[CVE-2026-46026][LOW] net: qrtr: ns: Limit the maximum number of lookups [ Upstream

[CVE-2026-46026][LOW] net: qrtr: ns: Limit the maximum number of lookups [ Upstream

[AL-KERNEL]

CVE: CVE-2026-46026
Priority: LOW
AL-KERNEL base severity: LOW
KPANIC flag: NO
Patch: net: qrtr: ns: Limit the maximum number of lookups [ Upstream
Commit: 0dbec101a7076e9b1e4bd1876f7cf07c56ff4ce3
Upstream patch: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=0dbec101a7076e9b1e4bd1876f7cf07c56ff4ce3
Original CVE announcement: https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-46026
Analysis date: Wed, 27 May 2026 10:53:44 -0400
ActionableScore: 2
ActionableScore lower bound: unknown
Actionable bucket: Ordinary Moderate / Low-like
Manual review required: NO

Summary:
A local QRTR client could create unbounded `NEW_LOOKUP` entries and exhaust kernel resources or disrupt the QRTR nameservice, but the issue is local DoS only with no memory corruption or privilege escalation.

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

The original Linux kernel CVE announcement for CVE-2026-46026 is available here:
https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-46026

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-2026-46026	LOW	CHECK	Maybe valid. Check manually. Hints by AL-KERNEL: The best (paranoid) CVSS is 'AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H';**CWE-400;CWE-770;*CWE-20;Other CVSS 'AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L';BEST CVSS score: '5.5';DESCR 'QRTR nameserver allowed a local client to create an unbounded number of NEW_LOOKUP entries because no maximum lookup count was enforced. A malicious local client could repeatedly send NEW_LOOKUP messages on the same socket and grow the kernel lookup list, causing resource pressure or denial of service. For the CVSS the PR:L is used because triggering requires a local process with access to the QRTR nameservice control path. The issue is not network reachable and does not involve UAF, out of bounds write, arbitrary write, information disclosure, or privilege escalation. Impact is denial of service only through resource exhaustion, with practical exposure depending on whether untrusted local workloads can access QRTR on the target platform.';NO MANUAL CHECK; ,and ActionableScore result is Ordinary Moderate / Low-like (with actual score 2)	YES	SIMPLEFIX LINUS  INCREASED_FROM_LOW_BASED_ON_HIGHCVSSSCORE DECREASED_TO_MODERATEREG_BASED_ON_ACTIONABLESCORELESSTHAN5 DECREASED_TO_LOW_FROM_MODERATE_BASED_ON_ACTIONABLESCORELESSTHAN3	NO	NO	checked

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

ActionableScore=2

## 1. ActionableScore

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

## 2. Signal breakdown

Triggered signals:

* Local unprivileged trigger: +1
  A local client with access to the QRTR nameservice control path can send repeated `NEW_LOOKUP` messages.

* Reliable resource-exhaustion DoS: +1
  Without a lookup limit, repeated messages can grow `qrtr_ns.lookups` and consume kernel memory or degrade QRTR nameservice behavior.

* Availability impact realistic: +1
  The realistic impact is local DoS through resource pressure or nameservice degradation.

Subtracting signals:

* Platform/configuration-dependent exposure: -1
  QRTR is mainly relevant on systems using Qualcomm IPC style infrastructure and is not a universally exposed local API.

No signals apply for remote reachability, memory corruption, UAF, OOB write, arbitrary write, information disclosure, privilege escalation, or sensitive-object access.

## 3. Reachability analysis

The bug is local-only. The code explicitly restricts lookup requests to the local node, so remote network attackers cannot directly trigger it. A malicious local client can repeatedly send `NEW_LOOKUP` messages over the same socket if QRTR is available and accessible on the platform.

Namespaces and containers matter only if QRTR access is delegated into a container or untrusted workload. The issue does not show a clear namespace escape or memcg/cgroup bypass. Practical exposure depends on whether untrusted local applications can access QRTR nameservice.

## 4. Severity interpretation

This behaves like an ordinary Moderate or Low-like local resource exhaustion issue. It is not a kernel memory corruption bug and does not provide a privilege escalation primitive.

Theoretical impact is kernel memory pressure or QRTR service disruption. Realistic evidence supports DoS only.

## 5. One-sentence report phrase

A local QRTR client could create unbounded `NEW_LOOKUP` entries and exhaust kernel resources or disrupt the QRTR nameservice, but the issue is local DoS only with no memory corruption or privilege escalation.

## 6. Manual review recommendation

NO MANUAL CHECK NEEDED

This is a local resource exhaustion issue in a platform-specific subsystem with no supported memory corruption, remote exposure, or privilege-escalation primitive.

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

Patch: net: qrtr: ns: Limit the maximum number of lookups [ Upstream
Commit: 0dbec101a7076e9b1e4bd1876f7cf07c56ff4ce3
Upstream URL: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=0dbec101a7076e9b1e4bd1876f7cf07c56ff4ce3

Changed files:
  net/qrtr/ns.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=0dbec101a7076e9b1e4bd1876f7cf07c56ff4ce3

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

The original Linux kernel CVE announcement for CVE-2026-46026 can be found here:
https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-46026

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:L/PR:L/UI:N/S:U/C:N/I:N/A:L
  The Best / paranoid CVSS vector: AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
  The Best / paranoid CVSS score: 5.5

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: unknown
  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).