static void arcmsr_hbaA_doorbell_isr(struct AdapterControlBlock *acb)
{
	uint32_t outbound_doorbell;
	struct MessageUnit_A __iomem *reg = acb->pmuA;
	outbound_doorbell = readl(&reg->outbound_doorbell);
	do {
		writel(outbound_doorbell, &reg->outbound_doorbell);
		if (outbound_doorbell & ARCMSR_OUTBOUND_IOP331_DATA_WRITE_OK)
			arcmsr_iop2drv_data_wrote_handle(acb);
		if (outbound_doorbell & ARCMSR_OUTBOUND_IOP331_DATA_READ_OK)
			arcmsr_iop2drv_data_read_handle(acb);
		outbound_doorbell = readl(&reg->outbound_doorbell);
	} while (outbound_doorbell & (ARCMSR_OUTBOUND_IOP331_DATA_WRITE_OK
		| ARCMSR_OUTBOUND_IOP331_DATA_READ_OK));
}

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.