Linux KernelOperating system · Linux

CVE-2024-39491

MEDIUM · 5.5 CVSS v3.1 Published 2024-07-10
Fix available
A fix is available. Upgrade to 6.6.33 / 6.9.4 or later.
See remediation →
57/100
Remediation priority · Elevated
Zero-click Patch available

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
In the Linux kernel, the following vulnerability has been resolved: ALSA: hda: cs35l56: Fix lifetime of cs_dsp instance The cs_dsp instance is initialized in the driver probe() so it should be freed in the driver remove(). Also fix a missing call to cs_dsp_remove() in the error path of cs35l56_hda_common_probe(). The call to cs_dsp_remove() was being done in the component unbind callback cs35l56_hda_unbind(). This meant that if the driver was unbound and then re-bound it would be using an uninitialized cs_dsp instance. It is best to initialize the cs_dsp instance in probe() so that it can return an error if it fails. The component binding API doesn't have any error handling so there's no way to handle a failure if cs_dsp was initialized in the bind.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis
How this class of weakness works · CWE-908

Memory or a resource is used before it has been initialised, so its contents are whatever happened to be there — sometimes leaking earlier data, sometimes values an attacker can influence. Behaviour becomes unpredictable and occasionally exploitable. Remediation is initialising every resource before use and ensuring initialisation happens on all code paths.

General guidance for the use of uninitialized resource class — the official description and references above are authoritative for this specific CVE. Want a bespoke review and a reviewed fix? Ask our team →

Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.

NVD · CPE data
Linux KernelOperating system
Affected:>= 6.6, < 6.6.33>= 6.7, < 6.9.4

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Local
Complexity
Low
Privileges
Low
User interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
None
Availability
High

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

dbcve · scoped
Upgrade available Upgrade to 6.6.33 / 6.9.4 or later
Fixed in 6.6.336.9.4
Vendor patch git.kernel.org →
Recommended fix High confidence

Linux Kernel 6.6.33 or later, or 6.9.4 or later (any later stable release such as 6.6.34, 6.9.5, etc.)

  1. Identify systems running affected kernel versions: 6.6.x before 6.6.33, or 6.7.x through 6.9.x before 6.9.4
  2. If the cs35l56 HDA audio driver is in use, unbind it before upgrade to avoid triggering the uninitialized resource bug
  3. Schedule a maintenance window for kernel upgrade
  4. Upgrade the Linux kernel to version 6.6.33 or later, or version 6.9.4 or later
  5. Reboot the system into the new kernel
  6. Verify the cs35l56 audio driver loads correctly: check dmesg for any cs35l56 or cs_dsp errors, and confirm audio functionality works

Generated from the published advisory — verify against the referenced sources before acting.

We can perform the upgrade in your staging environment and verify nothing breaks — typical engagement from $1,600. Get the upgrade done

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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2024-39491 in production — separate from our analysis above.

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What this is

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