Linux Kernel Vulnerability in Google Compute Engine Timer Management

CVE-2025-39900

What is CVE-2025-39900?

A flaw in the Linux kernel's timer management, specifically within the gen_estimator component, has been identified when using the CONFIG_PREEMPT_RT configuration. The issue arises from timer callbacks being preempted while executing, which can lead to warnings during timer operations. To mitigate this, the kernel has incorporated preempt_disable_nested() and preempt_enable_nested() calls in the est_timer() function, addressing potential race conditions that could disrupt timer execution.

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