[CVE-2026-80985][IMPORTANT] net/smc: carry oversized SMC-Rv2 LLC messages in the queue entry [ Upstream

[CVE-2026-80985][IMPORTANT] net/smc: carry oversized SMC-Rv2 LLC messages in the queue entry [ Upstream

[AL-KERNEL]

CVE: CVE-2026-80985
Priority: IMPORTANT
AL-KERNEL base severity: IMPORTANT
KPANIC flag: YES
Patch: net/smc: carry oversized SMC-Rv2 LLC messages in the queue entry [ Upstream
Commit: edf30d65e3ac52f886f7d87b1a7449742e79157d
Upstream patch: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=edf30d65e3ac52f886f7d87b1a7449742e79157d
Original CVE announcement: https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-80985
Analysis date: Fri, 11 Sep 2026 16:27:34 -0400
ActionableScore: 7
ActionableScore lower bound: 6
Actionable bucket: Strong Important candidate
Manual review required: YES

Summary:
No one-sentence report phrase was found.

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

The original Linux kernel CVE announcement for CVE-2026-80985 is available here:
https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-80985

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: IMPORTANT
Manual review required: YES

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

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

CVE-2026-80985	IMPORTANT	https://www.kernelcve.org/list/?q=CVE-2026-80985 CHECK WITH IMPACT FROM ORIG NN MODERATE	Maybe valid. Check manually. Hints by AL-KERNEL: The best (paranoid) CVSS is 'AV:A/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H';CWE-126;*CWE-20;CWE-908;Other CVSS 'AV:A/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:H';BEST CVSS score: '7.5';DESCR 'SMC/Rv2 LLC handlers could process rkeys beyond the actual received message length because DELETE_RKEY_V2 and ADD_LINK bounded parsing by the backing receive buffer rather than by the bytes delivered for the current message. On links with a shared v2 receive buffer, a short message that declares many rkeys can cause stale bytes from an earlier message to be interpreted as rkey entries and used to delete or install rtokens. For the CVSS the PR:N is used because a remote SMC/Rv2 peer does not need local privileges on the victim once it can reach and participate in the SMC/Rv2 link. The issue is network adjacent rather than Internet wide in typical deployments, because SMC/Rv2 usually depends on RDMA or RoCE capable local storage or data center networks. Impact is at least denial of service or SMC connection state corruption, and in the worst defensible case may affect confidentiality and integrity because RDMA rkeys and rtokens are authorization related memory access metadata.';YES REQUIRES MANUAL CHECK; ,and ActionableScore result is Strong Important candidate (with actual score 7)	YES	HARDWARE LINUS TEST  KPANIC INCREASED_TO_HIGH_BASED_ON_GUESSCVSS	YES	NO	checked

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

ActionableScore=7
ActionableScoreLower=6
PrimitiveClass=CLASS_A
RealUAF=NO
HostAdminRequired=NO
NamespaceScopedPrivilege=NO
ImportantCandidate=YES
ManualReview=REQUIRED
AutoDowngradeAllowed=NO

1. ActionableScore

* Raw conservative score: 6
* Conservative score: 6. No floor or cap applied.
* Raw paranoid score: 7
* Paranoid score: 7. No floor or cap applied.
* Final recommended bucket: **Strong Important candidate**::

2. Signal breakdown

Positive conservative signals:

* +2 Remote or network-adjacent trigger. The vulnerable operation is reached by SMC-Rv2 LLC messages from a peer on an established SMC-Rv2 link.
* +2 Strong attacker-influenced semantic reinterpretation. A short DELETE_RKEY_V2 message can declare more rkeys than actually arrived, causing stale bytes from the shared v2 receive buffer to be interpreted as active rkey entries.
* +1 Integrity impact plausible. The stale interpreted rkeys are passed to smc_rtoken_delete or used by ADD_LINK, so active rtoken state can be deleted or installed incorrectly.
* +1 Practical chain strongly implied. The commit states that one stale rkey matched a registered rtoken and deleted it, and that ADD_LINK can install up to 255 rtokens from stale bytes.

