iommu/io-pgtable: Sanitise map/unmap addresses

It may be an egregious error to attempt to use addresses outside the
range of the pagetable format, but that still doesn't mean we should
merrily wreak havoc by silently mapping/unmapping whatever truncated
portions of them might happen to correspond to real addresses.

Add some up-front checks to sanitise our inputs so that buggy callers
don't invite potential memory corruption.

Signed-off-by: Robin Murphy <robin.murphy@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
diff --git a/drivers/iommu/io-pgtable-arm-v7s.c b/drivers/iommu/io-pgtable-arm-v7s.c
index af330f5..d665d0d 100644
--- a/drivers/iommu/io-pgtable-arm-v7s.c
+++ b/drivers/iommu/io-pgtable-arm-v7s.c
@@ -479,6 +479,9 @@
 	if (!(prot & (IOMMU_READ | IOMMU_WRITE)))
 		return 0;
 
+	if (WARN_ON(upper_32_bits(iova) || upper_32_bits(paddr)))
+		return -ERANGE;
+
 	ret = __arm_v7s_map(data, iova, paddr, size, prot, 1, data->pgd);
 	/*
 	 * Synchronise all PTE updates for the new mapping before there's
@@ -659,6 +662,9 @@
 	struct arm_v7s_io_pgtable *data = io_pgtable_ops_to_data(ops);
 	size_t unmapped;
 
+	if (WARN_ON(upper_32_bits(iova)))
+		return 0;
+
 	unmapped = __arm_v7s_unmap(data, iova, size, 1, data->pgd);
 	if (unmapped)
 		io_pgtable_tlb_sync(&data->iop);
diff --git a/drivers/iommu/io-pgtable-arm.c b/drivers/iommu/io-pgtable-arm.c
index b182039..e8018a3 100644
--- a/drivers/iommu/io-pgtable-arm.c
+++ b/drivers/iommu/io-pgtable-arm.c
@@ -452,6 +452,10 @@
 	if (!(iommu_prot & (IOMMU_READ | IOMMU_WRITE)))
 		return 0;
 
+	if (WARN_ON(iova >= (1ULL << data->iop.cfg.ias) ||
+		    paddr >= (1ULL << data->iop.cfg.oas)))
+		return -ERANGE;
+
 	prot = arm_lpae_prot_to_pte(data, iommu_prot);
 	ret = __arm_lpae_map(data, iova, paddr, size, prot, lvl, ptep);
 	/*
@@ -610,6 +614,9 @@
 	arm_lpae_iopte *ptep = data->pgd;
 	int lvl = ARM_LPAE_START_LVL(data);
 
+	if (WARN_ON(iova >= (1ULL << data->iop.cfg.ias)))
+		return 0;
+
 	unmapped = __arm_lpae_unmap(data, iova, size, lvl, ptep);
 	if (unmapped)
 		io_pgtable_tlb_sync(&data->iop);