CVE-2026-98054

Executive Summary

CVE-2026-98054 is a resource-management defect in the Linux kernel's ASoC (ALSA System on Chip) Intel AVS (Audio Voice Speech) driver, where strace_open() acquires a module reference via try_module_get() but fails to release it when a subsequent operation causes the open path to fail, producing an unbalanced reference count. The flaw is localized to the kernel audio subsystem for Intel platforms and is not a remote code-execution or memory-corruption issue; its primary observable effect is a resource leak that can degrade audio-subsystem stability and block module unloading. Because exploitation requires local interaction with the audio device nodes and the driver is only relevant on Intel AVS-capable hardware, the practical attack surface is limited and no public proof-of-concept or in-the-wild exploitation has been observed.

Technical Analysis

The vulnerability is a classic resource-lifetime defect (CWE-772) in the Linux kernel's ASoC Intel AVS driver. The NVD description states that strace_open() invokes try_module_get(), which on success increments the module reference count. The defect is that the error-handling path for that same open routine does not call the corresponding module_put() when a later step in the open sequence fails. The result is a reference count that is incremented once per failed open and never decremented.

The mechanism is straightforward and does not involve memory corruption, pointer misuse, or attacker-controlled buffers:

1. try_module_get() successfully pins the module (refcount +1).
2. A follow-up operation within the same open flow fails for an unrelated reason (for example, device-state or allocation failure paths).
3. The function returns an error to the caller without executing the matching module_put().
4. The module reference count is left permanently elevated.

The attack surface is the device-open path exposed through the audio subsystem. This is a local interface reached via the kernel's character-device / ALSA device-node open path, not a network-facing endpoint. An actor with the ability to trigger repeated failed opens of the affected device can repeatedly inflate the refcount.

Notably, the CNA title supplied is empty, and the NVD description contains no CVE-specific advisory metadata beyond the fixing-commit prose. No kernel version numbers, commit hashes, affected file paths, or configuration options are provided in the source data, and this report does not invent them. The internal function name strace_open() is reproduced verbatim from the NVD description; no other identifier is asserted. Because the reference count is used to guard module removal and lifetime, the concrete downstream consequences (failure to unload the module, accumulated counter state, and any resulting warnings) follow from the class of the defect rather than from any specific, verifiable code path given in the available text.

Exploitation Scenarios

No public proof-of-concept exists for CVE-2026-98054, and no exploit-in-the-wild evidence is available. The attack chain below is inferred strictly from the vulnerability class (unbalanced module reference count) and the mechanism named in the NVD description.

1. Reconnaissance / target identification. The attacker identifies a target system running a Linux kernel that includes the vulnerable Intel AVS ASoC driver. This is a local-prerequisite vulnerability: the attacker needs some form of code execution, shell access, or an unprivileged local account on the host, or the ability to influence a process that opens audio devices. The relevant hardware is Intel AVS-capable audio hardware; the affected code is only reachable where that driver is built and active.

2. Triggering the flaw class. The attacker induces the open path of strace_open() to execute repeatedly such that try_module_get() succeeds and a subsequent operation fails. Each successful entry into the flawed branch increments the module reference count without a balancing module_put(). By repeating the failing open, the attacker causes the count to grow.

3. Payload / execution method (class level). There is no payload in the memory-corruption sense. The "trigger" is simply an operation that reaches and fails the open routine. Because the NVD description does not enumerate the exact follow-up operation that fails, no specific syscall sequence, ioctl, or device-node path can be asserted; this report does not fabricate one.

4. Post-exploitation impact. The elevated reference count prevents the module from reaching zero references, so the module cannot be cleanly unloaded and the refcount state is permanently skewed for the lifetime of the affected kernel object. The observable impact is denial of the intended resource-management behavior (module teardown) and potential instability of the audio subsystem, not privilege escalation or arbitrary code execution. Repeated triggering could contribute to resource exhaustion in the audio stack depending on how callers and cleanup paths behave.

Impact Assessment

CVE-2026-98054 is a local, low-complexity-adjacent availability and integrity-of-state defect rather than a confidentiality or integrity compromise of user data. The following subscores are inferred because no official CVSS vector was supplied in the source data (CVSS score: N/A, vector: N/A):

• Attack Vector (AV:L): The vulnerability is reachable through a local device/subsystem open path, not remotely.
• Attack Complexity (AC:H): Triggering requires the specific failure condition within the open routine to occur; the exact trigger conditions are not published, which constrains reliability.
• Privileges Required (PR:L): Reachability requires some local ability to interact with the audio device interface.
• User Interaction (UI:N): Once the actor has the requisite local access, no additional victim action is necessarily required.
• Scope (S:U): Impact remains within the same security authority (the kernel module state).
• Confidentiality (C:N) / Integrity (I:N): No data exposure or modification is described.
• Availability (A:H): The unbalanced reference count directly degrades the availability of module-removal/teardown behavior and can destabilize the audio subsystem.

Business impact is therefore concentrated in reliability and operations for hosts running affected Intel AVS audio hardware: the inability to unload the module cleanly, resource-state degradation, and possible audio-subsystem faults. Blast radius is bounded by hardware presence and driver activation; systems without Intel AVS-capable audio hardware are not exposed. There is no evidence of ransomware, lateral movement, or data-theft utility.

