[CVE-2026-45992][LOW] ALSA: caiaq: Fix potentially leftover ep1_in_urb at error path

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

CVE: CVE-2026-45992
Priority: LOW
AL-KERNEL base severity: LOW
KPANIC flag: NO
Patch: ALSA: caiaq: Fix potentially leftover ep1_in_urb at error path
Commit: be62c8bb03b6aec3790a943d4a7567d4d73b8be9
Upstream patch: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=be62c8bb03b6aec3790a943d4a7567d4d73b8be9
Original CVE announcement: https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-45992
Analysis date: Wed, 27 May 2026 17:47:06 -0400
ActionableScore: 0
ActionableScore lower bound: unknown
Actionable bucket: Ordinary Moderate / Low-like
Manual review required: NO

Summary:
No one-sentence report phrase was found.

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

The original Linux kernel CVE announcement for CVE-2026-45992 is available here:
https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-45992

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
======================================================================

CVE-2026-45992	LOW	CHECK	Maybe valid. Check manually. Hints by AL-KERNEL: The best (paranoid) CVSS is 'AV:P/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:L';*CWE-401;*CWE-772;CWE-459;CWE-703;BEST CVSS score: '2.1';DESCR 'ALSA caiaq can leave the internal ep1_in_urb submitted when setup_card() fails after partial probe initialization. A malformed or incompatible USB audio device can trigger the error path, causing a leftover URB or leaked USB request state until later cleanup. For the CVSS the PR:N is used because no software privileges are needed once the device is physically attached, but the attack vector is physical and usually requires device insertion or equivalent USB emulation. The issue is not network reachable and does not provide a kernel memory corruption primitive. Impact is limited denial of service through resource leakage or dangling USB activity during probe failure.';NO MANUAL CHECK; ,and ActionableScore result is Ordinary Moderate / Low-like (with actual score 0)  SKIP CVE-2026-45992  SKIP The Fixes patch not applied yet, so unlikely that actual: 28abd224db4a49560b452115bca3672a20e45b2f YES  NO NO unknown 	MAYBE	USB INIT SIMPLEFIX LEAK ERRORPATH HARDWARE LINUS 	-	-	checked

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

ActionableScore=0

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

2. Signal breakdown
* Availability/resource cleanup concern: +1. A submitted `ep1_in_urb` may be left over on a probe error path, causing a resource leak or dangling USB request state.
* Physical-only trigger: -2. Triggering requires a malformed/incompatible USB device or equivalent USB emulation attached to the host.
* Rare driver-specific exposure: -1. This is limited to the ALSA `caiaq` USB driver and a partial probe failure path.
* No memory corruption signal. The patch only routes failure through existing URB cleanup.
* No confidentiality, integrity, privilege escalation, or network reachability signal.

3. Reachability analysis
A physically attached malformed or incompatible CAIAQ USB audio device can reach the error path if `setup_card()` fails after `ep1_in_urb` was submitted. No Linux software privileges are needed once the device is attached, but practical attack requires physical access or USB emulation. Containers do not materially affect reachability because USB probing happens at the host driver layer.

4. Severity interpretation
This behaves like a Low-like resource cleanup bug. The realistic impact is a leftover URB or small resource leak during probe failure. There is no evidence of UAF, OOB access, arbitrary write, information disclosure, or privilege escalation.

5. One-sentence report phrase
A malformed CAIAQ USB audio device can trigger a probe error path that leaves `ep1_in_urb` submitted, causing only limited USB resource leakage or dangling URB state.

6. Manual review recommendation
NO MANUAL CHECK NEEDED. This is a physical, driver-specific cleanup leak with no memory corruption, security-boundary bypass, or remote trigger.

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

Patch: ALSA: caiaq: Fix potentially leftover ep1_in_urb at error path
Commit: be62c8bb03b6aec3790a943d4a7567d4d73b8be9
Upstream URL: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=be62c8bb03b6aec3790a943d4a7567d4d73b8be9

Commit description:

The previous fix for handling the error from setup_card() missed that
an internal URB cdev->ep1_in_urb might have been already submitted
beforehand.  In the normal case, this URB gets killed at the
disconnection, but in the error path, we didn't do it, hence there can
be a potential leak.

Fix it in the error path for setup_card(), too.

Fixes: 28abd22 ("ALSA: caiaq: Handle probe errors properly")
Cc: <stable@vger.kernel.org>
Link: https://patch.msgid.link/20260427123819.890185-1-tiwai@suse.de
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Changed files:
  sound/usb/caiaq/device.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=be62c8bb03b6aec3790a943d4a7567d4d73b8be9

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

The original Linux kernel CVE announcement for CVE-2026-45992 can be found here:
https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-45992

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: Not available
  The Best / paranoid CVSS vector: AV:P/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:L
  The Best / paranoid CVSS score: 2.1

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).