[CVE-2026-98488][LOW] net: atl1e: fix soft lockup on out-of-range hw_next_to_clean read

[CVE-2026-98488][LOW] net: atl1e: fix soft lockup on out-of-range hw_next_to_clean read

[AL-KERNEL]

CVE: CVE-2026-98488
Priority: LOW
AL-KERNEL base severity: LOW
KPANIC flag: NO
Patch: net: atl1e: fix soft lockup on out-of-range hw_next_to_clean read
Commit: ca862b1a4af7eac19429ca7ab92625f94ff4a46c
Upstream patch: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=ca862b1a4af7eac19429ca7ab92625f94ff4a46c
Original CVE announcement: https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-98488
Analysis date: Mon, 19 Oct 2026 00:56:45 -0400
ActionableScore: 1
ActionableScore lower bound: unknown
Actionable bucket: Ordinary Moderate
Manual review required: NO

Summary:
An out of range TX consumer index reported by atl1e hardware during PCIe or MAC reset can make the transmit cleanup loop run indefinitely and cause a CPU soft lockup, with no demonstrated memory corruption, remote trigger, or privilege escalation primitive.

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ABOUT THIS REPORT
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The original Linux kernel CVE announcement for CVE-2026-98488 is available here:
https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-98488

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-2026-98488	LOW	https://www.kernelcve.org/list/?q=CVE-2026-98488 CHECK WITH IMPACT FROM ORIG NN MODERATE | AEGIS IMPACT LOW AEGIS_AS=1 LEGACY=LOW RESULT=SAME (final reconciliation agrees; DECISION: both LOW)	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-835;CWE-754;**CWE-400;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 atl1e transmit cleanup path trusts the hardware TX consumer index even though the device can temporarily report an out of range value such as 0xffff while the PCIe link or MAC is resetting. Because this value cannot be reached by the valid ring index, atl1e_clean_tx_irq can remain in its cleanup loop indefinitely and cause a CPU soft lockup. For the CVSS the PR:L value is used for the paranoid score because a user or service with delegated network administration capability may be able to initiate link reset or recovery operations without having unrestricted host root access. The base assessment uses PR:H because reliable control of device reset normally requires administrative privileges. AC:H applies because triggering depends on reading the invalid hardware value during a transient reset state. The issue is not directly network reachable because the patch provides no evidence that ordinary incoming packets can force the required PCIe or MAC reset condition. Impact is denial of service through a stuck CPU and possible loss of network availability. No information disclosure, memory corruption, or privilege escalation primitive is supported by the affected loop. Automated impact decision path. The original SimpleNet classifier selected MODERATE_KPANIC. The primary LLM estimated paranoid CVSS 4.7 and the production ActionableScore returned 1 with recommendation Ordinary Moderate. The production rules then evaluated CVSS thresholds and ActionableScore thresholds. Recorded rule transitions were CVSS and initial triage stage MODERATE_KPANIC to MODERATE because the CVSS score, vector or bug class threshold rule was applied. ActionableScore thresholds stage MODERATE to LOW because the ActionableScore threshold rule was applied. final reconciliation stage LOW to LOW because KP specialist did not establish a qualifying panic. 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_MODERATE_REGULAR_FROM_MODERATE7_BASED_ON_GUESSCVSS_AND_CIANNH and DECREASED_TO_LOW_FROM_MODERATE_BASED_ON_ACTIONABLESCORELESSTHAN3 and KPANIC_UNSUPPORTED_REMOVED. The independent weaker Aegis shadow evaluated CVSS 1.9 and ActionableScore 1 with primitive class CLASS_C and manual review NO. Its independently reconciled impact was LOW. The shadow agreed with the final production impact and aggregation did not change that impact. The final reported impact is LOW.';NO MANUAL CHECK; ,and ActionableScore result is Ordinary Moderate (with actual score 1)	MAYBE	REMOTE OOB DEADLOCK SIMPLEFIX NETWORK HARDWARE DECREASED_TO_MODERATE_REGULAR_FROM_MODERATE7_BASED_ON_GUESSCVSS_AND_CIANNH DECREASED_TO_LOW_FROM_MODERATE_BASED_ON_ACTIONABLESCORELESSTHAN3 KPANIC_UNSUPPORTED_REMOVED	-	-	checked

