[CVE-2026-74697][MODERATE 7.0] bnxt_en: Disable EOP for TPA on all chips to prevent data corruption [ Upstream

[CVE-2026-74697][MODERATE 7.0] bnxt_en: Disable EOP for TPA on all chips to prevent data corruption [ Upstream

[AL-KERNEL]

CVE: CVE-2026-74697
Priority: MODERATE 7.0
AL-KERNEL base severity: MODERATE
KPANIC flag: YES
Patch: bnxt_en: Disable EOP for TPA on all chips to prevent data corruption [ Upstream
Commit: 68c181af7cd1ca9cbf29acd95911073bfd3c6397
Upstream patch: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=68c181af7cd1ca9cbf29acd95911073bfd3c6397
Original CVE announcement: https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-74697
Analysis date: Sat, 22 Aug 2026 15:18:43 -0400
ActionableScore: 6
ActionableScore lower bound: 4
Actionable bucket: Strong Important candidate / Actionable Moderate at minimum**:: Paranoid handling is justified because this is externally influenced RX data corruption in a NIC DMA path, but the evidence does not show arbitrary memory corruption, UAF, privilege escalation, or information disclosure.
Manual review required: YES

Summary:
bnxt_en may corrupt received packet data when EOP padding is used with TPA and Relaxed Ordering on affected Broadcom NICs, allowing network-influenced integrity loss under hardware-specific conditions without proven privilege escalation or information disclosure.

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

The original Linux kernel CVE announcement for CVE-2026-74697 is available here:
https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-74697

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: YES

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-2026-74697	MODERATE	CHECK WITH IMPACT FROM ORIG NN MODERATE	Maybe valid. Check manually. Hints by AL-KERNEL: The best (paranoid) CVSS is 'AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:L';*CWE-787;CWE-662;CWE-119;Other CVSS 'AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:L';BEST CVSS score: '6.5';DESCR 'bnxt_en can corrupt received packet data when EOP (End of frame padding) is used on AGG RX rings together with TPA and Relaxed Ordering. Zero padding at the end of one segment can overlap with data from the next segment, and on older chips such as P5 the hardware does not automatically disable Relaxed Ordering to prevent this. A remote peer may be able to influence the affected receive path by sending traffic to the Broadcom NIC, but practical triggering depends on specific hardware, ARM or ordering behavior, TPA being enabled, and RO being active. For the CVSS the PR:N is selected because the attacker does not need a local account when the vulnerable receive path is reachable by network traffic. Impact is primarily integrity loss due to corrupted received data and possible availability degradation, not a proven privilege escalation or information disclosure.';YES REQUIRES MANUAL CHECK; ,and ActionableScore result is Strong Important candidate / Actionable Moderate at minimum (with actual score 5)	YES	REMOTE DANGER SIMPLEFIX NETWORK KPANIC MEMORY 	NO	NO	checked

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

ActionableScore=6
ActionableScoreLower=4

## 1. ActionableScore

* Conservative score: 4
* Paranoid score: 6
* Final recommended bucket: **Strong Important candidate / Actionable Moderate at minimum**:: Paranoid handling is justified because this is externally influenced RX data corruption in a NIC DMA path, but the evidence does not show arbitrary memory corruption, UAF, privilege escalation, or information disclosure.

## 2. Signal breakdown

Conservative signals:

* Firmware-mediated external influence: +1
  Network traffic can influence the RX path, but the actual corruption depends on NIC behavior, TPA, EOP, Relaxed Ordering, and affected hardware.
* Constrained kernel buffer overwrite: +1
  The described overwrite is zero padding corrupting valid data in the following RX segment. The payload is fixed or low-control and the target is a bounded receive data buffer, not arbitrary kernel memory.
* Integrity impact plausible: +1
  Received packet data can be corrupted before higher layers consume it.
* Availability impact realistic: +1
  Data corruption may break network protocols, storage over network, or application traffic, but no reliable kernel crash is demonstrated.

Paranoid additional signals:

* Remote reachable / network-triggerable instead of firmware-mediated only: +1 additional
  A remote peer may trigger the vulnerable RX data path by sending traffic to the affected Broadcom NIC when the deployment exposes that interface.
* Privileged kernel/device/DMA-adjacent corruption path: +1
  The corruption occurs in a trusted NIC RX DMA path and affects kernel-managed packet buffers, even though the primitive is constrained.

Negative / limiting factors:

* Rare AND difficult-to-reach subsystem/configuration: -1
  Practical impact depends on Broadcom bnxt hardware, older P5 behavior such as 57508, TPA enabled, Relaxed Ordering active, and platform ordering behavior such as reported ARM systems.
* No strong memory corruption primitive counted
  The patch does not show UAF, double free, OOB write into kernel metadata, arbitrary write, attacker-controlled target selection, or reclaim-based exploitation.
* No privilege escalation signal counted
  Data corruption is plausible, but LPE is not supported by the patch context.

## 3. Reachability analysis

A remote network peer may influence the affected receive path by sending packets to a system using the affected Broadcom bnxt_en NIC configuration. No local account is required if the vulnerable interface is reachable by attacker-controlled traffic.

However, realistic triggering is configuration and hardware dependent. The issue requires TPA on AGG rings, EOP behavior, Relaxed Ordering, and older chip behavior where RO is not automatically disabled. The report specifically mentions data corruption on ARM systems with 57508 P5 chips.

Namespaces and containers do not materially lower the triggering requirement because the main influence is external packet reception, not a local privileged control-plane API. Local administrators may affect exposure by enabling or disabling NIC offloads and driver settings.

## 4. Severity interpretation

This is more than an ordinary Low correctness fix because it describes real data corruption in a network receive path. It is not a demonstrated Important-class memory corruption issue because the overwritten data appears constrained to RX segment contents and the overwrite is zero padding rather than attacker-chosen arbitrary data.

Conservatively this is Borderline / manual review recommended with score 4. Paranoid scoring reaches Actionable Moderate with score 6 because remote traffic can plausibly reach the affected path and integrity impact can be operationally significant. It should not be auto-closed without checking affected hardware and driver configuration.

## 5. One-sentence report phrase

bnxt_en may corrupt received packet data when EOP padding is used with TPA and Relaxed Ordering on affected Broadcom NICs, allowing network-influenced integrity loss under hardware-specific conditions without proven privilege escalation or information disclosure.

## 6. Manual review recommendation

MANUAL CHECK REQUIRED

Reason: the issue is externally influenced and affects packet data integrity in a NIC RX DMA path, but exploitability depends heavily on hardware generation, platform ordering behavior, TPA, and Relaxed Ordering configuration.

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

Patch: bnxt_en: Disable EOP for TPA on all chips to prevent data corruption [ Upstream
Commit: 68c181af7cd1ca9cbf29acd95911073bfd3c6397
Upstream URL: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=68c181af7cd1ca9cbf29acd95911073bfd3c6397

Changed files:
  drivers/net/ethernet/broadcom/bnxt/bnxt.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=68c181af7cd1ca9cbf29acd95911073bfd3c6397

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

The original Linux kernel CVE announcement for CVE-2026-74697 can be found here:
https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-74697

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:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:L
  The Best / paranoid CVSS vector: AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:L
  The Best / paranoid CVSS score: 6.5

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: 4
  Paranoid ActionableScore: 6

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).