[CVE-2026-72303][MODERATE REGULAR] ASoC: SOF: ipc4-control: Validate notification payload size commit 5bdfeccb7fbf6e000fc783cd8412732e67c1ad0c upstream.

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

CVE: CVE-2026-72303
Priority: MODERATE REGULAR
AL-KERNEL base severity: MODERATE
KPANIC flag: NO
Patch: ASoC: SOF: ipc4-control: Validate notification payload size commit 5bdfeccb7fbf6e000fc783cd8412732e67c1ad0c upstream.
Commit: c29f5b4498894aebb2f87b1a29bb320e2f9348f9
Upstream patch: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=c29f5b4498894aebb2f87b1a29bb320e2f9348f9
Original CVE announcement: https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-72303
Analysis date: Sat, 15 Aug 2026 08:58:36 -0400
ActionableScore: 4
ActionableScore lower bound: 2
Actionable bucket: Borderline Moderate, manual review recommended
Manual review required: YES

Summary:
A malformed SOF IPC4 MODULE_NOTIFICATION can make the ASoC SOF control update path read beyond the provided payload before validating bytes or channel array length, potentially causing a local kernel crash or limited exposure of adjacent IPC buffer data on affected audio systems.

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ABOUT THIS REPORT
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The original Linux kernel CVE announcement for CVE-2026-72303 is available here:
https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-72303

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.

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AL-KERNEL CLASSIFICATION RESULT
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CVE-2026-72303	MODERATE	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:L/UI:N/S:U/C:L/I:L/A:H';CWE-125;*CWE-20;CWE-130;Other CVSS 'AV:L/AC:H/PR:H/UI:N/S:U/C:L/I:N/A:L';BEST CVSS score: '5.8';DESCR 'ASoC/SOF IPC4 control update can read past the end of a MODULE_NOTIFICATION payload because msg_data num_elems is used before validating that the notification buffer is large enough for the bytes data or channel value array. A malformed notification from the SOF firmware or DSP control path can therefore cause an out of bounds read in kernel driver code and may lead to a crash or exposure of adjacent kernel IPC buffer contents through control state. For the CVSS the PR:L is used in the paranoid score to reflect a conservative case where a local user or service can indirectly reach the affected audio control path through delegated device access. The issue is not network reachable and requires a local host with affected SOF IPC4 audio support. Impact is at least local denial of service and in the worst still defensible case limited confidentiality or integrity impact from the out of bounds read.';YES REQUIRES MANUAL CHECK; ,and ActionableScore result is Borderline Moderate, manual review recommended (with actual score 3)  SKIP CVE-2026-72303 UNKNOWN SKIP The Fixes patch not applied yet, so unlikely that actual: 2a28b5240f2b YES  NO NO unknown 	MAYBE	SIMPLEFIX HARDWARE  INCREASED_FROM_LOW_BASED_ON_REQUIREMANUALCHECK DECREASED_TO_MODERATEREG_BASED_ON_ACTIONABLESCORELESSTHAN5	-	-	checked

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ACTIONABLESCORE ANALYSIS
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ActionableScore=4
ActionableScoreLower=2

## 1. ActionableScore

* Conservative score: 2
* Paranoid score: 4
* Final recommended bucket: **Borderline Moderate, manual review recommended**

## 2. Signal breakdown

Conservative signals:

* Firmware-mediated external influence: +1. The malformed `MODULE_NOTIFICATION` payload appears to come from the SOF firmware or DSP IPC path, not from a normal network or direct unprivileged syscall interface.
* Confidentiality impact plausible: +1. The missing `event_data_size` validation can cause an out-of-bounds read from the received IPC notification buffer before copying or interpreting bytes/channel data.
* Rare or difficult-to-reach subsystem/configuration: -1. The issue requires affected SOF IPC4 audio support and malformed firmware/DSP notification behavior.
* Constrained primitive / low attacker control: -1. The patch shows a bounds check preventing read past a firmware-provided notification buffer, but does not show an attacker-controlled overwrite, reclaim, callback control, or arbitrary read primitive.

