[CVE-2026-68227][LOW] media: cx231xx: fix devres lifetime

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

CVE: CVE-2026-68227
Priority: LOW
AL-KERNEL base severity: LOW
KPANIC flag: NO
Patch: media: cx231xx: fix devres lifetime
Commit: a373f1a5137e96549a795e7fb9efb5de0ae1d065
Upstream patch: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=a373f1a5137e96549a795e7fb9efb5de0ae1d065
Original CVE announcement: https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-68227
Analysis date: Mon, 10 Aug 2026 09:26:38 -0400
ActionableScore: 0
ActionableScore lower bound: unknown
Actionable bucket: Ordinary Moderate / Low-like
Manual review required: NO

Summary:
The cx231xx USB media driver tied devm managed allocations to the parent USB device instead of the USB interface, allowing memory to remain allocated after driver unbind and potentially causing resource exhaustion only after repeated privileged device-management operations.

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ABOUT THIS REPORT
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The original Linux kernel CVE announcement for CVE-2026-68227 is available here:
https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-68227

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.

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AL-KERNEL CLASSIFICATION RESULT
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CVE-2026-68227	LOW	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:H/UI:N/S:U/C:N/I:N/A:H';*CWE-401;*CWE-772;CWE-404;Other CVSS 'AV:L/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:L';BEST CVSS score: '4.4';DESCR 'The cx231xx USB media driver used device managed allocations tied to the parent USB device instead of the USB interface that the driver is bound to. When the driver is unbound without physically disconnecting the device, for example during probe deferral or configuration changes, those resources may remain allocated longer than intended and can accumulate as a memory leak. For the CVSS the PR:H is used for the paranoid score because reliable triggering normally requires administrative control over USB driver bind and unbind operations or equivalent device management access. The issue is not network reachable. Impact is denial of service through resource exhaustion only, with no evidence of memory corruption, information disclosure, or privilege escalation.';NO MANUAL CHECK; ,and ActionableScore result is Ordinary Moderate / Low-like (with actual score 0)	YES	USB SIMPLEFIX LEAK HARDWARE LINUS PACKET 	NO	NO	checked

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ACTIONABLESCORE ANALYSIS
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ActionableScore=0

## 1. ActionableScore

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

This is a devres lifetime / memory leak issue in a USB media driver. It does not show UAF, double free, OOB access, stale callback, type confusion, arbitrary write, page-cache corruption, or a practical privilege-escalation path.

## 2. Signal breakdown

Triggered signals:

* Availability impact possible: +1
  Repeated driver unbind / rebind or probe deferral can leak memory and may eventually contribute to resource exhaustion.

Negative signals:

* Requires admin/root/device-management privileges in typical deployments: -2
  Reliable triggering normally requires control over USB driver bind / unbind, probe behavior, or device configuration.
* Rare / hardware-specific subsystem: -1
  The affected path requires cx231xx USB media hardware and the specific driver path.

Not triggered:

* No remote reachability.
* No local unprivileged trigger in typical deployments.
* No generic memory corruption.
* No real lifetime corruption such as UAF or double free.
* No privilege escalation plausibility.
* No confidentiality or integrity impact.

Call-site confidence: high. The patch directly shows devm allocations moved from the parent USB device to the USB interface device, matching the stated lifetime problem.

## 3. Reachability analysis

The bug is reachable when the cx231xx USB media driver is used and the driver is unbound without physically disconnecting the USB device, or during probe deferral / configuration changes. In normal deployments, this requires local administrative device-management access. Containers or namespaces do not normally lower this requirement unless the environment deliberately delegates USB sysfs driver control or equivalent device-management permissions. The path is not network reachable and is not a default universal kernel exposure.

## 4. Severity interpretation

This behaves like a low-end resource leak / ordinary Moderate issue, not an Important-class vulnerability. The theoretical impact is memory exhaustion after repeated lifecycle operations, but the patch does not support memory corruption, sensitive data disclosure, privilege escalation, or cross-boundary bypass. Realistic exploitation is limited by hardware presence and privileged trigger requirements.

## 5. One-sentence report phrase

The cx231xx USB media driver tied devm managed allocations to the parent USB device instead of the USB interface, allowing memory to remain allocated after driver unbind and potentially causing resource exhaustion only after repeated privileged device-management operations.

## 6. Manual review recommendation

NO MANUAL CHECK NEEDED

Reason: this is a constrained memory leak with privileged local trigger requirements, rare hardware dependency, no network exposure, and no evidence of memory corruption or privilege escalation.

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

Patch: media: cx231xx: fix devres lifetime
Commit: a373f1a5137e96549a795e7fb9efb5de0ae1d065
Upstream URL: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=a373f1a5137e96549a795e7fb9efb5de0ae1d065

Commit description:

USB drivers bind to USB interfaces and any device managed resources
should have their lifetime tied to the interface rather than parent USB
device. This avoids issues like memory leaks when drivers are unbound
without their devices being physically disconnected (e.g. on probe
deferral or configuration changes).

Fix the driver state lifetime so that it is released on driver unbind.

Fixes: 184a827 ("[media] cx231xx: use devm_ functions to allocate memory")
Cc: stable@vger.kernel.org	# 3.17
Signed-off-by: Johan Hovold <johan@kernel.org>
Signed-off-by: Hans Verkuil <hverkuil+cisco@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Changed files:
  drivers/media/usb/cx231xx/cx231xx-cards.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=a373f1a5137e96549a795e7fb9efb5de0ae1d065

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

The original Linux kernel CVE announcement for CVE-2026-68227 can be found here:
https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-68227

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:H/UI:N/S:U/C:N/I:N/A:L
  The Best / paranoid CVSS vector: AV:L/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:H
  The Best / paranoid CVSS score: 4.4

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: 0

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).