Verifier Bug in Linux Kernel Affecting BPF Functionality

CVE-2025-40143

What is CVE-2025-40143?

A vulnerability in the Linux kernel has revealed a flaw in the BPF (Berkeley Packet Filter) functionality related to speculative execution paths. The code erroneously assumes that a struct bpf_scc_visit instance should be allocated for certain paths during verification processes. However, this assumption holds only for non-speculative paths. This results in a verifier bug being reported under specific conditions. A patch has been introduced to address this issue, ensuring improved reliability in the handling of BPF verification and execution paths.

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