Use-After-Free Vulnerability in Geneve Protocol of Linux Kernel

CVE-2025-21858

Summary

A vulnerability in the Geneve protocol implementation within the Linux kernel can lead to a use-after-free condition. This occurs in the geneve_find_dev() function when proper memory management is not executed following the dismantling of a network device. Specifically, if a network namespace is terminated, it may still reference a previously freed geneve_dev structure, potentially allowing unintended access to memory. Consequently, if a new Geneve device is created in the same namespace shortly after, it could interact with an invalid memory state, leading to undefined behavior and potential system instability. This vulnerability underscores the importance of robust memory management practices in networking protocols.

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