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CVE-2026-89979· NVD / CVE Program· CNA Linux

ALSA: pcm: Fix race between non-atomic ops and trigger-start

In the Linux kernel, the following vulnerability has been resolved: ALSA: pcm: Fix race between non-atomic ops and trigger-start We protect the races of the concurrent state transitions between atomic PCM ops, but the checks between the non-atomic ops (hw_params, hw_free and prepare) and the atomic ops aren't perfect; there is a check of the conflicting PCM state at the beginning of hw_params & co, but the atomic PCM ops can be still issued during the non-atomic PCM operations. An example such scenario is that a thread A re-issues the PREPARE or HW_PARAMS for the already prepared stream, while another thread B triggers the PCM start in the middle of the prepare operation. Although this usually doesn't lead to much serious issues, it can give some inconsistency as reported by syzkaller (such as ODEBUG warning). There are various atomic PCM ops, and basically the only problem is the PCM start as it operates from the PREPARED state. Other trigger commands (stop, etc) are for the running or the other special state, hence they are filtered as pre-condition. This patch is for preventing the PCM trigger-start during the non- atomic operations in order to address the problems above. Fortunately, the hw_params, hw_free and prepare operations call snd_pcm_buffer_access_lock(), and this can be used for checking the concurrent operations at the PCM trigger -- which sets the runtime->buffer_accessing to a negative (if possible), so the PCM trigger just needs to check the runtime->buffer_accessing value; if it's negative, it means the concurrent non-atomic PCM ops is running.

HighCVSS 7.8 · v3.1—No exploit Fix available
Published
Sep 16, 2026
Updated
Sep 17, 2026
EPSS
0.2% · 6th percentile
CWE
—
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Report tools

JSON

Action score

31

Monitor

Low priority for now.

CVSS
31 / 40 · 7.8 / 10
CISA KEV
0 / 30 · Not listed
EPSS
0 / 30 · 0.2%

CNA vs NVD score

NVD
—
CNA · Linux
7.8
NVD has not scored this yet; the score shown is the CNA’s.

The score given by the assigning authority versus NVD’s independent score. A gap means the severity is contested.

Affected systems

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Versions reported by the vendor

Affected version ranges reported by the assigning authority (Linux). Independent of NVD's CPE analysis and usually ahead of it.

  • Linux Linux

    • 2.6.12affected
    • 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 and later · before b1d12144557fceed5de6e22e2c2e30a40ed37702affected · git
    • 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 and later · before b2edc017f94c08bdd0b046a586e43ac771a2f942affected · git
    • 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 and later · before b599e7f16441386754ec083fa62a549bccb02fcaaffected · git
    • 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 and later · before ad29779736cfd6f5595f0cab300dd7611418e363affected · git
    • 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 and later · before 5abeb4f9f2023f001d693b4e5e1ebbf25e25d0ebaffected · git
    • 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 and later · before 7ad2ea7c10044b08ecf7b04376916faf12e17a99affected · git
    • 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 and later · before 50afadf1ea66597116eb14e73c24da7ae99b759faffected · git
    • 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 and later · before acac7b5e07349a9d10d78873afb4b93cd1dc721faffected · git
    • before 2.6.12not affected · semver

Package-level exposure

OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.

EcosystemPackageAffected rangeFix
Debian:12linuxall versions—
Debian:13linuxbefore 6.12.111-16.12.111-1
Debian:14linuxbefore 7.2.6-17.2.6-1

Same product

linux: all records

Other highest-scoring records for the same primary product.

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  • CVE-2026-74280crypto: marvell/octeontx - fix DMA cleanup using wrong loop index
    40Plan
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    40Plan

Remediation

Which version to upgrade to

Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.

Product / packageFixed versionSource
Linux Linux50afadf1ea66597116eb14e73c24da7ae99b759fVendor (CNA)
Linux Linux5abeb4f9f2023f001d693b4e5e1ebbf25e25d0ebVendor (CNA)
Linux Linux7ad2ea7c10044b08ecf7b04376916faf12e17a99Vendor (CNA)
Linux Linuxacac7b5e07349a9d10d78873afb4b93cd1dc721fVendor (CNA)
Linux Linuxad29779736cfd6f5595f0cab300dd7611418e363Vendor (CNA)
Linux Linuxb1d12144557fceed5de6e22e2c2e30a40ed37702Vendor (CNA)
Linux Linuxb2edc017f94c08bdd0b046a586e43ac771a2f942Vendor (CNA)
Linux Linuxb599e7f16441386754ec083fa62a549bccb02fcaVendor (CNA)
debian:linux6.12.111-1 · Debian:13Package registry (OSV)

Exploit status

No known public exploit

No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.

Research context

For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.

Timeline

From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.

No dated events beyond publication.

EPSS, last 120 days

FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).

Patch and commit links

Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.

No commit or PR link among the references.

Credits

All researchers

Finders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.

No credits in the CNA record.

Variant candidates

Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.

No nightly-computed relations.

Chain candidates

An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.

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Bug bounty scope

No known public program.

Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).

Technical details

Attack conditions

  • Someone with local access to the system can trigger it.
  • A low-privileged account is enough.
  • No user action is required.
  • No special conditions are required; it is repeatable.

If successful

Confidentiality
high · data can be read
Integrity
high · data or configuration can be modified
Availability
high · the service can be disrupted
Attack vector
Local
Attack complexity
Low
Privileges required
Low
User interaction
None
Scope
Unchanged
Confidentiality impact
High
Integrity impact
High
Availability impact
High

Weakness class (CWE)

—

CVSS vector

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

nvd-secondary

Attack context

MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.

MITRE has no CAPEC/ATT&CK mapping for this CWE.

Noroxi analysis

No Noroxi analysis for this record yet

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Change log

  1. Fix✗ → ✓

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References

Vendor advisories and official records. Exploit/PoC links are deliberately left out.

All records