[CVE-2026-64332][LOW] USB: ulpi: fix memory leak on registration failure

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

CVE: CVE-2026-64332
Priority: LOW
AL-KERNEL base severity: LOW
KPANIC flag: NO
Patch: USB: ulpi: fix memory leak on registration failure
Commit: d5b32f36c50894ac2df8fa184e6f35f3a6665ecd
Upstream patch: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=d5b32f36c50894ac2df8fa184e6f35f3a6665ecd
Original CVE announcement: https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-64332
Analysis date: Sat, 25 Jul 2026 09:59:22 -0400
ActionableScore: 1
ActionableScore lower bound: 0
Actionable bucket: Ordinary Moderate / Low-like
Manual review required: NO

Summary:
A memory leak in the USB ULPI registration failure path can leave an allocated device name unreleased, but reliable triggering typically requires privileged driver or device-management control and the impact is limited to gradual resource exhaustion.

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

The original Linux kernel CVE announcement for CVE-2026-64332 is available here:
https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-64332

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-2026-64332	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 'A memory leak in the USB ULPI registration path can occur when dev_set_name allocates a device name and registration fails before the device lifetime is handled through the normal device core release path. The leaked object is associated with early ULPI registration failure paths such as firmware node registration or ID read failure. For the CVSS the PR:H is used because reliable triggering normally requires administrator level control over driver probe, module loading, device registration, or fault injection around the ULPI hardware path. The issue is not network reachable and there is no evidence of a UAF, OOB access, arbitrary write, or information disclosure primitive. Impact is denial of service only through gradual resource exhaustion, with low practical severity in normal deployments.';NO MANUAL CHECK; ,and ActionableScore result is Ordinary Moderate / Low-like (with actual score 1)	YES	USB INIT LEAK UAF HARDWARE DEBUGFS 	NO	NO	checked

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

ActionableScore=1
ActionableScoreLower=0

## 1. ActionableScore

* Conservative score: 0
* Paranoid score: 1
* Final recommended bucket: **Ordinary Moderate / Low-like**

## 2. Signal breakdown

Conservative signals:

* Requires admin/root/CAP_* in typical deployments: -2. Reliable triggering normally requires control over driver probing, module/device registration, hardware fault conditions, or fault injection around the ULPI path.
* Rare AND difficult-to-reach subsystem/configuration: -1. ULPI registration failure is a narrow USB PHY/device-registration error path, not a broad default user-facing interface.
* Availability impact realistic: +1. Repeated failures can leak allocated device-name memory and may theoretically contribute to resource exhaustion, but this is gradual and low-confidence as a practical system-wide DoS.

Paranoid additional signal:

* Firmware-mediated external influence: +1. A failing or unusual ULPI device or firmware-described device path may influence whether registration reaches the leaking error paths, but this is not a normal remote attack surface.

No memory corruption signals apply:

* No UAF.
* No double free.
* No OOB read or write.
* No arbitrary write.
* No stale callback.
* No refcount takeover.
* No information disclosure.
* No plausible privilege escalation primitive.

## 3. Reachability analysis

The bug is reachable during ULPI device registration when an early registration step fails after `dev_set_name()` allocated the device name. In normal deployments, an attacker would need administrator-level control over driver loading, device probing, physical or firmware-level device behavior, or kernel fault injection to reliably repeat the failure path.

Namespaces and containers do not normally lower this requirement, because USB PHY registration and driver probing are host device-management operations. The path is not network reachable. It is also not a common unprivileged local API like syscalls, io_uring, AF_ALG, or netlink.

Call-site confidence: high. The patch shows the registration and failure path directly, including the move to `device_initialize()` and the later `put_device()` on failure.

## 4. Severity interpretation

This behaves like a Low-like or ordinary Moderate resource-leak issue, not an actionable Moderate or Important kernel vulnerability. The realistic impact is gradual memory/resource leakage on a privileged or hardware-mediated failure path. There is no evidence of memory corruption, sensitive-object access, policy bypass, or privilege escalation.

The paranoid score only accounts for the possibility of firmware or faulty-device influence plus repeated failure cycles. Even then, the issue remains resource exhaustion only and should not be treated as Important.

## 5. One-sentence report phrase

A memory leak in the USB ULPI registration failure path can leave an allocated device name unreleased, but reliable triggering typically requires privileged driver or device-management control and the impact is limited to gradual resource exhaustion.

## 6. Manual review recommendation

NO MANUAL CHECK NEEDED

This is a constrained memory leak in a privileged, narrow hardware registration error path with no memory corruption or security-boundary bypass evidence.

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

Patch: USB: ulpi: fix memory leak on registration failure
Commit: d5b32f36c50894ac2df8fa184e6f35f3a6665ecd
Upstream URL: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=d5b32f36c50894ac2df8fa184e6f35f3a6665ecd

Commit description:

The allocated device name is never freed on early ULPI device
registration failures.

Fix this by initialising the device structure earlier and releasing the
initial reference whenever registration fails.

Fixes: 289fcff ("usb: add bus type for USB ULPI")
Cc: stable <stable@kernel.org>
Cc: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Signed-off-by: Johan Hovold <johan@kernel.org>
Link: https://patch.msgid.link/20260608145803.69360-1-johan@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Changed files:
  drivers/usb/common/ulpi.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=d5b32f36c50894ac2df8fa184e6f35f3a6665ecd

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

The original Linux kernel CVE announcement for CVE-2026-64332 can be found here:
https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-64332

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: 0
  Paranoid ActionableScore: 1

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).