Race Condition in Linux Kernel Network Driver

CVE-2025-38440

What is CVE-2025-38440?

A race condition exists in the Linux kernel related to the use of Dynamic Interrupt Management (DIM) within network drivers. When DIM is disabled, if a NAPI callback checks the DIM state and observes it as still active, it may interact with an invalid memory pointer if DIM is disabled shortly thereafter. This can result in a NULL pointer dereference during operations that rely on the DIM context, potentially leading to system instability and crashes. The issue is mitigated by ensuring synchronization prior to freeing the DIM context, which allows any ongoing NAPI callbacks to complete safely before the DIM pointer is set to NULL.

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