[CVE-2026-98055][LOW] ASoC: Intel: avs: Clean up the bus when fetching ML caps fails [ Upstream

[CVE-2026-98055][LOW] ASoC: Intel: avs: Clean up the bus when fetching ML caps fails [ Upstream

[AL-KERNEL]

CVE: CVE-2026-98055
Priority: LOW
AL-KERNEL base severity: LOW
KPANIC flag: NO
Patch: ASoC: Intel: avs: Clean up the bus when fetching ML caps fails [ Upstream
Commit: 2d96325e8ed97ec70623f788c35cca5d68c34351
Upstream patch: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=2d96325e8ed97ec70623f788c35cca5d68c34351
Original CVE announcement: https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-98055
Analysis date: Sat, 26 Sep 2026 14:46:31 -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-2026-98055 is available here:
https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-98055

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-2026-98055	LOW	https://www.kernelcve.org/list/?q=CVE-2026-98055 CHECK WITH IMPACT FROM ORIG NN LOW	Maybe valid. Check manually. Hints by AL-KERNEL: The best (paranoid) CVSS is 'AV:L/AC:H/PR:H/UI:N/S:U/C:N/I:N/A:H';CWE-252;*CWE-401;*CWE-772;Other CVSS 'AV:L/AC:H/PR:H/UI:N/S:U/C:N/I:N/A:L';BEST CVSS score: '4.1';DESCR 'An error handling flaw in the Intel AVS PCI driver can leave HD audio extended link resources allocated when ML capability retrieval or a later probe stage fails. Repeated failed probe operations may accumulate unreleased resources and eventually affect system availability. For the CVSS the PR:H because reliably triggering repeated driver probe failures normally requires administrative control over PCI device binding, driver loading, or device reset operations. The issue is not network reachable and no memory corruption, information disclosure, or privilege escalation primitive is indicated by the affected error paths.';NO MANUAL CHECK; ,and ActionableScore result is Ordinary Moderate (with actual score 0)	YES	OOB INIT SIMPLEFIX ERRORPATH HARDWARE MEMORY  DECREASED_TO_MODERATE_REGULAR_FROM_MODERATE7_BASED_ON_GUESSCVSS DECREASED_TO_LOW_FROM_MODERATE_BASED_ON_ACTIONABLESCORELESSTHAN3	NO	NO	checked

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

ActionableScore=0
PrimitiveClass=NONE
RealUAF=NO
HostAdminRequired=YES
NamespaceScopedPrivilege=NO
ImportantCandidate=NO
ManualReview=NO
AutoDowngradeAllowed=YES

1. ActionableScore

* Raw conservative score: -1
* Conservative score: 0
* Raw paranoid score: -1
* Paranoid score: 0
* Conservative and paranoid scores are clamped to 0 because no security primitive beyond a privileged error-path resource leak is established.
* Final recommended bucket: **Ordinary Moderate**::

2. Signal breakdown

* +1 Concrete persistent kernel resource/reference leak. The patch directly adds `snd_hdac_ext_link_free_all(bus)` to the AVS PCI probe unwind path, establishing that extended HD-audio link resources could remain allocated after a failed probe stage.
* -2 Host-admin-equivalent requirement. Repeatedly reaching PCI driver probe failure paths requires administrative control of PCI driver bind/unbind, module loading, device reset, or comparable host device-management operations.
* No additional resource-exhaustion point. The patch establishes an error-path cleanup omission, but does not establish host-wide exhaustion, cgroup or namespace accounting bypass, persistent cross-tenant impact, or a small number of operations causing system failure.
* No memory-corruption signal. No UAF, double free, stale dereference, refcount underflow, OOB access, invalid DMA operation, or use of freed resources is shown.
* No reliable kernel-crash signal. The supplied patch describes cleanup and return-value handling, not an Oops, panic, hang, or device-induced host crash.
* No remote-reachability signal. ML capability retrieval occurs during local PCI driver probing and depends on device and firmware state.
* No confidentiality or integrity signal. The leaked resources are driver-owned HD-audio extended-link state, and no disclosure, unauthorized write, ownership violation, or security-boundary bypass is established.

3. Reachability analysis

The relevant vulnerable path is `avs_pci_probe()` during initialization or reprobe of an Intel AVS PCI audio device. The initial probe can occur automatically during boot, but an attacker cannot normally control the failing ML-capability condition merely through ordinary audio API access.

Reliably accumulating leaked resources would require repeated failed probe attempts. Such attempts normally require host-admin-equivalent control over PCI device lifecycle operations, including driver binding, unbinding, module reload, reset, or equivalent device-management actions. This is not a network or namespace-scoped path. No attacker-obtainable namespace capability has been established for the complete trigger sequence.

No special rare physical hardware penalty is applied. Intel AVS-capable audio hardware is device-specific, but the decisive reachability restriction is the host-administrative PCI driver lifecycle requirement.

4. Primitive and severity interpretation

The exact defect is incomplete error handling and resource cleanup in the Intel AVS PCI driver probe path. `snd_hdac_ext_bus_get_ml_capabilities()` could fail without its return value being handled. Also, extended-link resources created before a later probe failure were not released before probe cleanup continued.

This is a concrete resource-management leak, not a lifetime corruption bug. The patch does not establish that an object is freed while still referenced, that the same object is released twice, or that a stale object is subsequently dereferenced. There is no concrete repeated release/refcount mutation. Therefore, this is neither an ordinary stale cleanup dereference nor a second lifetime/refcount mutation through a dangling object.

PrimitiveClass is NONE because the patch establishes no meaningful corruption, authorization, ownership, lifetime, or security-boundary primitive. The practical consequence is limited to resource retention across failed and repeated privileged probe operations. ImportantCandidate is NO because no unresolved exploitation leverage beyond controlled resource accumulation is shown. AutoDowngradeAllowed is YES because the issue can be handled as a low-priority resource-cleanup defect unless environment-specific evidence shows broad persistent resource exhaustion.

5. One-sentence report phrase

A missing AVS PCI probe cleanup can leak extended HD-audio link resources after ML capability or later initialization failures, but repeated triggering normally requires host administrative control of PCI driver lifecycle operations and no memory-corruption or privilege-escalation primitive is established.

6. Manual review recommendation

NO MANUAL CHECK NEEDED

The patch fixes a privileged error-path resource leak without evidence of memory corruption, security-boundary bypass, remote reachability, kernel crash, or meaningful unresolved exploitation leverage.

7. Call-site confidence

Call-site confidence: medium

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

Patch: ASoC: Intel: avs: Clean up the bus when fetching ML caps fails [ Upstream
Commit: 2d96325e8ed97ec70623f788c35cca5d68c34351
Upstream URL: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=2d96325e8ed97ec70623f788c35cca5d68c34351

Changed files:
  sound/soc/intel/avs/core.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=2d96325e8ed97ec70623f788c35cca5d68c34351

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

The original Linux kernel CVE announcement for CVE-2026-98055 can be found here:
https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-98055

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:H/UI:N/S:U/C:N/I:N/A:H
  The Best / paranoid CVSS score: 4.1

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).