Linux Kernel BPF Signal Handling Vulnerability in Non-Preemptible Contexts

A vulnerability in the Linux kernel's BPF (Berkeley Packet Filter) implementation allows for improper signal handling in non-preemptible contexts. When a BPF program running in such a context calls the bpf_send_signal() kfunc, it can lead to issues because this function is designed to sleep. The vulnerability arises from the BPF program's ability to execute in various contexts, including non-preemptible ones.

Impact

Exploitation of this vulnerability can disrupt the intended asynchronous signal handling in BPF programs, potentially leading to unexpected behavior or system instability.