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ACTIONABLESCORE ANALYSIS
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ActionableScore=1
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 conservative score: 1
* Conservative score: 1
* Raw paranoid score: 1
* Paranoid score: 1
* No floor or cap was applied.
* Final recommended bucket: **Ordinary Moderate**::

## 2. Signal breakdown

* **+1 Reliable strong DoS:** an invalid hardware consumer index such as `0xffff` cannot be reached by the valid ring index, so the TX cleanup loop can run indefinitely and cause a CPU soft lockup.
* **+0 Memory corruption:** the patch establishes an invalid loop termination value, not an OOB read or write. The visible access continues to use the software-maintained `next_to_clean`.
* **+0 Remote reachability:** ordinary network traffic is not shown to force the required PCIe link or MAC reset state.
* **+0 Authorization impact:** no access-control decision or protected resource is involved.
* **+0 B5-R:** no retry-accumulated heap OOB write exists. Requirements 1 and 4 of that profile are absent.
* **+0 V32, V33, V34, or B3-PENDING:** no attacker-controlled checksum metadata, shared backing write, or privileged downstream consumer exists.
* No timing penalty was applied. Although the invalid value occurs during reset, the report shows this state was actually observed and does not establish that reproducing it requires a materially difficult race.
* No hardware rarity penalty was applied merely because the defect is in a device driver.
* No extra availability point was awarded for the same soft-lockup consequence.

## 3. Reachability analysis

The affected system must use the Atheros `atl1e` driver and encounter a PCIe link or MAC reset during which the hardware reports an invalid TX consumer index. The supplied evidence does not establish whether an attacker can initiate the complete reset sequence using delegated network-management rights, whether host-administrator authority is required, or whether the condition can arise only from hardware recovery.

Consequently, `HostAdminRequired` and `NamespaceScopedPrivilege` remain `UNKNOWN`. No complete namespace-scoped trigger, ordinary unprivileged trigger, remote packet trigger, or prior configuration controlled by an attacker is demonstrated.

## 4. Primitive and severity interpretation

The exact primitive is an attacker-unresolved invalid hardware state value used as the termination target of a kernel cleanup loop. It is not a lifetime violation, active structured-state corruption, OOB access, or authorization bypass.

The demonstrated consequence is a CPU soft lockup and associated availability loss. A host-wide panic is not guaranteed, although watchdog policy or loss of a critical CPU may increase operational impact. There is no patch-supported confidentiality, integrity, privilege-escalation, DMA-corruption, or reusable exploitation primitive.

`PrimitiveClass=CLASS_C` is appropriate because this is invalid-state and DoS behavior. `ImportantCandidate=NO` and `AutoDowngradeAllowed=YES` follow because no unresolved corruption or trust-boundary primitive would be lost by ordinary Moderate handling.

## 5. One-sentence report phrase

An out of range TX consumer index reported by atl1e hardware during PCIe or MAC reset can make the transmit cleanup loop run indefinitely and cause a CPU soft lockup, with no demonstrated memory corruption, remote trigger, or privilege escalation primitive.

## 6. Manual review recommendation

NO MANUAL CHECK NEEDED

The patch establishes a bounded invalid-state loop defect with DoS impact only, and none of the supplied Important-preserving profiles apply.

## 7. Call-site confidence

Call-site confidence: high

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

Patch: net: atl1e: fix soft lockup on out-of-range hw_next_to_clean read
Commit: ca862b1a4af7eac19429ca7ab92625f94ff4a46c
Upstream URL: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=ca862b1a4af7eac19429ca7ab92625f94ff4a46c

Commit description:

Same issue as atl1c (see the first commit in this series, "net:
atl1c: fix soft lockup on out-of-range tpd_cons read"): the hardware
can report an out-of-range hw_next_to_clean (seen as 0xffff) while
the PCIe link/MAC is resetting. An out-of-range value can never be
reached and the loop below would spin forever. Treat it as "nothing
new to clean" instead.

Fixes: a6a5325 ("atl1e: Atheros L1E Gigabit Ethernet driver")
Cc: stable@vger.kernel.org
Signed-off-by: Gajdos Tamás <tamas@rimpianto.com>
Link: https://patch.msgid.link/20260921091334.3571525-3-tamas@rimpianto.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Changed files:
  drivers/net/ethernet/atheros/atl1e/atl1e_main.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=ca862b1a4af7eac19429ca7ab92625f94ff4a46c

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

The original Linux kernel CVE announcement for CVE-2026-98488 can be found here:
https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-98488

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: 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).