static void arcmsr_enable_eoi_mode(struct AdapterControlBlock *acb)
{
	switch (acb->adapter_type) {
	case ACB_ADAPTER_TYPE_A:
		return;
	case ACB_ADAPTER_TYPE_B:
		{
			struct MessageUnit_B *reg = acb->pmuB;
			writel(ARCMSR_MESSAGE_ACTIVE_EOI_MODE, reg->drv2iop_doorbell);
			if (!arcmsr_hbaB_wait_msgint_ready(acb)) {
				printk(KERN_NOTICE "ARCMSR IOP enables EOI_MODE TIMEOUT");
				return;
			}
		}
		break;
	case ACB_ADAPTER_TYPE_C:
		return;
	}
	return;
}

The product performs operations on a memory buffer, but it reads from or writes to a memory location outside the buffer's intended boundary. This may result in read or write operations on unexpected memory locations that could be linked to other variables, data structures, or internal program data.