Kernel Vulnerability in Linux Affecting Null Pointer Dereference

CVE-2025-21852

Summary

A vulnerability in the Linux kernel allows a BPF program to trigger a null pointer dereference in trace_kfree_skb when it fails to validate the rx_sk argument. The addition of kfree_skb to raw_tp_null_args enables the BPF verifier to detect invalid memory accesses, mitigating the risk of system instability caused by such programs. This issue emphasizes the importance of validating all pointer arguments in BPF programs, ensuring robustness and security within the Linux environment.

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