[CVE-2026-72488][MODERATE REGULAR] soundwire: fix bug in sdw_add_element_group_count found by syzkaller [ Upstream

[CVE-2026-72488][MODERATE REGULAR] soundwire: fix bug in sdw_add_element_group_count found by syzkaller [ Upstream

[AL-KERNEL]

CVE: CVE-2026-72488
Priority: MODERATE REGULAR
AL-KERNEL base severity: MODERATE
KPANIC flag: NO
Patch: soundwire: fix bug in sdw_add_element_group_count found by syzkaller [ Upstream
Commit: a454f61747c97e2eadaa7a35ffc1f4b1645c6a53
Upstream patch: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=a454f61747c97e2eadaa7a35ffc1f4b1645c6a53
Original CVE announcement: https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-72488
Analysis date: Sat, 15 Aug 2026 08:11:21 -0400
ActionableScore: 3
ActionableScore lower bound: 2
Actionable bucket: Borderline Moderate. Manual review recommended because this is a kernel OOB read found by syzkaller, but not an Important candidate based on the supplied patch.
Manual review required: YES

Summary:
No one-sentence report phrase was found.

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

The original Linux kernel CVE announcement for CVE-2026-72488 is available here:
https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-72488

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: MODERATE REGULAR
Manual review required: YES

A detailed explanation of the methodology and priority rules is included
at the end of this message.

======================================================================
AL-KERNEL CLASSIFICATION RESULT
======================================================================

CVE-2026-72488	MODERATE	CHECK WITH IMPACT FROM ORIG NN IMPORTANT	Maybe valid. Check manually. Hints by AL-KERNEL: The best (paranoid) CVSS is 'AV:L/AC:H/PR:L/UI:N/S:U/C:L/I:N/A:H';CWE-125;CWE-193;*CWE-787;Other CVSS 'AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:L';BEST CVSS score: '5.3';DESCR 'An off by one bug in sdw_add_element_group_count can read group rates and group lanes at index group count while checking whether a rate and lane pair already exists. This is an out of bounds read in the SoundWire bandwidth allocation path and was found by syzkaller. For the CVSS the PR:L is used because practical triggering requires a local process able to exercise the affected audio or SoundWire path, usually through local device usage rather than remote network traffic. The issue is not network reachable. Impact is primarily local denial of service or a kernel warning and crash in hardened or debug configurations. A limited confidentiality impact is kept only in the paranoid score because the primitive is an invalid kernel read, but the patch does not show data being copied back to userspace or an out of bounds write. YES REQUIRES MANUAL CHECK';YES REQUIRES MANUAL CHECK; ,and ActionableScore result is Borderline Moderate. Manual review recommended because this is a kernel OOB read found by syzkaller, but not an Important candidate based on the supplied patch. (with actual score 3)	YES	WRITE OOB NOMEMCHK IMPROVEONLY  LOWERED_FROM_HIGH_BASED_ON_GUESSCVSS  DECREASED_TO_MODERATEREG_BASED_ON_ACTIONABLESCORELESSTHAN5	NO	NO	checked

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

ActionableScore=3
ActionableScoreLower=2

1. ActionableScore
* Conservative score: 2
* Paranoid score: 3
* Final recommended bucket: **Borderline Moderate. Manual review recommended because this is a kernel OOB read found by syzkaller, but not an Important candidate based on the supplied patch.**

2. Signal breakdown
* Local unprivileged trigger: +1. Practical triggering likely requires local access to an audio or SoundWire path, not network access.
* Weak or indirect corruption candidate: +1. The bug is an off-by-one array access in kernel memory, but the demonstrated primitive is read-only OOB access, not an OOB write, UAF, double free, or controlled overwrite.
* Reliable kernel crash / strong DoS: +1 in paranoid scoring only. Syzkaller found the issue and KASAN or hardened kernels may crash, but production impact is not proven as a reliable host-wide crash.
* Confidentiality impact plausible: +1 in paranoid scoring only. A kernel OOB read exists, but there is no shown copy-back or user-visible disclosure path.
* Rare and difficult-to-reach subsystem/configuration: -1. SoundWire is hardware and platform dependent and not a broad default kernel attack surface.

3. Reachability analysis
A local user may be able to reach the path indirectly by exercising audio or SoundWire device configuration paths, depending on hardware and permissions. There is no network reachability. Containers usually do not expose SoundWire device control unless device nodes or audio services are delegated. The path is not universally enabled because it depends on SoundWire hardware and driver use.

4. Severity interpretation
This behaves like a low-end to borderline Moderate kernel memory-safety issue. Theoretical concern exists because the kernel performs an out-of-bounds read, but the patch shows no write primitive, no UAF, no attacker-controlled reclaim, no callback corruption, and no direct information disclosure. It should not be treated as Important based only on this diff.

5. One-sentence report phrase
An off-by-one bug in `sdw_add_element_group_count()` can read one element past the valid SoundWire rate/lane arrays, potentially causing a local kernel warning or crash on affected SoundWire systems.

6. Manual review recommendation
MANUAL CHECK RECOMMENDED. This is not strong enough for Important-class handling, but syzkaller-found kernel OOB memory access should not be blindly auto-closed without confirming reachability on the target product.

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

Patch: soundwire: fix bug in sdw_add_element_group_count found by syzkaller [ Upstream
Commit: a454f61747c97e2eadaa7a35ffc1f4b1645c6a53
Upstream URL: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=a454f61747c97e2eadaa7a35ffc1f4b1645c6a53

Changed files:
  drivers/soundwire/generic_bandwidth_allocation.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=a454f61747c97e2eadaa7a35ffc1f4b1645c6a53

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

The original Linux kernel CVE announcement for CVE-2026-72488 can be found here:
https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-72488

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:L/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:L/I:N/A:H
  The Best / paranoid CVSS score: 5.3

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: 2
  Paranoid ActionableScore: 3

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: MODERATE
KPANIC detected for this report: NO
Published priority for this report (same as in Subject): MODERATE REGULAR

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).