Linux Kernel Vulnerability in ALSA Affecting Spin Lock Behavior

CVE-2025-40142

What is CVE-2025-40142?

A newly identified vulnerability in the Linux kernel relates to the Advanced Linux Sound Architecture (ALSA). It arises during the use of spin locks when handling interrupts, specifically in the context of the PREEMPT_RT kernel configuration. The flaw occurs because softirqs, which are intended to enable preemption, can still be invoked while a spin lock is held, potentially leading to a deadlock condition. The issue stems from the improper handling of softirq disabling before acquiring the lock, necessitating a fix to ensure softirqs are manually disabled beforehand.

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