# CVE-2025-40142: linux: In the Linux kernel, the following vulnerability has been resolved:  ALSA: pcm: Disable bottom softirqs as part of sp...

CVE-2025-40142 is fixed in 18 products on 1 platform, first by DEBIAN-CVE-2025-40142, released November 12, 2025. It is not reported as exploited. Patch Radar priority: Routine.

- Web page: https://patchblox.com/security/cve/CVE-2025-40142
- Priority: Routine
- CVSS: n/a
- EPSS: 0.0021
- CISA KEV: not listed
- Exploited (vendor report): no
- Publicly disclosed: no
- Published: Nov 12, 2025

## Description

In the Linux kernel, the following vulnerability has been resolved:  ALSA: pcm: Disable bottom softirqs as part of spin_lock_irq() on PREEMPT_RT  snd_pcm_group_lock_irq() acquires a spinlock_t and disables interrupts via spin_lock_irq(). This also implicitly disables the handling of softirqs such as TIMER_SOFTIRQ. On PREEMPT_RT softirqs are preemptible and spin_lock_irq() does not disable them. That means a timer can be invoked during spin_lock_irq() on the same CPU. Due to synchronisations reasons local_bh_disable() has a per-CPU lock named softirq_ctrl.lock which synchronizes individual softirq against each other. syz-bot managed to trigger a lockdep report where softirq_ctrl.lock is acquired in hrtimer_cancel() in addition to hrtimer_run_softirq(). This is a possible deadlock.  The softirq_ctrl.lock can not be made part of spin_lock_irq() as this would lead to too much synchronisation against individual threads on the system. To avoid the possible deadlock, softirqs must be manually disabled before the lock is acquired.  Disable softirqs before the lock is acquired on PREEMPT_RT.

