Improper Cleanup Vulnerability in Linux Kernel's Netpoll Feature

CVE-2025-68245

What is CVE-2025-68245?

In the Linux kernel, a vulnerability in the netpoll feature has led to improper reference count handling during cleanup processes. This issue arises when the netpoll associated with a network interface is not correctly managed, resulting in potential memory leaks. When multiple netpoll instances share a single netpoll info structure, improper cleanup can occur, potentially leaving allocated resources unreleased. The flaw stems from an incorrect sequence in cleanup operations, Specifically, when a netpoll instance attempts to clear its associated device's netpoll info without adequately checking the reference count, it results in nullifying the structure prematurely. Thus, subsequent netpoll instances may encounter failures during their cleanup attempts, ultimately leading to memory leaks as the associated resources are not cleaned up as intended. A patch has been implemented to restore proper cleanup behavior, ensuring that netpoll info is only cleared once its reference count reaches zero.

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