[CVE-2026-68294][IMPORTANT] net: qrtr: restrict socket creation to the initial network namespace [ Upstream

[AL-KERNEL <alkernel@kernelcve.org>]

CVE: CVE-2026-68294
Priority: IMPORTANT
AL-KERNEL base severity: IMPORTANT
KPANIC flag: NO
Patch: net: qrtr: restrict socket creation to the initial network namespace [ Upstream
Commit: 4b95e1f0d6e6342c427cb341ee18a894b146b789
Upstream patch: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=4b95e1f0d6e6342c427cb341ee18a894b146b789
Original CVE announcement: https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-68294
Analysis date: Mon, 10 Aug 2026 19:12:12 -0400
ActionableScore: 8
ActionableScore lower bound: 6
Actionable bucket: Strong Important candidate / Actionable Moderate at minimum
Manual review required: YES

Summary:
QRTR allowed AF_QIPCRTR sockets outside init_net even though QRTR state is global, enabling a local unprivileged namespace user to inject QRTR control-plane datagrams across network namespaces and bypass expected isolation.

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ABOUT THIS REPORT
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The original Linux kernel CVE announcement for CVE-2026-68294 is available here:
https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-68294

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.

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AL-KERNEL CLASSIFICATION RESULT
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CVE-2026-68294	IMPORTANT	CHECK WITH IMPACT FROM ORIG NN LOW	Maybe valid. Check manually. Hints by AL-KERNEL: The best (paranoid) CVSS is 'AV:L/AC:L/PR:L/UI:N/S:C/C:L/I:H/A:H';CWE-284;CWE-668;CWE-863;Other CVSS 'AV:L/AC:L/PR:L/UI:N/S:U/C:L/I:H/A:L';BEST CVSS score: '8.7';DESCR 'QRTR allowed AF_QIPCRTR socket creation outside the initial network namespace even though its port and node state is stored in module global data rather than per net namespace data. A local unprivileged process may create a user and network namespace and then send QRTR datagrams, including QRTR_TYPE_NEW_SERVER control plane messages, to QRTR sockets owned by another namespace. This breaks expected network namespace isolation because the receiver sees the message as coming from local node id 1 and cannot distinguish it from a legitimate local client. For the CVSS the PR:L is used because a local user or process is required to create the socket and trigger the namespace crossing behavior. The issue is not directly network reachable from a remote host and is triggered through local socket creation rather than packet traffic. Impact is primarily integrity impact through control plane spoofing and namespace isolation bypass, with possible limited confidentiality impact and denial of service depending on QRTR consumers and hardware endpoints present on the system.';YES REQUIRES MANUAL CHECK; ,and ActionableScore result is Strong Important candidate / Actionable Moderate at minimum (with actual score 8)	YES	INIT HARDWARE LINUS  INCREASED_TO_HIGH_BASED_ON_GUESSCVSS8.5PLUS	NO	NO	checked

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ACTIONABLESCORE ANALYSIS
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ActionableScore=8
ActionableScoreLower=6

## 1. ActionableScore

* Conservative score: 6
* Paranoid score: 8
* Final recommended bucket: **Strong Important candidate / Actionable Moderate at minimum**::

## 2. Signal breakdown

Conservative signals:

* Local unprivileged trigger: +1
  The commit explicitly describes an unprivileged process using `unshare(CLONE_NEWUSER | CLONE_NEWNET)` and creating an `AF_QIPCRTR` socket.

* Security-boundary bypass with practical sensitive-object access: +2
  The bug breaks network namespace isolation and allows one namespace to send QRTR datagrams to sockets owned by another namespace or the global QRTR control plane.

* Cross-boundary isolation/policy bypass: +1
  QRTR state is module-global, not per-netns, so socket activity crosses the namespace boundary.

* Integrity impact plausible: +1
  Control-plane messages such as `QRTR_TYPE_NEW_SERVER` can be spoofed across namespaces and appear to come from legitimate local node id 1.

* Practical exploit chain strongly implied: +1
  The commit gives a concrete chain: unprivileged namespace creation -> QRTR socket creation -> cross-namespace QRTR datagram injection.

Paranoid additional signals:

* Confidentiality impact plausible: +1
  Cross-namespace QRTR communication may expose service discovery or control-plane state depending on QRTR consumers.

* Availability impact realistic: +1
  Malicious control-plane messages may disrupt QRTR consumers or global hardware endpoint coordination on affected systems.

No memory corruption signals are counted. No remote-network signal is counted.

## 3. Reachability analysis

The bug is locally reachable by a user or process able to create a user namespace and network namespace, then create an `AF_QIPCRTR` socket. This is not remotely network-triggerable from an external host. Namespace configuration matters: if unprivileged user namespaces are disabled, practical reachability is reduced, but container or sandboxed environments may still expose a reduced-privilege namespace boundary.

The affected path is a socket creation path, and the patch directly blocks non-init network namespaces with `-EAFNOSUPPORT`. QRTR itself is platform/configuration dependent and most relevant on systems using Qualcomm IPC router endpoints such as modem or remote processor communication. On affected systems, the isolation bypass is direct and does not require memory corruption.

Call-site confidence: high, because the changed function is `qrtr_create()` and the commit explains the namespace-crossing send and receive behavior.

## 4. Severity interpretation

This is not ordinary DoS and not memory corruption. It behaves like an actionable namespace isolation and control-plane spoofing issue. The realistic impact is integrity-focused cross-namespace message injection, with possible confidentiality or availability consequences depending on QRTR users and hardware endpoints.

Conservative handling fits Actionable Moderate because a local unprivileged namespace user can cross an intended kernel isolation boundary. Paranoid handling reaches Strong Important candidate because the bypass affects a global QRTR control plane and can make messages appear as legitimate local node id 1.

## 5. One-sentence report phrase

QRTR allowed AF_QIPCRTR sockets outside init_net even though QRTR state is global, enabling a local unprivileged namespace user to inject QRTR control-plane datagrams across network namespaces and bypass expected isolation.

## 6. Manual review recommendation

MANUAL CHECK REQUIRED

This should not be auto-closed because it is an unprivileged namespace isolation bypass affecting a global control plane, even though it is not memory corruption and is not directly remote reachable.

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

Patch: net: qrtr: restrict socket creation to the initial network namespace [ Upstream
Commit: 4b95e1f0d6e6342c427cb341ee18a894b146b789
Upstream URL: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=4b95e1f0d6e6342c427cb341ee18a894b146b789

Changed files:
  net/qrtr/af_qrtr.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=4b95e1f0d6e6342c427cb341ee18a894b146b789

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

The original Linux kernel CVE announcement for CVE-2026-68294 can be found here:
https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-68294

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:L/I:H/A:L
  The Best / paranoid CVSS vector: AV:L/AC:L/PR:L/UI:N/S:C/C:L/I:H/A:H
  The Best / paranoid CVSS score: 8.7

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: 6
  Paranoid ActionableScore: 8

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: NO
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).