Paranoid additional signals:

* Availability impact realistic: +1. A kernel out-of-bounds read in driver IPC handling may plausibly crash or destabilize the host depending on buffer placement and fault behavior.
* Integrity impact plausible: +1. For channel controls, reading nonexistent `chanv` entries may corrupt or desynchronize control state, although no strong kernel memory write primitive is shown.
* Privileged kernel/device-management path: +1. The bug is in a trusted kernel audio driver path processing firmware-fed control notifications.
* The constrained primitive penalty still applies: -1. This remains an OOB read / malformed notification validation bug, not a demonstrated strong memory corruption or LPE primitive.

## 3. Reachability analysis

The most realistic trigger is a malformed SOF IPC4 `MODULE_NOTIFICATION` produced through the firmware/DSP notification path. A normal remote attacker cannot reach this path over the network. A local unprivileged user may interact with ALSA controls on some systems, but the patch does not show that such a user can directly forge the malformed notification payload. In typical deployments, practical triggering likely requires compromised or buggy firmware, privileged topology/control setup, or a local service with delegated access to the affected audio stack.

Namespaces and containers do not obviously make this broadly reachable unless the audio device and controls are passed through to the container. The affected path is hardware and configuration dependent, but SOF IPC4 is relevant on real Intel audio platforms, so it should not be dismissed as purely theoretical.

Call-site confidence: medium. The vulnerable reads and size checks are visible in the patch, but the exact producer and attacker control over `ipc_message` are not fully shown.

## 4. Severity interpretation

This behaves more like a borderline/actionable Moderate than an Important-class issue. The patch supports a concrete OOB read caused by missing payload-size validation, with plausible DoS and limited information/control-state impact. It does not support arbitrary write, UAF reclaim, type confusion, callback hijack, or a practical privilege escalation path.

Theoretical risk exists because malformed firmware-fed data is consumed in kernel context, but realistic exploitation evidence is limited. The paranoid score is therefore raised for manual-review sensitivity, but not into Important range.

## 5. One-sentence report phrase

A malformed SOF IPC4 MODULE_NOTIFICATION can make the ASoC SOF control update path read beyond the provided payload before validating bytes or channel array length, potentially causing a local kernel crash or limited exposure of adjacent IPC buffer data on affected audio systems.

## 6. Manual review recommendation

MANUAL CHECK RECOMMENDED

Reason: this is a kernel bounds-validation bug with a plausible OOB read in a firmware-fed driver path, but the patch does not demonstrate a strong corruption primitive, direct unprivileged trigger, or privilege escalation path.

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

Patch: ASoC: SOF: ipc4-control: Validate notification payload size commit 5bdfeccb7fbf6e000fc783cd8412732e67c1ad0c upstream.
Commit: c29f5b4498894aebb2f87b1a29bb320e2f9348f9
Upstream URL: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=c29f5b4498894aebb2f87b1a29bb320e2f9348f9

Commit description:

Validate MODULE_NOTIFICATION payload length before reading
bytes/channel data in control update handling.

Fixes: 2a28b5240f2b ("ASoC: SOF: ipc4-control: Add support for generic bytes control")
Cc: stable@vger.kernel.org
Signed-off-by: Peter Ujfalusi <peter.ujfalusi@linux.intel.com>
Reviewed-by: Liam Girdwood <liam.r.girdwood@intel.com>
Reviewed-by: Bard Liao <yung-chuan.liao@linux.intel.com>
Link: https://patch.msgid.link/20260609083458.31193-3-peter.ujfalusi@linux.intel.com
Signed-off-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat -rw-r--r-- sound/soc/sof/ipc4-control.c 23

Changed files:
  sound/soc/sof/ipc4-control.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=c29f5b4498894aebb2f87b1a29bb320e2f9348f9

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

The original Linux kernel CVE announcement for CVE-2026-72303 can be found here:
https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-72303

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:L/I:N/A:L
  The Best / paranoid CVSS vector: AV:L/AC:H/PR:L/UI:N/S:U/C:L/I:L/A:H
  The Best / paranoid CVSS score: 5.8

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: 4

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).