[CVE-2026-72494][LOW] RDMA/irdma: Replace waitqueue and flag with completion [ Upstream

[CVE-2026-72494][LOW] RDMA/irdma: Replace waitqueue and flag with completion [ Upstream

[AL-KERNEL]

CVE: CVE-2026-72494
Priority: LOW
AL-KERNEL base severity: LOW
KPANIC flag: NO
Patch: RDMA/irdma: Replace waitqueue and flag with completion [ Upstream
Commit: bde37aed0724c0139dea177f3aae8d989b6babb1
Upstream patch: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=bde37aed0724c0139dea177f3aae8d989b6babb1
Original CVE announcement: https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-72494
Analysis date: Sat, 15 Aug 2026 04:50:49 -0400
ActionableScore: 2
ActionableScore lower bound: 0
Actionable bucket: Ordinary Moderate / Low-like
Manual review required: NO

Summary:
RDMA/irdma used a waitqueue plus request_done flag without proper memory-ordering guarantees, allowing a local race to miss CQP completions and degrade RDMA device availability, with no evidence of memory corruption, privilege escalation, or remote reachability.

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

The original Linux kernel CVE announcement for CVE-2026-72494 is available here:
https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-72494

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.

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

CVE-2026-72494	LOW	CHECK WITH IMPACT FROM ORIG NN MODERATE	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-362;CWE-667;CWE-662;Other CVSS 'AV:L/AC:H/PR:H/UI:N/S:U/C:N/I:N/A:L';BEST CVSS score: '4.7';DESCR 'RDMA/irdma used a waitqueue plus request_done flag for CQP request completion without the required memory ordering guarantees. A racing waiter may miss or fail to observe the completion state and can time out or leave a driver operation stuck, which can degrade RDMA device availability. For the CVSS the PR:L is used for the paranoid score because some deployments expose RDMA verbs or device operations to non root local users, while reliable triggering still requires local access to the affected RDMA stack. The issue is not network reachable in the CVSS sense because it is driven through local driver or RDMA control paths rather than remote packets alone. Impact is denial of service only based on the available primitive, with no concrete evidence of information disclosure, integrity corruption, UAF, OOB access, or privilege escalation.';NO MANUAL CHECK; ,and ActionableScore result is Ordinary Moderate / Low-like (with actual score 1)	YES	INIT SIMPLEFIX NETWORK HARDWARE  DECREASED_TO_MODERATE_REGULAR_FROM_MODERATE7_BASED_ON_GUESSCVSS_AND_CIANNH DECREASED_TO_LOW_FROM_MODERATE_BASED_ON_ACTIONABLESCORELESSTHAN3	NO	NO	checked

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

ActionableScore=2
ActionableScoreLower=0

## 1. ActionableScore

* Conservative score: 0
* Paranoid score: 2
* Final recommended bucket: **Ordinary Moderate / Low-like**

## 2. Signal breakdown

Conservative signals:

* Hard or unreliable race / special timing required: -1. The issue depends on missing memory-ordering around a waitqueue flag and a racing waiter/completer.
* Requires admin/root/CAP_* in typical deployments: -2. Reliable triggering usually requires control of the RDMA device, driver operations, or privileged device-management paths.
* Availability impact realistic: +1. A missed completion can cause CQP command timeout or stuck driver operation.
* Reliable kernel crash / strong DoS: +0. The patch indicates timeout or stuck operation, not a demonstrated kernel panic.
* Generic memory corruption: +0. No UAF, OOB write, double-free, type confusion, stale callback, or refcount takeover is shown.
* Privilege escalation plausible: +0. No concrete LPE primitive is supported by the patch.
* RDMA high-control API bonus: +0. The patch does not show attacker control over memory layout, object lifetime, callbacks, refcounts, DMA mappings, or page ownership.

Paranoid additional signals:

* Local unprivileged trigger: +1. Some RDMA deployments expose verbs or device operations to non-root local users, so PR:L is plausible for triage sensitivity.
* Reliable driver DoS concern: +1. CQP completion loss can affect RDMA device availability or recovery behavior.
* Hard race remains: -1. The race depends on ordering/timing.
* No rare-subsystem penalty applied in paranoid score because installed RDMA devices are reachable through ordinary local RDMA interfaces.

## 3. Reachability analysis

The affected path is local to the Intel irdma RDMA driver CQP request completion flow. It is not network-triggerable in the CVSS sense because remote packets alone do not directly drive the vulnerable waitqueue flag synchronization. In typical deployments, reliable triggering likely requires administrative control over the RDMA device or driver lifecycle. In more permissive RDMA environments, a non-root local user with access to RDMA verbs or device nodes may be able to induce CQP operations, so a paranoid PR:L interpretation is defensible. Namespaces do not automatically make this unprivileged unless RDMA device access is delegated.

Call-site confidence: high. The patch includes completion, allocation, free/reuse, pending cleanup, and wait paths.

## 4. Severity interpretation

This behaves like an ordinary Moderate or Low-like synchronization DoS issue. The theoretical concern is missed completion or timeout due to incorrect memory ordering, but the patch does not support memory corruption, object reuse, stale callback execution, arbitrary write, information disclosure, or privilege escalation. The issue should not be treated as Important-class based on the provided evidence.

## 5. One-sentence report phrase

RDMA/irdma used a waitqueue plus request_done flag without proper memory-ordering guarantees, allowing a local race to miss CQP completions and degrade RDMA device availability, with no evidence of memory corruption, privilege escalation, or remote reachability.

## 6. Manual review recommendation

NO MANUAL CHECK NEEDED

Reason: this is a low-actionability synchronization DoS with no demonstrated memory corruption primitive, no remote trigger, and no supported LPE path.

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

Patch: RDMA/irdma: Replace waitqueue and flag with completion [ Upstream
Commit: bde37aed0724c0139dea177f3aae8d989b6babb1
Upstream URL: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=bde37aed0724c0139dea177f3aae8d989b6babb1

Changed files:
  drivers/infiniband/hw/irdma/hw.c
  drivers/infiniband/hw/irdma/main.h
  drivers/infiniband/hw/irdma/utils.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=bde37aed0724c0139dea177f3aae8d989b6babb1

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

The original Linux kernel CVE announcement for CVE-2026-72494 can be found here:
https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-72494

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:L
  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: 0
  Paranoid ActionableScore: 2

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).