2026-98597][MODERATE REGULAR] net: usb: sr9700: include receive overhead in the length check [ Upstream

[CVE-2026-98597][MODERATE REGULAR] net: usb: sr9700: include receive overhead in the length check [ Upstream

[AL-KERNEL]

CVE: CVE-2026-98597
Priority: MODERATE REGULAR
AL-KERNEL base severity: MODERATE
KPANIC flag: NO
Patch: net: usb: sr9700: include receive overhead in the length check [ Upstream
Commit: 92d88c88390fc62444c00a1a22078f838e03891f
Upstream patch: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=92d88c88390fc62444c00a1a22078f838e03891f
Original CVE announcement: https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-98597
Analysis date: Sat, 24 Oct 2026 09:57:34 -0400
ActionableScore: 1
ActionableScore lower bound: unknown
Actionable bucket: Ordinary Moderate
Manual review required: NO

Summary:
A malicious SR9700 USB device can supply malformed receive lengths causing a bounded skb over-read and potentially repeated non-progressing receive processing.

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

The original Linux kernel CVE announcement for CVE-2026-98597 is available here:
https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-98597

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: NO

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

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

CVE-2026-98597	MODERATE	https://www.kernelcve.org/list/?q=CVE-2026-98597 CHECK WITH IMPACT FROM ORIG NN LOW | AEGIS IMPACT MODERATE AEGIS_AS=2 LEGACY=MODERATE RESULT=SAME (final reconciliation agrees; DECISION: both 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:L/I:N/A:H';CWE-125;*CWE-20;**CWE-400;BEST CVSS score: '5.2';DESCR 'sr9700_rx_fixup subtracts the Ethernet CRC from the reported packet length but previously compared the resulting payload length with the entire remaining skb without reserving the three byte receive header and four byte CRC. A malicious or faulty SR9700 compatible USB device can provide a malformed length that makes the copy read up to three bytes beyond the receive buffer, while the later cursor advance can exceed the remaining skb and fail to make progress. This creates a limited confidentiality risk through copied adjacent bytes and a significant availability risk through repeated packet processing, memory consumption, or a kernel fault. For the CVSS the PR:N rating applies because a device controlling the USB receive data does not need an authenticated host user context, but AV:P is used because direct control of the USB framing is required and ordinary remote Ethernet traffic is not proven to provide that control. Automated impact decision path. The original SimpleNet classifier selected MODERATE_KPANIC. The primary LLM estimated paranoid CVSS 5.2 and the production ActionableScore returned 1 with recommendation Ordinary Moderate. The production rules then evaluated CVSS thresholds and ActionableScore thresholds. Recorded rule transitions were ActionableScore thresholds stage MODERATE_KPANIC to MODERATE because the ActionableScore threshold 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 DECREASED_TO_MODERATEREG_BASED_ON_ACTIONABLESCORELESSTHAN4. The independent weaker Aegis shadow evaluated CVSS 0.0 and ActionableScore 2 with primitive class CLASS_C and manual review REQUIRED. Its independently reconciled impact was MODERATE. The shadow agreed with the final production impact and aggregation did not change that impact. The final reported impact is MODERATE.';YES REQUIRES MANUAL CHECK; ,and ActionableScore result is Ordinary Moderate (with actual score 1)	MAYBE	USB SIMPLEFIX NETWORK SKB LINUS PACKET  DECREASED_TO_MODERATEREG_BASED_ON_ACTIONABLESCORELESSTHAN4	-	-	checked

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

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

1. ActionableScore

* Raw base score: 1.
* Conservative score: 1; no floor or cap applied.
* Raw paranoid score: 1.
* Paranoid score: 1; unsupported stronger consequences were not added.
* Final recommended bucket: **Ordinary Moderate**::

2. Signal breakdown

* +1 weak bounded OOB-read concern: `len` was checked against the full remaining skb even though processing begins after a three-byte header, permitting consumption up to three bytes beyond the logical receive data.
* +1 reliable DoS concern: an excessive `len + SR_RX_OVERHEAD` cursor advance can fail to consume input, permitting repeated processing, allocation pressure, or a kernel fault.
* +1 confidentiality plausible: supplied analysis connects the over-read bytes to the copied receive packet, creating a limited disclosure path.
* -2 physical/special-device prerequisite: exploitation requires control of malformed SR9700 USB receive framing; ordinary remote Ethernet traffic is not shown to control it.
* No write is shown, so NEW52/B5-R does not apply. No UAF, arbitrary write, controlled object corruption, authorization bypass, or separate integrity impact is established.
* The same crash/resource-consumption path was not counted again as additional availability impact.

3. Reachability analysis

A malicious or faulty attached SR9700-compatible USB device can influence the reported receive length without host UID 0 or host-administrator credentials. Direct remote-packet reachability is unproven because USB framing is device-generated. No namespace capability, prior privileged software configuration, or race is indicated; physical attachment and affected hardware are the material prerequisites.

4. Primitive and severity reading

The proven defect is a small receive-buffer over-read plus potentially non-progressing packet processing, not a heap OOB write. Its shown effects are limited disclosure and host availability risk. There is no active structured-state corruption or credible unknown privilege boundary requiring Important preservation. Thus this is CLASS_C, not a B5-R candidate, and automatic downgrade remains permissible.

5. One-sentence report phrase

A malicious SR9700 USB device can supply malformed receive lengths causing a bounded skb over-read and potentially repeated non-progressing receive processing.

6. Manual review advice

MANUAL CHECK RECOMMENDED

Confirm whether the copied excess bytes are observable outside the receive path and whether failed cursor advancement reliably creates an allocation loop or kernel fault.

7. Call-site confidence

Call-site confidence: medium

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

Patch: net: usb: sr9700: include receive overhead in the length check [ Upstream
Commit: 92d88c88390fc62444c00a1a22078f838e03891f
Upstream URL: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=92d88c88390fc62444c00a1a22078f838e03891f

Changed files:
  drivers/net/usb/sr9700.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=92d88c88390fc62444c00a1a22078f838e03891f

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

The original Linux kernel CVE announcement for CVE-2026-98597 can be found here:
https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-98597

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: Not available
  The Best / paranoid CVSS vector: AV:P/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:H
  The Best / paranoid CVSS score: 5.2

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: 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).