Detection Guidance

Sigma Rule

title: Linux Kernel ASoC Intel AVS Unbalanced Module Reference Count Attempt
id: 8f2c4a10-98054-4b7e-9c1d-avsmodref
status: experimental
description: Detects repeated failed opens against the Intel AVS ASoC audio device path that may indicate triggering of the unbalanced module reference count (CVE-2026-98054).
references:
  - https://nvd.nist.gov/vuln/detail/CVE-2026-98054
author: valtersit.com
date: 2026/01/01
logsource:
  product: linux
  service: auditd
detection:
  selection_open:
    type: 'SYSCALL'
    syscall: 'openat'
  selection_path:
    name|contains: '/dev/snd/'
  selection_failure:
    exit: '-EIO'
  condition: selection_open and selection_path and selection_failure
falsepositives:
  - Legitimate applications retrying audio device access on busy or unavailable devices
  - Faulty audio hardware causing repeated open failures
level: low
tags:
  - attack.impact
  - cve.2026.98054

YARA Rule

rule CVE_2026_98054_Linux_ASoC_AVS_Module_Refcount
{
    meta:
        description = "Detects the ASoC Intel AVS driver symbol context associated with an unbalanced module reference count (CVE-2026-98054). Targets kernel images or modules containing the AVS driver code path."
        author = "valtersit.com"
        reference = "https://nvd.nist.gov/vuln/detail/CVE-2026-98054"
        date = "2026-01-01"
        severity = "low"

    strings:
        $avs = "avs" ascii wide nocase
        $asoc = "ASoC" ascii wide
        $snd = "/dev/snd" ascii wide
        $trymod = "try_module_get" ascii
        $modput = "module_put" ascii

    condition:
        uint32(0) == 0x464C457F and
        $asoc and
        $avs and
        (2 of ($trymod, $modput, $snd))
}

Suricata IDS Rule

alert tcp $HOME_NET any -> $EXTERNAL_NET any (msg:"CVE-2026-98054 Potential Probe - Linux Intel AVS ASoC Driver Fingerprint Attempt"; flow:to_server,established; content:"|00 00 00 00|"; classtype:attempted-recon; sid:202698054; rev:1; metadata:created_at 2026_01_01, cve CVE-2026-98054, affected_product Linux_Kernel, confidence Low;)

Note: CVE-2026-98054 is a local resource-lifetime defect with no network-facing protocol component, so no meaningful network signature can be constructed. The rule above is a placeholder for environment-specific fingerprinting only and should not be relied upon for exploitation detection; network-layer detection is not applicable to this vulnerability class.

Elastic Detection

process where host.os.type == "linux" and event.action in ("exec", "start") and
process.name in ("unload_module", "modprobe", "rmmod") and
process.args : ("snd_soc_avs*", "snd_soc_avs") and
not user.name == "root"

This query surfaces non-root attempts to unload the affected ASoC AVS module, which may indicate an attacker or operator attempting to force teardown of a module whose reference count has been inflated by CVE-2026-98054.

Splunk SPL Query

index=linux sourcetype=auditd OR sourcetype=syslog
(("module" AND "refcount") OR ("snd_soc_avs") OR ("try_module_get"))
NOT process=*kernel*
| stats count min(_time) as first_seen max(_time) as last_seen by host process pid message
| where count > 5
| sort - count

Wazuh OSSEC Rule

<group name="linux,cve_2026_98054,">
  <rule id="202698054" level="4">
    <decoded_as>auditd</decoded_as>
    <field name="syscall">openat|open|ioctl</field>
    <field name="name">/dev/snd</field>
    <description>CVE-2026-98054: Possible repeated failed access to Intel AVS ASoC audio device node; resource-state anomaly</description>
    <options>no_full_log</options>
  </rule>
  <rule id="202698055" level="6">
    <if_sid>202698054</if_sid>
    <field name="exit">EIO|ENODEV|EBUSY</field>
    <frequency>5</frequency>
    <timeframe>60</timeframe>
    <description>CVE-2026-98054: Repeated failed opens against ASoC AVS device may indicate unbalanced module reference count condition</description>
  </rule>
</group>

Mitigation & Patch Guidance

Patch confidence: 0/4 (UNPATCHED — no patch evidence from any tracked source). No vendor advisory, upstream commit hash, or fixed kernel version was supplied. The remediation steps below are generic and must be validated against a current authoritative kernel source before deployment.

1. Immediate mitigations

   • On systems where the Intel AVS ASoC driver is not required, disable the driver/module so the vulnerable code path is not built or loadable, subject to hardware support requirements (audio will fall back to an alternative driver if the hardware supports it).
   • Restrict local access and reduce exposure of audio device interfaces to unprivileged users where operationally possible, limiting the ability to repeatedly trigger the open path.
   • Monitor kernel logs for refcount/trace warnings referencing the ASoC Intel AVS driver and for failed module-unload attempts.

2. Patch / upgrade steps

   • Because no patch reference is available, treat this as unpatched. Track the upstream Linux kernel stable and mainline release notes for a fix to "ASoC: Intel: avs: Fix unbalanced module reference count".
   • When a fixed kernel version is published, schedule an upgrade and reboot to load the corrected kernel.
   • Validate through the distribution's security tracker before upgrading, since no CVE-specific advisory metadata was provided.

3. Long-term hardening

   • Maintain a kernel patch-management process that continuously reconciles against the upstream stable tree.
   • Enforce least privilege on systems with unusual or embedded audio hardware, and audit module load/unload activity.
   • Where AVS audio is not a business requirement, exclude it from the kernel configuration at build time to eliminate the entire attack surface.

References

• NVD entry: https://nvd.nist.gov/vuln/detail/CVE-2026-98054
• NVD description text (source of all technical claims in this report): resolved issue titled "ASoC: Intel: avs: Fix unbalanced module reference count" in the Linux kernel.
• Linux kernel stable and mainline release announcements (track for the fixing commit and affected version range once published).
• CWE-772: Missing Release of Resource after Effective Lifetime — https://cwe.mitre.org/data/definitions/772.html
• No CISA KEV entry, no vendor advisory, and no known threat actor campaign or exploit-in-the-wild evidence is associated with CVE-2026-98054 in the provided data.