CVE-2025-40142

System hang via PREEMPT_RT PCM lock inversion

Published Nov 12, 2025 · Updated May 11, 2026

Deadlock in Linux ALSA PCM 6.12 through 6.17.2 allows attackers to hang PREEMPT_RT systems via concurrent PCM and timer activity. On PREEMPT_RT, snd_pcm_group_lock_irq() uses spin_lock_irq() without disabling bottom halves, allowing TIMER_SOFTIRQ to run while the PCM group lock is held and invert the softirq_ctrl.lock order. The issue requires the affected ALSA PCM code and PREEMPT_RT semantics; triggering the lock inversion deadlocks the kernel and interrupts the system.

CVSS severityUnavailable
Unscored
EPSS probability0.20%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Deadlock in Linux ALSA PCM 6.12 through 6.17.2 allows attackers to hang PREEMPT_RT systems via concurrent PCM and timer activity. On PREEMPT_RT, snd_pcm_group_lock_irq() uses spin_lock_irq() without disabling bottom halves, allowing TIMER_SOFTIRQ to run while the PCM group lock is held and invert the softirq_ctrl.lock order. The issue requires the affected ALSA PCM code and PREEMPT_RT semantics; triggering the lock inversion deadlocks the kernel and interrupts the system.

The record

CVE
CVE-2025-40142
Published
Nov 12, 2025
Updated
May 11, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
Unavailable
Attack vector
local
Privileges
Unavailable

Timeline

How it unfolded

  1. Nov 12, 2025CVE publishedPublication date reported by the CVE source.
  2. May 11, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=6.12
  2. Affected versionversion=d2d6422f8bd17c6bb205133e290625a564194496 <3969b6193cb7a45aa5fb4ec68f215e9e7f93d39a
  3. Affected versionversion=d2d6422f8bd17c6bb205133e290625a564194496 <63ee96c7f47df239ee0a6e8108b6bfd8c98334ae
  4. Affected versionversion=d2d6422f8bd17c6bb205133e290625a564194496 <9fc4a3da9a0259a0500848b5d8657918efde176b

What conditions does exploitation require?

Attack vectorlocal
Required privilegesUnavailable in this record.

What is affected?

The Linux Kernel Organization · Linuxversion=6.12; version=d2d6422f8bd17c6bb205133e290625a564194496 <3969b6193cb7a45aa5fb4ec68f215e9e7f93d39a; version=d2d6422f8bd17c6bb205133e290625a564194496 <63ee96c7f47df239ee0a6e8108b6bfd8c98334ae; version=d2d6422f8bd17c6bb205133e290625a564194496 <9fc4a3da9a0259a0500848b5d8657918efde176b

Published CVSS scores

No CVSS assessment is available in this record.

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
PrivilegesUnavailable
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

No sourced classifications are available.

Public exploit references

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Technologies

Your stack

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Your stack

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