## Where it's fixed

| Platform | Product | Fixed in | Fix | Released |
|---|---|---|---|---|
| Linux | dtb-aarch64 opensuse-leap 16.0 | 6.12.0-160000.8.1 | [OPENSUSE-SU-2025:20172-1](https://patchblox.com/security/data/fix/linux/opensuse-su-2025-20172-1.md) | Dec 19, 2025 |
| Linux | kernel-64kb opensuse-leap 16.0 | 6.12.0-160000.8.1 | [OPENSUSE-SU-2025:20172-1](https://patchblox.com/security/data/fix/linux/opensuse-su-2025-20172-1.md) | Dec 19, 2025 |
| Linux | kernel-64kb sles 15.7 | 6.4.0-150700.53.31.1 | [SUSE-SU-2026:0447-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-0447-1.md) | Feb 11, 2026 |
| Linux | kernel-64kb sles 16.0 | 6.12.0-160000.8.1 | [SUSE-SU-2026:20015-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-20015-1.md) | Dec 19, 2025 |
| Linux | kernel-azure sles 15.7 | 6.4.0-150700.20.27.1 | [SUSE-SU-2026:0472-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-0472-1.md) | Feb 12, 2026 |
| Linux | kernel-default opensuse-leap 16.0 | 6.12.0-160000.8.1 | [OPENSUSE-SU-2025:20172-1](https://patchblox.com/security/data/fix/linux/opensuse-su-2025-20172-1.md) | Dec 19, 2025 |
| Linux | kernel-default sles 15.7 | 6.4.0-150700.53.31.1 | [SUSE-SU-2026:0447-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-0447-1.md) | Feb 11, 2026 |
| Linux | kernel-default sles 16.0 | 6.12.0-160000.8.1 | [SUSE-SU-2026:20015-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-20015-1.md) | Dec 19, 2025 |
| Linux | kernel-default-base opensuse-leap 16.0 | 6.12.0-160000.8.1.160000.2.5 | [OPENSUSE-SU-2025:20172-1](https://patchblox.com/security/data/fix/linux/opensuse-su-2025-20172-1.md) | Dec 19, 2025 |
| Linux | kernel-default-base sles 15.7 | 6.4.0-150700.53.31.1.150700.17.21.1 | [SUSE-SU-2026:0447-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-0447-1.md) | Feb 11, 2026 |
| Linux | kernel-default-base sles 16.0 | 6.12.0-160000.8.1.160000.2.5 | [SUSE-SU-2026:20015-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-20015-1.md) | Dec 19, 2025 |
| Linux | kernel-docs opensuse-leap 16.0 | 6.12.0-160000.8.1 | [OPENSUSE-SU-2025:20172-1](https://patchblox.com/security/data/fix/linux/opensuse-su-2025-20172-1.md) | Dec 19, 2025 |
| Linux | kernel-docs sles 15.7 | 6.4.0-150700.53.31.1 | [SUSE-SU-2026:0447-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-0447-1.md) | Feb 11, 2026 |
| Linux | kernel-docs sles 16.0 | 6.12.0-160000.8.1 | [SUSE-SU-2026:20015-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-20015-1.md) | Dec 19, 2025 |
| Linux | kernel-kvmsmall opensuse-leap 16.0 | 6.12.0-160000.8.1 | [OPENSUSE-SU-2025:20172-1](https://patchblox.com/security/data/fix/linux/opensuse-su-2025-20172-1.md) | Dec 19, 2025 |
| Linux | kernel-kvmsmall sles 16.0 | 6.12.0-160000.8.1 | [SUSE-SU-2026:20015-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-20015-1.md) | Dec 19, 2025 |
| Linux | kernel-livepatch-SLE15-SP7-RT_Update_9 sles 15.7 | 1-150700.1.3.2 | [SUSE-SU-2026:0587-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-0587-1.md) | Feb 20, 2026 |
| Linux | kernel-livepatch-SLE15-SP7_Update_9 sles 15.7 | 1-150700.15.3.1 | [SUSE-SU-2026:0447-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-0447-1.md) | Feb 11, 2026 |
| Linux | kernel-obs-build opensuse-leap 16.0 | 6.12.0-160000.8.1 | [OPENSUSE-SU-2025:20172-1](https://patchblox.com/security/data/fix/linux/opensuse-su-2025-20172-1.md) | Dec 19, 2025 |
| Linux | kernel-obs-build sles 15.7 | 6.4.0-150700.53.31.1 | [SUSE-SU-2026:0447-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-0447-1.md) | Feb 11, 2026 |
| Linux | kernel-obs-qa opensuse-leap 16.0 | 6.12.0-160000.8.1 | [OPENSUSE-SU-2025:20172-1](https://patchblox.com/security/data/fix/linux/opensuse-su-2025-20172-1.md) | Dec 19, 2025 |
| Linux | kernel-obs-qa sles 16.0 | 6.12.0-160000.8.1 | [SUSE-SU-2026:20015-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-20015-1.md) | Dec 19, 2025 |
| Linux | kernel-rt opensuse-leap 16.0 | 6.12.0-160000.8.1 | [OPENSUSE-SU-2025:20172-1](https://patchblox.com/security/data/fix/linux/opensuse-su-2025-20172-1.md) | Dec 19, 2025 |
| Linux | kernel-source opensuse-leap 16.0 | 6.12.0-160000.8.1 | [OPENSUSE-SU-2025:20172-1](https://patchblox.com/security/data/fix/linux/opensuse-su-2025-20172-1.md) | Dec 19, 2025 |
| Linux | kernel-source sles 15.7 | 6.4.0-150700.53.31.1 | [SUSE-SU-2026:0447-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-0447-1.md) | Feb 11, 2026 |
| Linux | kernel-source sles 16.0 | 6.12.0-160000.8.1 | [SUSE-SU-2026:20015-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-20015-1.md) | Dec 19, 2025 |
| Linux | kernel-source-azure sles 15.7 | 6.4.0-150700.20.27.1 | [SUSE-SU-2026:0472-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-0472-1.md) | Feb 12, 2026 |
| Linux | kernel-syms opensuse-leap 16.0 | 6.12.0-160000.8.1 | [OPENSUSE-SU-2025:20172-1](https://patchblox.com/security/data/fix/linux/opensuse-su-2025-20172-1.md) | Dec 19, 2025 |
| Linux | kernel-syms sles 15.7 | 6.4.0-150700.53.31.1 | [SUSE-SU-2026:0447-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-0447-1.md) | Feb 11, 2026 |
| Linux | kernel-syms sles 16.0 | 6.12.0-160000.8.1 | [SUSE-SU-2026:20015-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-20015-1.md) | Dec 19, 2025 |
| Linux | kernel-syms-azure sles 15.7 | 6.4.0-150700.20.27.1 | [SUSE-SU-2026:0472-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-0472-1.md) | Feb 12, 2026 |
| Linux | kernel-zfcpdump opensuse-leap 16.0 | 6.12.0-160000.8.1 | [OPENSUSE-SU-2025:20172-1](https://patchblox.com/security/data/fix/linux/opensuse-su-2025-20172-1.md) | Dec 19, 2025 |
| Linux | kernel-zfcpdump sles 15.7 | 6.4.0-150700.53.31.1 | [SUSE-SU-2026:0447-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-0447-1.md) | Feb 11, 2026 |
| Linux | kernel-zfcpdump sles 16.0 | 6.12.0-160000.8.1 | [SUSE-SU-2026:20015-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-20015-1.md) | Dec 19, 2025 |
| Linux | linux Debian 13.5 (trixie) | 6.12.57-1 | [DEBIAN-CVE-2025-40142](https://patchblox.com/security/data/fix/linux/debian-cve-2025-40142.md) | Nov 12, 2025 |
| Linux | linux Debian 14 | 6.17.6-1 | [DEBIAN-CVE-2025-40142](https://patchblox.com/security/data/fix/linux/debian-cve-2025-40142.md) | Nov 12, 2025 |

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Data as of 2026-11-08T13:06:02Z UTC. Source: Patchblox Patch Radar (https://patchblox.com/security/patch-radar). Patchblox finds out-of-date software on Windows, macOS and Linux and updates it through release rings: https://patchblox.com/demo

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