* [CVE-2025-37881][LOW] usb: gadget: aspeed: Add NULL pointer check in ast_vhub_init_dev() [ Upstream
@ 2026-10-13 0:26 21% AL-KERNEL
0 siblings, 0 replies; 1+ results
From: AL-KERNEL @ 2026-10-13 0:26 UTC (permalink / raw)
To: kernel-cve
CVE: CVE-2025-37881
Priority: LOW
AL-KERNEL base severity: LOW
KPANIC flag: NO
Patch: usb: gadget: aspeed: Add NULL pointer check in ast_vhub_init_dev() [ Upstream
Commit: a777ccfb9ba8d43f745e41b69ba39d4a506a081e
Upstream patch: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=a777ccfb9ba8d43f745e41b69ba39d4a506a081e
Original CVE announcement: https://lore.kernel.org/linux-cve-announce/?q=CVE-2025-37881
Analysis date: Mon, 12 Oct 2026 20:26:26 -0400
ActionableScore: 0
ActionableScore lower bound: unknown
Actionable bucket: Ordinary Moderate
Manual review required: NO
Summary:
No one-sentence report phrase was found.
======================================================================
ABOUT THIS REPORT
======================================================================
The original Linux kernel CVE announcement for CVE-2025-37881 is available here:
https://lore.kernel.org/linux-cve-announce/?q=CVE-2025-37881
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-2025-37881 LOW https://www.kernelcve.org/list/?q=CVE-2025-37881 CHECK WITH IMPACT FROM ORIG NN NONE | AEGIS IMPACT MODERATE AEGIS_AS=0 LEGACY=LOW RESULT=DIFF (independent Legacy and Aegis differ; FINAL: LOW, Aegis: 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-476;CWE-252;Other CVSS 'AV:L/AC:H/PR:H/UI:N/S:U/C:N/I:N/A:L';BEST CVSS score: '4.7';DESCR 'An unchecked allocation failure in ast_vhub_init_dev can leave d name set to NULL because devm_kasprintf may fail under memory pressure. Continued Aspeed USB virtual hub initialization with the missing name can reach code that expects a valid string and may cause an initialization failure, warning, or NULL pointer dereference. Reliable triggering requires the small GFP_KERNEL allocation to fail at the same time that the Aspeed virtual hub device is being initialized, so attack complexity is high. For the CVSS the PR:L value is used in the paranoid score because a local unprivileged process may contribute to memory pressure while another component initializes the driver, although control over this specific allocation failure is not demonstrated. The issue is not network reachable. Impact is limited to availability, with no UAF, OOB access, information disclosure, or write primitive supported by the provided code.';NO MANUAL CHECK; ,and ActionableScore result is Ordinary Moderate (with actual score 0) MAYBE NULLPTR USB NOMEMCHK SIMPLEFIX IMPROVEONLY LINUS - - checked
======================================================================
ACTIONABLESCORE ANALYSIS
======================================================================
ActionableScore=0
PrimitiveClass=CLASS_C
RealUAF=NO
HostAdminRequired=UNKNOWN
NamespaceScopedPrivilege=UNKNOWN
ImportantCandidate=NO
ManualReview=NO
AutoDowngradeAllowed=YES
RequiresHostUID0=UNKNOWN
AuthorizationDecisionBypass=NO
ProtectedResourceImpact=NONE
B4PendingReview=NO
B4PendingConfirmed=NO
1. ActionableScore
* Raw conservative score: 0
* Conservative score: 0
* Raw paranoid score: 0
* Paranoid score: 0
* No floor or cap was applied.
* Final recommended bucket: **Ordinary Moderate**::
2. Signal breakdown
* +0 Potential NULL dereference. The patch establishes an unchecked `devm_kasprintf()` failure, but no observed crash or downstream dereference of `d->name` is supplied.
* +0 Weak corruption concern. A NULL pointer is possible, but there is no UAF, OOB access, write primitive, stale object, or lifetime violation.
* +0 Availability. A warning, initialization failure, or kernel fault is plausible, but a reliable host-wide crash is not demonstrated.
* No privilege penalty was applied because host-admin-equivalent privilege for the complete trigger is not established.
* No hardware penalty was applied merely because this is an Aspeed device driver.
* No race penalty was applied. The issue is an ordered allocation-failure path, not a timing race.
* No remote, local-unprivileged, high-control API, confidentiality, integrity, authorization-bypass, or resource-leak signal was awarded.
* NEW52 B5-R does not apply. There is no heap OOB write, retry-accumulated offset, or later consumption of corrupted structured state.
* NEW53 B3-PENDING does not apply. There is no shared-backing write or missing writable isolation.
* NEW54 B4-PENDING does not apply. No authorization decision or mandatory security check is involved.
3. Reachability analysis
`ast_vhub_init_dev()` is an Aspeed USB virtual-hub initialization path. The supplied evidence does not show an ordinary user interface that directly invokes it. Triggering requires `devm_kasprintf()` to fail during device initialization, normally because of memory pressure, but an attacker cannot be shown to control this particular small allocation failure reliably.
Administrative driver reprobe or device-management operations may provide one route into initialization, but they are not established as the only route. Therefore `HostAdminRequired=UNKNOWN` rather than YES. No user-namespace or network-namespace capability path is shown, and no remote trigger exists. Aspeed hardware and the relevant driver are prerequisites, but no rarity penalty is applied without stronger deployment evidence.
4. Primitive and severity interpretation
The exact defect is missing allocation-failure handling. If `devm_kasprintf()` returns NULL, initialization continues with `d->name == NULL`. The patch prevents this invalid state by returning `-ENOMEM`.
This is a potential invalid NULL-pointer consumption and therefore CLASS_C, not memory corruption. It is not an active structured-object UAF or fixed stale-storage UAF. No release, repeated refcount mutation, authorization bypass, OOB operation, controlled overwrite, or semantic reinterpretation exists.
The demonstrated consequence is incomplete error handling. A later initialization failure or NULL dereference is plausible, but the supplied context does not establish a reliable kernel crash. There is no leverage beyond possible availability impact. Consequently, this is not an Important candidate and automatic downgrade is allowed.
5. One-sentence report phrase
An unchecked `devm_kasprintf()` failure can leave the Aspeed virtual hub device name NULL during initialization, but the supplied evidence establishes only a potential invalid dereference without memory corruption or reliable attacker control.
6. Manual review recommendation
NO MANUAL CHECK NEEDED
The patch addresses a static-analysis finding with no demonstrated UAF, OOB access, authorization bypass, reliable crash, or attacker-controlled corruption primitive.
7. Call-site confidence
Call-site confidence: low
======================================================================
UPSTREAM PATCH SUMMARY
======================================================================
Patch: usb: gadget: aspeed: Add NULL pointer check in ast_vhub_init_dev() [ Upstream
Commit: a777ccfb9ba8d43f745e41b69ba39d4a506a081e
Upstream URL: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=a777ccfb9ba8d43f745e41b69ba39d4a506a081e
Changed files:
drivers/usb/gadget/udc/aspeed-vhub/dev.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=a777ccfb9ba8d43f745e41b69ba39d4a506a081e
======================================================================
DETAILED REPORT METHODOLOGY
======================================================================
The original Linux kernel CVE announcement for CVE-2025-37881 can be found here:
https://lore.kernel.org/linux-cve-announce/?q=CVE-2025-37881
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: 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 [email protected] (and both
send reply to CVE record itself too and see "reply" button below for howto reply).
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