Additional paranoid signal:

* +1 Paranoid memory access or ownership concern. RDMA rkeys and rtokens are authorization-related memory access metadata, so stale-buffer reinterpretation may affect more than ordinary connection state.

Non-awarded signals:

* RealUAF not awarded because no object is shown to be used after free.
* Controlled reclaim not demonstrated.
* Arbitrary kernel read or write not demonstrated.
* Concrete repeated release/refcount mutation not present.
* Race/timing penalty not applied because this is not a timing race.
* Rare subsystem penalty not applied because SMC-Rv2/RDMA deployment is a prerequisite, but the supplied evidence does not prove an attacker-restrictive rare mode beyond the affected configuration.
* Extra availability point not awarded because no distinct host-wide crash mechanism is established beyond protocol state corruption.
* Confidentiality is not awarded conservatively because direct read-back or disclosure is not demonstrated.

3. Reachability analysis

The evaluated attacker is a remote or adjacent SMC-Rv2 peer able to send LLC messages on an SMC-Rv2 link. No local victim host account or host-admin-equivalent privilege is required for that peer once the service and RDMA or RoCE fabric are reachable.

This is not Internet-wide generic TCP exposure. It is network-adjacent in practice because SMC-Rv2 normally depends on RDMA/RoCE capable storage or data-center networks and an established SMC path. The complete trigger is not namespace-scoped. Namespace capability analysis is not applicable here.

Prior deployment setup is required in the ordinary operational sense: SMC-Rv2 must be enabled and the relevant link must exist. That does not make the attacker HostAdminRequired=YES, because the vulnerable input is peer-supplied LLC traffic. No special race is required.

4. Primitive and severity interpretation

The exact primitive is stale receive-buffer semantic reinterpretation: code bounds parsing by the backing receive buffer rather than by the actual received message length. This lets bytes from an earlier message be consumed as rkeys for the current message.

This is not a UAF and not fixed stale storage after free. It is an active protocol-state and authorization-metadata bug. The affected values are not passive metadata; they drive rtoken deletion and installation.

PrimitiveClass=CLASS_A is justified by strong semantic reinterpretation of stale attacker-influenced protocol data into active RDMA rkey/rtoken operations. Demonstrated consequence is SMC connection or rtoken state corruption and likely DoS. Speculative but technically defensible consequence is broader confidentiality or integrity impact because rtokens are tied to RDMA memory access authorization.

ImportantCandidate=YES because the primitive affects active memory-access metadata and is peer-triggerable. AutoDowngradeAllowed=NO because automatic downgrade would discard a meaningful security primitive beyond ordinary crash-only behavior.

5. One-sentence report phrase

SMC-Rv2 LLC parsing could treat stale shared receive-buffer bytes as rkeys beyond the actual received message length, allowing a network-adjacent peer to delete or install rtokens and potentially corrupt RDMA memory access state.

6. Manual review recommendation

MANUAL CHECK REQUIRED

The issue is not a simple DoS-only crash. It affects active RDMA rkey/rtoken state, and the worst defensible interpretation includes unresolved confidentiality and integrity consequences.

7. Call-site confidence

Call-site confidence: high

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

Patch: net/smc: carry oversized SMC-Rv2 LLC messages in the queue entry [ Upstream
Commit: edf30d65e3ac52f886f7d87b1a7449742e79157d
Upstream URL: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=edf30d65e3ac52f886f7d87b1a7449742e79157d

Changed files:
  net/smc/smc_llc.c
  net/smc/smc_wr.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=edf30d65e3ac52f886f7d87b1a7449742e79157d

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

The original Linux kernel CVE announcement for CVE-2026-80985 can be found here:
https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-80985

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:A/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:H
  The Best / paranoid CVSS vector: AV:A/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H
  The Best / paranoid CVSS score: 7.5

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: 6
  Paranoid ActionableScore: 7

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: IMPORTANT
KPANIC detected for this report: YES
Published priority for this report (same as in Subject): IMPORTANT

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).