Linux Kernel BPF Processor ID Function Vulnerability in Non-SMP Configurations

A vulnerability in the Linux kernel's BPF (Berkeley Packet Filter) subsystem has been addressed. The issue arose on x86-64 architectures when calling the function 'bpf_get_smp_processor_id()' in a kernel with 'CONFIG_SMP' disabled. This situation can lead to a page fault error because 'pcpu_hot' is unavailable, causing a supervisor read access violation in kernel mode. The vulnerability has been fixed by modifying the function to return 0 when 'CONFIG_SMP' is not enabled.

Impact

The vulnerability could cause a kernel panic by triggering a page fault error, disrupting normal system operations.