[CVE-2026-53291][LOW] ALSA: hda/conexant: Fix missing error check for jack detection [ Upstream

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

CVE: CVE-2026-53291
Priority: LOW
AL-KERNEL base severity: LOW
KPANIC flag: NO
Patch: ALSA: hda/conexant: Fix missing error check for jack detection [ Upstream
Commit: 49c2c5924552e1d2f8b635dee663abebbb7cf63b
Upstream patch: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=49c2c5924552e1d2f8b635dee663abebbb7cf63b
Original CVE announcement: https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-53291
Analysis date: Fri, 26 Jun 2026 16:51:11 -0400
ActionableScore: 1
ActionableScore lower bound: 0
Actionable bucket: Ordinary Moderate / Low-like
Manual review required: NO

Summary:
A missing IS_ERR check in the ALSA HDA Conexant probe path can allow the driver to continue after jack callback registration failure, potentially causing a later local kernel crash on affected hardware.

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

The original Linux kernel CVE announcement for CVE-2026-53291 is available here:
https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-53291

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
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CVE-2026-53291	LOW	CHECK	Maybe valid. Check manually. Hints by AL-KERNEL: The best (paranoid) CVSS is 'AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H';CWE-252;CWE-754;**CWE-476;Other CVSS 'AV:L/AC:H/PR:H/UI:N/S:U/C:N/I:N/A:H';BEST CVSS score: '4.7';DESCR 'ALSA hda conexant probe ignored an error pointer returned by snd_hda_jack_detect_enable_callback for specific Conexant codecs. If callback registration fails, for example during memory allocation failure, the driver can continue probing without a valid jack detection callback and may later crash when jack events are handled or related state is accessed. For the CVSS the PR:L is used in the paranoid score because a local unprivileged user may be able to contribute to memory pressure around probe or device recovery, but reliable reprobe or driver rebind is usually administrative. The issue is not network reachable and requires affected local audio hardware and a failed callback registration path. Impact is denial of service via kernel crash only.';NO MANUAL CHECK; ,and ActionableScore result is Ordinary Moderate / Low-like (with actual score 1)	YES	DANGER SIMPLEFIX HARDWARE LINUS  DECREASED_TO_MODERATE_REGULAR_FROM_MODERATE7_BASED_ON_GUESSCVSS_AND_CIANNH DECREASED_TO_LOW_FROM_MODERATE_BASED_ON_ACTIONABLESCORELESSTHAN3	YES	NO	checked

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ACTIONABLESCORE ANALYSIS
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ActionableScore=1
ActionableScoreLower=0

## 1. ActionableScore

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

## 2. Signal breakdown

Conservative signals:

* Reliable kernel crash / strong DoS: +1. If callback registration fails and the driver continues probing, later jack handling may crash the kernel.
* Requires admin/root/device reprobe in typical deployments: -2. Reliable triggering generally needs driver probe/rebind/reload or boot-time device initialization control.
* Rare AND difficult-to-reach subsystem/configuration: -1. The issue is limited to specific Conexant HDA codec IDs and a failed allocation path during probe.
* Floor applied at 0.

Paranoid signals:

* Local unprivileged trigger: +1. A local user may be able to contribute to memory pressure and trigger jack events, but this does not reliably control probe timing.
* Reliable kernel crash / strong DoS: +1. The described consequence is a later kernel crash.
* Hard or unreliable timing / special condition required: -1. The failure requires callback allocation failure during probe plus later jack-event handling.
* Rare AND difficult-to-reach subsystem/configuration: -1. Specific hardware and codec path are required.
* No memory corruption signal. The patch shows missing ERR_PTR handling, not UAF, OOB write, double free, refcount misuse, type confusion, or attacker-controlled reuse.
* No LPE signal. There is no demonstrated write primitive, callback hijack, object replacement, or privilege boundary bypass.

## 3. Reachability analysis

The realistic trigger is local and hardware-specific. The affected path runs during HDA Conexant codec probe for specific device IDs, and the vulnerable condition requires snd_hda_jack_detect_enable_callback() to fail, most plausibly due to allocation failure. In normal deployments, forcing a reprobe or driver rebind is administrative, while an unprivileged user may only indirectly influence memory pressure or jack events. Containers and namespaces generally do not help unless the container has delegated device-management access, which is uncommon. The path is not network reachable.

## 4. Severity interpretation

This behaves like an ordinary Moderate or Low-like local DoS issue. The theoretical impact is a kernel crash after an inconsistent probe state, but the patch does not show a practical memory-corruption primitive or privilege-escalation path. The issue is constrained by specific audio hardware, probe-time allocation failure, and later jack-event handling, so it should not be treated as Important.

## 5. One-sentence report phrase

A missing IS_ERR check in the ALSA HDA Conexant probe path can allow the driver to continue after jack callback registration failure, potentially causing a later local kernel crash on affected hardware.

## 6. Manual review recommendation

NO MANUAL CHECK NEEDED

This can be handled as auto-closable or low-priority triage unless additional evidence appears showing UAF, attacker-controlled callback state, object reuse, or a reproducible unprivileged crash path.

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

Patch: ALSA: hda/conexant: Fix missing error check for jack detection [ Upstream
Commit: 49c2c5924552e1d2f8b635dee663abebbb7cf63b
Upstream URL: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=49c2c5924552e1d2f8b635dee663abebbb7cf63b

Changed files:
  sound/pci/hda/patch_conexant.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=49c2c5924552e1d2f8b635dee663abebbb7cf63b

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

The original Linux kernel CVE announcement for CVE-2026-53291 can be found here:
https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-53291

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:H
  The Best / paranoid CVSS vector: AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H
  The Best / paranoid CVSS score: 4.7

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: 0
  Paranoid ActionableScore: 1

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).