CVE-2025-40003: 
Linux Debian vulnerability analysis and mitigation

A use-after-free vulnerability was discovered in the Linux kernel's networking subsystem, specifically in the MSCC Ocelot switch statistics handling code (CVE-2025-40003). The vulnerability was disclosed on October 18, 2025, affecting the Linux kernel's net/mscc/ocelot component (NVD).

The vulnerability stems from improper handling of delayed work items in the ocelotstatsdeinit() function. The issue occurs when canceldelayedwork() fails to cancel a work item that is already executing, while destroyworkqueue() cannot prevent the delayed work item from being rescheduled within the ocelotcheckstatswork() function. This creates a race condition where the work queue can be destroyed before the delayed work item is processed, leading to a use-after-free condition (NVD).

The vulnerability could potentially lead to system instability or crashes due to the use-after-free condition in the kernel's networking subsystem. The issue affects the MSCC Ocelot switch statistics functionality and could potentially be exploited to cause denial of service conditions (NVD).

The fix involves replacing canceldelayedwork() with disabledelayedwork_sync() to ensure proper cancellation of delayed work items and completion of any currently executing work before the workqueue is deallocated. This change has been implemented in the kernel codebase (NVD).