[PATCH v5 4/7] vfio/type1: check dma map request is within a valid iova range

Shameer Kolothum
2018-03-15T16:35:06Z

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

Signed-off-by: Shameer Kolothum <shameerali.kolothum.thodi-hv44wF8Li93QT0dZR+AlfA@public.gmane.org>
---
drivers/vfio/vfio_iommu_type1.c | 22 ++++++++++++++++++++++
1 file changed, 22 insertions(+)

diff --git a/drivers/vfio/vfio_iommu_type1.c b/drivers/vfio/vfio_iommu_type1.c
index 25e6920..d59db31 100644
--- a/drivers/vfio/vfio_iommu_type1.c
+++ b/drivers/vfio/vfio_iommu_type1.c
@@ -982,6 +982,23 @@ 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;
+ }
+
+ return false;
+}
+
static int vfio_dma_do_map(struct vfio_iommu *iommu,
struct vfio_iommu_type1_dma_map *map)
{
@@ -1020,6 +1037,11 @@ 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;
--
2.7.4