Memory Leak in Linux Kernel's TCP Socket with SO_ATTACH_REUSEPORT_EBPF

CVE-2025-21683

Summary

A vulnerability exists in the Linux kernel that affects TCP socket handling when using the SO_ATTACH_REUSEPORT_EBPF option. A memory leak can occur when a TCP socket, previously marked for reuse with this option, becomes established. The issue arises due to improper reference counting, leading to an unreferenced object in memory. This can facilitate resource exhaustion and potential system performance degradation, especially in high-traffic environments. The fix involves ensuring that socket references are appropriately handled in both error and normal processing paths, preventing memory leaks associated with TCP socket reuse.

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