[PATCH v8 4/6] vfio/type1: check dma map request is within a valid iova range

[Shameer Kolothum]

This checks and rejects any dma map request outside valid iova
range.

Signed-off-by: Shameer Kolothum <shameerali.kolothum.th...@huawei.com>
Reviewed-by: Eric Auger <eric.au...@redhat.com>
---
 drivers/vfio/vfio_iommu_type1.c | 26 ++++++++++++++++++++++++++
 1 file changed, 26 insertions(+)

diff --git a/drivers/vfio/vfio_iommu_type1.c b/drivers/vfio/vfio_iommu_type1.c
index 7005a8cfca1b..56cf55776d6c 100644
--- a/drivers/vfio/vfio_iommu_type1.c
+++ b/drivers/vfio/vfio_iommu_type1.c
@@ -1038,6 +1038,27 @@ static int vfio_pin_map_dma(struct vfio_iommu *iommu, 
struct vfio_dma *dma,
        return ret;
 }
 
+/*
+ * Check dma map request is within a valid iova range
+ */
+static bool vfio_iommu_iova_dma_valid(struct vfio_iommu *iommu,
+                                     dma_addr_t start, dma_addr_t end)
+{
+       struct list_head *iova = &iommu->iova_list;
+       struct vfio_iova *node;
+
+       list_for_each_entry(node, iova, list) {
+               if (start >= node->start && end <= node->end)
+                       return true;
+       }
+
+       /*
+        * Check for list_empty() as well since a container with
+        * a single mdev device will have an empty list.
+        */
+       return list_empty(iova);
+}
+
 static int vfio_dma_do_map(struct vfio_iommu *iommu,
                           struct vfio_iommu_type1_dma_map *map)
 {
@@ -1081,6 +1102,11 @@ static int vfio_dma_do_map(struct vfio_iommu *iommu,
                goto out_unlock;
        }
 
+       if (!vfio_iommu_iova_dma_valid(iommu, iova, iova + size - 1)) {
+               ret = -EINVAL;
+               goto out_unlock;
+       }
+
        dma = kzalloc(sizeof(*dma), GFP_KERNEL);
        if (!dma) {
                ret = -ENOMEM;
-- 
2.17.1


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