[CVE-2026-74317][MODERATE 7.0] ixgbe: do not configure xps for XDP queues [ Upstream

[CVE-2026-74317][MODERATE 7.0] ixgbe: do not configure xps for XDP queues [ Upstream

[AL-KERNEL]

CVE: CVE-2026-74317
Priority: MODERATE 7.0
AL-KERNEL base severity: MODERATE
KPANIC flag: NO
Patch: ixgbe: do not configure xps for XDP queues [ Upstream
Commit: a2a224f5e344ccb1ec3693a0735822db9214e2ca
Upstream patch: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=a2a224f5e344ccb1ec3693a0735822db9214e2ca
Original CVE announcement: https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-74317
Analysis date: Sun, 16 Aug 2026 06:34:53 -0400
ActionableScore: 5
ActionableScore lower bound: 3
Actionable bucket: Actionable Moderate at minimum
Manual review required: YES

Summary:
An ixgbe XDP setup bug can call XPS configuration for non netdev exposed XDP Tx queues, causing a KASAN reported slab out of bounds write during XDP program load on specific high CPU queue layouts.

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

The original Linux kernel CVE announcement for CVE-2026-74317 is available here:
https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-74317

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
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CVE-2026-74317	MODERATE	CHECK WITH IMPACT FROM ORIG NN 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:H/I:H/A:H';*CWE-787;CWE-119;*CWE-20;Other CVSS 'AV:L/AC:H/PR:H/UI:N/S:U/C:L/I:L/A:H';BEST CVSS score: '7';DESCR 'An out of bounds write in the ixgbe XDP setup path can occur because netif_set_xps_queue is called for XDP Tx queues that are not exposed as normal netdev Tx queues. On systems with at least 64 CPUs and an affected queue layout, loading an XDP program can configure one more XDP queue than the netdev XPS code expects, leading to a KASAN reported slab out of bounds write in __netif_set_xps_queue. For the CVSS the PR:L is used in the paranoid score because XDP attach is privileged but may be delegated through CAP_NET_ADMIN, container networking rights, or service accounts rather than full root. The issue is not directly network reachable and requires local control over XDP or network device configuration. Impact is at least local denial of service via kernel crash and in worst case may allow confidentiality and integrity impact due to kernel memory corruption.';YES REQUIRES MANUAL CHECK; ,and ActionableScore result is Actionable Moderate at minimum (with actual score 4)	YES	REMOTE WRITE KASAN OOB INIT NETWORK KERNEL_PANIC_PLUS_UAF HARDWARE  DECREASED_TO_MODERATEREG_BASED_ON_ACTIONABLESCORELESSTHAN5	NO	NO	checked

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

ActionableScore=5
ActionableScoreLower=3

## 1. ActionableScore

* Conservative score: 3
* Paranoid score: 5
* Final recommended bucket: **Actionable Moderate at minimum**

## 2. Signal breakdown

Conservative signals:

* Constrained kernel buffer overwrite: +1
  KASAN reports a slab out of bounds write in `__netif_set_xps_queue`, but the write appears tied to XPS queue bookkeeping rather than an attacker chosen arbitrary target or payload.

* Reliable kernel crash / strong DoS: +1
  The report includes a WARN and KASAN slab out of bounds write during XDP program load. On systems with `panic_on_warn` or KASAN enabled this can become a reliable crash.

* Privileged kernel/device-management memory corruption path: +1
  The corruption occurs in a trusted NIC driver configuration path while setting up ixgbe XDP Tx queues and XPS state.

* Weak LPE concern: +1
  Kernel OOB write creates theoretical LPE concern, but there is no demonstrated reclaim, arbitrary write, controlled target, function pointer overwrite, or object replacement.

* Requires admin/root/CAP_* in typical deployments: -2
  Loading or attaching XDP normally requires privileged BPF or CAP_NET_ADMIN/CAP_BPF/root controlled configuration.

* Physical-only or rare hardware-only condition: -2
  The described trigger needs a specific queue layout, CPUs >= 64, and the affected Intel adapter configuration.

* No attacker-controlled payload or overwrite target: -1
  The write is driven by kernel XPS bookkeeping and queue configuration rather than attacker supplied data.

Paranoid adjustment:

* Treat the confirmed slab OOB write as actionable memory corruption despite constraints.
  Because this is a real kernel write past an allocated object, not just a WARN or validation failure, the paranoid score is raised to 5 for manual triage sensitivity.

## 3. Reachability analysis

The bug is locally triggered through XDP program load or network device reconfiguration on affected ixgbe hardware. In typical deployments this requires administrative privileges, CAP_NET_ADMIN, CAP_BPF, or equivalent service level control. It is not directly network reachable through packet traffic.

Namespaces and containers may matter if CAP_NET_ADMIN or XDP attachment is delegated to a container or service account. Such a reduced capability context is not equivalent to full host root, so the paranoid interpretation treats the issue as more actionable than a pure root only crash.

The path is not universally default reachable because it depends on ixgbe hardware, XDP being used, at least 64 CPUs, and a queue count mismatch. Call-site confidence: high, because the commit message includes the direct call path from `ixgbe_xdp` to `ixgbe_configure_tx_ring` to `netif_set_xps_queue` and the KASAN write report.

## 4. Severity interpretation

This is stronger than an ordinary Moderate correctness bug because the failure mode is a confirmed slab out of bounds write in kernel space. Realistic exploitation is constrained by privileged XDP access, special hardware and queue conditions, and apparently low control over the overwritten value and target.

It does not reach a strong Important candidate by default because there is no demonstrated arbitrary write, controlled object replacement, UAF reclaim, callback control, or practical LPE chain. It should be treated as Actionable Moderate at minimum and not auto-closed without human review.

## 5. One-sentence report phrase

An ixgbe XDP setup bug can call XPS configuration for non netdev exposed XDP Tx queues, causing a KASAN reported slab out of bounds write during XDP program load on specific high CPU queue layouts.

## 6. Manual review recommendation

MANUAL CHECK REQUIRED

Reason: this is confirmed kernel memory corruption via slab out of bounds write, even though the primitive appears constrained and typically requires privileged XDP or network device control.

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

Patch: ixgbe: do not configure xps for XDP queues [ Upstream
Commit: a2a224f5e344ccb1ec3693a0735822db9214e2ca
Upstream URL: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=a2a224f5e344ccb1ec3693a0735822db9214e2ca

Changed files:
  net/core/dev.c
  drivers/net/ethernet/intel/ixgbe/ixgbe_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=a2a224f5e344ccb1ec3693a0735822db9214e2ca

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

The original Linux kernel CVE announcement for CVE-2026-74317 can be found here:
https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-74317

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:L/I:L/A:H
  The Best / paranoid CVSS vector: AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H
  The Best / paranoid CVSS score: 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: 3
  Paranoid ActionableScore: 5

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 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).