Linux Kernel SCSI LPFC Preemption Vulnerability

A vulnerability in the Linux kernel's SCSI LPFC driver was introduced by using 'smp_processor_id()' in a preemptible context, which can lead to call trace issues during I/O operations with Connection Management Function (CMF) enabled. This problem was observed with 'systemd-udevd', where the improper use of 'smp_processor_id()' in a preemptible context caused a bug that was logged. The vulnerability has been addressed by modifying the code to use 'per_cpu_ptr()' with 'raw_smp_processor_id()', eliminating the preemption issue.

Impact

Exploitation of this vulnerability could disrupt normal I/O operations by causing improper call traces, potentially leading to more significant issues in systemd-udevd processing.