[PATCH v4 4/6] vfio/type1: check dma map request is within a valid iova range

From: Shameer Kolothum <shameerali.kolothum.thodi@huawei.com>
To: <alex.williamson@redhat.com>, <eric.auger@redhat.com>,
	<pmorel@linux.vnet.ibm.com>
Cc: <kvm@vger.kernel.org>, <linux-kernel@vger.kernel.org>,
	<linuxarm@huawei.com>, <john.garry@huawei.com>,
	<xuwei5@hisilicon.com>,
	Shameer Kolothum <shameerali.kolothum.thodi@huawei.com>
Subject: [PATCH v4 4/6] vfio/type1: check dma map request is within a valid iova range
Date: Wed, 21 Feb 2018 12:22:07 +0000	[thread overview]
Message-ID: <20180221122209.9292-5-shameerali.kolothum.thodi@huawei.com> (raw)
In-Reply-To: <20180221122209.9292-1-shameerali.kolothum.thodi@huawei.com>

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

Signed-off-by: Shameer Kolothum <shameerali.kolothum.thodi@huawei.com>
---
 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 a80884e..3049393 100644
--- a/drivers/vfio/vfio_iommu_type1.c
+++ b/drivers/vfio/vfio_iommu_type1.c
@@ -970,6 +970,23 @@ 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)
 {
@@ -1008,6 +1025,11 @@ 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
