static int arcmsr_iop_confirm(struct AdapterControlBlock *acb)
{
	uint32_t cdb_phyaddr, cdb_phyaddr_hi32;
	dma_addr_t dma_coherent_handle;

	/*
	********************************************************************
	** here we need to tell iop 331 our freeccb.HighPart
	** if freeccb.HighPart is not zero
	********************************************************************
	*/
	switch (acb->adapter_type) {
	case ACB_ADAPTER_TYPE_B:
	case ACB_ADAPTER_TYPE_D:
		dma_coherent_handle = acb->dma_coherent_handle2;
		break;
	default:
		dma_coherent_handle = acb->dma_coherent_handle;
		break;
	}
	cdb_phyaddr = lower_32_bits(dma_coherent_handle);
	cdb_phyaddr_hi32 = upper_32_bits(dma_coherent_handle);
	acb->cdb_phyaddr_hi32 = cdb_phyaddr_hi32;
	/*
	***********************************************************************
	**    if adapter type B, set window of "post command Q"
	***********************************************************************
	*/
	switch (acb->adapter_type) {

	case ACB_ADAPTER_TYPE_A: {
		if (cdb_phyaddr_hi32 != 0) {
			struct MessageUnit_A __iomem *reg = acb->pmuA;
			writel(ARCMSR_SIGNATURE_SET_CONFIG, \
						&reg->message_rwbuffer[0]);
			writel(cdb_phyaddr_hi32, &reg->message_rwbuffer[1]);
			writel(ARCMSR_INBOUND_MESG0_SET_CONFIG, \
							&reg->inbound_msgaddr0);
			if (!arcmsr_hbaA_wait_msgint_ready(acb)) {
				printk(KERN_NOTICE "arcmsr%d: ""set ccb high \
				part physical address timeout\n",
				acb->host->host_no);
				return 1;
			}
		}
		}
		break;

	case ACB_ADAPTER_TYPE_B: {
		uint32_t __iomem *rwbuffer;

		struct MessageUnit_B *reg = acb->pmuB;
		reg->postq_index = 0;
		reg->doneq_index = 0;
		writel(ARCMSR_MESSAGE_SET_POST_WINDOW, reg->drv2iop_doorbell);
		if (!arcmsr_hbaB_wait_msgint_ready(acb)) {
			printk(KERN_NOTICE "arcmsr%d: cannot set driver mode\n", \
				acb->host->host_no);
			return 1;
		}
		rwbuffer = reg->message_rwbuffer;
		/* driver "set config" signature */
		writel(ARCMSR_SIGNATURE_SET_CONFIG, rwbuffer++);
		/* normal should be zero */
		writel(cdb_phyaddr_hi32, rwbuffer++);
		/* postQ size (256 + 8)*4	 */
		writel(cdb_phyaddr, rwbuffer++);
		/* doneQ size (256 + 8)*4	 */
		writel(cdb_phyaddr + 1056, rwbuffer++);
		/* ccb maxQ size must be --> [(256 + 8)*4]*/
		writel(1056, rwbuffer);

		writel(ARCMSR_MESSAGE_SET_CONFIG, reg->drv2iop_doorbell);
		if (!arcmsr_hbaB_wait_msgint_ready(acb)) {
			printk(KERN_NOTICE "arcmsr%d: 'set command Q window' \
			timeout \n",acb->host->host_no);
			return 1;
		}
		writel(ARCMSR_MESSAGE_START_DRIVER_MODE, reg->drv2iop_doorbell);
		if (!arcmsr_hbaB_wait_msgint_ready(acb)) {
			pr_err("arcmsr%d: can't set driver mode.\n",
				acb->host->host_no);
			return 1;
		}
		}
		break;
	case ACB_ADAPTER_TYPE_C: {
		if (cdb_phyaddr_hi32 != 0) {
			struct MessageUnit_C __iomem *reg = acb->pmuC;

			printk(KERN_NOTICE "arcmsr%d: cdb_phyaddr_hi32=0x%x\n",
					acb->adapter_index, cdb_phyaddr_hi32);
			writel(ARCMSR_SIGNATURE_SET_CONFIG, &reg->msgcode_rwbuffer[0]);
			writel(cdb_phyaddr_hi32, &reg->msgcode_rwbuffer[1]);
			writel(ARCMSR_INBOUND_MESG0_SET_CONFIG, &reg->inbound_msgaddr0);
			writel(ARCMSR_HBCMU_DRV2IOP_MESSAGE_CMD_DONE, &reg->inbound_doorbell);
			if (!arcmsr_hbaC_wait_msgint_ready(acb)) {
				printk(KERN_NOTICE "arcmsr%d: 'set command Q window' \
				timeout \n", acb->host->host_no);
				return 1;
			}
		}
		}
		break;
	case ACB_ADAPTER_TYPE_D: {
		uint32_t __iomem *rwbuffer;
		struct MessageUnit_D *reg = acb->pmuD;
		reg->postq_index = 0;
		reg->doneq_index = 0;
		rwbuffer = reg->msgcode_rwbuffer;
		writel(ARCMSR_SIGNATURE_SET_CONFIG, rwbuffer++);
		writel(cdb_phyaddr_hi32, rwbuffer++);
		writel(cdb_phyaddr, rwbuffer++);
		writel(cdb_phyaddr + (ARCMSR_MAX_ARC1214_POSTQUEUE *
			sizeof(struct InBound_SRB)), rwbuffer++);
		writel(0x100, rwbuffer);
		writel(ARCMSR_INBOUND_MESG0_SET_CONFIG, reg->inbound_msgaddr0);
		if (!arcmsr_hbaD_wait_msgint_ready(acb)) {
			pr_notice("arcmsr%d: 'set command Q window' timeout\n",
				acb->host->host_no);
			return 1;
		}
		}
		break;
	}
	return 0;
}

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.