IPv6 Vulnerability in Linux Kernel Affecting Networking Components

CVE-2025-21757

Summary

A vulnerability in the Linux kernel's IPv6 implementation affects the handling of destination cache references. Specifically, in scenarios involving RPL (Routing Protocol for Low-Power and Lossy Networks), Segment Routing Header (SRH), and Inband OAM over IPv6 (IOAM6) lightweight tunneling, the dst_cache_get() function fails to properly release memory references, leading to potential memory leaks. This issue was identified through the ioam6.sh test, which helped in the recent enhancement of kmemleak to detect per-CPU memory issues. Proper management of references is essential to maintain system stability and security.

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