static bool arcmsr_remap_pciregion(struct AdapterControlBlock *acb)
{
	struct pci_dev *pdev = acb->pdev;
	switch (acb->adapter_type){
	case ACB_ADAPTER_TYPE_A:{
		acb->pmuA = ioremap(pci_resource_start(pdev,0), pci_resource_len(pdev,0));
		if (!acb->pmuA) {
			printk(KERN_NOTICE "arcmsr%d: memory mapping region fail \n", acb->host->host_no);
			return false;
		}
		break;
	}
	case ACB_ADAPTER_TYPE_B:{
		void __iomem *mem_base0, *mem_base1;
		mem_base0 = ioremap(pci_resource_start(pdev, 0), pci_resource_len(pdev, 0));
		if (!mem_base0) {
			printk(KERN_NOTICE "arcmsr%d: memory mapping region fail \n", acb->host->host_no);
			return false;
		}
		mem_base1 = ioremap(pci_resource_start(pdev, 2), pci_resource_len(pdev, 2));
		if (!mem_base1) {
			iounmap(mem_base0);
			printk(KERN_NOTICE "arcmsr%d: memory mapping region fail \n", acb->host->host_no);
			return false;
		}
		acb->mem_base0 = mem_base0;
		acb->mem_base1 = mem_base1;
		break;
	}
	case ACB_ADAPTER_TYPE_C:{
		acb->pmuC = ioremap_nocache(pci_resource_start(pdev, 1), pci_resource_len(pdev, 1));
		if (!acb->pmuC) {
			printk(KERN_NOTICE "arcmsr%d: memory mapping region fail \n", acb->host->host_no);
			return false;
		}
		if (readl(&acb->pmuC->outbound_doorbell) & ARCMSR_HBCMU_IOP2DRV_MESSAGE_CMD_DONE) {
			writel(ARCMSR_HBCMU_IOP2DRV_MESSAGE_CMD_DONE_DOORBELL_CLEAR, &acb->pmuC->outbound_doorbell_clear);/*clear interrupt*/
			return true;
		}
		break;
	}
	case ACB_ADAPTER_TYPE_D: {
		void __iomem *mem_base0;
		unsigned long addr, range, flags;

		addr = (unsigned long)pci_resource_start(pdev, 0);
		range = pci_resource_len(pdev, 0);
		flags = pci_resource_flags(pdev, 0);
		mem_base0 = ioremap(addr, range);
		if (!mem_base0) {
			pr_notice("arcmsr%d: memory mapping region fail\n",
				acb->host->host_no);
			return false;
		}
		acb->mem_base0 = mem_base0;
		break;
		}
	}
	return true;
}

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.